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// Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
part of dart.core;
// Frequently used character codes.
const int _SPACE = 0x20;
const int _PERCENT = 0x25;
const int _AMPERSAND = 0x26;
const int _PLUS = 0x2B;
const int _DOT = 0x2E;
const int _SLASH = 0x2F;
const int _COLON = 0x3A;
const int _EQUALS = 0x3d;
const int _UPPER_CASE_A = 0x41;
const int _UPPER_CASE_Z = 0x5A;
const int _LEFT_BRACKET = 0x5B;
const int _BACKSLASH = 0x5C;
const int _RIGHT_BRACKET = 0x5D;
const int _LOWER_CASE_A = 0x61;
const int _LOWER_CASE_F = 0x66;
const int _LOWER_CASE_Z = 0x7A;
const String _hexDigits = "0123456789ABCDEF";
/// A parsed URI, such as a URL.
///
/// **See also:**
///
/// * [URIs][uris] in the [library tour][libtour]
/// * [RFC-3986](http://tools.ietf.org/html/rfc3986)
///
/// [uris]: https://dart.dev/guides/libraries/library-tour#uris
/// [libtour]: https://dart.dev/guides/libraries/library-tour
abstract class Uri {
/// The natural base URI for the current platform.
///
/// When running in a browser this is the current URL of the current page
/// (from `window.location.href`).
///
/// When not running in a browser this is the file URI referencing
/// the current working directory.
external static Uri get base;
/// Creates a new URI from its components.
///
/// Each component is set through a named argument. Any number of
/// components can be provided. The [path] and [query] components can be set
/// using either of two different named arguments.
///
/// The scheme component is set through [scheme]. The scheme is
/// normalized to all lowercase letters. If the scheme is omitted or empty,
/// the URI will not have a scheme part.
///
/// The user info part of the authority component is set through
/// [userInfo]. It defaults to the empty string, which will be omitted
/// from the string representation of the URI.
///
/// The host part of the authority component is set through
/// [host]. The host can either be a hostname, an IPv4 address or an
/// IPv6 address, contained in '[' and ']'. If the host contains a
/// ':' character, the '[' and ']' are added if not already provided.
/// The host is normalized to all lowercase letters.
///
/// The port part of the authority component is set through
/// [port].
/// If [port] is omitted or `null`, it implies the default port for
/// the URI's scheme, and is equivalent to passing that port explicitly.
/// The recognized schemes, and their default ports, are "http" (80) and
/// "https" (443). All other schemes are considered as having zero as the
/// default port.
///
/// If any of `userInfo`, `host` or `port` are provided,
/// the URI has an authority according to [hasAuthority].
///
/// The path component is set through either [path] or
/// [pathSegments].
/// When [path] is used, it should be a valid URI path,
/// but invalid characters, except the general delimiters ':/@[]?#',
/// will be escaped if necessary.
/// When [pathSegments] is used, each of the provided segments
/// is first percent-encoded and then joined using the forward slash
/// separator.
///
/// The percent-encoding of the path segments encodes all
/// characters except for the unreserved characters and the following
/// list of characters: `!$&'()*+,;=:@`. If the other components
/// necessitate an absolute path, a leading slash `/` is prepended if
/// not already there.
///
/// The query component is set through either [query] or [queryParameters].
/// When [query] is used, the provided string should be a valid URI query,
/// but invalid characters, other than general delimiters,
/// will be escaped if necessary.
/// When [queryParameters] is used the query is built from the
/// provided map. Each key and value in the map is percent-encoded
/// and joined using equal and ampersand characters.
/// A value in the map must be either a string, or an [Iterable] of strings,
/// where the latter corresponds to multiple values for the same key.
///
/// The percent-encoding of the keys and values encodes all characters
/// except for the unreserved characters, and replaces spaces with `+`.
/// If `query` is the empty string, it is equivalent to omitting it.
/// To have an actual empty query part,
/// use an empty map for `queryParameters`.
///
/// If both `query` and `queryParameters` are omitted or `null`,
/// the URI has no query part.
///
/// The fragment component is set through [fragment].
/// It should be a valid URI fragment, but invalid characters other than
/// general delimiters, are escaped if necessary.
/// If `fragment` is omitted or `null`, the URI has no fragment part.
factory Uri(
{String? scheme,
String? userInfo,
String? host,
int? port,
String? path,
Iterable<String>? pathSegments,
String? query,
Map<String, dynamic /*String|Iterable<String>*/ >? queryParameters,
String? fragment}) = _Uri;
/// Creates a new `http` URI from authority, path and query.
///
/// Examples:
///
/// ```dart
/// // http://example.org/path?q=dart.
/// Uri.http("example.org", "/path", { "q" : "dart" });
///
/// // http://user:pass@localhost:8080
/// Uri.http("user:pass@localhost:8080", "");
///
/// // http://example.org/a%20b
/// Uri.http("example.org", "a b");
///
/// // http://example.org/a%252F
/// Uri.http("example.org", "/a%2F");
/// ```
///
/// The `scheme` is always set to `http`.
///
/// The `userInfo`, `host` and `port` components are set from the
/// [authority] argument. If `authority` is `null` or empty,
/// the created `Uri` has no authority, and isn't directly usable
/// as an HTTP URL, which must have a non-empty host.
///
/// The `path` component is set from the [unencodedPath]
/// argument. The path passed must not be encoded as this constructor
/// encodes the path.
///
/// The `query` component is set from the optional [queryParameters]
/// argument.
factory Uri.http(String authority, String unencodedPath,
[Map<String, dynamic>? queryParameters]) = _Uri.http;
/// Creates a new `https` URI from authority, path and query.
///
/// This constructor is the same as [Uri.http] except for the scheme
/// which is set to `https`.
factory Uri.https(String authority, String unencodedPath,
[Map<String, dynamic>? queryParameters]) = _Uri.https;
/// Creates a new file URI from an absolute or relative file path.
///
/// The file path is passed in [path].
///
/// This path is interpreted using either Windows or non-Windows
/// semantics.
///
/// With non-Windows semantics the slash (`/`) is used to separate
/// path segments in the input [path].
///
/// With Windows semantics, backslash (`\`) and forward-slash (`/`)
/// are used to separate path segments in the input [path],
/// except if the path starts with `\\?\` in which case
/// only backslash (`\`) separates path segments in [path].
///
/// If the path starts with a path separator, an absolute URI (with the
/// `file` scheme and an empty authority) is created.
/// Otherwise a relative URI reference with no scheme or authority is created.
/// One exception from this rule is that when Windows semantics is used
/// and the path starts with a drive letter followed by a colon (":") and a
/// path separator, then an absolute URI is created.
///
/// The default for whether to use Windows or non-Windows semantics
/// determined from the platform Dart is running on. When running in
/// the standalone VM, this is detected by the VM based on the
/// operating system. When running in a browser non-Windows semantics
/// is always used.
///
/// To override the automatic detection of which semantics to use pass
/// a value for [windows]. Passing `true` will use Windows
/// semantics and passing `false` will use non-Windows semantics.
///
/// Examples using non-Windows semantics:
///
/// ```dart
/// // xxx/yyy
/// Uri.file("xxx/yyy", windows: false);
///
/// // xxx/yyy/
/// Uri.file("xxx/yyy/", windows: false);
///
/// // file:///xxx/yyy
/// Uri.file("/xxx/yyy", windows: false);
///
/// // file:///xxx/yyy/
/// Uri.file("/xxx/yyy/", windows: false);
///
/// // C%3A
/// Uri.file("C:", windows: false);
/// ```
///
/// Examples using Windows semantics:
///
/// ```dart
/// // xxx/yyy
/// Uri.file(r"xxx\yyy", windows: true);
///
/// // xxx/yyy/
/// Uri.file(r"xxx\yyy\", windows: true);
///
/// file:///xxx/yyy
/// Uri.file(r"\xxx\yyy", windows: true);
///
/// file:///xxx/yyy/
/// Uri.file(r"\xxx\yyy/", windows: true);
///
/// // file:///C:/xxx/yyy
/// Uri.file(r"C:\xxx\yyy", windows: true);
///
/// // This throws an error. A path with a drive letter, but no following
/// // path, is not allowed.
/// Uri.file(r"C:", windows: true);
///
/// // This throws an error. A path with a drive letter is not absolute.
/// Uri.file(r"C:xxx\yyy", windows: true);
///
/// // file://server/share/file
/// Uri.file(r"\\server\share\file", windows: true);
/// ```
///
/// If the path passed is not a valid file path, an error is thrown.
factory Uri.file(String path, {bool? windows}) = _Uri.file;
/// Like [Uri.file] except that a non-empty URI path ends in a slash.
///
/// If [path] is not empty, and it doesn't end in a directory separator,
/// then a slash is added to the returned URI's path.
/// In all other cases, the result is the same as returned by `Uri.file`.
factory Uri.directory(String path, {bool? windows}) = _Uri.directory;
/// Creates a `data:` URI containing the [content] string.
///
/// Converts the content to a bytes using [encoding] or the charset specified
/// in [parameters] (defaulting to US-ASCII if not specified or unrecognized),
/// then encodes the bytes into the resulting data URI.
///
/// Defaults to encoding using percent-encoding (any non-ASCII or non-URI-valid
/// bytes is replaced by a percent encoding). If [base64] is true, the bytes
/// are instead encoded using [base64].
///
/// If [encoding] is not provided and [parameters] has a `charset` entry,
/// that name is looked up using [Encoding.getByName],
/// and if the lookup returns an encoding, that encoding is used to convert
/// [content] to bytes.
/// If providing both an [encoding] and a charset in [parameters], they should
/// agree, otherwise decoding won't be able to use the charset parameter
/// to determine the encoding.
///
/// If [mimeType] and/or [parameters] are supplied, they are added to the
/// created URI. If any of these contain characters that are not allowed
/// in the data URI, the character is percent-escaped. If the character is
/// non-ASCII, it is first UTF-8 encoded and then the bytes are percent
/// encoded. An omitted [mimeType] in a data URI means `text/plain`, just
/// as an omitted `charset` parameter defaults to meaning `US-ASCII`.
///
/// To read the content back, use [UriData.contentAsString].
factory Uri.dataFromString(String content,
{String? mimeType,
Encoding? encoding,
Map<String, String>? parameters,
bool base64 = false}) {
UriData data = UriData.fromString(content,
mimeType: mimeType,
encoding: encoding,
parameters: parameters,
base64: base64);
return data.uri;
}
/// Creates a `data:` URI containing an encoding of [bytes].
///
/// Defaults to Base64 encoding the bytes, but if [percentEncoded]
/// is `true`, the bytes will instead be percent encoded (any non-ASCII
/// or non-valid-ASCII-character byte is replaced by a percent encoding).
///
/// To read the bytes back, use [UriData.contentAsBytes].
///
/// It defaults to having the mime-type `application/octet-stream`.
/// The [mimeType] and [parameters] are added to the created URI.
/// If any of these contain characters that are not allowed
/// in the data URI, the character is percent-escaped. If the character is
/// non-ASCII, it is first UTF-8 encoded and then the bytes are percent
/// encoded.
factory Uri.dataFromBytes(List<int> bytes,
{String mimeType = "application/octet-stream",
Map<String, String>? parameters,
bool percentEncoded = false}) {
UriData data = UriData.fromBytes(bytes,
mimeType: mimeType,
parameters: parameters,
percentEncoded: percentEncoded);
return data.uri;
}
/// The scheme component of the URI.
///
/// The value is the empty string if there is no scheme component.
///
/// A URI scheme is case insensitive.
/// The returned scheme is canonicalized to lowercase letters.
String get scheme;
/// The authority component.
///
/// The authority is formatted from the [userInfo], [host] and [port]
/// parts.
///
/// The value is the empty string if there is no authority component.
String get authority;
/// The user info part of the authority component.
///
/// Th value is the empty string if there is no user info in the
/// authority component.
String get userInfo;
/// The host part of the authority component.
///
/// The value is the empty string if there is no authority component and
/// hence no host.
///
/// If the host is an IP version 6 address, the surrounding `[` and `]` is
/// removed.
///
/// The host string is case-insensitive.
/// The returned host name is canonicalized to lower-case
/// with upper-case percent-escapes.
String get host;
/// The port part of the authority component.
///
/// The value is the default port if there is no port number in the authority
/// component. That's 80 for http, 443 for https, and 0 for everything else.
int get port;
/// The path component.
///
/// The path is the actual substring of the URI representing the path,
/// and it is encoded where necessary. To get direct access to the decoded
/// path use [pathSegments].
///
/// The path value is the empty string if there is no path component.
String get path;
/// The query component.
///
/// The value is the actual substring of the URI representing the query part,
/// and it is encoded where necessary.
/// To get direct access to the decoded query use [queryParameters].
///
/// The value is the empty string if there is no query component.
String get query;
/// The fragment identifier component.
///
/// The value is the empty string if there is no fragment identifier
/// component.
String get fragment;
/// The URI path split into its segments.
///
/// Each of the segments in the list have been decoded.
/// If the path is empty the empty list will
/// be returned. A leading slash `/` does not affect the segments returned.
///
/// The list is unmodifiable and will throw [UnsupportedError] on any
/// calls that would mutate it.
List<String> get pathSegments;
/// The URI query split into a map according to the rules
/// specified for FORM post in the [HTML 4.01 specification section
/// 17.13.4](http://www.w3.org/TR/REC-html40/interact/forms.html#h-17.13.4 "HTML 4.01 section 17.13.4").
///
/// Each key and value in the resulting map has been decoded.
/// If there is no query the empty map is returned.
///
/// Keys in the query string that have no value are mapped to the
/// empty string.
/// If a key occurs more than once in the query string, it is mapped to
/// an arbitrary choice of possible value.
/// The [queryParametersAll] getter can provide a map
/// that maps keys to all of their values.
///
/// The map is unmodifiable.
Map<String, String> get queryParameters;
/// Returns the URI query split into a map according to the rules
/// specified for FORM post in the [HTML 4.01 specification section
/// 17.13.4](http://www.w3.org/TR/REC-html40/interact/forms.html#h-17.13.4 "HTML 4.01 section 17.13.4").
///
/// Each key and value in the resulting map has been decoded. If there is no
/// query the map is empty.
///
/// Keys are mapped to lists of their values. If a key occurs only once,
/// its value is a singleton list. If a key occurs with no value, the
/// empty string is used as the value for that occurrence.
///
/// The map and the lists it contains are unmodifiable.
Map<String, List<String>> get queryParametersAll;
/// Whether the URI is absolute.
///
/// A URI is an absolute URI in the sense of RFC 3986 if it has a scheme
/// and no fragment.
bool get isAbsolute;
/// Whether the URI has a [scheme] component.
bool get hasScheme => scheme.isNotEmpty;
/// Whether the URI has an [authority] component.
bool get hasAuthority;
/// Whether the URI has an explicit port.
///
/// If the port number is the default port number
/// (zero for unrecognized schemes, with http (80) and https (443) being
/// recognized),
/// then the port is made implicit and omitted from the URI.
bool get hasPort;
/// Whether the URI has a query part.
bool get hasQuery;
/// Whether the URI has a fragment part.
bool get hasFragment;
/// Whether the URI has an empty path.
bool get hasEmptyPath;
/// Whether the URI has an absolute path (starting with '/').
bool get hasAbsolutePath;
/// Returns the origin of the URI in the form scheme://host:port for the
/// schemes http and https.
///
/// It is an error if the scheme is not "http" or "https", or if the host name
/// is missing or empty.
///
/// See: http://www.w3.org/TR/2011/WD-html5-20110405/origin-0.html#origin
String get origin;
/// Whether the scheme of this [Uri] is [scheme].
///
/// The [scheme] should be the same as the one returned by [Uri.scheme],
/// but doesn't have to be case-normalized to lower-case characters.
///
/// Example:
/// ```dart
/// var uri = Uri.parse("http://example.com/");
/// print(uri.isScheme("HTTP")); // Prints true.
/// ```
///
/// An empty [scheme] string matches a URI with no scheme
/// (one where [hasScheme] returns false).
bool isScheme(String scheme);
/// Creates a file path from a file URI.
///
/// The returned path has either Windows or non-Windows
/// semantics.
///
/// For non-Windows semantics the slash ("/") is used to separate
/// path segments.
///
/// For Windows semantics the backslash ("\\") separator is used to
/// separate path segments.
///
/// If the URI is absolute the path starts with a path separator
/// unless Windows semantics is used and the first path segment is a
/// drive letter. When Windows semantics is used a host component in
/// the uri in interpreted as a file server and a UNC path is
/// returned.
///
/// The default for whether to use Windows or non-Windows semantics
/// determined from the platform Dart is running on. When running in
/// the standalone VM this is detected by the VM based on the
/// operating system. When running in a browser non-Windows semantics
/// is always used.
///
/// To override the automatic detection of which semantics to use pass
/// a value for [windows]. Passing `true` will use Windows
/// semantics and passing `false` will use non-Windows semantics.
///
/// If the URI ends with a slash (i.e. the last path component is
/// empty) the returned file path will also end with a slash.
///
/// With Windows semantics URIs starting with a drive letter cannot
/// be relative to the current drive on the designated drive. That is
/// for the URI `file:///c:abc` calling `toFilePath` will throw as a
/// path segment cannot contain colon on Windows.
///
/// Examples using non-Windows semantics (resulting of calling
/// toFilePath in comment):
/// ```dart
/// Uri.parse("xxx/yyy"); // xxx/yyy
/// Uri.parse("xxx/yyy/"); // xxx/yyy/
/// Uri.parse("file:///xxx/yyy"); // /xxx/yyy
/// Uri.parse("file:///xxx/yyy/"); // /xxx/yyy/
/// Uri.parse("file:///C:"); // /C:
/// Uri.parse("file:///C:a"); // /C:a
/// ```
/// Examples using Windows semantics (resulting URI in comment):
/// ```dart
/// Uri.parse("xxx/yyy"); // xxx\yyy
/// Uri.parse("xxx/yyy/"); // xxx\yyy\
/// Uri.parse("file:///xxx/yyy"); // \xxx\yyy
/// Uri.parse("file:///xxx/yyy/"); // \xxx\yyy\
/// Uri.parse("file:///C:/xxx/yyy"); // C:\xxx\yyy
/// Uri.parse("file:C:xxx/yyy"); // Throws as a path segment
/// // cannot contain colon on Windows.
/// Uri.parse("file://server/share/file"); // \\server\share\file
/// ```
/// If the URI is not a file URI calling this throws
/// [UnsupportedError].
///
/// If the URI cannot be converted to a file path calling this throws
/// [UnsupportedError].
// TODO(lrn): Deprecate and move functionality to File class or similar.
// The core libraries should not worry about the platform.
String toFilePath({bool? windows});
/// Access the structure of a `data:` URI.
///
/// Returns a [UriData] object for `data:` URIs and `null` for all other
/// URIs.
/// The [UriData] object can be used to access the media type and data
/// of a `data:` URI.
UriData? get data;
/// Returns a hash code computed as `toString().hashCode`.
///
/// This guarantees that URIs with the same normalized string representation
/// have the same hash code.
int get hashCode;
/// A URI is equal to another URI with the same normalized representation.
bool operator ==(Object other);
/// The normalized string representation of the URI.
