| // Copyright (c) 2015, 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. |
| |
| import 'dart:async'; |
| import 'dart:io'; |
| import 'dart:math' as math; |
| |
| import 'package:convert/convert.dart'; |
| import 'package:http_parser/http_parser.dart'; |
| import 'package:mime/mime.dart'; |
| import 'package:path/path.dart' as p; |
| import 'package:shelf/shelf.dart'; |
| |
| import 'directory_listing.dart'; |
| import 'util.dart'; |
| |
| /// The default resolver for MIME types based on file extensions. |
| final _defaultMimeTypeResolver = MimeTypeResolver(); |
| |
| // TODO option to exclude hidden files? |
| |
| /// Creates a Shelf [Handler] that serves files from the provided |
| /// [fileSystemPath]. |
| /// |
| /// Accessing a path containing symbolic links will succeed only if the resolved |
| /// path is within [fileSystemPath]. To allow access to paths outside of |
| /// [fileSystemPath], set [serveFilesOutsidePath] to `true`. |
| /// |
| /// When a existing directory is requested and a [defaultDocument] is specified |
| /// the directory is checked for a file with that name. If it exists, it is |
| /// served. |
| /// |
| /// If no [defaultDocument] is found and [listDirectories] is true, then the |
| /// handler produces a listing of the directory. |
| /// |
| /// If [useHeaderBytesForContentType] is `true`, the contents of the |
| /// file will be used along with the file path to determine the content type. |
| /// |
| /// Specify a custom [contentTypeResolver] to customize automatic content type |
| /// detection. |
| Handler createStaticHandler(String fileSystemPath, |
| {bool serveFilesOutsidePath = false, |
| String? defaultDocument, |
| bool listDirectories = false, |
| bool useHeaderBytesForContentType = false, |
| MimeTypeResolver? contentTypeResolver}) { |
| final rootDir = Directory(fileSystemPath); |
| if (!rootDir.existsSync()) { |
| throw ArgumentError('A directory corresponding to fileSystemPath ' |
| '"$fileSystemPath" could not be found'); |
| } |
| |
| fileSystemPath = rootDir.resolveSymbolicLinksSync(); |
| |
| if (defaultDocument != null) { |
| if (defaultDocument != p.basename(defaultDocument)) { |
| throw ArgumentError('defaultDocument must be a file name.'); |
| } |
| } |
| |
| final mimeResolver = contentTypeResolver ?? _defaultMimeTypeResolver; |
| |
| return (Request request) { |
| final segs = [fileSystemPath, ...request.url.pathSegments]; |
| |
| final fsPath = p.joinAll(segs); |
| |
| final entityType = FileSystemEntity.typeSync(fsPath); |
| |
| File? fileFound; |
| |
| if (entityType == FileSystemEntityType.file) { |
| fileFound = File(fsPath); |
| } else if (entityType == FileSystemEntityType.directory) { |
| fileFound = _tryDefaultFile(fsPath, defaultDocument); |
| if (fileFound == null && listDirectories) { |
| final uri = request.requestedUri; |
| if (!uri.path.endsWith('/')) return _redirectToAddTrailingSlash(uri); |
| return listDirectory(fileSystemPath, fsPath); |
| } |
| } |
| |
| if (fileFound == null) { |
| return Response.notFound('Not Found'); |
| } |
| final file = fileFound; |
| |
| if (!serveFilesOutsidePath) { |
| final resolvedPath = file.resolveSymbolicLinksSync(); |
| |
| // Do not serve a file outside of the original fileSystemPath |
| if (!p.isWithin(fileSystemPath, resolvedPath)) { |
| return Response.notFound('Not Found'); |
| } |
| } |
| |
| // when serving the default document for a directory, if the requested |
| // path doesn't end with '/', redirect to the path with a trailing '/' |
| final uri = request.requestedUri; |
| if (entityType == FileSystemEntityType.directory && |
| !uri.path.endsWith('/')) { |
| return _redirectToAddTrailingSlash(uri); |
| } |
| |
| return _handleFile(request, file, () async { |
| if (useHeaderBytesForContentType) { |
| final length = |
| math.min(mimeResolver.magicNumbersMaxLength, file.lengthSync()); |
| |
| final byteSink = ByteAccumulatorSink(); |
| |
| await file.openRead(0, length).listen(byteSink.add).asFuture(); |
| |
| return mimeResolver.lookup(file.path, headerBytes: byteSink.bytes); |
| } else { |
| return mimeResolver.lookup(file.path); |
| } |
| }); |
| }; |
| } |
| |
| Response _redirectToAddTrailingSlash(Uri uri) { |
| final location = Uri( |
| scheme: uri.scheme, |
| userInfo: uri.userInfo, |
| host: uri.host, |
| port: uri.port, |
| path: '${uri.path}/', |
| query: uri.query); |
| |
