The Tor Browser: toolkit/components/osfile/modules/osfile_async_worker.js@129ffea94266 (annotated)

toolkit/components/osfile/modules/osfile_async_worker.js@129ffea94266 (annotated)

toolkit/components/osfile/modules/osfile_async_worker.js

Sat, 03 Jan 2015 20:18:00 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Sat, 03 Jan 2015 20:18:00 +0100
branch: TOR_BUG_3246
changeset 7: 129ffea94266
permissions: -rw-r--r--

Conditionally enable double key logic according to:
private browsing mode or privacy.thirdparty.isolate preference and
implement in GetCookieStringCommon and FindCookie where it counts...
With some reservations of how to convince FindCookie users to test
condition and pass a nullptr when disabling double key logic.

 if (this.Components) {
   throw new Error("This worker can only be loaded from a worker thread");
 }
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
 // Worker thread for osfile asynchronous front-end
 // Exception names to be posted from the worker thread to main thread
 const EXCEPTION_NAMES = {
   EvalError: "EvalError",
   InternalError: "InternalError",
   RangeError: "RangeError",
   ReferenceError: "ReferenceError",
   SyntaxError: "SyntaxError",
   TypeError: "TypeError",
   URIError: "URIError"
 };
 (function(exports) {
   "use strict";
   // Timestamps, for use in Telemetry.
   // The object is set to |null| once it has been sent
   // to the main thread.
   let timeStamps = {
     entered: Date.now(),
     loaded: null
   };
   importScripts("resource://gre/modules/osfile.jsm");
   let SharedAll = require("resource://gre/modules/osfile/osfile_shared_allthreads.jsm");
   let LOG = SharedAll.LOG.bind(SharedAll, "Agent");
   // Post a message to the parent, decorate it with statistics if
   // necessary. Use this instead of self.postMessage.
   function post(message, ...transfers) {
     if (timeStamps) {
       message.timeStamps = timeStamps;
       timeStamps = null;
     }
     self.postMessage(message, ...transfers);
   }
  /**
   * Communications with the controller.
   *
   * Accepts messages:
   * {fun:function_name, args:array_of_arguments_or_null, id:id}
   *
   * Sends messages:
   * {ok: result, id:id} / {fail: serialized_form_of_OS.File.Error, id:id}
   */
   self.onmessage = function onmessage(msg) {
    let data = msg.data;
    LOG("Received message", data);
    let id = data.id;
    let start;
    let options;
    if (data.args) {
      options = data.args[data.args.length - 1];
    }
    // If |outExecutionDuration| option was supplied, start measuring the
    // duration of the operation.
    if (options && typeof options === "object" && "outExecutionDuration" in options) {
      start = Date.now();
    }
    let result;
    let exn;
    let durationMs;
    try {
      let method = data.fun;
      LOG("Calling method", method);
      result = Agent[method].apply(Agent, data.args);
      LOG("Method", method, "succeeded");
    } catch (ex) {
      exn = ex;
      LOG("Error while calling agent method", exn, exn.moduleStack || exn.stack || "");
    }
    if (start) {
      // Record duration
      durationMs = Date.now() - start;
      LOG("Method took", durationMs, "ms");
    }
    // Now, post a reply, possibly as an uncaught error.
    // We post this message from outside the |try ... catch| block
    // to avoid capturing errors that take place during |postMessage| and
    // built-in serialization.
    if (!exn) {
      LOG("Sending positive reply", result, "id is", id);
      if (result instanceof Meta) {
        if ("transfers" in result.meta) {
          // Take advantage of zero-copy transfers
          post({ok: result.data, id: id, durationMs: durationMs},
            result.meta.transfers);
        } else {
          post({ok: result.data, id:id, durationMs: durationMs});
        }
        if (result.meta.shutdown || false) {
          // Time to close the worker
          self.close();
        }
      } else {
        post({ok: result, id:id, durationMs: durationMs});
      }
    } else if (exn == StopIteration) {
      // StopIteration cannot be serialized automatically
      LOG("Sending back StopIteration");
      post({StopIteration: true, id: id, durationMs: durationMs});
    } else if (exn instanceof exports.OS.File.Error) {
      LOG("Sending back OS.File error", exn, "id is", id);
      // Instances of OS.File.Error know how to serialize themselves
      // (deserialization ensures that we end up with OS-specific
      // instances of |OS.File.Error|)
      post({fail: exports.OS.File.Error.toMsg(exn), id:id, durationMs: durationMs});
    } else if (exn.constructor.name in EXCEPTION_NAMES) {
      LOG("Sending back exception", exn.constructor.name);
      post({fail: {exn: exn.constructor.name, message: exn.message,
                   fileName: exn.moduleName || exn.fileName, lineNumber: exn.lineNumber},
            id: id, durationMs: durationMs});
    } else {
      // Other exceptions do not, and should be propagated through DOM's
      // built-in mechanism for uncaught errors, although this mechanism
      // may lose interesting information.