String toString();
/// Creates a new `Uri` based on this one, but with some parts replaced.
///
/// This method takes the same parameters as the [Uri] constructor,
/// and they have the same meaning.
///
/// At most one of [path] and [pathSegments] must be provided.
/// Likewise, at most one of [query] and [queryParameters] must be provided.
///
/// Each part that is not provided will default to the corresponding
/// value from this `Uri` instead.
///
/// This method is different from [Uri.resolve] which overrides in a
/// hierarchical manner,
/// and can instead replace each part of a `Uri` individually.
///
/// Example:
/// ```dart
/// Uri uri1 = Uri.parse("a://b@c:4/d/e?f#g");
/// Uri uri2 = uri1.replace(scheme: "A", path: "D/E/E", fragment: "G");
/// print(uri2); // prints "a://b@c:4/D/E/E?f#G"
/// ```
/// This method acts similarly to using the `Uri` constructor with
/// some of the arguments taken from this `Uri`. Example:
/// ```dart
/// Uri uri3 = Uri(
/// scheme: "A",
/// userInfo: uri1.userInfo,
/// host: uri1.host,
/// port: uri1.port,
/// path: "D/E/E",
/// query: uri1.query,
/// fragment: "G");
/// print(uri3); // prints "a://b@c:4/D/E/E?f#G"
/// print(uri2 == uri3); // prints true.
/// ```
/// Using this method can be seen as a shorthand for the `Uri` constructor
/// call above, but may also be slightly faster because the parts taken
/// from this `Uri` need not be checked for validity again.
Uri replace(
{String? scheme,
String? userInfo,
String? host,
int? port,
String? path,
Iterable<String>? pathSegments,
String? query,
Map<String, dynamic /*String|Iterable<String>*/ >? queryParameters,
String? fragment});
/// Creates a `Uri` that differs from this only in not having a fragment.
///
/// If this `Uri` does not have a fragment, it is itself returned.
Uri removeFragment();
/// Resolve [reference] as an URI relative to `this`.
///
/// First turn [reference] into a URI using [Uri.parse]. Then resolve the
/// resulting URI relative to `this`.
///
/// Returns the resolved URI.
///
/// See [resolveUri] for details.
Uri resolve(String reference);
/// Resolve [reference] as an URI relative to `this`.
///
/// Returns the resolved URI.
///
/// The algorithm "Transform Reference" for resolving a reference is described
/// in [RFC-3986 Section 5](http://tools.ietf.org/html/rfc3986#section-5 "RFC-1123").
///
/// Updated to handle the case where the base URI is just a relative path -
/// that is: when it has no scheme and no authority and the path does not start
/// with a slash.
/// In that case, the paths are combined without removing leading "..", and
/// an empty path is not converted to "/".
Uri resolveUri(Uri reference);
/// Returns a URI where the path has been normalized.
///
/// A normalized path does not contain `.` segments or non-leading `..`
/// segments.
/// Only a relative path with no scheme or authority may contain
/// leading `..` segments,
/// a path that starts with `/` will also drop any leading `..` segments.
///
/// This uses the same normalization strategy as `Uri().resolve(this)`.
///
/// Does not change any part of the URI except the path.
///
/// The default implementation of `Uri` always normalizes paths, so calling
/// this function has no effect.
Uri normalizePath();
/// Creates a new `Uri` object by parsing a URI string.
///
/// If [start] and [end] are provided, they must specify a valid substring
/// of [uri], and only the substring from `start` to `end` is parsed as a URI.
///
/// If the [uri] string is not valid as a URI or URI reference,
/// a [FormatException] is thrown.
static Uri parse(String uri, [int start = 0, int? end]) {
// This parsing will not validate percent-encoding, IPv6, etc.
// When done splitting into parts, it will call, e.g., [_makeFragment]
// to do the final parsing.
//
// Important parts of the RFC 3986 used here:
// URI = scheme ":" hier-part [ "?" query ] [ "#" fragment ]
//
// hier-part = "//" authority path-abempty
// / path-absolute
// / path-rootless
// / path-empty
//
// URI-reference = URI / relative-ref
//
// absolute-URI = scheme ":" hier-part [ "?" query ]
//
// relative-ref = relative-part [ "?" query ] [ "#" fragment ]
//
// relative-part = "//" authority path-abempty
// / path-absolute
// / path-noscheme
// / path-empty
//
// scheme = ALPHA *( ALPHA / DIGIT / "+" / "-" / "." )
//
// authority = [ userinfo "@" ] host [ ":" port ]
// userinfo = *( unreserved / pct-encoded / sub-delims / ":" )
// host = IP-literal / IPv4address / reg-name
// IP-literal = "[" ( IPv6address / IPv6addrz / IPvFuture ) "]"
// IPv6addrz = IPv6address "%25" ZoneID
// ZoneID = 1*( unreserved / pct-encoded )
// port = *DIGIT
// reg-name = *( unreserved / pct-encoded / sub-delims )
//
// path = path-abempty ; begins with "/" or is empty
// / path-absolute ; begins with "/" but not "//"
// / path-noscheme ; begins with a non-colon segment
// / path-rootless ; begins with a segment
// / path-empty ; zero characters
//
// path-abempty = *( "/" segment )
// path-absolute = "/" [ segment-nz *( "/" segment ) ]
// path-noscheme = segment-nz-nc *( "/" segment )
// path-rootless = segment-nz *( "/" segment )
// path-empty = 0<pchar>
//
// segment = *pchar
// segment-nz = 1*pchar
// segment-nz-nc = 1*( unreserved / pct-encoded / sub-delims / "@" )
// ; non-zero-length segment without any colon ":"
//
// pchar = unreserved / pct-encoded / sub-delims / ":" / "@"
//
// query = *( pchar / "/" / "?" )
//
// fragment = *( pchar / "/" / "?" )
end ??= uri.length;
// Special case data:URIs. Ignore case when testing.
if (end >= start + 5) {
int dataDelta = _startsWithData(uri, start);
if (dataDelta == 0) {
// The case is right.
if (start > 0 || end < uri.length) uri = uri.substring(start, end);
return UriData._parse(uri, 5, null).uri;
} else if (dataDelta == 0x20) {
return UriData._parse(uri.substring(start + 5, end), 0, null).uri;
}
// Otherwise the URI doesn't start with "data:" or any case variant of it.
}
// The following index-normalization belongs with the scanning, but is
// easier to do here because we already have extracted variables from the
// indices list.
var indices = List<int>.filled(8, 0, growable: false);
// Set default values for each position.
// The value will either be correct in some cases where it isn't set
// by the scanner, or it is clearly recognizable as an unset value.
indices
..[0] = 0
..[_schemeEndIndex] = start - 1
..[_hostStartIndex] = start - 1
..[_notSimpleIndex] = start - 1
..[_portStartIndex] = start
..[_pathStartIndex] = start
..[_queryStartIndex] = end
..[_fragmentStartIndex] = end;
var state = _scan(uri, start, end, _uriStart, indices);
// Some states that should be non-simple, but the URI ended early.
// Paths that end at a ".." must be normalized to end in "../".
if (state >= _nonSimpleEndStates) {
indices[_notSimpleIndex] = end;
}
int schemeEnd = indices[_schemeEndIndex];
if (schemeEnd >= start) {
// Rescan the scheme part now that we know it's not a path.
state = _scan(uri, start, schemeEnd, _schemeStart, indices);
if (state == _schemeStart) {
// Empty scheme.
indices[_notSimpleIndex] = schemeEnd;
}
}
// The returned positions are limited by the scanners ability to write only
// one position per character, and only the current position.
// Scanning from left to right, we only know whether something is a scheme
// or a path when we see a `:` or `/`, and likewise we only know if the first
// `/` is part of the path or is leading an authority component when we see
// the next character.
int hostStart = indices[_hostStartIndex] + 1;
int portStart = indices[_portStartIndex];
int pathStart = indices[_pathStartIndex];
int queryStart = indices[_queryStartIndex];
int fragmentStart = indices[_fragmentStartIndex];
// We may discover the scheme while handling special cases.
String? scheme;
// Derive some positions that weren't set to normalize the indices.
if (fragmentStart < queryStart) queryStart = fragmentStart;
// If pathStart isn't set (it's before scheme end or host start), then
// the path is empty, or there is no authority part and the path
// starts with a non-simple character.
if (pathStart < hostStart) {
// There is an authority, but no path. The path would start with `/`
// if it was there.
pathStart = queryStart;
} else if (pathStart <= schemeEnd) {
// There is a scheme, but no authority.
pathStart = schemeEnd + 1;
}
// If there is an authority with no port, set the port position
// to be at the end of the authority (equal to pathStart).
// This also handles a ":" in a user-info component incorrectly setting
// the port start position.
if (portStart < hostStart) portStart = pathStart;
assert(hostStart == start || schemeEnd <= hostStart);
assert(hostStart <= portStart);
assert(schemeEnd <= pathStart);
assert(portStart <= pathStart);
assert(pathStart <= queryStart);
assert(queryStart <= fragmentStart);
bool isSimple = indices[_notSimpleIndex] < start;
if (isSimple) {
// Check/do normalizations that weren't detected by the scanner.
// This includes removal of empty port or userInfo,
// or scheme specific port and path normalizations.
if (hostStart > schemeEnd + 3) {
// Always be non-simple if URI contains user-info.
// The scanner doesn't set the not-simple position in this case because
// it's setting the host-start position instead.
isSimple = false;
} else if (portStart > start && portStart + 1 == pathStart) {
// If the port is empty, it should be omitted.
// Pathological case, don't bother correcting it.
isSimple = false;
} else if (queryStart < end &&
(queryStart == pathStart + 2 &&
uri.startsWith("..", pathStart)) ||
(queryStart > pathStart + 2 &&
uri.startsWith("/..", queryStart - 3))) {
// The path ends in a ".." segment. This should be normalized to "../".
// We didn't detect this while scanning because a query or fragment was
// detected at the same time (which is why we only need to check this
// if there is something after the path).
isSimple = false;
} else {
// There are a few scheme-based normalizations that
// the scanner couldn't check.
// That means that the input is very close to simple, so just do
// the normalizations.
if (schemeEnd == start + 4) {
// Do scheme based normalizations for file, http.
if (uri.startsWith("file", start)) {
scheme = "file";
if (hostStart <= start) {
// File URIs should have an authority.
// Paths after an authority should be absolute.
String schemeAuth = "file://";
int delta = 2;
if (!uri.startsWith("/", pathStart)) {
schemeAuth = "file:///";
delta = 3;
}
uri = schemeAuth + uri.substring(pathStart, end);
schemeEnd -= start;
hostStart = 7;
portStart = 7;
pathStart = 7;
queryStart += delta - start;
fragmentStart += delta - start;
start = 0;
end = uri.length;
} else if (pathStart == queryStart) {
// Uri has authority and empty path. Add "/" as path.
if (start == 0 && end == uri.length) {
uri = uri.replaceRange(pathStart, queryStart, "/");
queryStart += 1;
fragmentStart += 1;
end += 1;
} else {
uri = "${uri.substring(start, pathStart)}/"
"${uri.substring(queryStart, end)}";
schemeEnd -= start;
hostStart -= start;
portStart -= start;
pathStart -= start;
queryStart += 1 - start;
fragmentStart += 1 - start;
start = 0;
end = uri.length;
}
}
} else if (uri.startsWith("http", start)) {
scheme = "http";
// HTTP URIs should not have an explicit port of 80.
if (portStart > start &&
portStart + 3 == pathStart &&
uri.startsWith("80", portStart + 1)) {
if (start == 0 && end == uri.length) {
uri = uri.replaceRange(portStart, pathStart, "");
pathStart -= 3;
queryStart -= 3;
fragmentStart -= 3;
end -= 3;
} else {
uri = uri.substring(start, portStart) +
uri.substring(pathStart, end);
schemeEnd -= start;
hostStart -= start;
portStart -= start;
pathStart -= 3 + start;
queryStart -= 3 + start;
fragmentStart -= 3 + start;
start = 0;
end = uri.length;
}
}
}
} else if (schemeEnd == start + 5 && uri.startsWith("https", start)) {
scheme = "https";
// HTTPS URIs should not have an explicit port of 443.
if (portStart > start &&
portStart + 4 == pathStart &&
uri.startsWith("443", portStart + 1)) {
if (start == 0 && end == uri.length) {
uri = uri.replaceRange(portStart, pathStart, "");
pathStart -= 4;
queryStart -= 4;
fragmentStart -= 4;
end -= 3;
} else {
uri = uri.substring(start, portStart) +
uri.substring(pathStart, end);
schemeEnd -= start;
hostStart -= start;
portStart -= start;
pathStart -= 4 + start;
queryStart -= 4 + start;
fragmentStart -= 4 + start;
start = 0;
end = uri.length;
}
}
}
}
}
if (isSimple) {
if (start > 0 || end < uri.length) {
uri = uri.substring(start, end);
schemeEnd -= start;
hostStart -= start;
portStart -= start;
pathStart -= start;
queryStart -= start;
fragmentStart -= start;
}
return _SimpleUri(uri, schemeEnd, hostStart, portStart, pathStart,
queryStart, fragmentStart, scheme);
}
return _Uri.notSimple(uri, start, end, schemeEnd, hostStart, portStart,
pathStart, queryStart, fragmentStart, scheme);
}
/// Creates a new `Uri` object by parsing a URI string.
///
/// If [start] and [end] are provided, they must specify a valid substring
/// of [uri], and only the substring from `start` to `end` is parsed as a URI.
///
/// Returns `null` if the [uri] string is not valid as a URI or URI reference.
static Uri? tryParse(String uri, [int start = 0, int? end]) {
// TODO: Optimize to avoid throwing-and-recatching.
try {
return parse(uri, start, end);
} on FormatException {
return null;
}
}
/// Encode the string [component] using percent-encoding to make it
/// safe for literal use as a URI component.
///
/// All characters except uppercase and lowercase letters, digits and
/// the characters `-_.!~*'()` are percent-encoded. This is the
/// set of characters specified in RFC 2396 and the which is
/// specified for the encodeUriComponent in ECMA-262 version 5.1.
///
/// When manually encoding path segments or query components remember
/// to encode each part separately before building the path or query
/// string.
///
/// For encoding the query part consider using
/// [encodeQueryComponent].
///
/// To avoid the need for explicitly encoding use the [pathSegments]
/// and [queryParameters] optional named arguments when constructing
/// a [Uri].
static String encodeComponent(String component) {
return _Uri._uriEncode(_Uri._unreserved2396Table, component, utf8, false);
}
/**
* Encodes the string [component] according to the HTML 4.01 rules
* for encoding the posting of a HTML form as a query string
* component.
*
* Encode the string [component] according to the HTML 4.01 rules
* for encoding the posting of a HTML form as a query string
* component.
* The component is first encoded to bytes using [encoding].
* The default is to use [utf8] encoding, which preserves all
* the characters that don't need encoding.
* Then the resulting bytes are "percent-encoded". This transforms
* spaces (U+0020) to a plus sign ('+') and all bytes that are not
* the ASCII decimal digits, letters or one of '-._~' are written as
* a percent sign '%' followed by the two-digit hexadecimal
* representation of the byte.
* Note that the set of characters which are percent-encoded is a
* superset of what HTML 4.01 requires, since it refers to RFC 1738
* for reserved characters.
*
* When manually encoding query components remember to encode each
* part separately before building the query string.
*
* To avoid the need for explicitly encoding the query use the
* [queryParameters] optional named arguments when constructing a
* [Uri].
*
* See http://www.w3.org/TR/html401/interact/forms.html#h-17.13.4.2 for more
* details.
*/
static String encodeQueryComponent(String component,
{Encoding encoding = utf8}) {
return _Uri._uriEncode(_Uri._unreservedTable, component, encoding, true);
}
/// Decodes the percent-encoding in [encodedComponent].
///
/// Note that decoding a URI component might change its meaning as
/// some of the decoded characters could be characters with are
/// delimiters for a given URI component type. Always split a URI
/// component using the delimiters for the component before decoding
/// the individual parts.
///
/// For handling the [path] and [query] components consider using
/// [pathSegments] and [queryParameters] to get the separated and
/// decoded component.
static String decodeComponent(String encodedComponent) {
return _Uri._uriDecode(
encodedComponent, 0, encodedComponent.length, utf8, false);
}
/// Decodes the percent-encoding in [encodedComponent], converting
/// pluses to spaces.
///
/// It will create a byte-list of the decoded characters, and then use
/// [encoding] to decode the byte-list to a String. The default encoding is
/// UTF-8.
static String decodeQueryComponent(String encodedComponent,
{Encoding encoding = utf8}) {
return _Uri._uriDecode(
encodedComponent, 0, encodedComponent.length, encoding, true);
}
/// Encodes the string [uri] using percent-encoding to make it
/// safe for literal use as a full URI.
///
/// All characters except uppercase and lowercase letters, digits and
/// the characters `!#$&'()*+,-./:;=?@_~` are percent-encoded. This
/// is the set of characters specified in in ECMA-262 version 5.1 for
/// the encodeURI function .
static String encodeFull(String uri) {
return _Uri._uriEncode(_Uri._encodeFullTable, uri, utf8, false);
}
/// Decodes the percent-encoding in [uri].
///
/// Note that decoding a full URI might change its meaning as some of
/// the decoded characters could be reserved characters. In most
/// cases an encoded URI should be parsed into components using
/// [Uri.parse] before decoding the separate components.
static String decodeFull(String uri) {
return _Uri._uriDecode(uri, 0, uri.length, utf8, false);
}
/// Splits the [query] into a map according to the rules
/// specified for FORM post in the [HTML 4.01 specification section
/// 17.13.4](http://www.w3.org/TR/REC-html40/interact/forms.html#h-17.13.4 "HTML 4.01 section 17.13.4").
///
/// Each key and value in the returned map has been decoded. If the [query]
/// is the empty string an empty map is returned.
///
/// Keys in the query string that have no value are mapped to the
/// empty string.
///
/// Each query component will be decoded using [encoding]. The default encoding
/// is UTF-8.
static Map<String, String> splitQueryString(String query,
{Encoding encoding = utf8}) {
return query.split("&").fold({}, (map, element) {
int index = element.indexOf("=");
if (index == -1) {
if (element != "") {
map[decodeQueryComponent(element, encoding: encoding)] = "";
}
} else if (index != 0) {
var key = element.substring(0, index);
var value = element.substring(index + 1);
map[decodeQueryComponent(key, encoding: encoding)] =
decodeQueryComponent(value, encoding: encoding);
}
return map;
});
}
/// Parses the [host] as an IP version 4 (IPv4) address, returning the address
/// as a list of 4 bytes in network byte order (big endian).
