lib/src/config_cache.dart - dart_style - Git at Google

 // Copyright (c) 2024, 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 'package:package_config/package_config.dart';
 import 'package:pub_semver/pub_semver.dart';

 import 'analysis_options/analysis_options_file.dart';
 import 'analysis_options/io_file_system.dart';
 import 'dart_formatter.dart';
 import 'profile.dart';

 /// Caches the nearest surrounding package config file for files in directories.
 ///
 /// The formatter reads `.dart_tool/package_config.json` files in order to
 /// determine the default language version of files in that package and to
 /// resolve "package:" URIs in "analysis_options.yaml" files.
 ///
 /// Walking the file system to find the package config and then reading it off
 /// disk is very slow. We know that every formatted file in the same directory
 /// will share the same package config, so this caches a previously read
 /// config for each directory.
 ///
 /// (When formatting dart_style on a Mac laptop, it would spend as much time
 /// looking for package configs for each file as it did formatting if we don't
 /// cache. Caching makes it ~10x faster to find the config for each file.)
 ///
 /// This class also directly caches the language versions and page widths that
 /// are then inferred from the package config and analysis_options.yaml files.
 final class ConfigCache {
   /// The previously cached package config for all files immediately within a
   /// given directory.
   final Map<String, PackageConfig?> _directoryConfigs = {};

   /// The previously cached default language version for all files immediately
   /// within a given directory.
   ///
   /// The version may be `null` if we formatted a file in that directory and
   /// discovered that there is no surrounding package.
   final Map<String, Version?> _directoryVersions = {};

   /// The previously cached configured options for all files immediately within
   /// a given directory.
   final Map<String, _FormatterOptions> _directoryOptions = {};

   final IOFileSystem _fileSystem = IOFileSystem();

   /// Looks for a package surrounding [file] and, if found, returns the default
   /// language version specified by that package.
   Future<Version?> findLanguageVersion(File file, String displayPath) async {
     // Use the cached version (which may be `null`) if present.
     var directory = file.parent.path;
     if (_directoryVersions.containsKey(directory)) {
       return _directoryVersions[directory];
     }

     // Otherwise, walk the file system and look for it.
     var config = await _findPackageConfig(
       file,
       displayPath,
       forLanguageVersion: true,
     );

     if (config?.packageOf(file.absolute.uri)?.languageVersion
         case var languageVersion?) {
       // Store the version as pub_semver's [Version] type because that's
       // what the analyzer parser uses, which is where the version
       // ultimately gets used.
       var version = Version(languageVersion.major, languageVersion.minor, 0);
       return _directoryVersions[directory] = version;
     }

     // We weren't able to resolve this file's version, so don't try again.
     return _directoryVersions[directory] = null;
   }

   /// Looks for an "analysis_options.yaml" file surrounding [file] and, if
   /// found and valid, returns the page width specified by that config file.
   ///
   /// Otherwise returns `null`.
   ///
   /// The schema looks like:
   ///
   ///     formatter:
   ///       page_width: 123
   Future<int?> findPageWidth(File file) async {
     return (await _findFormatterOptions(file)).pageWidth;
   }

   /// Looks for an "analysis_options.yaml" file surrounding [file] and, if
   /// found and valid, returns the trailing comma handling specified by that
   /// config file.
   ///
   /// Otherwise returns `null`.
   ///
   /// The schema looks like:
   ///
   ///     formatter:
   ///       trailing_commas: preserve # Or "automate".
   Future<TrailingCommas?> findTrailingCommas(File file) async {
     return (await _findFormatterOptions(file)).trailingCommas;
   }

   /// Looks for an "analysis_options.yaml" file surrounding [file] and, if
   /// found and valid, returns the configured options.
   ///
   /// If no options file could be found or it doesn't contain a "formatter" key
   /// whose value is a map, returns a default set of options where all settings
   /// are `null`.
   Future<_FormatterOptions> _findFormatterOptions(File file) async {
     // Use the cached version if present.
     var directory = file.parent.path;
     if (_directoryOptions[directory] case var options?) return options;

     int? pageWidth;
     TrailingCommas? trailingCommas;

     try {
       // Look for a surrounding "analysis_options.yaml" file.
       var optionsFile = await findAnalysisOptions(
         _fileSystem,
         await _fileSystem.makePath(file.path),
         resolvePackageUri: (uri) => _resolvePackageUri(file, uri),
       );

       if (optionsFile['formatter'] case Map<Object?, Object?> formatter) {
         if (formatter case {'page_width': int width}) {
           pageWidth = width;
         }

         if (formatter case {'trailing_commas': var commas}) {
           switch (commas) {
             case 'automate':
               trailingCommas = TrailingCommas.automate;
             case 'preserve':
               trailingCommas = TrailingCommas.preserve;
             default:
               stderr.writeln(
                 'Warning: "trailing_commas" option should be "automate" or '
                 '"preserve", but was "$commas".',
               );
           }
         }
       }
     } on PackageResolutionException catch (exception) {
       // Report the error, but use the default settings and keep going.
       stderr.writeln(
         'Warning: Package resolution error when reading '
         '"analysis_options.yaml" file:\n$exception',
       );
     }