      LOG("Sending back regular error", exn, exn.moduleStack || exn.stack, "id is", id);
      throw exn;
    }
   };
  /**
   * A data structure used to track opened resources
   */
   let ResourceTracker = function ResourceTracker() {
    // A number used to generate ids
    this._idgen = 0;
    // A map from id to resource
    this._map = new Map();
   };
   ResourceTracker.prototype = {
    /**
     * Get a resource from its unique identifier.
     */
    get: function(id) {
      let result = this._map.get(id);
      if (result == null) {
        return result;
      }
      return result.resource;
    },
    /**
     * Remove a resource from its unique identifier.
     */
    remove: function(id) {
      if (!this._map.has(id)) {
        throw new Error("Cannot find resource id " + id);
      }
      this._map.delete(id);
    },
    /**
     * Add a resource, return a new unique identifier
     *
     * @param {*} resource A resource.
     * @param {*=} info Optional information. For debugging purposes.
     *
     * @return {*} A unique identifier. For the moment, this is a number,
     * but this might not remain the case forever.
     */
    add: function(resource, info) {
      let id = this._idgen++;
      this._map.set(id, {resource:resource, info:info});
      return id;
    },
    /**
     * Return a list of all open resources i.e. the ones still present in
     * ResourceTracker's _map.
     */
    listOpenedResources: function listOpenedResources() {
      return [resource.info.path for ([id, resource] of this._map)];
    }
   };
  /**
   * A map of unique identifiers to opened files.
   */
   let OpenedFiles = new ResourceTracker();
  /**
   * Execute a function in the context of a given file.
   *
   * @param {*} id A unique identifier, as used by |OpenFiles|.
   * @param {Function} f A function to call.
   * @param {boolean} ignoreAbsent If |true|, the error is ignored. Otherwise, the error causes an exception.
   * @return The return value of |f()|
   *
   * This function attempts to get the file matching |id|. If
   * the file exists, it executes |f| within the |this| set
   * to the corresponding file. Otherwise, it throws an error.
   */
   let withFile = function withFile(id, f, ignoreAbsent) {
    let file = OpenedFiles.get(id);
    if (file == null) {
      if (!ignoreAbsent) {
        throw OS.File.Error.closed("accessing file");
      }
      return undefined;
    }
    return f.call(file);
   };
   let OpenedDirectoryIterators = new ResourceTracker();
   let withDir = function withDir(fd, f, ignoreAbsent) {
    let file = OpenedDirectoryIterators.get(fd);
    if (file == null) {
      if (!ignoreAbsent) {
        throw OS.File.Error.closed("accessing directory");
      }
      return undefined;
    }
    if (!(file instanceof File.DirectoryIterator)) {
      throw new Error("file is not a directory iterator " + file.__proto__.toSource());
    }
    return f.call(file);
   };
   let Type = exports.OS.Shared.Type;
   let File = exports.OS.File;
   /**
    * A constructor used to return data to the caller thread while
    * also executing some specific treatment (e.g. shutting down
    * the current thread, transmitting data instead of copying it).
    *
    * @param {object=} data The data to return to the caller thread.
    * @param {object=} meta Additional instructions, as an object
    * that may contain the following fields:
    * - {bool} shutdown If |true|, shut down the current thread after
    *   having sent the result.
    * - {Array} transfers An array of objects that should be transferred
    *   instead of being copied.
    *
    * @constructor
    */
   let Meta = function Meta(data, meta) {
     this.data = data;
     this.meta = meta;
   };
  /**
   * The agent.