///
/// Throws a [FormatException] if [host] is not a valid IPv4 address
/// representation.
static List<int> parseIPv4Address(String host) =>
_parseIPv4Address(host, 0, host.length);
/// Implementation of [parseIPv4Address] that can work on a substring.
static List<int> _parseIPv4Address(String host, int start, int end) {
void error(String msg, int position) {
throw FormatException('Illegal IPv4 address, $msg', host, position);
}
var result = Uint8List(4);
int partIndex = 0;
int partStart = start;
for (int i = start; i < end; i++) {
int char = host.codeUnitAt(i);
if (char != _DOT) {
if (char ^ 0x30 > 9) {
// Fail on a non-digit character.
error("invalid character", i);
}
} else {
if (partIndex == 3) {
error('IPv4 address should contain exactly 4 parts', i);
}
int part = int.parse(host.substring(partStart, i));
if (part > 255) {
error("each part must be in the range 0..255", partStart);
}
result[partIndex++] = part;
partStart = i + 1;
}
}
if (partIndex != 3) {
error('IPv4 address should contain exactly 4 parts', end);
}
int part = int.parse(host.substring(partStart, end));
if (part > 255) {
error("each part must be in the range 0..255", partStart);
}
result[partIndex] = part;
return result;
}
/// Parses the [host] as an IP version 6 (IPv6) address.
///
/// Returns the address as a list of 16 bytes in network byte order
/// (big endian).
///
/// Throws a [FormatException] if [host] is not a valid IPv6 address
/// representation.
///
/// Acts on the substring from [start] to [end]. If [end] is omitted, it
/// defaults ot the end of the string.
///
/// Some examples of IPv6 addresses:
/// * `::1`
/// * `FEDC:BA98:7654:3210:FEDC:BA98:7654:3210`
/// * `3ffe:2a00:100:7031::1`
/// * `::FFFF:129.144.52.38`
/// * `2010:836B:4179::836B:4179`
static List<int> parseIPv6Address(String host, [int start = 0, int? end]) {
end ??= host.length;
// An IPv6 address consists of exactly 8 parts of 1-4 hex digits, separated
// by `:`'s, with the following exceptions:
//
// - One (and only one) wildcard (`::`) may be present, representing a fill
// of 0's. The IPv6 `::` is thus 16 bytes of `0`.
// - The last two parts may be replaced by an IPv4 "dotted-quad" address.
// Helper function for reporting a badly formatted IPv6 address.
void error(String msg, [position]) {
throw FormatException('Illegal IPv6 address, $msg', host, position);
}
// Parse a hex block.
int parseHex(int start, int end) {
if (end - start > 4) {
error('an IPv6 part can only contain a maximum of 4 hex digits', start);
}
int value = int.parse(host.substring(start, end), radix: 16);
if (value < 0 || value > 0xFFFF) {
error('each part must be in the range of `0x0..0xFFFF`', start);
}
return value;
}
if (host.length < 2) error('address is too short');
List<int> parts = [];
bool wildcardSeen = false;
// Set if seeing a ".", suggesting that there is an IPv4 address.
bool seenDot = false;
int partStart = start;
// Parse all parts, except a potential last one.
for (int i = start; i < end; i++) {
int char = host.codeUnitAt(i);
if (char == _COLON) {
if (i == start) {
// If we see a `:` in the beginning, expect wildcard.
i++;
if (host.codeUnitAt(i) != _COLON) {
error('invalid start colon.', i);
}
partStart = i;
}
if (i == partStart) {
// Wildcard. We only allow one.
if (wildcardSeen) {
error('only one wildcard `::` is allowed', i);
}
wildcardSeen = true;
parts.add(-1);
} else {
// Found a single colon. Parse [partStart..i] as a hex entry.
parts.add(parseHex(partStart, i));
}
partStart = i + 1;
} else if (char == _DOT) {
seenDot = true;
}
}
if (parts.length == 0) error('too few parts');
bool atEnd = (partStart == end);
bool isLastWildcard = (parts.last == -1);
if (atEnd && !isLastWildcard) {
error('expected a part after last `:`', end);
}
if (!atEnd) {
if (!seenDot) {
parts.add(parseHex(partStart, end));
} else {
List<int> last = _parseIPv4Address(host, partStart, end);
parts.add(last[0] << 8 | last[1]);
parts.add(last[2] << 8 | last[3]);
}
}
if (wildcardSeen) {
if (parts.length > 7) {
error('an address with a wildcard must have less than 7 parts');
}
} else if (parts.length != 8) {
error('an address without a wildcard must contain exactly 8 parts');
}
List<int> bytes = Uint8List(16);
for (int i = 0, index = 0; i < parts.length; i++) {
int value = parts[i];
if (value == -1) {
int wildCardLength = 9 - parts.length;
for (int j = 0; j < wildCardLength; j++) {
bytes[index] = 0;
bytes[index + 1] = 0;
index += 2;
}
} else {
bytes[index] = value >> 8;
bytes[index + 1] = value & 0xff;
index += 2;
}
}
return bytes;
}
}
class _Uri implements Uri {
// We represent the missing scheme as an empty string.
// A valid scheme cannot be empty.
final String scheme;
/// The user-info part of the authority.
///
/// Does not distinguish between an empty user-info and an absent one.
/// The value is always non-null.
/// Is considered absent if [_host] is `null`.
final String _userInfo;
/// The host name of the URI.
///
/// Set to `null` if there is no authority in the URI.
/// The host name is the only mandatory part of an authority, so we use
/// it to mark whether an authority part was present or not.
final String? _host;
/// The port number part of the authority.
///
/// The port. Set to null if there is no port. Normalized to null if
/// the port is the default port for the scheme.
int? _port;
/// The path of the URI.
///
/// Always non-null.
final String path;
/// The query content, or null if there is no query.
final String? _query;
// The fragment content, or null if there is no fragment.
final String? _fragment;
/// Cache of the full normalized text representation of the URI.
late final String _text = this._initializeText();
/// Cache of the list of path segments.
late final List<String> pathSegments = _computePathSegments(this.path);
/// Lazily computed and cached hashCode of [_text].
late final int hashCode = this._text.hashCode;
/// Cache the computed return value of [queryParameters].
late final Map<String, String> queryParameters =
UnmodifiableMapView<String, String>(Uri.splitQueryString(this.query));
/// Cache the computed return value of [queryParametersAll].
late final Map<String, List<String>> queryParametersAll =
_computeQueryParametersAll(this.query);
/// Internal non-verifying constructor. Only call with validated arguments.
///
/// The components must be properly normalized.
///
/// Use `null` for [_host] if there is no authority. In that case, always
/// pass `null` for [_port] and an empty string for [_userInfo] as well.
///
/// Use `null` for [_port], [_query] and [_fragment] if there is
/// component of that type, and empty string for [_userInfo].
///
/// The [path] and [scheme] are never empty.
_Uri._internal(this.scheme, this._userInfo, this._host, this._port, this.path,
this._query, this._fragment);
/// Create a [_Uri] from parts of [uri].
///
/// The parameters specify the start/end of particular components of the URI.
/// The [scheme] may contain a string representing a normalized scheme
/// component if one has already been discovered.
factory _Uri.notSimple(
String uri,
int start,
int end,
int schemeEnd,
int hostStart,
int portStart,
int pathStart,
int queryStart,
int fragmentStart,
String? scheme) {
if (scheme == null) {
scheme = "";
if (schemeEnd > start) {
scheme = _makeScheme(uri, start, schemeEnd);
} else if (schemeEnd == start) {
_fail(uri, start, "Invalid empty scheme");
}
}
String userInfo = "";
String? host;
int? port;
if (hostStart > start) {
int userInfoStart = schemeEnd + 3;
if (userInfoStart < hostStart) {
userInfo = _makeUserInfo(uri, userInfoStart, hostStart - 1);
}
host = _makeHost(uri, hostStart, portStart, false);
if (portStart + 1 < pathStart) {
int portNumber =
int.tryParse(uri.substring(portStart + 1, pathStart)) ??
(throw FormatException("Invalid port", uri, portStart + 1));
port = _makePort(portNumber, scheme);
}
}
String path =
_makePath(uri, pathStart, queryStart, null, scheme, host != null);
String? query;
if (queryStart < fragmentStart) {
query = _makeQuery(uri, queryStart + 1, fragmentStart, null);
}
String? fragment;
if (fragmentStart < end) {
fragment = _makeFragment(uri, fragmentStart + 1, end);
}
return _Uri._internal(scheme, userInfo, host, port, path, query, fragment);
}
/// Implementation of [Uri.Uri].
factory _Uri(
{String? scheme,
String? userInfo,
String? host,
int? port,
String? path,
Iterable<String>? pathSegments,
String? query,
Map<String, dynamic /*String|Iterable<String>*/ >? queryParameters,
String? fragment}) {
if (scheme == null) {
scheme = "";
} else {
scheme = _makeScheme(scheme, 0, scheme.length);
}
userInfo = _makeUserInfo(userInfo, 0, _stringOrNullLength(userInfo));
if (userInfo == null) {
// TODO(dart-lang/language#440): Remove when promotion works.
throw "unreachable";
}
host = _makeHost(host, 0, _stringOrNullLength(host), false);
// Special case this constructor for backwards compatibility.
if (query == "") query = null;
query = _makeQuery(query, 0, _stringOrNullLength(query), queryParameters);
fragment = _makeFragment(fragment, 0, _stringOrNullLength(fragment));
port = _makePort(port, scheme);
bool isFile = (scheme == "file");
if (host == null && (userInfo.isNotEmpty || port != null || isFile)) {
host = "";
}
bool hasAuthority = (host != null);
path = _makePath(
path, 0, _stringOrNullLength(path), pathSegments, scheme, hasAuthority);
if (path == null) {
// TODO(dart-lang/language#440): Remove when promotion works.
throw "unreachable";
}
if (scheme.isEmpty && host == null && !path.startsWith('/')) {
bool allowScheme = scheme.isNotEmpty || host != null;
path = _normalizeRelativePath(path, allowScheme);
} else {
path = _removeDotSegments(path);
}
if (host == null && path.startsWith("//")) {
host = "";
}
return _Uri._internal(scheme, userInfo, host, port, path, query, fragment);
}
/// Implementation of [Uri.http].
factory _Uri.http(String authority, String unencodedPath,
[Map<String, dynamic>? queryParameters]) {
return _makeHttpUri("http", authority, unencodedPath, queryParameters);
}
/// Implementation of [Uri.https].
factory _Uri.https(String authority, String unencodedPath,
[Map<String, dynamic>? queryParameters]) {
return _makeHttpUri("https", authority, unencodedPath, queryParameters);
}
String get authority {
if (!hasAuthority) return "";
var sb = StringBuffer();
_writeAuthority(sb);
return sb.toString();
}
String get userInfo => _userInfo;
String get host {
String? host = _host;
if (host == null) return "";
if (host.startsWith('[')) {
return host.substring(1, host.length - 1);
}
return host;
}
int get port {
return _port ?? _defaultPort(scheme);
}
/// The default port for the scheme of this Uri.
static int _defaultPort(String scheme) {
if (scheme == "http") return 80;
if (scheme == "https") return 443;
return 0;
}
String get query => _query ?? "";
String get fragment => _fragment ?? "";
bool isScheme(String scheme) {
String thisScheme = this.scheme;
if (scheme == null) return thisScheme.isEmpty;
if (scheme.length != thisScheme.length) return false;
return _compareScheme(scheme, thisScheme);
}
/// Compares scheme characters in [scheme] and at the start of [uri].
///
/// Returns `true` if [scheme] represents the same scheme as the start of
/// [uri]. That means having the same characters, but possibly different case
/// for letters.
///
/// This function doesn't check that the characters are valid URI scheme
/// characters. The [uri] is assumed to be valid, so if [scheme] matches
/// it, it has to be valid too.
///
/// The length should be tested before calling this function,
/// so the scheme part of [uri] is known to have the same length as [scheme].
static bool _compareScheme(String scheme, String uri) {
for (int i = 0; i < scheme.length; i++) {
int schemeChar = scheme.codeUnitAt(i);
int uriChar = uri.codeUnitAt(i);
int delta = schemeChar ^ uriChar;
if (delta != 0) {
if (delta == 0x20) {
// Might be a case difference.
int lowerChar = uriChar | delta;
if (0x61 /*a*/ <= lowerChar && lowerChar <= 0x7a /*z*/) {
continue;
}
}
return false;
}
}
return true;
}
/// Report a parse failure.
static Never _fail(String uri, int index, String message) {
throw FormatException(message, uri, index);
}
static _Uri _makeHttpUri(String scheme, String? authority,
String unencodedPath, Map<String, dynamic>? queryParameters) {
var userInfo = "";
String? host;
int? port;
if (authority != null && authority.isNotEmpty) {
var hostStart = 0;
// Split off the user info.
for (int i = 0; i < authority.length; i++) {
const int atSign = 0x40;
if (authority.codeUnitAt(i) == atSign) {
userInfo = authority.substring(0, i);
hostStart = i + 1;
break;
}
}
var hostEnd = hostStart;
if (hostStart < authority.length &&
authority.codeUnitAt(hostStart) == _LEFT_BRACKET) {
// IPv6 host.
int escapeForZoneID = -1;
for (; hostEnd < authority.length; hostEnd++) {
int char = authority.codeUnitAt(hostEnd);
if (char == _PERCENT && escapeForZoneID < 0) {
escapeForZoneID = hostEnd;
if (authority.startsWith("25", hostEnd + 1)) {
hostEnd += 2; // Might as well skip the already checked escape.
}
} else if (char == _RIGHT_BRACKET) {
break;
}
}
if (hostEnd == authority.length) {
throw FormatException(
"Invalid IPv6 host entry.", authority, hostStart);
}
Uri.parseIPv6Address(authority, hostStart + 1,
(escapeForZoneID < 0) ? hostEnd : escapeForZoneID);
hostEnd++; // Skip the closing bracket.
if (hostEnd != authority.length &&
authority.codeUnitAt(hostEnd) != _COLON) {
throw FormatException("Invalid end of authority", authority, hostEnd);
}
}
// Split host and port.
for (; hostEnd < authority.length; hostEnd++) {
if (authority.codeUnitAt(hostEnd) == _COLON) {
var portString = authority.substring(hostEnd + 1);
// We allow the empty port - falling back to initial value.
if (portString.isNotEmpty) port = int.parse(portString);
break;
}
}
host = authority.substring(hostStart, hostEnd);
}
return _Uri(
scheme: scheme,
userInfo: userInfo,
host: host,
port: port,
pathSegments: unencodedPath.split("/"),
queryParameters: queryParameters);
}
/// Implementation of [Uri.file].
factory _Uri.file(String path, {bool? windows}) {
return (windows ?? _Uri._isWindows)
? _makeWindowsFileUrl(path, false)
: _makeFileUri(path, false);
}
/// Implementation of [Uri.directory].
factory _Uri.directory(String path, {bool? windows}) {
return (windows ?? _Uri._isWindows)
? _makeWindowsFileUrl(path, true)
: _makeFileUri(path, true);
}
/// Used internally in path-related constructors.
external static bool get _isWindows;
static void _checkNonWindowsPathReservedCharacters(
List<String> segments, bool argumentError) {
for (var segment in segments) {
if (segment.contains("/")) {
if (argumentError) {
throw ArgumentError("Illegal path character $segment");
} else {
throw UnsupportedError("Illegal path character $segment");
}
}
}
}
static void _checkWindowsPathReservedCharacters(
List<String> segments, bool argumentError,
[int firstSegment = 0]) {
for (var segment in segments.skip(firstSegment)) {
if (segment.contains(RegExp(r'["*/:<>?\\|]'))) {
if (argumentError) {
throw ArgumentError("Illegal character in path");
} else {
throw UnsupportedError("Illegal character in path: $segment");
}
}
}
}
static void _checkWindowsDriveLetter(int charCode, bool argumentError) {
if ((_UPPER_CASE_A <= charCode && charCode <= _UPPER_CASE_Z) ||
(_LOWER_CASE_A <= charCode && charCode <= _LOWER_CASE_Z)) {
return;
}
if (argumentError) {
throw ArgumentError(
"Illegal drive letter " + String.fromCharCode(charCode));
} else {
throw UnsupportedError(
"Illegal drive letter " + String.fromCharCode(charCode));
}
}
static Uri _makeFileUri(String path, bool slashTerminated) {
const String sep = "/";
var segments = path.split(sep);
if (slashTerminated && segments.isNotEmpty && segments.last.isNotEmpty) {
segments.add(""); // Extra separator at end.
}
if (path.startsWith(sep)) {
// Absolute file:// URI.
return Uri(scheme: "file", pathSegments: segments);
} else {
// Relative URI.
return Uri(pathSegments: segments);
}
}
static _makeWindowsFileUrl(String path, bool slashTerminated) {
if (path.startsWith(r"\\?\")) {
if (path.startsWith(r"UNC\", 4)) {
path = path.replaceRange(0, 7, r'\');
} else {
path = path.substring(4);
if (path.length < 3 ||
path.codeUnitAt(1) != _COLON ||
path.codeUnitAt(2) != _BACKSLASH) {
throw ArgumentError(
r"Windows paths with \\?\ prefix must be absolute");
}
}
} else {
path = path.replaceAll("/", r'\');
}
const String sep = r'\';
if (path.length > 1 && path.codeUnitAt(1) == _COLON) {
_checkWindowsDriveLetter(path.codeUnitAt(0), true);
if (path.length == 2 || path.codeUnitAt(2) != _BACKSLASH) {
throw ArgumentError("Windows paths with drive letter must be absolute");
}
// Absolute file://C:/ URI.
var pathSegments = path.split(sep);
if (slashTerminated && pathSegments.last.isNotEmpty) {
pathSegments.add(""); // Extra separator at end.
}
_checkWindowsPathReservedCharacters(pathSegments, true, 1);
return Uri(scheme: "file", pathSegments: pathSegments);
}
if (path.startsWith(sep)) {
if (path.startsWith(sep, 1)) {
// Absolute file:// URI with host.
int pathStart = path.indexOf(r'\', 2);
String hostPart =
(pathStart < 0) ? path.substring(2) : path.substring(2, pathStart);
String pathPart = (pathStart < 0) ? "" : path.substring(pathStart + 1);
var pathSegments = pathPart.split(sep);
_checkWindowsPathReservedCharacters(pathSegments, true);
if (slashTerminated && pathSegments.last.isNotEmpty) {
pathSegments.add(""); // Extra separator at end.
}
return Uri(scheme: "file", host: hostPart, pathSegments: pathSegments);
} else {
// Absolute file:// URI.
var pathSegments = path.split(sep);
if (slashTerminated && pathSegments.last.isNotEmpty) {
pathSegments.add(""); // Extra separator at end.
}
_checkWindowsPathReservedCharacters(pathSegments, true);
return Uri(scheme: "file", pathSegments: pathSegments);
}
} else {
// Relative URI.
var pathSegments = path.split(sep);
_checkWindowsPathReservedCharacters(pathSegments, true);
if (slashTerminated &&
pathSegments.isNotEmpty &&
pathSegments.last.isNotEmpty) {
pathSegments.add(""); // Extra separator at end.
}
return Uri(pathSegments: pathSegments);
}
}
Uri replace(
{String? scheme,
String? userInfo,
String? host,
int? port,
String? path,
Iterable<String>? pathSegments,
String? query,
Map<String, dynamic /*String|Iterable<String>*/ >? queryParameters,
String? fragment}) {
// Set to true if the scheme has (potentially) changed.