     // Cache whichever options we found (or `null` if we didn't find them).
     return _directoryOptions[directory] = _FormatterOptions(
       pageWidth,
       trailingCommas,
     );
   }

   /// Look for and cache the nearest package surrounding [file].
   Future<PackageConfig?> _findPackageConfig(
     File file,
     String displayPath, {
     required bool forLanguageVersion,
   }) async {
     Profile.begin('look up package config');
     try {
       // Use the cached one (which might be `null`) if we have it.
       var directory = file.parent.path;
       if (_directoryConfigs.containsKey(directory)) {
         return _directoryConfigs[directory];
       }

       // Otherwise, walk the file system and look for it. If we fail to find it,
       // store `null` so that we don't look again in that same directory.
       return _directoryConfigs[directory] = await findPackageConfig(
         file.parent,
       );
     } catch (error) {
       // We need a language version, so report an error if we can't find one.
       // We don't need a page width because we happily use the default, so say
       // nothing in that case.
       if (forLanguageVersion) {
         stderr.writeln(
           'Could not read package configuration for '
           '$displayPath:\n$error',
         );
         stderr.writeln(
           'To avoid searching for a package configuration, '
           'specify a language version using "--language-version".',
         );
       }
       return null;
     } finally {
       Profile.end('look up package config');
     }
   }

   /// Resolves a "package:" [packageUri] using the nearest package config file
   /// surrounding [file].
   ///
   /// If there is no package config file around [file], or the package config
   /// doesn't contain the package for [packageUri], returns `null`. Otherwise,
   /// returns an absolute file path for where [packageUri] can be found on disk.
   Future<String?> _resolvePackageUri(File file, Uri packageUri) async {
     var config = await _findPackageConfig(
       file,
       file.path,
       forLanguageVersion: false,
     );
     if (config == null) return null;

     return config.resolve(packageUri)?.toFilePath();
   }
 }

 /// The formatter options that can be configured in the "analysis_options.yaml"
 /// file.
 final class _FormatterOptions {
   /// The configured page width, or `null` if there is no options file or the
   /// options file doesn't specify it.
   final int? pageWidth;

   /// The configured comma handling, or `null` if there is no options file or
   /// the options file doesn't specify it.
   final TrailingCommas? trailingCommas;

   _FormatterOptions(this.pageWidth, this.trailingCommas);
 }
	// Copyright (c) 2024, 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 'package:package_config/package_config.dart';
	import 'package:pub_semver/pub_semver.dart';

	import 'analysis_options/analysis_options_file.dart';
	import 'analysis_options/io_file_system.dart';
	import 'dart_formatter.dart';
	import 'profile.dart';

	/// Caches the nearest surrounding package config file for files in directories.
	///
	/// The formatter reads `.dart_tool/package_config.json` files in order to
	/// determine the default language version of files in that package and to
	/// resolve "package:" URIs in "analysis_options.yaml" files.
	///
	/// Walking the file system to find the package config and then reading it off
	/// disk is very slow. We know that every formatted file in the same directory
	/// will share the same package config, so this caches a previously read
	/// config for each directory.
	///
	/// (When formatting dart_style on a Mac laptop, it would spend as much time
	/// looking for package configs for each file as it did formatting if we don't
	/// cache. Caching makes it ~10x faster to find the config for each file.)
	///
	/// This class also directly caches the language versions and page widths that
	/// are then inferred from the package config and analysis_options.yaml files.
	final class ConfigCache {
	/// The previously cached package config for all files immediately within a
	/// given directory.
	final Map<String, PackageConfig?> _directoryConfigs = {};

	/// The previously cached default language version for all files immediately
	/// within a given directory.
	///
	/// The version may be `null` if we formatted a file in that directory and
	/// discovered that there is no surrounding package.
	final Map<String, Version?> _directoryVersions = {};

	/// The previously cached configured options for all files immediately within
	/// a given directory.
	final Map<String, _FormatterOptions> _directoryOptions = {};

	final IOFileSystem _fileSystem = IOFileSystem();

	/// Looks for a package surrounding [file] and, if found, returns the default
	/// language version specified by that package.
	Future<Version?> findLanguageVersion(File file, String displayPath) async {
	// Use the cached version (which may be `null`) if present.
	var directory = file.parent.path;
	if (_directoryVersions.containsKey(directory)) {
	return _directoryVersions[directory];
	}

	// Otherwise, walk the file system and look for it.
	var config = await _findPackageConfig(
	file,
	displayPath,
	forLanguageVersion: true,
	);

	if (config?.packageOf(file.absolute.uri)?.languageVersion
	case var languageVersion?) {
	// Store the version as pub_semver's [Version] type because that's
	// what the analyzer parser uses, which is where the version
	// ultimately gets used.
	var version = Version(languageVersion.major, languageVersion.minor, 0);
	return _directoryVersions[directory] = version;
	}