   *
   * It is in charge of performing method-specific deserialization
   * of messages, calling the function/method of OS.File and serializing
   * back the results.
   */
   let Agent = {
    // Update worker's OS.Shared.DEBUG flag message from controller.
    SET_DEBUG: function(aDEBUG) {
      SharedAll.Config.DEBUG = aDEBUG;
    },
    // Return worker's current OS.Shared.DEBUG value to controller.
    // Note: This is used for testing purposes.
    GET_DEBUG: function() {
      return SharedAll.Config.DEBUG;
    },
    /**
     * Execute shutdown sequence, returning data on leaked file descriptors.
     *
     * @param {bool} If |true|, kill the worker if this would not cause
     * leaks.
     */
    Meta_shutdown: function(kill) {
      let result = {
        openedFiles: OpenedFiles.listOpenedResources(),
        openedDirectoryIterators: OpenedDirectoryIterators.listOpenedResources(),
        killed: false // Placeholder
      };
      // Is it safe to kill the worker?
      let safe = result.openedFiles.length == 0
            && result.openedDirectoryIterators.length == 0;
      result.killed = safe && kill;
      return new Meta(result, {shutdown: result.killed});
    },
    // Functions of OS.File
    stat: function stat(path, options) {
      return exports.OS.File.Info.toMsg(
        exports.OS.File.stat(Type.path.fromMsg(path), options));
    },
    setPermissions: function setPermissions(path, options = {}) {
      return exports.OS.File.setPermissions(Type.path.fromMsg(path), options);
    },
    setDates: function setDates(path, accessDate, modificationDate) {
      return exports.OS.File.setDates(Type.path.fromMsg(path), accessDate,
                                      modificationDate);
    },
    getCurrentDirectory: function getCurrentDirectory() {
      return exports.OS.Shared.Type.path.toMsg(File.getCurrentDirectory());
    },
    setCurrentDirectory: function setCurrentDirectory(path) {
      File.setCurrentDirectory(exports.OS.Shared.Type.path.fromMsg(path));
    },
    copy: function copy(sourcePath, destPath, options) {
      return File.copy(Type.path.fromMsg(sourcePath),
        Type.path.fromMsg(destPath), options);
    },
    move: function move(sourcePath, destPath, options) {
      return File.move(Type.path.fromMsg(sourcePath),
        Type.path.fromMsg(destPath), options);
    },
    getAvailableFreeSpace: function getAvailableFreeSpace(sourcePath) {
      return Type.uint64_t.toMsg(
        File.getAvailableFreeSpace(Type.path.fromMsg(sourcePath)));
    },
    makeDir: function makeDir(path, options) {
      return File.makeDir(Type.path.fromMsg(path), options);
    },
    removeEmptyDir: function removeEmptyDir(path, options) {
      return File.removeEmptyDir(Type.path.fromMsg(path), options);
    },
    remove: function remove(path) {
      return File.remove(Type.path.fromMsg(path));
    },
    open: function open(path, mode, options) {
      let filePath = Type.path.fromMsg(path);
      let file = File.open(filePath, mode, options);
      return OpenedFiles.add(file, {
        // Adding path information to keep track of opened files
        // to report leaks when debugging.
        path: filePath
      });
    },
    openUnique: function openUnique(path, options) {
      let filePath = Type.path.fromMsg(path);
      let openedFile = OS.Shared.AbstractFile.openUnique(filePath, options);
      let resourceId = OpenedFiles.add(openedFile.file, {
        // Adding path information to keep track of opened files
        // to report leaks when debugging.
        path: openedFile.path
      });
      return {
        path: openedFile.path,
        file: resourceId
      };
    },
    read: function read(path, bytes, options) {
      let data = File.read(Type.path.fromMsg(path), bytes, options);
      if (typeof data == "string") {
        return data;
      }
      return new Meta({
          buffer: data.buffer,
          byteOffset: data.byteOffset,
          byteLength: data.byteLength
      }, {
        transfers: [data.buffer]
      });
    },
    exists: function exists(path) {
      return File.exists(Type.path.fromMsg(path));
    },
    writeAtomic: function writeAtomic(path, buffer, options) {
      if (options.tmpPath) {
        options.tmpPath = Type.path.fromMsg(options.tmpPath);
      }
      return File.writeAtomic(Type.path.fromMsg(path),
                              Type.voidptr_t.fromMsg(buffer),
                              options
                             );
    },
    removeDir: function(path, options) {
      return File.removeDir(Type.path.fromMsg(path), options);
    },
    new_DirectoryIterator: function new_DirectoryIterator(path, options) {
      let directoryPath = Type.path.fromMsg(path);
      let iterator = new File.DirectoryIterator(directoryPath, options);
      return OpenedDirectoryIterators.add(iterator, {
        // Adding path information to keep track of opened directory
        // iterators to report leaks when debugging.