// In that case, the default port may also have changed and we need
// to check even the existing port.
bool schemeChanged = false;
if (scheme != null) {
scheme = _makeScheme(scheme, 0, scheme.length);
schemeChanged = (scheme != this.scheme);
} else {
scheme = this.scheme;
}
bool isFile = (scheme == "file");
if (userInfo != null) {
userInfo = _makeUserInfo(userInfo, 0, userInfo.length);
} else {
userInfo = this._userInfo;
}
if (port != null) {
port = _makePort(port, scheme);
} else {
port = this._port;
if (schemeChanged) {
// The default port might have changed.
port = _makePort(port, scheme);
}
}
if (host != null) {
host = _makeHost(host, 0, host.length, false);
} else if (this.hasAuthority) {
host = this._host;
} else if (userInfo.isNotEmpty || port != null || isFile) {
host = "";
}
bool hasAuthority = host != null;
if (path != null || pathSegments != null) {
path = _makePath(path, 0, _stringOrNullLength(path), pathSegments, scheme,
hasAuthority);
} else {
var currentPath = this.path;
if ((isFile || (hasAuthority && !currentPath.isEmpty)) &&
!currentPath.startsWith('/')) {
currentPath = "/" + currentPath;
}
path = currentPath;
}
if (query != null || queryParameters != null) {
query = _makeQuery(query, 0, _stringOrNullLength(query), queryParameters);
} else {
query = this._query;
}
if (fragment != null) {
fragment = _makeFragment(fragment, 0, fragment.length);
} else {
fragment = this._fragment;
}
return _Uri._internal(scheme, userInfo, host, port, path, query, fragment);
}
Uri removeFragment() {
if (!this.hasFragment) return this;
return _Uri._internal(scheme, _userInfo, _host, _port, path, _query, null);
}
static List<String> _computePathSegments(String pathToSplit) {
if (pathToSplit.isNotEmpty && pathToSplit.codeUnitAt(0) == _SLASH) {
pathToSplit = pathToSplit.substring(1);
}
return (pathToSplit.isEmpty)
? const <String>[]
: List<String>.unmodifiable(
pathToSplit.split("/").map(Uri.decodeComponent));
}
static Map<String, List<String>> _computeQueryParametersAll(String? query) {
if (query == null || query.isEmpty) return const <String, List<String>>{};
Map<String, List<String>> queryParameterLists = _splitQueryStringAll(query);
queryParameterLists.updateAll(_toUnmodifiableStringList);
return Map<String, List<String>>.unmodifiable(queryParameterLists);
}
Uri normalizePath() {
String path = _normalizePath(this.path, scheme, hasAuthority);
if (identical(path, this.path)) return this;
return this.replace(path: path);
}
static int? _makePort(int? port, String scheme) {
// Perform scheme specific normalization.
if (port != null && port == _defaultPort(scheme)) return null;
return port;
}
/// Check and normalize a host name.
///
/// If the host name starts and ends with '[' and ']', it is considered an
/// IPv6 address. If [strictIPv6] is false, the address is also considered
/// an IPv6 address if it contains any ':' character.
///
/// If it is not an IPv6 address, it is case- and escape-normalized.
/// This escapes all characters not valid in a reg-name,
/// and converts all non-escape upper-case letters to lower-case.
static String? _makeHost(String? host, int start, int end, bool strictIPv6) {
// TODO(lrn): Should we normalize IPv6 addresses according to RFC 5952?
if (host == null) return null;
if (start == end) return "";
// Host is an IPv6 address if it starts with '[' or contains a colon.
if (host.codeUnitAt(start) == _LEFT_BRACKET) {
if (host.codeUnitAt(end - 1) != _RIGHT_BRACKET) {
_fail(host, start, 'Missing end `]` to match `[` in host');
}
String zoneID = "";
int index = _checkZoneID(host, start + 1, end - 1);
if (index < end - 1) {
int zoneIDstart =
(host.startsWith("25", index + 1)) ? index + 3 : index + 1;
zoneID = _normalizeZoneID(host, zoneIDstart, end - 1, "%25");
}
Uri.parseIPv6Address(host, start + 1, index);
// RFC 5952 requires hex digits to be lower case.
return host.substring(start, index).toLowerCase() + zoneID + ']';
}
if (!strictIPv6) {
// TODO(lrn): skip if too short to be a valid IPv6 address?
for (int i = start; i < end; i++) {
if (host.codeUnitAt(i) == _COLON) {
String zoneID = "";
int index = _checkZoneID(host, start, end);
if (index < end) {
int zoneIDstart =
(host.startsWith("25", index + 1)) ? index + 3 : index + 1;
zoneID = _normalizeZoneID(host, zoneIDstart, end, "%25");
}
Uri.parseIPv6Address(host, start, index);
return '[${host.substring(start, index)}' + zoneID + ']';
}
}
}
return _normalizeRegName(host, start, end);
}
/// RFC 6874 check for ZoneID
/// Return the index of first appeared `%`.
static int _checkZoneID(String host, int start, int end) {
int index = host.indexOf('%', start);
index = (index >= start && index < end) ? index : end;
return index;
}
static bool _isZoneIDChar(int char) {
return char < 127 && (_zoneIDTable[char >> 4] & (1 << (char & 0xf))) != 0;
}
/// Validates and does case- and percent-encoding normalization.
///
/// The same as [_normalizeOrSubstring]
/// except this function does not convert characters to lower case.
/// The [host] must be an RFC6874 "ZoneID".
/// ZoneID = 1*(unreserved / pct-encoded)
static String _normalizeZoneID(String host, int start, int end,
[String prefix = '']) {
StringBuffer? buffer;
if (prefix != '') {
buffer = StringBuffer(prefix);
}
int sectionStart = start;
int index = start;
// Whether all characters between sectionStart and index are normalized,
bool isNormalized = true;
while (index < end) {
int char = host.codeUnitAt(index);
if (char == _PERCENT) {
String? replacement = _normalizeEscape(host, index, true);
if (replacement == null && isNormalized) {
index += 3;
continue;
}
buffer ??= StringBuffer();
String slice = host.substring(sectionStart, index);
buffer.write(slice);
int sourceLength = 3;
if (replacement == null) {
replacement = host.substring(index, index + 3);
} else if (replacement == "%") {
_fail(host, index, "ZoneID should not contain % anymore");
}
buffer.write(replacement);
index += sourceLength;
sectionStart = index;
isNormalized = true;
} else if (_isZoneIDChar(char)) {
if (isNormalized && _UPPER_CASE_A <= char && _UPPER_CASE_Z >= char) {
// Put initial slice in buffer and continue in non-normalized mode
buffer ??= StringBuffer();
if (sectionStart < index) {
buffer.write(host.substring(sectionStart, index));
sectionStart = index;
}
isNormalized = false;
}
index++;
} else {
int sourceLength = 1;
if ((char & 0xFC00) == 0xD800 && (index + 1) < end) {
int tail = host.codeUnitAt(index + 1);
if ((tail & 0xFC00) == 0xDC00) {
char = 0x10000 | ((char & 0x3ff) << 10) | (tail & 0x3ff);
sourceLength = 2;
}
}
String slice = host.substring(sectionStart, index);
(buffer ??= StringBuffer())..write(slice)..write(_escapeChar(char));
index += sourceLength;
sectionStart = index;
}
}
if (buffer == null) return host.substring(start, end);
if (sectionStart < end) {
String slice = host.substring(sectionStart, end);
buffer.write(slice);
}
return buffer.toString();
}
static bool _isRegNameChar(int char) {
return char < 127 && (_regNameTable[char >> 4] & (1 << (char & 0xf))) != 0;
}
/// Validates and does case- and percent-encoding normalization.
///
/// The [host] must be an RFC3986 "reg-name". It is converted
/// to lower case, and percent escapes are converted to either
/// lower case unreserved characters or upper case escapes.
static String _normalizeRegName(String host, int start, int end) {
StringBuffer? buffer;
int sectionStart = start;
int index = start;
// Whether all characters between sectionStart and index are normalized,
bool isNormalized = true;
while (index < end) {
int char = host.codeUnitAt(index);
if (char == _PERCENT) {
// The _regNameTable contains "%", so we check that first.
String? replacement = _normalizeEscape(host, index, true);
if (replacement == null && isNormalized) {
index += 3;
continue;
}
buffer ??= StringBuffer();
String slice = host.substring(sectionStart, index);
if (!isNormalized) slice = slice.toLowerCase();
buffer.write(slice);
int sourceLength = 3;
if (replacement == null) {
replacement = host.substring(index, index + 3);
} else if (replacement == "%") {
replacement = "%25";
sourceLength = 1;
}
buffer.write(replacement);
index += sourceLength;
sectionStart = index;
isNormalized = true;
} else if (_isRegNameChar(char)) {
if (isNormalized && _UPPER_CASE_A <= char && _UPPER_CASE_Z >= char) {
// Put initial slice in buffer and continue in non-normalized mode
buffer ??= StringBuffer();
if (sectionStart < index) {
buffer.write(host.substring(sectionStart, index));
sectionStart = index;
}
isNormalized = false;
}
index++;
} else if (_isGeneralDelimiter(char)) {
_fail(host, index, "Invalid character");
} else {
int sourceLength = 1;
if ((char & 0xFC00) == 0xD800 && (index + 1) < end) {
int tail = host.codeUnitAt(index + 1);
if ((tail & 0xFC00) == 0xDC00) {
char = 0x10000 | ((char & 0x3ff) << 10) | (tail & 0x3ff);
sourceLength = 2;
}
}
String slice = host.substring(sectionStart, index);
if (!isNormalized) slice = slice.toLowerCase();
(buffer ??= StringBuffer())..write(slice)..write(_escapeChar(char));
index += sourceLength;
sectionStart = index;
}
}
if (buffer == null) return host.substring(start, end);
if (sectionStart < end) {
String slice = host.substring(sectionStart, end);
if (!isNormalized) slice = slice.toLowerCase();
buffer.write(slice);
}
return buffer.toString();
}
/// Validates scheme characters and does case-normalization.
///
/// Schemes are converted to lower case. They cannot contain escapes.
static String _makeScheme(String scheme, int start, int end) {
if (start == end) return "";
final int firstCodeUnit = scheme.codeUnitAt(start);
if (!_isAlphabeticCharacter(firstCodeUnit)) {
_fail(scheme, start, "Scheme not starting with alphabetic character");
}
bool containsUpperCase = false;
for (int i = start; i < end; i++) {
final int codeUnit = scheme.codeUnitAt(i);
if (!_isSchemeCharacter(codeUnit)) {
_fail(scheme, i, "Illegal scheme character");
}
if (_UPPER_CASE_A <= codeUnit && codeUnit <= _UPPER_CASE_Z) {
containsUpperCase = true;
}
}
scheme = scheme.substring(start, end);
if (containsUpperCase) scheme = scheme.toLowerCase();
return _canonicalizeScheme(scheme);
}
/// Canonicalize a few often-used scheme strings.
///
/// This improves memory usage and makes comparison faster.
static String _canonicalizeScheme(String scheme) {
if (scheme == "http") return "http";
if (scheme == "file") return "file";
if (scheme == "https") return "https";
if (scheme == "package") return "package";
return scheme;
}
static String _makeUserInfo(String? userInfo, int start, int end) {
if (userInfo == null) return "";
return _normalizeOrSubstring(userInfo, start, end, _userinfoTable);
}
static String _makePath(String? path, int start, int end,
Iterable<String>? pathSegments, String scheme, bool hasAuthority) {
bool isFile = (scheme == "file");
bool ensureLeadingSlash = isFile || hasAuthority;
String result;
if (path == null) {
if (pathSegments == null) return isFile ? "/" : "";
result = pathSegments
.map((s) => _uriEncode(_pathCharTable, s, utf8, false))
.join("/");
} else if (pathSegments != null) {
throw ArgumentError('Both path and pathSegments specified');
} else {
result = _normalizeOrSubstring(path, start, end, _pathCharOrSlashTable,
escapeDelimiters: true);
}
if (result.isEmpty) {
if (isFile) return "/";
} else if (ensureLeadingSlash && !result.startsWith('/')) {
result = "/" + result;
}
result = _normalizePath(result, scheme, hasAuthority);
return result;
}
/// Performs path normalization (remove dot segments) on a path.
///
/// If the URI has neither scheme nor authority, it's considered a
/// "pure path" and normalization won't remove leading ".." segments.
/// Otherwise it follows the RFC 3986 "remove dot segments" algorithm.
static String _normalizePath(String path, String scheme, bool hasAuthority) {
if (scheme.isEmpty && !hasAuthority && !path.startsWith('/')) {
return _normalizeRelativePath(path, scheme.isNotEmpty || hasAuthority);
}
return _removeDotSegments(path);
}
static String? _makeQuery(String? query, int start, int end,
Map<String, dynamic /*String|Iterable<String>*/ >? queryParameters) {
if (query != null) {
if (queryParameters != null) {
throw ArgumentError('Both query and queryParameters specified');
}
return _normalizeOrSubstring(query, start, end, _queryCharTable,
escapeDelimiters: true);
}
if (queryParameters == null) return null;
var result = StringBuffer();
var separator = "";
void writeParameter(String key, String? value) {
result.write(separator);
separator = "&";
result.write(Uri.encodeQueryComponent(key));
if (value != null && value.isNotEmpty) {
result.write("=");
result.write(Uri.encodeQueryComponent(value));
}
}
queryParameters.forEach((key, value) {
if (value == null || value is String) {
writeParameter(key, value);
} else {
Iterable values = value;
for (String value in values) {
writeParameter(key, value);
}
}
});
return result.toString();
}
static String? _makeFragment(String? fragment, int start, int end) {
if (fragment == null) return null;
return _normalizeOrSubstring(fragment, start, end, _queryCharTable,
escapeDelimiters: true);
}
/// Performs RFC 3986 Percent-Encoding Normalization.
///
/// Returns a replacement string that should be replace the original escape.
/// Returns null if no replacement is necessary because the escape is
/// not for an unreserved character and is already non-lower-case.
///
/// Returns "%" if the escape is invalid (not two valid hex digits following
/// the percent sign). The calling code should replace the percent
/// sign with "%25", but leave the following two characters unmodified.
///
/// If [lowerCase] is true, a single character returned is always lower case,
static String? _normalizeEscape(String source, int index, bool lowerCase) {
assert(source.codeUnitAt(index) == _PERCENT);
if (index + 2 >= source.length) {
return "%"; // Marks the escape as invalid.
}
int firstDigit = source.codeUnitAt(index + 1);
int secondDigit = source.codeUnitAt(index + 2);
int firstDigitValue = hexDigitValue(firstDigit);
int secondDigitValue = hexDigitValue(secondDigit);
if (firstDigitValue < 0 || secondDigitValue < 0) {
return "%"; // Marks the escape as invalid.
}
int value = firstDigitValue * 16 + secondDigitValue;
if (_isUnreservedChar(value)) {
if (lowerCase && _UPPER_CASE_A <= value && _UPPER_CASE_Z >= value) {
value |= 0x20;
}
return String.fromCharCode(value);
}
if (firstDigit >= _LOWER_CASE_A || secondDigit >= _LOWER_CASE_A) {
// Either digit is lower case.
return source.substring(index, index + 3).toUpperCase();
}
// Escape is retained, and is already non-lower case, so return null to
// represent "no replacement necessary".
return null;
}
static String _escapeChar(int char) {
assert(char <= 0x10ffff); // It's a valid unicode code point.
List<int> codeUnits;
if (char < 0x80) {
// ASCII, a single percent encoded sequence.
codeUnits = Uint8List(3);
codeUnits[0] = _PERCENT;
codeUnits[1] = _hexDigits.codeUnitAt(char >> 4);
codeUnits[2] = _hexDigits.codeUnitAt(char & 0xf);
} else {
// Do UTF-8 encoding of character, then percent encode bytes.
int flag = 0xc0; // The high-bit markers on the first byte of UTF-8.
int encodedBytes = 2;
if (char > 0x7ff) {
flag = 0xe0;
encodedBytes = 3;
if (char > 0xffff) {
encodedBytes = 4;
flag = 0xf0;
}
}
codeUnits = Uint8List(3 * encodedBytes);
int index = 0;
while (--encodedBytes >= 0) {
int byte = ((char >> (6 * encodedBytes)) & 0x3f) | flag;
codeUnits[index] = _PERCENT;
codeUnits[index + 1] = _hexDigits.codeUnitAt(byte >> 4);
codeUnits[index + 2] = _hexDigits.codeUnitAt(byte & 0xf);
index += 3;
flag = 0x80; // Following bytes have only high bit set.
}
}
return String.fromCharCodes(codeUnits);
}
/// Normalizes using [_normalize] or returns substring of original.
///
/// If [_normalize] returns `null` (original content is already normalized),
/// this methods returns the substring if [component] from [start] to [end].
static String _normalizeOrSubstring(
String component, int start, int end, List<int> charTable,
{bool escapeDelimiters = false}) {
return _normalize(component, start, end, charTable,
escapeDelimiters: escapeDelimiters) ??
component.substring(start, end);
}
/// Runs through component checking that each character is valid and
/// normalize percent escapes.
///
/// Uses [charTable] to check if a non-`%` character is allowed.
/// Each `%` character must be followed by two hex digits.
/// If the hex-digits are lower case letters, they are converted to
/// upper case.
///
/// Returns `null` if the original content was already normalized.
static String? _normalize(
String component, int start, int end, List<int> charTable,
{bool escapeDelimiters = false}) {
StringBuffer? buffer;
int sectionStart = start;
int index = start;
// Loop while characters are valid and escapes correct and upper-case.
while (index < end) {
int char = component.codeUnitAt(index);
if (char < 127 && (charTable[char >> 4] & (1 << (char & 0x0f))) != 0) {
index++;
} else {
String? replacement;
int sourceLength;
if (char == _PERCENT) {
replacement = _normalizeEscape(component, index, false);
// Returns null if we should keep the existing escape.
if (replacement == null) {
index += 3;
continue;
}
// Returns "%" if we should escape the existing percent.
if ("%" == replacement) {
replacement = "%25";
sourceLength = 1;
} else {
sourceLength = 3;
}
} else if (!escapeDelimiters && _isGeneralDelimiter(char)) {
_fail(component, index, "Invalid character");
throw "unreachable"; // TODO(lrn): Remove when Never-returning functions are recognized as throwing.