| return Response.movedPermanently(location.toString()); |
| } |
| |
| File? _tryDefaultFile(String dirPath, String? defaultFile) { |
| if (defaultFile == null) return null; |
| |
| final filePath = p.join(dirPath, defaultFile); |
| |
| final file = File(filePath); |
| |
| if (file.existsSync()) { |
| return file; |
| } |
| |
| return null; |
| } |
| |
| /// Creates a shelf [Handler] that serves the file at [path]. |
| /// |
| /// This returns a 404 response for any requests whose [Request.url] doesn't |
| /// match [url]. The [url] defaults to the basename of [path]. |
| /// |
| /// This uses the given [contentType] for the Content-Type header. It defaults |
| /// to looking up a content type based on [path]'s file extension, and failing |
| /// that doesn't sent a [contentType] header at all. |
| Handler createFileHandler(String path, {String? url, String? contentType}) { |
| final file = File(path); |
| if (!file.existsSync()) { |
| throw ArgumentError.value(path, 'path', 'does not exist.'); |
| } else if (url != null && !p.url.isRelative(url)) { |
| throw ArgumentError.value(url, 'url', 'must be relative.'); |
| } |
| |
| final mimeType = contentType ?? _defaultMimeTypeResolver.lookup(path); |
| url ??= p.toUri(p.basename(path)).toString(); |
| |
| return (request) { |
| if (request.url.path != url) return Response.notFound('Not Found'); |
| return _handleFile(request, file, () => mimeType); |
| }; |
| } |
| |
| /// Serves the contents of [file] in response to [request]. |
| /// |
| /// This handles caching, and sends a 304 Not Modified response if the request |
| /// indicates that it has the latest version of a file. Otherwise, it calls |
| /// [getContentType] and uses it to populate the Content-Type header. |
| Future<Response> _handleFile(Request request, File file, |
| FutureOr<String?> Function() getContentType) async { |
| final stat = file.statSync(); |
| final ifModifiedSince = request.ifModifiedSince; |
| |
| if (ifModifiedSince != null) { |
| final fileChangeAtSecResolution = toSecondResolution(stat.modified); |
| if (!fileChangeAtSecResolution.isAfter(ifModifiedSince)) { |
| return Response.notModified(); |
| } |
| } |
| |
| final headers = { |
| HttpHeaders.lastModifiedHeader: formatHttpDate(stat.modified), |
| HttpHeaders.acceptRangesHeader: 'bytes', |
| }; |
| |
| final contentType = await getContentType(); |
| final length = await file.length(); |
| final range = request.headers[HttpHeaders.rangeHeader]; |
| if (contentType != null) headers[HttpHeaders.contentTypeHeader] = contentType; |
| if (range != null) { |
| // We only support one range, where the standard support several. |
| final matches = RegExp(r'^bytes=(\d*)\-(\d*)$').firstMatch(range); |
| // If the range header have the right format, handle it. |
| if (matches != null) { |
| final startMatch = matches[1]!; |
| final endMatch = matches[2]!; |
| if (startMatch.isNotEmpty || endMatch.isNotEmpty) { |
| // Serve sub-range. |
| int start; // First byte position - inclusive. |
| int end; // Last byte position - inclusive. |
| if (startMatch.isEmpty) { |
| start = length - int.parse(endMatch); |
| if (start < 0) start = 0; |
| end = length - 1; |
| } else { |
| start = int.parse(startMatch); |
| end = endMatch.isEmpty ? length - 1 : int.parse(endMatch); |
| } |
| // If the range is syntactically invalid the Range header |
| // MUST be ignored (RFC 2616 section 14.35.1). |
| if (start <= end) { |
| if (end >= length) { |
| end = length - 1; |
| } |
| if (start >= length) { |
| return Response( |
| HttpStatus.requestedRangeNotSatisfiable, |
| headers: headers, |
| ); |
| } |
| |
| // Override Content-Length with the actual bytes sent. |
| headers[HttpHeaders.contentLengthHeader] = |
| (end - start + 1).toString(); |
| |
| // Set 'Partial Content' status code. |
| headers[HttpHeaders.contentRangeHeader] = 'bytes $start-$end/$length'; |
| // Pipe the 'range' of the file. |
| if (request.method == 'HEAD') { |
| return Response( |
| HttpStatus.partialContent, |
| headers: headers, |
| ); |
| } else { |
| return Response( |
| HttpStatus.partialContent, |
| body: file.openRead(start, end + 1), |
| headers: headers, |
| ); |
| } |
| } |
| } |
| } |
| } |
| headers[HttpHeaders.contentLengthHeader] = stat.size.toString(); |
| |
| return Response.ok( |
| request.method == 'HEAD' ? null : file.openRead(), |
| headers: headers, |
| ); |
| } |