        path: directoryPath
      });
    },
    // Methods of OS.File
    File_prototype_close: function close(fd) {
      return withFile(fd,
        function do_close() {
          try {
            return this.close();
          } finally {
            OpenedFiles.remove(fd);
          }
      });
    },
    File_prototype_stat: function stat(fd) {
      return withFile(fd,
        function do_stat() {
          return exports.OS.File.Info.toMsg(this.stat());
        });
    },
    File_prototype_setPermissions: function setPermissions(fd, options = {}) {
      return withFile(fd,
        function do_setPermissions() {
          return this.setPermissions(options);
        });
    },
    File_prototype_setDates: function setDates(fd, accessTime, modificationTime) {
      return withFile(fd,
        function do_setDates() {
          return this.setDates(accessTime, modificationTime);
        });
    },
    File_prototype_read: function read(fd, nbytes, options) {
      return withFile(fd,
        function do_read() {
          let data = this.read(nbytes, options);
          return new Meta({
              buffer: data.buffer,
              byteOffset: data.byteOffset,
              byteLength: data.byteLength
          }, {
            transfers: [data.buffer]
          });
        }
      );
    },
    File_prototype_readTo: function readTo(fd, buffer, options) {
      return withFile(fd,
        function do_readTo() {
          return this.readTo(exports.OS.Shared.Type.voidptr_t.fromMsg(buffer),
          options);
        });
    },
    File_prototype_write: function write(fd, buffer, options) {
      return withFile(fd,
        function do_write() {
          return this.write(exports.OS.Shared.Type.voidptr_t.fromMsg(buffer),
          options);
        });
    },
    File_prototype_setPosition: function setPosition(fd, pos, whence) {
      return withFile(fd,
        function do_setPosition() {
          return this.setPosition(pos, whence);
        });
    },
    File_prototype_getPosition: function getPosition(fd) {
      return withFile(fd,
        function do_getPosition() {
          return this.getPosition();
        });
    },
    File_prototype_flush: function flush(fd) {
      return withFile(fd,
        function do_flush() {
          return this.flush();
        });
    },
    // Methods of OS.File.DirectoryIterator
    DirectoryIterator_prototype_next: function next(dir) {
      return withDir(dir,
        function do_next() {
          try {
            return File.DirectoryIterator.Entry.toMsg(this.next());
          } catch (x) {
            if (x == StopIteration) {
              OpenedDirectoryIterators.remove(dir);
            }
            throw x;
          }
        }, false);
    },
    DirectoryIterator_prototype_nextBatch: function nextBatch(dir, size) {
      return withDir(dir,
        function do_nextBatch() {
          let result;
          try {
            result = this.nextBatch(size);
          } catch (x) {
            OpenedDirectoryIterators.remove(dir);
            throw x;
          }
          return result.map(File.DirectoryIterator.Entry.toMsg);
        }, false);
    },
    DirectoryIterator_prototype_close: function close(dir) {
      return withDir(dir,
        function do_close() {
          this.close();
          OpenedDirectoryIterators.remove(dir);
        }, true);// ignore error to support double-closing |DirectoryIterator|
    },
    DirectoryIterator_prototype_exists: function exists(dir) {
      return withDir(dir,
        function do_exists() {
          return this.exists();
        });
    }
   };
   if (!SharedAll.Constants.Win) {
     Agent.unixSymLink = function unixSymLink(sourcePath, destPath) {
       return File.unixSymLink(Type.path.fromMsg(sourcePath),
         Type.path.fromMsg(destPath));
     };
   }
   timeStamps.loaded = Date.now();
 })(this);