} else {
sourceLength = 1;
if ((char & 0xFC00) == 0xD800) {
// Possible lead surrogate.
if (index + 1 < end) {
int tail = component.codeUnitAt(index + 1);
if ((tail & 0xFC00) == 0xDC00) {
// Tail surrogate.
sourceLength = 2;
char = 0x10000 | ((char & 0x3ff) << 10) | (tail & 0x3ff);
}
}
}
replacement = _escapeChar(char);
}
(buffer ??= StringBuffer())
..write(component.substring(sectionStart, index))
..write(replacement);
index += sourceLength;
sectionStart = index;
}
}
if (buffer == null) {
return null;
}
if (sectionStart < end) {
buffer.write(component.substring(sectionStart, end));
}
return buffer.toString();
}
static bool _isSchemeCharacter(int ch) {
return ch < 128 && ((_schemeTable[ch >> 4] & (1 << (ch & 0x0f))) != 0);
}
static bool _isGeneralDelimiter(int ch) {
return ch <= _RIGHT_BRACKET &&
((_genDelimitersTable[ch >> 4] & (1 << (ch & 0x0f))) != 0);
}
/// Whether the URI is absolute.
bool get isAbsolute => scheme != "" && fragment == "";
String _mergePaths(String base, String reference) {
// Optimize for the case: absolute base, reference beginning with "../".
int backCount = 0;
int refStart = 0;
// Count number of "../" at beginning of reference.
while (reference.startsWith("../", refStart)) {
refStart += 3;
backCount++;
}
// Drop last segment - everything after last '/' of base.
int baseEnd = base.lastIndexOf('/');
// Drop extra segments for each leading "../" of reference.
while (baseEnd > 0 && backCount > 0) {
int newEnd = base.lastIndexOf('/', baseEnd - 1);
if (newEnd < 0) {
break;
}
int delta = baseEnd - newEnd;
// If we see a "." or ".." segment in base, stop here and let
// _removeDotSegments handle it.
if ((delta == 2 || delta == 3) &&
base.codeUnitAt(newEnd + 1) == _DOT &&
(delta == 2 || base.codeUnitAt(newEnd + 2) == _DOT)) {
break;
}
baseEnd = newEnd;
backCount--;
}
return base.replaceRange(
baseEnd + 1, null, reference.substring(refStart - 3 * backCount));
}
/// Make a guess at whether a path contains a `..` or `.` segment.
///
/// This is a primitive test that can cause false positives.
/// It's only used to avoid a more expensive operation in the case where
/// it's not necessary.
static bool _mayContainDotSegments(String path) {
if (path.startsWith('.')) return true;
int index = path.indexOf("/.");
return index != -1;
}
/// Removes '.' and '..' segments from a path.
///
/// Follows the RFC 2986 "remove dot segments" algorithm.
/// This algorithm is only used on paths of URIs with a scheme,
/// and it treats the path as if it is absolute (leading '..' are removed).
static String _removeDotSegments(String path) {
if (!_mayContainDotSegments(path)) return path;
assert(path.isNotEmpty); // An empty path would not have dot segments.
List<String> output = [];
bool appendSlash = false;
for (String segment in path.split("/")) {
appendSlash = false;
if (segment == "..") {
if (output.isNotEmpty) {
output.removeLast();
if (output.isEmpty) {
output.add("");
}
}
appendSlash = true;
} else if ("." == segment) {
appendSlash = true;
} else {
output.add(segment);
}
}
if (appendSlash) output.add("");
return output.join("/");
}
/// Removes all `.` segments and any non-leading `..` segments.
///
/// If the path starts with something that looks like a scheme,
/// and [allowScheme] is false, the colon is escaped.
///
/// Removing the ".." from a "bar/foo/.." sequence results in "bar/"
/// (trailing "/"). If the entire path is removed (because it contains as
/// many ".." segments as real segments), the result is "./".
/// This is different from an empty string, which represents "no path",
/// when you resolve it against a base URI with a path with a non-empty
/// final segment.
static String _normalizeRelativePath(String path, bool allowScheme) {
assert(!path.startsWith('/')); // Only get called for relative paths.
if (!_mayContainDotSegments(path)) {
if (!allowScheme) path = _escapeScheme(path);
return path;
}
assert(path.isNotEmpty); // An empty path would not have dot segments.
List<String> output = [];
bool appendSlash = false;
for (String segment in path.split("/")) {
appendSlash = false;
if (".." == segment) {
if (!output.isEmpty && output.last != "..") {
output.removeLast();
appendSlash = true;
} else {
output.add("..");
}
} else if ("." == segment) {
appendSlash = true;
} else {
output.add(segment);
}
}
if (output.isEmpty || (output.length == 1 && output[0].isEmpty)) {
return "./";
}
if (appendSlash || output.last == '..') output.add("");
if (!allowScheme) output[0] = _escapeScheme(output[0]);
return output.join("/");
}
/// If [path] starts with a valid scheme, escape the percent.
static String _escapeScheme(String path) {
if (path.length >= 2 && _isAlphabeticCharacter(path.codeUnitAt(0))) {
for (int i = 1; i < path.length; i++) {
int char = path.codeUnitAt(i);
if (char == _COLON) {
return "${path.substring(0, i)}%3A${path.substring(i + 1)}";
}
if (char > 127 ||
((_schemeTable[char >> 4] & (1 << (char & 0x0f))) == 0)) {
break;
}
}
}
return path;
}
Uri resolve(String reference) {
return resolveUri(Uri.parse(reference));
}
// Returns the index of the `/` after the package name of a package URI.
//
// Returns negative if the URI is not a valid package URI:
// * Scheme must be "package".
// * No authority.
// * Path starts with "something"/
// * where "something" is not all "." characters,
// * and contains no escapes or colons.
//
// The characters are necessarily valid path characters.
static int _packageNameEnd(Uri uri, String path) {
if (uri.isScheme("package") && !uri.hasAuthority) {
return _skipPackageNameChars(path, 0, path.length);
}
return -1;
}
Uri resolveUri(Uri reference) {
// From RFC 3986.
String targetScheme;
String targetUserInfo = "";
String? targetHost;
int? targetPort;
String targetPath;
String? targetQuery;
if (reference.scheme.isNotEmpty) {
targetScheme = reference.scheme;
if (reference.hasAuthority) {
targetUserInfo = reference.userInfo;
targetHost = reference.host;
targetPort = reference.hasPort ? reference.port : null;
}
targetPath = _removeDotSegments(reference.path);
if (reference.hasQuery) {
targetQuery = reference.query;
}
} else {
targetScheme = this.scheme;
if (reference.hasAuthority) {
targetUserInfo = reference.userInfo;
targetHost = reference.host;
targetPort =
_makePort(reference.hasPort ? reference.port : null, targetScheme);
targetPath = _removeDotSegments(reference.path);
if (reference.hasQuery) targetQuery = reference.query;
} else {
targetUserInfo = this._userInfo;
targetHost = this._host;
targetPort = this._port;
if (reference.path == "") {
targetPath = this.path;
if (reference.hasQuery) {
targetQuery = reference.query;
} else {
targetQuery = this._query;
}
} else {
String basePath = this.path;
int packageNameEnd = _packageNameEnd(this, basePath);
if (packageNameEnd > 0) {
assert(targetScheme == "package");
assert(!this.hasAuthority);
assert(!this.hasEmptyPath);
// Merging a path into a package URI.
String packageName = basePath.substring(0, packageNameEnd);
if (reference.hasAbsolutePath) {
targetPath = packageName + _removeDotSegments(reference.path);
} else {
targetPath = packageName +
_removeDotSegments(_mergePaths(
basePath.substring(packageName.length), reference.path));
}
} else if (reference.hasAbsolutePath) {
targetPath = _removeDotSegments(reference.path);
} else {
// This is the RFC 3986 behavior for merging.
if (this.hasEmptyPath) {
if (!this.hasAuthority) {
if (!this.hasScheme) {
// Keep the path relative if no scheme or authority.
targetPath = reference.path;
} else {
// Remove leading dot-segments if the path is put
// beneath a scheme.
targetPath = _removeDotSegments(reference.path);
}
} else {
// RFC algorithm for base with authority and empty path.
targetPath = _removeDotSegments("/" + reference.path);
}
} else {
var mergedPath = _mergePaths(this.path, reference.path);
if (this.hasScheme || this.hasAuthority || this.hasAbsolutePath) {
targetPath = _removeDotSegments(mergedPath);
} else {
// Non-RFC 3986 behavior.
// If both base and reference are relative paths,
// allow the merged path to start with "..".
// The RFC only specifies the case where the base has a scheme.
targetPath = _normalizeRelativePath(
mergedPath, this.hasScheme || this.hasAuthority);
}
}
}
if (reference.hasQuery) targetQuery = reference.query;
}
}
}
String? fragment = reference.hasFragment ? reference.fragment : null;
return _Uri._internal(targetScheme, targetUserInfo, targetHost, targetPort,
targetPath, targetQuery, fragment);
}
bool get hasScheme => scheme.isNotEmpty;
bool get hasAuthority => _host != null;
bool get hasPort => _port != null;
bool get hasQuery => _query != null;
bool get hasFragment => _fragment != null;
bool get hasEmptyPath => path.isEmpty;
bool get hasAbsolutePath => path.startsWith('/');
String get origin {
if (scheme == "") {
throw StateError("Cannot use origin without a scheme: $this");
}
if (scheme != "http" && scheme != "https") {
throw StateError(
"Origin is only applicable schemes http and https: $this");
}
String? host = _host;
if (host == null || host == "") {
throw StateError(
"A $scheme: URI should have a non-empty host name: $this");
}
int? port = _port;
if (port == null) return "$scheme://$host";
return "$scheme://$host:$port";
}
String toFilePath({bool? windows}) {
if (scheme != "" && scheme != "file") {
throw UnsupportedError("Cannot extract a file path from a $scheme URI");
}
if (query != "") {
throw UnsupportedError(
"Cannot extract a file path from a URI with a query component");
}
if (fragment != "") {
throw UnsupportedError(
"Cannot extract a file path from a URI with a fragment component");
}
return (windows ?? _isWindows) ? _toWindowsFilePath(this) : _toFilePath();
}
String _toFilePath() {
if (hasAuthority && host != "") {
throw UnsupportedError(
"Cannot extract a non-Windows file path from a file URI "
"with an authority");
}
// Use path segments to have any escapes unescaped.
var pathSegments = this.pathSegments;
_checkNonWindowsPathReservedCharacters(pathSegments, false);
var result = StringBuffer();
if (hasAbsolutePath) result.write("/");
result.writeAll(pathSegments, "/");
return result.toString();
}
static String _toWindowsFilePath(Uri uri) {
bool hasDriveLetter = false;
var segments = uri.pathSegments;
if (segments.length > 0 &&
segments[0].length == 2 &&
segments[0].codeUnitAt(1) == _COLON) {
_checkWindowsDriveLetter(segments[0].codeUnitAt(0), false);
_checkWindowsPathReservedCharacters(segments, false, 1);
hasDriveLetter = true;
} else {
_checkWindowsPathReservedCharacters(segments, false, 0);
}
var result = StringBuffer();
if (uri.hasAbsolutePath && !hasDriveLetter) result.write(r"\");
if (uri.hasAuthority) {
var host = uri.host;
if (host.isNotEmpty) {
result.write(r"\");
result.write(host);
result.write(r"\");
}
}
result.writeAll(segments, r"\");
if (hasDriveLetter && segments.length == 1) result.write(r"\");
return result.toString();
}
void _writeAuthority(StringSink ss) {
if (_userInfo.isNotEmpty) {
ss.write(_userInfo);
ss.write("@");
}
if (_host != null) ss.write(_host);
if (_port != null) {
ss.write(":");
ss.write(_port);
}
}
/// Access the structure of a `data:` URI.
///
/// Returns a [UriData] object for `data:` URIs and `null` for all other
/// URIs.
/// The [UriData] object can be used to access the media type and data
/// of a `data:` URI.
UriData? get data => (scheme == "data") ? UriData.fromUri(this) : null;
String toString() => _text;
String _initializeText() {
StringBuffer sb = StringBuffer();
if (scheme.isNotEmpty) sb..write(scheme)..write(":");
if (hasAuthority || (scheme == "file")) {
// File URIS always have the authority, even if it is empty.
// The empty URI means "localhost".
sb.write("//");
_writeAuthority(sb);
}
sb.write(path);
if (_query != null) sb..write("?")..write(_query);
if (_fragment != null) sb..write("#")..write(_fragment);
return sb.toString();
}
bool operator ==(Object other) {
if (identical(this, other)) return true;
return other is Uri &&
scheme == other.scheme &&
hasAuthority == other.hasAuthority &&
userInfo == other.userInfo &&
host == other.host &&
port == other.port &&
path == other.path &&
hasQuery == other.hasQuery &&
query == other.query &&
hasFragment == other.hasFragment &&
fragment == other.fragment;
}
static List<String> _createList() => <String>[];
static Map<String, List<String>> _splitQueryStringAll(String query,
{Encoding encoding = utf8}) {
var result = <String, List<String>>{};
int i = 0;
int start = 0;
int equalsIndex = -1;
void parsePair(int start, int equalsIndex, int end) {
String key;
String value;
if (start == end) return;
if (equalsIndex < 0) {
key = _uriDecode(query, start, end, encoding, true);
value = "";
} else {
key = _uriDecode(query, start, equalsIndex, encoding, true);
value = _uriDecode(query, equalsIndex + 1, end, encoding, true);
}
result.putIfAbsent(key, _createList).add(value);
}
while (i < query.length) {
int char = query.codeUnitAt(i);
if (char == _EQUALS) {
if (equalsIndex < 0) equalsIndex = i;
} else if (char == _AMPERSAND) {
parsePair(start, equalsIndex, i);
start = i + 1;
equalsIndex = -1;
}
i++;
}
parsePair(start, equalsIndex, i);
return result;
}
external static String _uriEncode(List<int> canonicalTable, String text,
Encoding encoding, bool spaceToPlus);
/// Convert a byte (2 character hex sequence) in string [s] starting
/// at position [pos] to its ordinal value
static int _hexCharPairToByte(String s, int pos) {
int byte = 0;
for (int i = 0; i < 2; i++) {
var charCode = s.codeUnitAt(pos + i);
if (0x30 <= charCode && charCode <= 0x39) {
byte = byte * 16 + charCode - 0x30;
} else {
// Check ranges A-F (0x41-0x46) and a-f (0x61-0x66).
charCode |= 0x20;
if (0x61 <= charCode && charCode <= 0x66) {
byte = byte * 16 + charCode - 0x57;
} else {
throw ArgumentError("Invalid URL encoding");
}
}
}
return byte;
}
/// Uri-decode a percent-encoded string.
///
/// It unescapes the string [text] and returns the unescaped string.
///
/// This function is similar to the JavaScript-function `decodeURI`.
///
/// If [plusToSpace] is `true`, plus characters will be converted to spaces.
///
/// The decoder will create a byte-list of the percent-encoded parts, and then
/// decode the byte-list using [encoding]. The default encodings UTF-8.
static String _uriDecode(
String text, int start, int end, Encoding encoding, bool plusToSpace) {
assert(0 <= start);
assert(start <= end);
assert(end <= text.length);
// First check whether there is any characters which need special handling.
bool simple = true;
for (int i = start; i < end; i++) {
var codeUnit = text.codeUnitAt(i);
if (codeUnit > 127 ||
codeUnit == _PERCENT ||
(plusToSpace && codeUnit == _PLUS)) {
simple = false;
break;
}
}
List<int> bytes;
if (simple) {
if (utf8 == encoding || latin1 == encoding || ascii == encoding) {
return text.substring(start, end);
} else {
bytes = text.substring(start, end).codeUnits;
}
} else {
bytes = <int>[];
for (int i = start; i < end; i++) {
var codeUnit = text.codeUnitAt(i);
if (codeUnit > 127) {
throw ArgumentError("Illegal percent encoding in URI");
}
if (codeUnit == _PERCENT) {
if (i + 3 > text.length) {
throw ArgumentError('Truncated URI');
}
bytes.add(_hexCharPairToByte(text, i + 1));
i += 2;
} else if (plusToSpace && codeUnit == _PLUS) {
bytes.add(_SPACE);
} else {
bytes.add(codeUnit);
}
}
}
return encoding.decode(bytes);
}
static bool _isAlphabeticCharacter(int codeUnit) {
var lowerCase = codeUnit | 0x20;
return (_LOWER_CASE_A <= lowerCase && lowerCase <= _LOWER_CASE_Z);
}
static bool _isUnreservedChar(int char) {
return char < 127 &&
((_unreservedTable[char >> 4] & (1 << (char & 0x0f))) != 0);
}
// Tables of char-codes organized as a bit vector of 128 bits where
// each bit indicate whether a character code on the 0-127 needs to
// be escaped or not.
// The unreserved characters of RFC 3986.
static const _unreservedTable = <int>[
// LSB MSB
// | |
0x0000, // 0x00 - 0x0f 0000000000000000
0x0000, // 0x10 - 0x1f 0000000000000000
// -.
0x6000, // 0x20 - 0x2f 0000000000000110
// 0123456789
0x03ff, // 0x30 - 0x3f 1111111111000000
// ABCDEFGHIJKLMNO
0xfffe, // 0x40 - 0x4f 0111111111111111
// PQRSTUVWXYZ _
0x87ff, // 0x50 - 0x5f 1111111111100001
// abcdefghijklmno
0xfffe, // 0x60 - 0x6f 0111111111111111
// pqrstuvwxyz ~
0x47ff, // 0x70 - 0x7f 1111111111100010
];
// The unreserved characters of RFC 2396.
static const _unreserved2396Table = <int>[
// LSB MSB
// | |
0x0000, // 0x00 - 0x0f 0000000000000000
0x0000, // 0x10 - 0x1f 0000000000000000
// ! '()* -.
0x6782, // 0x20 - 0x2f 0100000111100110
// 0123456789
0x03ff, // 0x30 - 0x3f 1111111111000000
// ABCDEFGHIJKLMNO
0xfffe, // 0x40 - 0x4f 0111111111111111
// PQRSTUVWXYZ _
0x87ff, // 0x50 - 0x5f 1111111111100001
// abcdefghijklmno
0xfffe, // 0x60 - 0x6f 0111111111111111
// pqrstuvwxyz ~
0x47ff, // 0x70 - 0x7f 1111111111100010
];
// Table of reserved characters specified by ECMAScript 5.
static const _encodeFullTable = <int>[
// LSB MSB
// | |
0x0000, // 0x00 - 0x0f 0000000000000000
0x0000, // 0x10 - 0x1f 0000000000000000
// ! #$ &'()*+,-./
0xffda, // 0x20 - 0x2f 0101101111111111
// 0123456789:; = ?
0xafff, // 0x30 - 0x3f 1111111111110101
// @ABCDEFGHIJKLMNO
0xffff, // 0x40 - 0x4f 1111111111111111
// PQRSTUVWXYZ _
0x87ff, // 0x50 - 0x5f 1111111111100001
// abcdefghijklmno
0xfffe, // 0x60 - 0x6f 0111111111111111
// pqrstuvwxyz ~
0x47ff, // 0x70 - 0x7f 1111111111100010
];
// Characters allowed in the scheme.
static const _schemeTable = <int>[
// LSB MSB
// | |
0x0000, // 0x00 - 0x0f 0000000000000000
0x0000, // 0x10 - 0x1f 0000000000000000
// + -.
0x6800, // 0x20 - 0x2f 0000000000010110
// 0123456789
0x03ff, // 0x30 - 0x3f 1111111111000000
// ABCDEFGHIJKLMNO
0xfffe, // 0x40 - 0x4f 0111111111111111
// PQRSTUVWXYZ
0x07ff, // 0x50 - 0x5f 1111111111100001
// abcdefghijklmno
0xfffe, // 0x60 - 0x6f 0111111111111111
// pqrstuvwxyz
0x07ff, // 0x70 - 0x7f 1111111111100010
];
// General delimiter characters, RFC 3986 section 2.2.
// gen-delims = ":" / "/" / "?" / "#" / "[" / "]" / "@"
//
static const _genDelimitersTable = <int>[
// LSB MSB
// | |
0x0000, // 0x00 - 0x0f 0000000000000000
0x0000, // 0x10 - 0x1f 0000000000000000
// # /
0x8008, // 0x20 - 0x2f 0001000000000001
// : ?