	// We weren't able to resolve this file's version, so don't try again.
	return _directoryVersions[directory] = null;
	}

	/// Looks for an "analysis_options.yaml" file surrounding [file] and, if
	/// found and valid, returns the page width specified by that config file.
	///
	/// Otherwise returns `null`.
	///
	/// The schema looks like:
	///
	/// formatter:
	/// page_width: 123
	Future<int?> findPageWidth(File file) async {
	return (await _findFormatterOptions(file)).pageWidth;
	}

	/// Looks for an "analysis_options.yaml" file surrounding [file] and, if
	/// found and valid, returns the trailing comma handling specified by that
	/// config file.
	///
	/// Otherwise returns `null`.
	///
	/// The schema looks like:
	///
	/// formatter:
	/// trailing_commas: preserve # Or "automate".
	Future<TrailingCommas?> findTrailingCommas(File file) async {
	return (await _findFormatterOptions(file)).trailingCommas;
	}

	/// Looks for an "analysis_options.yaml" file surrounding [file] and, if
	/// found and valid, returns the configured options.
	///
	/// If no options file could be found or it doesn't contain a "formatter" key
	/// whose value is a map, returns a default set of options where all settings
	/// are `null`.
	Future<_FormatterOptions> _findFormatterOptions(File file) async {
	// Use the cached version if present.
	var directory = file.parent.path;
	if (_directoryOptions[directory] case var options?) return options;

	int? pageWidth;
	TrailingCommas? trailingCommas;

	try {
	// Look for a surrounding "analysis_options.yaml" file.
	var optionsFile = await findAnalysisOptions(
	_fileSystem,
	await _fileSystem.makePath(file.path),
	resolvePackageUri: (uri) => _resolvePackageUri(file, uri),
	);

	if (optionsFile['formatter'] case Map<Object?, Object?> formatter) {
	if (formatter case {'page_width': int width}) {
	pageWidth = width;
	}

	if (formatter case {'trailing_commas': var commas}) {
	switch (commas) {
	case 'automate':
	trailingCommas = TrailingCommas.automate;
	case 'preserve':
	trailingCommas = TrailingCommas.preserve;
	default:
	stderr.writeln(
	'Warning: "trailing_commas" option should be "automate" or '
	'"preserve", but was "$commas".',
	);
	}
	}
	}
	} on PackageResolutionException catch (exception) {
	// Report the error, but use the default settings and keep going.
	stderr.writeln(
	'Warning: Package resolution error when reading '
	'"analysis_options.yaml" file:\n$exception',
	);
	}

	// Cache whichever options we found (or `null` if we didn't find them).
	return _directoryOptions[directory] = _FormatterOptions(
	pageWidth,
	trailingCommas,
	);
	}

	/// Look for and cache the nearest package surrounding [file].
	Future<PackageConfig?> _findPackageConfig(
	File file,
	String displayPath, {
	required bool forLanguageVersion,
	}) async {
	Profile.begin('look up package config');
	try {
	// Use the cached one (which might be `null`) if we have it.
	var directory = file.parent.path;
	if (_directoryConfigs.containsKey(directory)) {
	return _directoryConfigs[directory];
	}

	// Otherwise, walk the file system and look for it. If we fail to find it,
	// store `null` so that we don't look again in that same directory.
	return _directoryConfigs[directory] = await findPackageConfig(
	file.parent,
	);
	} catch (error) {
	// We need a language version, so report an error if we can't find one.
	// We don't need a page width because we happily use the default, so say
	// nothing in that case.
	if (forLanguageVersion) {
	stderr.writeln(
	'Could not read package configuration for '
	'$displayPath:\n$error',
	);
	stderr.writeln(
	'To avoid searching for a package configuration, '
	'specify a language version using "--language-version".',
	);
	}
	return null;
	} finally {
	Profile.end('look up package config');
	}
	}

	/// Resolves a "package:" [packageUri] using the nearest package config file
	/// surrounding [file].
	///
	/// If there is no package config file around [file], or the package config
	/// doesn't contain the package for [packageUri], returns `null`. Otherwise,
	/// returns an absolute file path for where [packageUri] can be found on disk.
	Future<String?> _resolvePackageUri(File file, Uri packageUri) async {
	var config = await _findPackageConfig(
	file,
	file.path,
	forLanguageVersion: false,
	);
	if (config == null) return null;

	return config.resolve(packageUri)?.toFilePath();
	}
	}

	/// The formatter options that can be configured in the "analysis_options.yaml"
	/// file.
	final class _FormatterOptions {
	/// The configured page width, or `null` if there is no options file or the
	/// options file doesn't specify it.
	final int? pageWidth;

	/// The configured comma handling, or `null` if there is no options file or
	/// the options file doesn't specify it.
	final TrailingCommas? trailingCommas;

	_FormatterOptions(this.pageWidth, this.trailingCommas);
	}