Remove unused option in server API

pkg/analysis_server/lib/src/source/caching_pub_package_map_provider.dart

Index: pkg/analysis_server/lib/src/source/caching_pub_package_map_provider.dart
diff --git a/pkg/analysis_server/lib/src/source/caching_pub_package_map_provider.dart b/pkg/analysis_server/lib/src/source/caching_pub_package_map_provider.dart
deleted file mode 100644
index 964e7dec57871bac973570ad62e4869d9b13ec1f..0000000000000000000000000000000000000000
--- a/pkg/analysis_server/lib/src/source/caching_pub_package_map_provider.dart
+++ /dev/null
@@ -1,260 +0,0 @@
-// 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.
-
-library source.caching_pub_package_map_provider;
-
-import 'dart:convert';
-import 'dart:core';
-import 'dart:io' as io;
-
-import 'package:analyzer/file_system/file_system.dart';
-import 'package:analyzer/source/package_map_provider.dart';
-import 'package:analyzer/source/pub_package_map_provider.dart';
-import 'package:analyzer/src/dart/sdk/sdk.dart';
-import 'package:analyzer/src/generated/engine.dart';
-import 'package:analyzer/src/generated/source.dart';
-
-/**
- * The function used to write the cache file.
- * Returns the modification stamp for the newly written file.
- */
-typedef int WriteFile(File file, String content);
-
-/**
- * [PubPackageMapProvider] extension which caches pub list results.
- * These results are cached in memory and in a single place on disk that is
- * shared cross session and between different simultaneous sessions.
- *
- * TODO(paulberry): before this class is used again, it should be ported over
- * to extend OptimizingPubPackageMapProvider instead of PubPackageMapProvider.
- */
-class CachingPubPackageMapProvider extends PubPackageMapProvider {
-  static const cacheKey = 'pub_list_cache';
-  static const cacheVersion = 1;
-  static const cacheVersionKey = 'pub_list_cache_version';
-  static const pubListResultKey = 'pub_list_result';
-  static const modificationStampsKey = 'modification_stamps';
-
-  /**
-   * A cache of folder path to pub list information as shown below
-   * or `null` if the cache has not yet been initialized.
-   *
-   *     {
-   *       "path/to/folder": {
-   *         "pub_list_result": {
-   *           "packages": {
-   *             "foo": "path/to/foo",
-   *             "bar": ["path/to/bar1", "path/to/bar2"],
-   *             "myapp": "path/to/myapp",  // self link is included
-   *           },
-   *           "input_files": [
-   *             "path/to/myapp/pubspec.lock"
-   *           ]
-   *         },
-   *         "modification_stamps": {
-   *           "path/to/myapp/pubspec.lock": 1424305309
-   *         }
-   *       }
-   *       "path/to/another/folder": {
-   *         ...
-   *       }
-   *       ...
-   *     }
-   */
-  Map<String, Map> _cache;
-
-  /**
-   * The modification time of the cache file
-   * or `null` if it has not yet been read.
-   */
-  int _cacheModificationTime;
-
-  /**
-   * The function used to write the cache file.
-   */
-  WriteFile _writeFile;
-
-  /**
-   * Construct a new instance.
-   * [RunPubList] and [WriteFile] implementations may be injected for testing
-   */
-  CachingPubPackageMapProvider(
-      ResourceProvider resourceProvider, FolderBasedDartSdk sdk,
-      [RunPubList runPubList, this._writeFile])
-      : super(resourceProvider, sdk, runPubList) {
-    if (_writeFile == null) {
-      _writeFile = _writeFileDefault;
-    }
-  }
-
-  File get cacheFile => _cacheDir.getChild('cache');
-  Folder get _cacheDir => resourceProvider.getStateLocation('.pub-list');
-  File get _touchFile => _cacheDir.getChild('touch');
-
-  @override
-  PackageMapInfo computePackageMap(Folder folder) {
-    //
-    // Return error if folder does not exist, but don't remove previously
-    // cached result because folder may be only temporarily inaccessible
-    //
-    if (!folder.exists) {
-      return computePackageMapError(folder);
-    }
-    // Ensure cache is up to date
-    _readCache();
-    // Check for cached entry
-    Map entry = _cache[folder.path];
-    if (entry != null) {
-      Map<String, int> modificationStamps =
-          entry[modificationStampsKey] as Map<String, int>;
-      if (modificationStamps != null) {
-        //
-        // Check to see if any dependencies have changed
-        // before returning cached result
-        //
-        if (!_haveDependenciesChanged(modificationStamps)) {
-          return parsePackageMap(entry[pubListResultKey], folder);
-        }
-      }
-    }
-    int runCount = 0;
-    PackageMapInfo info;
-    while (true) {
-      // Capture the current time so that we can tell if an input file
-      // has changed while running pub list. This is done
-      // by writing to a file rather than getting millisecondsSinceEpoch
-      // because file modification time has different granularity
-      // on diferent systems.