0x8400, // 0x30 - 0x3f 0000000000100001
// @
0x0001, // 0x40 - 0x4f 1000000000000000
// [ ]
0x2800, // 0x50 - 0x5f 0000000000010100
//
0x0000, // 0x60 - 0x6f 0000000000000000
//
0x0000, // 0x70 - 0x7f 0000000000000000
];
// Characters allowed in the userinfo as of RFC 3986.
// RFC 3986 Appendix A
// userinfo = *( unreserved / pct-encoded / sub-delims / ':')
static const _userinfoTable = <int>[
// LSB MSB
// | |
0x0000, // 0x00 - 0x0f 0000000000000000
0x0000, // 0x10 - 0x1f 0000000000000000
// ! $ &'()*+,-.
0x7fd2, // 0x20 - 0x2f 0100101111111110
// 0123456789:; =
0x2fff, // 0x30 - 0x3f 1111111111110100
// ABCDEFGHIJKLMNO
0xfffe, // 0x40 - 0x4f 0111111111111111
// PQRSTUVWXYZ _
0x87ff, // 0x50 - 0x5f 1111111111100001
// abcdefghijklmno
0xfffe, // 0x60 - 0x6f 0111111111111111
// pqrstuvwxyz ~
0x47ff, // 0x70 - 0x7f 1111111111100010
];
// Characters allowed in the reg-name as of RFC 3986.
// RFC 3986 Appendix A
// reg-name = *( unreserved / pct-encoded / sub-delims )
static const _regNameTable = <int>[
// LSB MSB
// | |
0x0000, // 0x00 - 0x0f 0000000000000000
0x0000, // 0x10 - 0x1f 0000000000000000
// ! $%&'()*+,-.
0x7ff2, // 0x20 - 0x2f 0100111111111110
// 0123456789 ; =
0x2bff, // 0x30 - 0x3f 1111111111010100
// ABCDEFGHIJKLMNO
0xfffe, // 0x40 - 0x4f 0111111111111111
// PQRSTUVWXYZ _
0x87ff, // 0x50 - 0x5f 1111111111100001
// abcdefghijklmno
0xfffe, // 0x60 - 0x6f 0111111111111111
// pqrstuvwxyz ~
0x47ff, // 0x70 - 0x7f 1111111111100010
];
// Characters allowed in the path as of RFC 3986.
// RFC 3986 section 3.3.
// pchar = unreserved / pct-encoded / sub-delims / ":" / "@"
static const _pathCharTable = <int>[
// LSB MSB
// | |
0x0000, // 0x00 - 0x0f 0000000000000000
0x0000, // 0x10 - 0x1f 0000000000000000
// ! $ &'()*+,-.
0x7fd2, // 0x20 - 0x2f 0100101111111110
// 0123456789:; =
0x2fff, // 0x30 - 0x3f 1111111111110100
// @ABCDEFGHIJKLMNO
0xffff, // 0x40 - 0x4f 1111111111111111
// PQRSTUVWXYZ _
0x87ff, // 0x50 - 0x5f 1111111111100001
// abcdefghijklmno
0xfffe, // 0x60 - 0x6f 0111111111111111
// pqrstuvwxyz ~
0x47ff, // 0x70 - 0x7f 1111111111100010
];
// Characters allowed in the path as of RFC 3986.
// RFC 3986 section 3.3 *and* slash.
static const _pathCharOrSlashTable = [
// LSB MSB
// | |
0x0000, // 0x00 - 0x0f 0000000000000000
0x0000, // 0x10 - 0x1f 0000000000000000
// ! $ &'()*+,-./
0xffd2, // 0x20 - 0x2f 0100101111111111
// 0123456789:; =
0x2fff, // 0x30 - 0x3f 1111111111110100
// @ABCDEFGHIJKLMNO
0xffff, // 0x40 - 0x4f 1111111111111111
// PQRSTUVWXYZ _
0x87ff, // 0x50 - 0x5f 1111111111100001
// abcdefghijklmno
0xfffe, // 0x60 - 0x6f 0111111111111111
// pqrstuvwxyz ~
0x47ff, // 0x70 - 0x7f 1111111111100010
];
// Characters allowed in the query as of RFC 3986.
// RFC 3986 section 3.4.
// query = *( pchar / "/" / "?" )
static const _queryCharTable = [
// LSB MSB
// | |
0x0000, // 0x00 - 0x0f 0000000000000000
0x0000, // 0x10 - 0x1f 0000000000000000
// ! $ &'()*+,-./
0xffd2, // 0x20 - 0x2f 0100101111111111
// 0123456789:; = ?
0xafff, // 0x30 - 0x3f 1111111111110101
// @ABCDEFGHIJKLMNO
0xffff, // 0x40 - 0x4f 1111111111111111
// PQRSTUVWXYZ _
0x87ff, // 0x50 - 0x5f 1111111111100001
// abcdefghijklmno
0xfffe, // 0x60 - 0x6f 0111111111111111
// pqrstuvwxyz ~
0x47ff, // 0x70 - 0x7f 1111111111100010
];
// Characters allowed in the ZoneID as of RFC 6874.
// ZoneID = 1*( unreserved / pct-encoded )
static const _zoneIDTable = <int>[
// LSB MSB
// | |
0x0000, // 0x00 - 0x0f 0000000000000000
0x0000, // 0x10 - 0x1f 0000000000000000
// ! $%&'()*+,-.
0x6000, // 0x20 - 0x2f 0000000000000110
// 0123456789 ; =
0x03ff, // 0x30 - 0x3f 1111111111000000
// ABCDEFGHIJKLMNO
0xfffe, // 0x40 - 0x4f 0111111111111111
// PQRSTUVWXYZ _
0x87ff, // 0x50 - 0x5f 1111111111100001
// abcdefghijklmno
0xfffe, // 0x60 - 0x6f 0111111111111111
// pqrstuvwxyz ~
0x47ff, // 0x70 - 0x7f 1111111111100010
];
}
// --------------------------------------------------------------------
// Data URI
// --------------------------------------------------------------------
/// A way to access the structure of a `data:` URI.
///
/// Data URIs are non-hierarchical URIs that can contain any binary data.
/// They are defined by [RFC 2397](https://tools.ietf.org/html/rfc2397).
///
/// This class allows parsing the URI text and extracting individual parts of the
/// URI, as well as building the URI text from structured parts.
class UriData {
static const int _noScheme = -1;
/// Contains the text content of a `data:` URI, with or without a
/// leading `data:`.
///
/// If [_separatorIndices] starts with `4` (the index of the `:`), then
/// there is a leading `data:`, otherwise [_separatorIndices] starts with
/// `-1`.
final String _text;
/// List of the separators (';', '=' and ',') in the text.
///
/// Starts with the index of the `:` in `data:` of the mimeType.
/// That is always either -1 or 4, depending on whether `_text` includes the
/// `data:` scheme or not.
///
/// The first speparator ends the mime type. We don't bother with finding
/// the '/' inside the mime type.
///
/// Each two separators after that marks a parameter key and value.
///
/// If there is a single separator left, it ends the "base64" marker.
///
/// So the following separators are found for a text:
/// ```plaintext
/// data:text/plain;foo=bar;base64,ARGLEBARGLE=
/// ^ ^ ^ ^ ^
/// ```
final List<int> _separatorIndices;
/// Cache of the result returned by [uri].
Uri? _uriCache;
UriData._(this._text, this._separatorIndices, this._uriCache);
// Avoid shadowing by argument.
static const Base64Codec _base64 = base64;
/// Creates a `data:` URI containing the [content] string.
///
/// Equivalent to `Uri.dataFromString(...).data`, but may
/// be more efficient if the [uri] itself isn't used.
factory UriData.fromString(String content,
{String? mimeType,
Encoding? encoding,
Map<String, String>? parameters,
bool base64 = false}) {
StringBuffer buffer = StringBuffer();
List<int> indices = [_noScheme];
String? charsetName = parameters?["charset"];
String? encodingName;
if (encoding == null) {
if (charsetName != null) {
encoding = Encoding.getByName(charsetName);
}
} else if (charsetName == null) {
// Non-null only if parameters does not contain "charset".
encodingName = encoding.name;
}
encoding ??= ascii;
_writeUri(mimeType, encodingName, parameters, buffer, indices);
indices.add(buffer.length);
if (base64) {
buffer.write(';base64,');
indices.add(buffer.length - 1);
buffer.write(encoding.fuse(_base64).encode(content));
} else {
buffer.write(',');
_uriEncodeBytes(_uricTable, encoding.encode(content), buffer);
}
return UriData._(buffer.toString(), indices, null);
}
/// Creates a `data:` URI containing an encoding of [bytes].
///
/// Equivalent to `Uri.dataFromBytes(...).data`, but may
/// be more efficient if the [uri] itself isn't used.
factory UriData.fromBytes(List<int> bytes,
{String mimeType = "application/octet-stream",
Map<String, String>? parameters,
bool percentEncoded = false}) {
StringBuffer buffer = StringBuffer();
List<int> indices = [_noScheme];
_writeUri(mimeType, null, parameters, buffer, indices);
indices.add(buffer.length);
if (percentEncoded) {
buffer.write(',');
_uriEncodeBytes(_uricTable, bytes, buffer);
} else {
buffer.write(';base64,');
indices.add(buffer.length - 1);
_base64.encoder
.startChunkedConversion(StringConversionSink.fromStringSink(buffer))
.addSlice(bytes, 0, bytes.length, true);
}
return UriData._(buffer.toString(), indices, null);
}
/// Creates a `DataUri` from a [Uri] which must have `data` as [Uri.scheme].
///
/// The [uri] must have scheme `data` and no authority or fragment,
/// and the path (concatenated with the query, if there is one) must be valid
/// as data URI content with the same rules as [parse].
factory UriData.fromUri(Uri uri) {
if (uri.scheme != "data") {
throw ArgumentError.value(uri, "uri", "Scheme must be 'data'");
}
if (uri.hasAuthority) {
throw ArgumentError.value(uri, "uri", "Data uri must not have authority");
}
if (uri.hasFragment) {
throw ArgumentError.value(
uri, "uri", "Data uri must not have a fragment part");
}
if (!uri.hasQuery) {
return _parse(uri.path, 0, uri);
}
// Includes path and query (and leading "data:").
return _parse(uri.toString(), 5, uri);
}
/// Writes the initial part of a `data:` uri, from after the "data:"
/// until just before the ',' before the data, or before a `;base64,`
/// marker.
///
/// Of an [indices] list is passed, separator indices are stored in that
/// list.
static void _writeUri(
String? mimeType,
String? charsetName,
Map<String, String>? parameters,
StringBuffer buffer,
List<int>? indices) {
if (mimeType == null || mimeType == "text/plain") {
mimeType = "";
}
if (mimeType.isEmpty || identical(mimeType, "application/octet-stream")) {
buffer.write(mimeType); // Common cases need no escaping.
} else {
int slashIndex = _validateMimeType(mimeType);
if (slashIndex < 0) {
throw ArgumentError.value(mimeType, "mimeType", "Invalid MIME type");
}
buffer.write(_Uri._uriEncode(
_tokenCharTable, mimeType.substring(0, slashIndex), utf8, false));
buffer.write("/");
buffer.write(_Uri._uriEncode(
_tokenCharTable, mimeType.substring(slashIndex + 1), utf8, false));
}
if (charsetName != null) {
// TODO(39209): Use ?.. when sequences are properly supported.
if (indices != null) indices..add(buffer.length)..add(buffer.length + 8);
buffer.write(";charset=");
buffer.write(_Uri._uriEncode(_tokenCharTable, charsetName, utf8, false));
}
parameters?.forEach((key, value) {
if (key.isEmpty) {
throw ArgumentError.value("", "Parameter names must not be empty");
}
if (value.isEmpty) {
throw ArgumentError.value(
"", "Parameter values must not be empty", 'parameters["$key"]');
}
indices?.add(buffer.length);
buffer.write(';');
// Encode any non-RFC2045-token character and both '%' and '#'.
buffer.write(_Uri._uriEncode(_tokenCharTable, key, utf8, false));
indices?.add(buffer.length);
buffer.write('=');
buffer.write(_Uri._uriEncode(_tokenCharTable, value, utf8, false));
});
}
/// Checks mimeType is valid-ish (`token '/' token`).
///
/// Returns the index of the slash, or -1 if the mime type is not
/// considered valid.
///
/// Currently only looks for slashes, all other characters will be
/// percent-encoded as UTF-8 if necessary.
static int _validateMimeType(String mimeType) {
int slashIndex = -1;
for (int i = 0; i < mimeType.length; i++) {
var char = mimeType.codeUnitAt(i);
if (char != _SLASH) continue;
if (slashIndex < 0) {
slashIndex = i;
continue;
}
return -1;
}
return slashIndex;
}
/// Parses a string as a `data` URI.
///
/// The string must have the format:
///
/// ```plaintext
/// 'data:' (type '/' subtype)? (';' attribute '=' value)* (';base64')? ',' data
/// ````
///
/// where `type`, `subtype`, `attribute` and `value` are specified in RFC-2045,
/// and `data` is a sequence of URI-characters (RFC-2396 `uric`).
///
/// This means that all the characters must be ASCII, but the URI may contain
/// percent-escapes for non-ASCII byte values that need an interpretation
/// to be converted to the corresponding string.
///
/// Parsing checks that Base64 encoded data is valid, and it normalizes it
/// to use the default Base64 alphabet and to use padding.
/// Non-Base64 data is escaped using percent-escapes as necessary to make
/// it valid, and existing escapes are case normalized.
///
/// Accessing the individual parts may fail later if they turn out to have
/// content that can't be decoded successfully as a string, for example if
/// existing percent escapes represent bytes that cannot be decoded
/// by the chosen [Encoding] (see [contentAsString]).
///
/// A [FormatException] is thrown if [uri] is not a valid data URI.
static UriData parse(String uri) {
if (uri.length >= 5) {
int dataDelta = _startsWithData(uri, 0);
if (dataDelta == 0) {
// Exact match on "data:".
return _parse(uri, 5, null);
}
if (dataDelta == 0x20) {
// Starts with a non-normalized "data" scheme containing upper-case
// letters. Parse anyway, but throw away the scheme.
return _parse(uri.substring(5), 0, null);
}
}
throw FormatException("Does not start with 'data:'", uri, 0);
}
/// The [Uri] that this `UriData` is giving access to.
///
/// Returns a `Uri` with scheme `data` and the remainder of the data URI
/// as path.
Uri get uri {
return _uriCache ??= _computeUri();
}
Uri _computeUri() {
String path = _text;
String? query;
int colonIndex = _separatorIndices[0];
int queryIndex = _text.indexOf('?', colonIndex + 1);
int end = _text.length;
if (queryIndex >= 0) {
query = _Uri._normalizeOrSubstring(
_text, queryIndex + 1, end, _Uri._queryCharTable);
end = queryIndex;
}
path = _Uri._normalizeOrSubstring(
_text, colonIndex + 1, end, _Uri._pathCharOrSlashTable);
return _DataUri(this, path, query);
}
/// The MIME type of the data URI.
///
/// A data URI consists of a "media type" followed by data.
/// The media type starts with a MIME type and can be followed by
/// extra parameters.
/// If the MIME type representation in the URI text contains URI escapes,
/// they are unescaped in the returned string.
/// If the value contain non-ASCII percent escapes, they are decoded as UTF-8.
///
/// Example:
/// ```dart
/// data:text/plain;charset=utf-8,Hello%20World!
/// ```
/// This data URI has the media type `text/plain;charset=utf-8`, which is the
/// MIME type `text/plain` with the parameter `charset` with value `utf-8`.
/// See [RFC 2045](https://tools.ietf.org/html/rfc2045) for more detail.
///
/// If the first part of the data URI is empty, it defaults to `text/plain`.
String get mimeType {
int start = _separatorIndices[0] + 1;
int end = _separatorIndices[1];
if (start == end) return "text/plain";
return _Uri._uriDecode(_text, start, end, utf8, false);
}
/// The charset parameter of the media type.
///
/// If the parameters of the media type contains a `charset` parameter
/// then this returns its value, otherwise it returns `US-ASCII`,
/// which is the default charset for data URIs.
/// If the value contain non-ASCII percent escapes, they are decoded as UTF-8.
///
/// If the MIME type representation in the URI text contains URI escapes,
/// they are unescaped in the returned string.
String get charset {
int parameterStart = 1;
int parameterEnd = _separatorIndices.length - 1; // The ',' before data.
if (isBase64) {
// There is a ";base64" separator, so subtract one for that as well.
parameterEnd -= 1;
}
for (int i = parameterStart; i < parameterEnd; i += 2) {
var keyStart = _separatorIndices[i] + 1;
var keyEnd = _separatorIndices[i + 1];
if (keyEnd == keyStart + 7 && _text.startsWith("charset", keyStart)) {
return _Uri._uriDecode(
_text, keyEnd + 1, _separatorIndices[i + 2], utf8, false);
}
}
return "US-ASCII";
}
/// Whether the data is Base64 encoded or not.
bool get isBase64 => _separatorIndices.length.isOdd;
/// The content part of the data URI, as its actual representation.
///
/// This string may contain percent escapes.
String get contentText => _text.substring(_separatorIndices.last + 1);
/// The content part of the data URI as bytes.
///
/// If the data is Base64 encoded, it will be decoded to bytes.
///
/// If the data is not Base64 encoded, it will be decoded by unescaping
/// percent-escaped characters and returning byte values of each unescaped
/// character. The bytes will not be, e.g., UTF-8 decoded.
Uint8List contentAsBytes() {
String text = _text;
int start = _separatorIndices.last + 1;
if (isBase64) {
return base64.decoder.convert(text, start);
}
// Not base64, do percent-decoding and return the remaining bytes.
// Compute result size.
const int percent = 0x25;
int length = text.length - start;
for (int i = start; i < text.length; i++) {
var codeUnit = text.codeUnitAt(i);
if (codeUnit == percent) {
i += 2;
length -= 2;
}
}
// Fill result array.
Uint8List result = Uint8List(length);
if (length == text.length) {
result.setRange(0, length, text.codeUnits, start);
return result;
}
int index = 0;
for (int i = start; i < text.length; i++) {
var codeUnit = text.codeUnitAt(i);
if (codeUnit != percent) {
result[index++] = codeUnit;
} else {
if (i + 2 < text.length) {
int byte = parseHexByte(text, i + 1);
if (byte >= 0) {
result[index++] = byte;
i += 2;
continue;
}
}
throw FormatException("Invalid percent escape", text, i);
}
}
assert(index == result.length);
return result;
}
/// Creates a string from the content of the data URI.
///
/// If the content is Base64 encoded, it will be decoded to bytes and then
/// decoded to a string using [encoding].
/// If encoding is omitted, the value of a `charset` parameter is used
/// if it is recognized by [Encoding.getByName], otherwise it defaults to
/// the [ascii] encoding, which is the default encoding for data URIs
/// that do not specify an encoding.
///
/// If the content is not Base64 encoded, it will first have percent-escapes
/// converted to bytes and then the character codes and byte values are
/// decoded using [encoding].
String contentAsString({Encoding? encoding}) {
if (encoding == null) {
var charset = this.charset; // Returns "US-ASCII" if not present.
encoding = Encoding.getByName(charset);
if (encoding == null) {
throw UnsupportedError("Unknown charset: $charset");
}
}
String text = _text;
int start = _separatorIndices.last + 1;
if (isBase64) {
var converter = base64.decoder.fuse(encoding.decoder);
return converter.convert(text.substring(start));
}
return _Uri._uriDecode(text, start, text.length, encoding, false);
}
/// A map representing the parameters of the media type.
///
/// A data URI may contain parameters between the MIME type and the
/// data. This converts these parameters to a map from parameter name
/// to parameter value.
/// The map only contains parameters that actually occur in the URI.
/// The `charset` parameter has a default value even if it doesn't occur
/// in the URI, which is reflected by the [charset] getter. This means that
/// [charset] may return a value even if `parameters["charset"]` is `null`.
///
/// If the values contain non-ASCII values or percent escapes,
/// they are decoded as UTF-8.
Map<String, String> get parameters {
var result = <String, String>{};
for (int i = 3; i < _separatorIndices.length; i += 2) {
var start = _separatorIndices[i - 2] + 1;
var equals = _separatorIndices[i - 1];
var end = _separatorIndices[i];
String key = _Uri._uriDecode(_text, start, equals, utf8, false);
String value = _Uri._uriDecode(_text, equals + 1, end, utf8, false);
result[key] = value;
}
return result;
}
static UriData _parse(String text, int start, Uri? sourceUri) {
assert(start == 0 || start == 5);
assert((start == 5) == text.startsWith("data:"));
/// Character codes.
const int comma = 0x2c;
const int slash = 0x2f;
const int semicolon = 0x3b;
const int equals = 0x3d;
List<int> indices = [start - 1];
int slashIndex = -1;
var char;
int i = start;
for (; i < text.length; i++) {
char = text.codeUnitAt(i);
if (char == comma || char == semicolon) break;
if (char == slash) {
if (slashIndex < 0) {
slashIndex = i;
continue;
}
throw FormatException("Invalid MIME type", text, i);
}
}
if (slashIndex < 0 && i > start) {
// An empty MIME type is allowed, but if non-empty it must contain
// exactly one slash.
throw FormatException("Invalid MIME type", text, i);
}
while (char != comma) {
// Parse parameters and/or "base64".
indices.add(i);
i++;
int equalsIndex = -1;
for (; i < text.length; i++) {
char = text.codeUnitAt(i);
if (char == equals) {
if (equalsIndex < 0) equalsIndex = i;
} else if (char == semicolon || char == comma) {
break;
}
}
if (equalsIndex >= 0) {
indices.add(equalsIndex);
} else {
// Have to be final "base64".
var lastSeparator = indices.last;
if (char != comma ||
i != lastSeparator + 7 /* "base64,".length */ ||
!text.startsWith("base64", lastSeparator + 1)) {
throw FormatException("Expecting '='", text, i);
}
break;
}
}
indices.add(i);
bool isBase64 = indices.length.isOdd;
if (isBase64) {
text = base64.normalize(text, i + 1, text.length);
} else {
// Validate "data" part, must only contain RFC 2396 'uric' characters
// (reserved, unreserved, or escape sequences).
// Normalize to this (throws on a fragment separator).
var data = _Uri._normalize(text, i + 1, text.length, _uricTable,
escapeDelimiters: true);
if (data != null) {
text = text.replaceRange(i + 1, text.length, data);
}
}
return UriData._(text, indices, sourceUri);
}
/// Like [Uri._uriEncode] but takes the input as bytes, not a string.
///
/// Encodes into [buffer] instead of creating its own buffer.
static void _uriEncodeBytes(
List<int> canonicalTable, List<int> bytes, StringSink buffer) {
// Encode the string into bytes then generate an ASCII only string
// by percent encoding selected bytes.
int byteOr = 0;
for (int i = 0; i < bytes.length; i++) {
int byte = bytes[i];
byteOr |= byte;
if (byte < 128 &&
((canonicalTable[byte >> 4] & (1 << (byte & 0x0f))) != 0)) {
buffer.writeCharCode(byte);
} else {
buffer.writeCharCode(_PERCENT);
buffer.writeCharCode(_hexDigits.codeUnitAt(byte >> 4));
buffer.writeCharCode(_hexDigits.codeUnitAt(byte & 0x0f));
}
}
if ((byteOr & ~0xFF) != 0) {
for (int i = 0; i < bytes.length; i++) {
var byte = bytes[i];
if (byte < 0 || byte > 255) {
throw ArgumentError.value(byte, "non-byte value");
}
}
}
}
String toString() =>
(_separatorIndices[0] == _noScheme) ? "data:$_text" : _text;
// Table of the `token` characters of RFC 2045 in a URI.
//
// A token is any US-ASCII character except SPACE, control characters and
// `tspecial` characters. The `tspecial` category is:
// '(', ')', '<', '>', '@', ',', ';', ':', '\', '"', '/', '[, ']', '?', '='.
//
// In a data URI, we also need to escape '%' and '#' characters.
static const _tokenCharTable = [
// LSB MSB
// | |
0x0000, // 0x00 - 0x0f 00000000 00000000
0x0000, // 0x10 - 0x1f 00000000 00000000
// ! $ &' *+ -.
0x6cd2, // 0x20 - 0x2f 01001011 00110110
// 01234567 89
0x03ff, // 0x30 - 0x3f 11111111 11000000
// ABCDEFG HIJKLMNO
0xfffe, // 0x40 - 0x4f 01111111 11111111
// PQRSTUVW XYZ ^_
0xc7ff, // 0x50 - 0x5f 11111111 11100011
// `abcdefg hijklmno
0xffff, // 0x60 - 0x6f 11111111 11111111
// pqrstuvw xyz{|}~
0x7fff, // 0x70 - 0x7f 11111111 11111110
];
// All non-escape RFC-2396 uric characters.
//
// uric = reserved | unreserved | escaped
// reserved = ";" | "/" | "?" | ":" | "@" | "&" | "=" | "+" | "$" | ","
// unreserved = alphanum | mark
// mark = "-" | "_" | "." | "!" | "~" | "*" | "'" | "(" | ")"
//
// This is the same characters as in a URI query (which is URI pchar plus '?')
static const _uricTable = _Uri._queryCharTable;
}
// --------------------------------------------------------------------
// Constants used to read the scanner result.
// The indices points into the table filled by [_scan] which contains
// recognized positions in the scanned URI.
// The `0` index is only used internally.
/// Index of the position of that `:` after a scheme.
const int _schemeEndIndex = 1;
/// Index of the position of the character just before the host name.
const int _hostStartIndex = 2;
/// Index of the position of the `:` before a port value.
const int _portStartIndex = 3;
/// Index of the position of the first character of a path.
const int _pathStartIndex = 4;
/// Index of the position of the `?` before a query.
const int _queryStartIndex = 5;
/// Index of the position of the `#` before a fragment.
const int _fragmentStartIndex = 6;
/// Index of a position where the URI was determined to be "non-simple".
const int _notSimpleIndex = 7;
// Initial state for scanner.
const int _uriStart = 00;
// If scanning of a URI terminates in this state or above,
// consider the URI non-simple
const int _nonSimpleEndStates = 14;
// Initial state for scheme validation.
const int _schemeStart = 20;
/// Transition tables used to scan a URI to determine its structure.
///
/// The tables represent a state machine with output.
///
/// To scan the URI, start in the [_uriStart] state, then read each character
/// of the URI in order, from start to end, and for each character perform a
/// transition to a new state while writing the current position into the output
/// buffer at a designated index.
///
/// Each state, represented by an integer which is an index into
/// [_scannerTables], has a set of transitions, one for each character.
/// The transitions are encoded as a 5-bit integer representing the next state
/// and a 3-bit index into the output table.
///
/// For URI scanning, only characters in the range U+0020 through U+007E are
/// interesting, all characters outside that range are treated the same.
/// The tables only contain 96 entries, representing that characters in the
/// interesting range, plus one more to represent all values outside the range.
/// The character entries are stored in one `Uint8List` per state, with the
/// transition for a character at position `character ^ 0x60`,
/// which maps the range U+0020 .. U+007F into positions 0 .. 95.
/// All remaining characters are mapped to position 31 (`0x7f ^ 0x60`) which
/// represents the transition for all remaining characters.
final List<Uint8List> _scannerTables = _createTables();
// ----------------------------------------------------------------------
// Code to create the URI scanner table.
/// Creates the tables for [_scannerTables] used by [Uri.parse].
///
/// See [_scannerTables] for the generated format.
///
/// The concrete tables are chosen as a trade-off between the number of states
/// needed and the precision of the result.
/// This allows definitely recognizing the general structure of the URI
/// (presence and location of scheme, user-info, host, port, path, query and
/// fragment) while at the same time detecting that some components are not
/// in canonical form (anything containing a `%`, a host-name containing a
/// capital letter). Since the scanner doesn't know whether something is a
/// scheme or a path until it sees `:`, or user-info or host until it sees
/// a `@`, a second pass is needed to validate the scheme and any user-info
/// is considered non-canonical by default.
///
/// The states (starting from [_uriStart]) write positions while scanning
/// a string from `start` to `end` as follows:
///
/// - [_schemeEndIndex]: Should be initialized to `start-1`.
/// If the URI has a scheme, it is set to the position of the `:` after
/// the scheme.
/// - [_hostStartIndex]: Should be initialized to `start - 1`.
/// If the URI has an authority, it is set to the character before the
/// host name - either the second `/` in the `//` leading the authority,
/// or the `@` after a user-info. Comparing this value to the scheme end
/// position can be used to detect that there is a user-info component.
/// - [_portStartIndex]: Should be initialized to `start`.
/// Set to the position of the last `:` in an authority, and unchanged
/// if there is no authority or no `:` in an authority.
/// If this position is after the host start, there is a port, otherwise it
/// is just marking a colon in the user-info component.
/// - [_pathStartIndex]: Should be initialized to `start`.
/// Is set to the first path character unless the path is empty.
/// If the path is empty, the position is either unchanged (`start`) or
/// the first slash of an authority. So, if the path start is before a
/// host start or scheme end, the path is empty.
/// - [_queryStartIndex]: Should be initialized to `end`.
/// The position of the `?` leading a query if the URI contains a query.
/// - [_fragmentStartIndex]: Should be initialized to `end`.
/// The position of the `#` leading a fragment if the URI contains a fragment.
/// - [_notSimpleIndex]: Should be initialized to `start - 1`.
/// Set to another value if the URI is considered "not simple".
/// This is elaborated below.
///
/// # Simple URIs
/// A URI is considered "simple" if it is in a normalized form containing no
/// escapes. This allows us to skip normalization and checking whether escapes
/// are valid, and to extract components without worrying about unescaping.
///
/// The scanner computes a conservative approximation of being "simple".
/// It rejects any URI with an escape, with a user-info component (mainly
/// because they are rare and would increase the number of states in the
/// scanner significantly), with an IPV6 host or with a capital letter in
/// the scheme or host name (the scheme is handled in a second scan using
/// a separate two-state table).
/// Further, paths containing `..` or `.` path segments are considered
/// non-simple except for pure relative paths (no scheme or authority) starting
/// with a sequence of "../" segments.
///
/// The transition tables cannot detect a trailing ".." in the path,
/// followed by a query or fragment, because the segment is not known to be
/// complete until we are past it, and we then need to store the query/fragment
/// start instead. This cast is checked manually post-scanning (such a path
/// needs to be normalized to end in "../", so the URI shouldn't be considered
/// simple).
List<Uint8List> _createTables() {
// TODO(lrn): Use a precomputed table.
// Total number of states for the scanner.
const int stateCount = 22;
// States used to scan a URI from scratch.
const int schemeOrPath = 01;
const int authOrPath = 02;
const int authOrPathSlash = 03;
const int uinfoOrHost0 = 04;
const int uinfoOrHost = 05;
const int uinfoOrPort0 = 06;
const int uinfoOrPort = 07;
const int ipv6Host = 08;
const int relPathSeg = 09;
const int pathSeg = 10;
const int path = 11;
const int query = 12;
const int fragment = 13;
const int schemeOrPathDot = 14;
const int schemeOrPathDot2 = 15;
const int relPathSegDot = 16;
const int relPathSegDot2 = 17;
const int pathSegDot = 18;
const int pathSegDot2 = 19;
// States used to validate a scheme after its end position has been found.
const int scheme0 = _schemeStart;
const int scheme = 21;
// Constants encoding the write-index for the state transition into the top 5
// bits of a byte.
const int schemeEnd = _schemeEndIndex << 5;
const int hostStart = _hostStartIndex << 5;
const int portStart = _portStartIndex << 5;
const int pathStart = _pathStartIndex << 5;
const int queryStart = _queryStartIndex << 5;
const int fragmentStart = _fragmentStartIndex << 5;
const int notSimple = _notSimpleIndex << 5;
/// The `unreserved` characters of RFC 3986.
const unreserved =
"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz-._~";
/// The `sub-delim` characters of RFC 3986.
const subDelims = r"!$&'()*+,;=";
// The `pchar` characters of RFC 3986: characters that may occur in a path,
// excluding escapes.
const pchar = "$unreserved$subDelims";
var tables = List<Uint8List>.generate(stateCount, (_) => Uint8List(96));
// Helper function which initialize the table for [state] with a default
// transition and returns the table.
Uint8List build(state, defaultTransition) =>
tables[state]..fillRange(0, 96, defaultTransition);
// Helper function which sets the transition for each character in [chars]
// to [transition] in the [target] table.
// The [chars] string must contain only characters in the U+0020 .. U+007E
// range.
void setChars(Uint8List target, String chars, int transition) {
for (int i = 0; i < chars.length; i++) {
var char = chars.codeUnitAt(i);
target[char ^ 0x60] = transition;
}
}
/// Helper function which sets the transition for all characters in the
/// range from `range[0]` to `range[1]` to [transition] in the [target] table.
///
/// The [range] must be a two-character string where both characters are in
/// the U+0020 .. U+007E range and the former character must have a lower
/// code point than the latter.
void setRange(Uint8List target, String range, int transition) {
for (int i = range.codeUnitAt(0), n = range.codeUnitAt(1); i <= n; i++) {
target[i ^ 0x60] = transition;
}
}
// Create the transitions for each state.
var b;
// Validate as path, if it is a scheme, we handle it later.
b = build(_uriStart, schemeOrPath | notSimple);
setChars(b, pchar, schemeOrPath);
setChars(b, ".", schemeOrPathDot);
setChars(b, ":", authOrPath | schemeEnd); // Handle later.
setChars(b, "/", authOrPathSlash);
setChars(b, "?", query | queryStart);
setChars(b, "#", fragment | fragmentStart);
b = build(schemeOrPathDot, schemeOrPath | notSimple);
setChars(b, pchar, schemeOrPath);
setChars(b, ".", schemeOrPathDot2);
setChars(b, ':', authOrPath | schemeEnd);
setChars(b, "/", pathSeg | notSimple);
setChars(b, "?", query | queryStart);
setChars(b, "#", fragment | fragmentStart);
b = build(schemeOrPathDot2, schemeOrPath | notSimple);
setChars(b, pchar, schemeOrPath);
setChars(b, "%", schemeOrPath | notSimple);
setChars(b, ':', authOrPath | schemeEnd);
setChars(b, "/", relPathSeg);
setChars(b, "?", query | queryStart);
setChars(b, "#", fragment | fragmentStart);
b = build(schemeOrPath, schemeOrPath | notSimple);
setChars(b, pchar, schemeOrPath);
setChars(b, ':', authOrPath | schemeEnd);
setChars(b, "/", pathSeg);
setChars(b, "?", query | queryStart);
setChars(b, "#", fragment | fragmentStart);
b = build(authOrPath, path | notSimple);
setChars(b, pchar, path | pathStart);
setChars(b, "/", authOrPathSlash | pathStart);
setChars(b, ".", pathSegDot | pathStart);
setChars(b, "?", query | queryStart);
setChars(b, "#", fragment | fragmentStart);
b = build(authOrPathSlash, path | notSimple);
setChars(b, pchar, path);
setChars(b, "/", uinfoOrHost0 | hostStart);
setChars(b, ".", pathSegDot);
setChars(b, "?", query | queryStart);
setChars(b, "#", fragment | fragmentStart);
b = build(uinfoOrHost0, uinfoOrHost | notSimple);
setChars(b, pchar, uinfoOrHost);
setRange(b, "AZ", uinfoOrHost | notSimple);
setChars(b, ":", uinfoOrPort0 | portStart);
setChars(b, "@", uinfoOrHost0 | hostStart);
setChars(b, "[", ipv6Host | notSimple);
setChars(b, "/", pathSeg | pathStart);
setChars(b, "?", query | queryStart);
setChars(b, "#", fragment | fragmentStart);
b = build(uinfoOrHost, uinfoOrHost | notSimple);
setChars(b, pchar, uinfoOrHost);
setRange(b, "AZ", uinfoOrHost | notSimple);
setChars(b, ":", uinfoOrPort0 | portStart);
setChars(b, "@", uinfoOrHost0 | hostStart);
setChars(b, "/", pathSeg | pathStart);
setChars(b, "?", query | queryStart);
setChars(b, "#", fragment | fragmentStart);
b = build(uinfoOrPort0, uinfoOrPort | notSimple);
setRange(b, "19", uinfoOrPort);
setChars(b, "@", uinfoOrHost0 | hostStart);
setChars(b, "/", pathSeg | pathStart);
setChars(b, "?", query | queryStart);
setChars(b, "#", fragment | fragmentStart);
b = build(uinfoOrPort, uinfoOrPort | notSimple);
setRange(b, "09", uinfoOrPort);
setChars(b, "@", uinfoOrHost0 | hostStart);
setChars(b, "/", pathSeg | pathStart);
setChars(b, "?", query | queryStart);
setChars(b, "#", fragment | fragmentStart);
b = build(ipv6Host, ipv6Host);
setChars(b, "]", uinfoOrHost);
b = build(relPathSeg, path | notSimple);
setChars(b, pchar, path);
setChars(b, ".", relPathSegDot);
setChars(b, "/", pathSeg | notSimple);
setChars(b, "?", query | queryStart);
setChars(b, "#", fragment | fragmentStart);
b = build(relPathSegDot, path | notSimple);
setChars(b, pchar, path);
setChars(b, ".", relPathSegDot2);
setChars(b, "/", pathSeg | notSimple);
setChars(b, "?", query | queryStart);
setChars(b, "#", fragment | fragmentStart);
b = build(relPathSegDot2, path | notSimple);
setChars(b, pchar, path);
setChars(b, "/", relPathSeg);
setChars(b, "?", query | queryStart); // This should be non-simple.
setChars(b, "#", fragment | fragmentStart); // This should be non-simple.
b = build(pathSeg, path | notSimple);
setChars(b, pchar, path);
setChars(b, ".", pathSegDot);
setChars(b, "/", pathSeg | notSimple);
setChars(b, "?", query | queryStart);
setChars(b, "#", fragment | fragmentStart);
b = build(pathSegDot, path | notSimple);
setChars(b, pchar, path);
setChars(b, ".", pathSegDot2);
setChars(b, "/", pathSeg | notSimple);
setChars(b, "?", query | queryStart);
setChars(b, "#", fragment | fragmentStart);
b = build(pathSegDot2, path | notSimple);
setChars(b, pchar, path);
setChars(b, "/", pathSeg | notSimple);
setChars(b, "?", query | queryStart);
setChars(b, "#", fragment | fragmentStart);
b = build(path, path | notSimple);
setChars(b, pchar, path);
setChars(b, "/", pathSeg);
setChars(b, "?", query | queryStart);
setChars(b, "#", fragment | fragmentStart);
b = build(query, query | notSimple);
setChars(b, pchar, query);
setChars(b, "?", query);
setChars(b, "#", fragment | fragmentStart);
b = build(fragment, fragment | notSimple);
setChars(b, pchar, fragment);
setChars(b, "?", fragment);
// A separate two-state validator for lower-case scheme names.