-      int startStamp;
-      try {
-        startStamp = _writeFile(_touchFile, 'touch');
-      } catch (exception, stackTrace) {
-        AnalysisEngine.instance.logger.logInformation(
-            'Exception writing $_touchFile\n$exception\n$stackTrace');
-        startStamp = new DateTime.now().millisecondsSinceEpoch;
-      }
-      // computePackageMap calls parsePackageMap which caches the result
-      info = super.computePackageMap(folder);
-      ++runCount;
-      if (!_haveDependenciesChangedSince(info, startStamp)) {
-        // If no dependencies have changed while running pub then finished
-        break;
-      }
-      if (runCount == 4) {
-        // Don't run forever
-        AnalysisEngine.instance.logger
-            .logInformation('pub list called $runCount times: $folder');
-        break;
-      }
-    }
-    _writeCache();
-    return info;
-  }
-
-  @override
-  PackageMapInfo parsePackageMap(Map obj, Folder folder) {
-    PackageMapInfo info = super.parsePackageMap(obj, folder);
-    Map<String, int> modificationStamps = new Map<String, int>();
-    for (String path in info.dependencies) {
-      Resource res = resourceProvider.getResource(path);
-      if (res is File && res.exists) {
-        modificationStamps[path] = res.createSource().modificationStamp;
-      }
-    }
-    // Assumes entry has been initialized by computePackageMap
-    _cache[folder.path] = <String, Map>{
-      pubListResultKey: obj,
-      modificationStampsKey: modificationStamps
-    };
-    return info;
-  }
-
-  /**
-   * Determine if any of the dependencies have changed.
-   */
-  bool _haveDependenciesChanged(Map<String, int> modificationStamps) {
-    for (String path in modificationStamps.keys) {
-      Resource res = resourceProvider.getResource(path);
-      if (res is File) {
-        if (!res.exists ||
-            res.createSource().modificationStamp != modificationStamps[path]) {
-          return true;
-        }
-      } else {
-        return true;
-      }
-    }
-    return false;
-  }
-
-  /**
-   * Determine if any of the dependencies have changed since the given time.
-   */
-  bool _haveDependenciesChangedSince(PackageMapInfo info, int startStamp) {
-    for (String path in info.dependencies) {
-      Resource res = resourceProvider.getResource(path);
-      if (res is File) {
-        int modStamp = res.createSource().modificationStamp;
-        if (modStamp != null && modStamp >= startStamp) {
-          return true;
-        }
-      }
-    }
-    return false;
-  }
-
-  /**
-   * Read the cache from disk if it has not been read before.
-   */
-  void _readCache() {
-    // TODO(danrubel) This implementation assumes that
-    // two separate processes are not accessing the cache file at the same time
-    Source source = cacheFile.createSource();
-    if (source.exists() &&
-        (_cache == null ||
-            _cacheModificationTime != source.modificationStamp)) {
-      try {
-        TimestampedData<String> data = source.contents;
-        Map map = JSON.decode(data.data);
-        if (map[cacheVersionKey] == cacheVersion) {
-          _cache = map[cacheKey] as Map<String, Map>;
-          _cacheModificationTime = data.modificationTime;
-        }
-      } catch (exception, stackTrace) {
-        AnalysisEngine.instance.logger.logInformation(
-            'Exception reading $cacheFile\n$exception\n$stackTrace');
-      }
-    }
-    if (_cache == null) {
-      _cache = new Map<String, Map>();
-    }
-  }
-
-  /**
-   * Write the cache to disk.
-   */
-  void _writeCache() {
-    try {
-      _cacheModificationTime = _writeFile(cacheFile,
-          JSON.encode({cacheVersionKey: cacheVersion, cacheKey: _cache}));
-    } catch (exception, stackTrace) {
-      AnalysisEngine.instance.logger.logInformation(
-          'Exception writing $cacheFile\n$exception\n$stackTrace');
-    }
-  }
-
-  /**
-   * Update the given file with the specified content.
-   */
-  int _writeFileDefault(File cacheFile, String content) {
-    // TODO(danrubel) This implementation assumes that
-    // two separate processes are not accessing the cache file at the same time
-    io.File file = new io.File(cacheFile.path);
-    if (!file.parent.existsSync()) {
-      file.parent.createSync(recursive: true);
-    }
-    file.writeAsStringSync(content, flush: true);
-    return file.lastModifiedSync().millisecondsSinceEpoch;
-  }
-}