// Any non-scheme character or upper-case letter is marked as non-simple.
b = build(scheme0, scheme | notSimple);
setRange(b, "az", scheme);
b = build(scheme, scheme | notSimple);
setRange(b, "az", scheme);
setRange(b, "09", scheme);
setChars(b, "+-.", scheme);
return tables;
}
// --------------------------------------------------------------------
// Code that uses the URI scanner table.
/// Scan a string using the [_scannerTables] state machine.
///
/// Scans [uri] from [start] to [end], starting in state [state] and
/// writing output into [indices].
///
/// Returns the final state.
int _scan(String uri, int start, int end, int state, List<int> indices) {
var tables = _scannerTables;
assert(end <= uri.length);
for (int i = start; i < end; i++) {
var table = tables[state];
// Xor with 0x60 to move range 0x20-0x7f into 0x00-0x5f
int char = uri.codeUnitAt(i) ^ 0x60;
// Use 0x1f (nee 0x7f) to represent all unhandled characters.
if (char > 0x5f) char = 0x1f;
int transition = table[char];
state = transition & 0x1f;
indices[transition >> 5] = i;
}
return state;
}
class _SimpleUri implements Uri {
final String _uri;
final int _schemeEnd;
final int _hostStart;
final int _portStart;
final int _pathStart;
final int _queryStart;
final int _fragmentStart;
/// The scheme is often used to distinguish URIs.
/// To make comparisons more efficient, we cache the value, and
/// canonicalize a few known types.
String? _schemeCache;
int? _hashCodeCache;
_SimpleUri(
this._uri,
this._schemeEnd,
this._hostStart,
this._portStart,
this._pathStart,
this._queryStart,
this._fragmentStart,
this._schemeCache);
bool get hasScheme => _schemeEnd > 0;
bool get hasAuthority => _hostStart > 0;
bool get hasUserInfo => _hostStart > _schemeEnd + 4;
bool get hasPort => _hostStart > 0 && _portStart + 1 < _pathStart;
bool get hasQuery => _queryStart < _fragmentStart;
bool get hasFragment => _fragmentStart < _uri.length;
bool get _isFile => _schemeEnd == 4 && _uri.startsWith("file");
bool get _isHttp => _schemeEnd == 4 && _uri.startsWith("http");
bool get _isHttps => _schemeEnd == 5 && _uri.startsWith("https");
bool get _isPackage => _schemeEnd == 7 && _uri.startsWith("package");
/// Like [isScheme] but expects argument to be case normalized.
bool _isScheme(String scheme) =>
_schemeEnd == scheme.length && _uri.startsWith(scheme);
bool get hasAbsolutePath => _uri.startsWith("/", _pathStart);
bool get hasEmptyPath => _pathStart == _queryStart;
bool get isAbsolute => hasScheme && !hasFragment;
bool isScheme(String scheme) {
if (scheme == null || scheme.isEmpty) return _schemeEnd < 0;
if (scheme.length != _schemeEnd) return false;
return _Uri._compareScheme(scheme, _uri);
}
String get scheme {
return _schemeCache ??= _computeScheme();
}
String _computeScheme() {
if (_schemeEnd <= 0) return "";
if (_isHttp) return "http";
if (_isHttps) return "https";
if (_isFile) return "file";
if (_isPackage) return "package";
return _uri.substring(0, _schemeEnd);
}
String get authority =>
_hostStart > 0 ? _uri.substring(_schemeEnd + 3, _pathStart) : "";
String get userInfo => (_hostStart > _schemeEnd + 3)
? _uri.substring(_schemeEnd + 3, _hostStart - 1)
: "";
String get host =>
_hostStart > 0 ? _uri.substring(_hostStart, _portStart) : "";
int get port {
if (hasPort) return int.parse(_uri.substring(_portStart + 1, _pathStart));
if (_isHttp) return 80;
if (_isHttps) return 443;
return 0;
}
String get path => _uri.substring(_pathStart, _queryStart);
String get query => (_queryStart < _fragmentStart)
? _uri.substring(_queryStart + 1, _fragmentStart)
: "";
String get fragment =>
(_fragmentStart < _uri.length) ? _uri.substring(_fragmentStart + 1) : "";
String get origin {
// Check original behavior - W3C spec is wonky!
bool isHttp = _isHttp;
if (_schemeEnd < 0) {
throw StateError("Cannot use origin without a scheme: $this");
}
if (!isHttp && !_isHttps) {
throw StateError(
"Origin is only applicable to schemes http and https: $this");
}
if (_hostStart == _portStart) {
throw StateError(
"A $scheme: URI should have a non-empty host name: $this");
}
if (_hostStart == _schemeEnd + 3) {
return _uri.substring(0, _pathStart);
}
// Need to drop anon-empty userInfo.
return _uri.substring(0, _schemeEnd + 3) +
_uri.substring(_hostStart, _pathStart);
}
List<String> get pathSegments {
int start = _pathStart;
int end = _queryStart;
if (_uri.startsWith("/", start)) start++;
if (start == end) return const <String>[];
List<String> parts = [];
for (int i = start; i < end; i++) {
var char = _uri.codeUnitAt(i);
if (char == _SLASH) {
parts.add(_uri.substring(start, i));
start = i + 1;
}
}
parts.add(_uri.substring(start, end));
return List<String>.unmodifiable(parts);
}
Map<String, String> get queryParameters {
if (!hasQuery) return const <String, String>{};
return UnmodifiableMapView<String, String>(Uri.splitQueryString(query));
}
Map<String, List<String>> get queryParametersAll {
if (!hasQuery) return const <String, List<String>>{};
Map<String, List<String>> queryParameterLists =
_Uri._splitQueryStringAll(query);
queryParameterLists.updateAll(_toUnmodifiableStringList);
return Map<String, List<String>>.unmodifiable(queryParameterLists);
}
bool _isPort(String port) {
int portDigitStart = _portStart + 1;
return portDigitStart + port.length == _pathStart &&
_uri.startsWith(port, portDigitStart);
}
Uri normalizePath() => this;
Uri removeFragment() {
if (!hasFragment) return this;
return _SimpleUri(_uri.substring(0, _fragmentStart), _schemeEnd, _hostStart,
_portStart, _pathStart, _queryStart, _fragmentStart, _schemeCache);
}
Uri replace(
{String? scheme,
String? userInfo,
String? host,
int? port,
String? path,
Iterable<String>? pathSegments,
String? query,
Map<String, dynamic /*String|Iterable<String>*/ >? queryParameters,
String? fragment}) {
bool schemeChanged = false;
if (scheme != null) {
scheme = _Uri._makeScheme(scheme, 0, scheme.length);
schemeChanged = !_isScheme(scheme);
} else {
scheme = this.scheme;
}
bool isFile = (scheme == "file");
if (userInfo != null) {
userInfo = _Uri._makeUserInfo(userInfo, 0, userInfo.length);
} else if (_hostStart > 0) {
userInfo = _uri.substring(_schemeEnd + 3, _hostStart);
} else {
userInfo = "";
}
if (port != null) {
port = _Uri._makePort(port, scheme);
} else {
port = this.hasPort ? this.port : null;
if (schemeChanged) {
// The default port might have changed.
port = _Uri._makePort(port, scheme);
}
}
if (host != null) {
host = _Uri._makeHost(host, 0, host.length, false);
} else if (_hostStart > 0) {
host = _uri.substring(_hostStart, _portStart);
} else if (userInfo.isNotEmpty || port != null || isFile) {
host = "";
}
bool hasAuthority = host != null;
if (path != null || pathSegments != null) {
path = _Uri._makePath(path, 0, _stringOrNullLength(path), pathSegments,
scheme, hasAuthority);
} else {
path = _uri.substring(_pathStart, _queryStart);
if ((isFile || (hasAuthority && !path.isEmpty)) &&
!path.startsWith('/')) {
path = "/" + path;
}
}
if (query != null || queryParameters != null) {
query = _Uri._makeQuery(
query, 0, _stringOrNullLength(query), queryParameters);
} else if (_queryStart < _fragmentStart) {
query = _uri.substring(_queryStart + 1, _fragmentStart);
}
if (fragment != null) {
fragment = _Uri._makeFragment(fragment, 0, fragment.length);
} else if (_fragmentStart < _uri.length) {
fragment = _uri.substring(_fragmentStart + 1);
}
return _Uri._internal(scheme, userInfo, host, port, path, query, fragment);
}
Uri resolve(String reference) {
return resolveUri(Uri.parse(reference));
}
Uri resolveUri(Uri reference) {
if (reference is _SimpleUri) {
return _simpleMerge(this, reference);
}
return _toNonSimple().resolveUri(reference);
}
// Returns the index of the `/` after the package name of a package URI.
//
// Returns negative if the URI is not a valid package URI:
// * Scheme must be "package".
// * No authority.
// * Path starts with "something"/
// * where "something" is not all "." characters,
// * and contains no escapes or colons.
//
// The characters are necessarily valid path characters.
static int _packageNameEnd(_SimpleUri uri) {
if (uri._isPackage && !uri.hasAuthority) {
// Becomes Non zero if seeing any non-dot character.
// Also guards against empty package names.
return _skipPackageNameChars(uri._uri, uri._pathStart, uri._queryStart);
}
return -1;
}
// Merge two simple URIs. This should always result in a prefix of
// one concatenated with a suffix of the other, possibly with a `/` in
// the middle of two merged paths, which is again simple.
// In a few cases, there might be a need for extra normalization, when
// resolving on top of a known scheme.
Uri _simpleMerge(_SimpleUri base, _SimpleUri ref) {
if (ref.hasScheme) return ref;
if (ref.hasAuthority) {
if (!base.hasScheme) return ref;
bool isSimple = true;
if (base._isFile) {
isSimple = !ref.hasEmptyPath;
} else if (base._isHttp) {
isSimple = !ref._isPort("80");
} else if (base._isHttps) {
isSimple = !ref._isPort("443");
}
if (isSimple) {
var delta = base._schemeEnd + 1;
var newUri = base._uri.substring(0, base._schemeEnd + 1) +
ref._uri.substring(ref._schemeEnd + 1);
return _SimpleUri(
newUri,
base._schemeEnd,
ref._hostStart + delta,
ref._portStart + delta,
ref._pathStart + delta,
ref._queryStart + delta,
ref._fragmentStart + delta,
base._schemeCache);
} else {
// This will require normalization, so use the _Uri implementation.
return _toNonSimple().resolveUri(ref);
}
}
if (ref.hasEmptyPath) {
if (ref.hasQuery) {
int delta = base._queryStart - ref._queryStart;
var newUri = base._uri.substring(0, base._queryStart) +
ref._uri.substring(ref._queryStart);
return _SimpleUri(
newUri,
base._schemeEnd,
base._hostStart,
base._portStart,
base._pathStart,
ref._queryStart + delta,
ref._fragmentStart + delta,
base._schemeCache);
}
if (ref.hasFragment) {
int delta = base._fragmentStart - ref._fragmentStart;
var newUri = base._uri.substring(0, base._fragmentStart) +
ref._uri.substring(ref._fragmentStart);
return _SimpleUri(
newUri,
base._schemeEnd,
base._hostStart,
base._portStart,
base._pathStart,
base._queryStart,
ref._fragmentStart + delta,
base._schemeCache);
}
return base.removeFragment();
}
if (ref.hasAbsolutePath) {
int basePathStart = base._pathStart;
int packageNameEnd = _packageNameEnd(this);
if (packageNameEnd > 0) basePathStart = packageNameEnd;
var delta = basePathStart - ref._pathStart;
var newUri = base._uri.substring(0, basePathStart) +
ref._uri.substring(ref._pathStart);
return _SimpleUri(
newUri,
base._schemeEnd,
base._hostStart,
base._portStart,
base._pathStart,
ref._queryStart + delta,
ref._fragmentStart + delta,
base._schemeCache);
}
if (base.hasEmptyPath && base.hasAuthority) {
// ref has relative non-empty path.
// Add a "/" in front, then leading "/../" segments are folded to "/".
int refStart = ref._pathStart;
while (ref._uri.startsWith("../", refStart)) {
refStart += 3;
}
var delta = base._pathStart - refStart + 1;
var newUri = "${base._uri.substring(0, base._pathStart)}/"
"${ref._uri.substring(refStart)}";
return _SimpleUri(
newUri,
base._schemeEnd,
base._hostStart,
base._portStart,
base._pathStart,
ref._queryStart + delta,
ref._fragmentStart + delta,
base._schemeCache);
}
// Merge paths.
// The RFC 3986 algorithm merges the base path without its final segment
// (anything after the final "/", or everything if the base path doesn't
// contain any "/"), and the reference path.
// Then it removes "." and ".." segments using the remove-dot-segment
// algorithm.
// This code combines the two steps. It is simplified by knowing that
// the base path contains no "." or ".." segments, and the reference
// path can only contain leading ".." segments.
String baseUri = base._uri;
String refUri = ref._uri;
int baseStart = base._pathStart;
int baseEnd = base._queryStart;
int packageNameEnd = _packageNameEnd(this);
if (packageNameEnd >= 0) {
baseStart = packageNameEnd; // At the `/` after the first package name.
} else {
while (baseUri.startsWith("../", baseStart)) baseStart += 3;
}
int refStart = ref._pathStart;
int refEnd = ref._queryStart;
/// Count of leading ".." segments in reference path.
/// The count is decremented when the segment is matched with a
/// segment of the base path, and both are then omitted from the result.
int backCount = 0;
/// Count "../" segments and advance `refStart` to after the segments.
while (refStart + 3 <= refEnd && refUri.startsWith("../", refStart)) {
refStart += 3;
backCount += 1;
}
// Extra slash inserted between base and reference path parts if
// the base path contains any slashes, or empty string if none.
// (We could use a slash from the base path in most cases, but not if
// we remove the entire base path).
String insert = "";
/// Remove segments from the base path.
/// Start with the segment trailing the last slash,
/// then remove segments for each leading "../" segment
/// from the reference path, or as many of them as are available.
while (baseEnd > baseStart) {
baseEnd--;
int char = baseUri.codeUnitAt(baseEnd);
if (char == _SLASH) {
insert = "/";
if (backCount == 0) break;
backCount--;
}
}
if (baseEnd == baseStart && !base.hasScheme && !base.hasAbsolutePath) {
// If the base is *just* a relative path (no scheme or authority),
// then merging with another relative path doesn't follow the
// RFC-3986 behavior.
// Don't need to check `base.hasAuthority` since the base path is
// non-empty - if there is an authority, a non-empty path is absolute.
// We reached the start of the base path, and want to stay relative,
// so don't insert a slash.
insert = "";
// If we reached the start of the base path with more "../" left over
// in the reference path, include those segments in the result.
refStart -= backCount * 3;
}
var delta = baseEnd - refStart + insert.length;
var newUri = "${base._uri.substring(0, baseEnd)}$insert"
"${ref._uri.substring(refStart)}";
return _SimpleUri(
newUri,
base._schemeEnd,
base._hostStart,
base._portStart,
base._pathStart,
ref._queryStart + delta,
ref._fragmentStart + delta,
base._schemeCache);
}
String toFilePath({bool? windows}) {
if (_schemeEnd >= 0 && !_isFile) {
throw UnsupportedError("Cannot extract a file path from a $scheme URI");
}
if (_queryStart < _uri.length) {
if (_queryStart < _fragmentStart) {
throw UnsupportedError(
"Cannot extract a file path from a URI with a query component");
}
throw UnsupportedError(
"Cannot extract a file path from a URI with a fragment component");
}
return (windows ?? _Uri._isWindows)
? _Uri._toWindowsFilePath(this)
: _toFilePath();
}
String _toFilePath() {
if (_hostStart < _portStart) {
// Has authority and non-empty host.
throw UnsupportedError(
"Cannot extract a non-Windows file path from a file URI "
"with an authority");
}
return this.path;
}
UriData? get data {
assert(scheme != "data");
return null;
}
int get hashCode => _hashCodeCache ??= _uri.hashCode;
bool operator ==(Object other) {
if (identical(this, other)) return true;
return other is Uri && _uri == other.toString();
}
Uri _toNonSimple() {
return _Uri._internal(
this.scheme,
this.userInfo,
this.hasAuthority ? this.host : null,
this.hasPort ? this.port : null,
this.path,
this.hasQuery ? this.query : null,
this.hasFragment ? this.fragment : null);
}
String toString() => _uri;
}
/// Special [_Uri] created from an existing [UriData].
class _DataUri extends _Uri {
final UriData _data;
_DataUri(this._data, String path, String? query)
: super._internal("data", "", null, null, path, query, null);
UriData? get data => _data;
}
/// Checks whether [text] starts with "data:" at position [start].
///
/// The text must be long enough to allow reading five characters
/// from the [start] position.
///
/// Returns an integer value which is zero if text starts with all-lowercase
/// "data:" and 0x20 if the text starts with "data:" that isn't all lower-case.
/// All other values means the text starts with some other character.
int _startsWithData(String text, int start) {
// Multiply by 3 to avoid a non-colon character making delta be 0x20.
int delta = (text.codeUnitAt(start + 4) ^ _COLON) * 3;
delta |= text.codeUnitAt(start) ^ 0x64 /*d*/;
delta |= text.codeUnitAt(start + 1) ^ 0x61 /*a*/;
delta |= text.codeUnitAt(start + 2) ^ 0x74 /*t*/;
delta |= text.codeUnitAt(start + 3) ^ 0x61 /*a*/;
return delta;
}
/// Helper function returning the length of a string, or `0` for `null`.
int _stringOrNullLength(String? s) => (s == null) ? 0 : s.length;
List<String> _toUnmodifiableStringList(String key, List<String> list) =>
List<String>.unmodifiable(list);
/// Counts valid package name characters in [source].
///
/// If [source] starts at [start] with a valid package name,
/// followed by a `/`, no later than [end],
/// then the position of the `/` is returned.
/// If not, a negative value is returned.
/// (Assumes source characters are valid path characters.)
/// A name only consisting of `.` characters is not a valid
/// package name.
int _skipPackageNameChars(String source, int start, int end) {
// Becomes non-zero when seeing a non-dot character.
// Also guards against empty package names.
var dots = 0;
for (var i = start; i < end; i++) {
var char = source.codeUnitAt(i);
if (char == _SLASH) return (dots != 0) ? i : -1;
if (char == _PERCENT || char == _COLON) return -1;
dots |= char ^ _DOT;
}
return -1;
}