You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

1476 lines
47 KiB

/* 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/. */
/**
* Asynchronous front-end for OS.File.
*
* This front-end is meant to be imported from the main thread. In turn,
* it spawns one worker (perhaps more in the future) and delegates all
* disk I/O to this worker.
*
* Documentation note: most of the functions and methods in this module
* return promises. For clarity, we denote as follows a promise that may resolve
* with type |A| and some value |value| or reject with type |B| and some
* reason |reason|
* @resolves {A} value
* @rejects {B} reason
*/
"use strict";
this.EXPORTED_SYMBOLS = ["OS"];
const Cu = Components.utils;
const Ci = Components.interfaces;
var SharedAll = {};
Cu.import("resource://gre/modules/osfile/osfile_shared_allthreads.jsm", SharedAll);
Cu.import("resource://gre/modules/XPCOMUtils.jsm", this);
Cu.import("resource://gre/modules/Timer.jsm", this);
// Boilerplate, to simplify the transition to require()
var LOG = SharedAll.LOG.bind(SharedAll, "Controller");
var isTypedArray = SharedAll.isTypedArray;
// The constructor for file errors.
var SysAll = {};
if (SharedAll.Constants.Win) {
Cu.import("resource://gre/modules/osfile/osfile_win_allthreads.jsm", SysAll);
} else if (SharedAll.Constants.libc) {
Cu.import("resource://gre/modules/osfile/osfile_unix_allthreads.jsm", SysAll);
} else {
throw new Error("I am neither under Windows nor under a Posix system");
}
var OSError = SysAll.Error;
var Type = SysAll.Type;
var Path = {};
Cu.import("resource://gre/modules/osfile/ospath.jsm", Path);
// The library of promises.
Cu.import("resource://gre/modules/Promise.jsm", this);
Cu.import("resource://gre/modules/Task.jsm", this);
// The implementation of communications
Cu.import("resource://gre/modules/PromiseWorker.jsm", this);
Cu.import("resource://gre/modules/Services.jsm", this);
Cu.import("resource://gre/modules/AsyncShutdown.jsm", this);
var Native = Cu.import("resource://gre/modules/osfile/osfile_native.jsm", {});
// It's possible for osfile.jsm to get imported before the profile is
// set up. In this case, some path constants aren't yet available.
// Here, we make them lazy loaders.
function lazyPathGetter(constProp, dirKey) {
return function () {
let path;
try {
path = Services.dirsvc.get(dirKey, Ci.nsIFile).path;
delete SharedAll.Constants.Path[constProp];
SharedAll.Constants.Path[constProp] = path;
} catch (ex) {
// Ignore errors if the value still isn't available. Hopefully
// the next access will return it.
}
return path;
};
}
for (let [constProp, dirKey] of [
["localProfileDir", "ProfLD"],
["profileDir", "ProfD"],
["userApplicationDataDir", "UAppData"],
["winAppDataDir", "AppData"],
["winStartMenuProgsDir", "Progs"],
]) {
if (constProp in SharedAll.Constants.Path) {
continue;
}
LOG("Installing lazy getter for OS.Constants.Path." + constProp +
" because it isn't defined and profile may not be loaded.");
Object.defineProperty(SharedAll.Constants.Path, constProp, {
get: lazyPathGetter(constProp, dirKey),
});
}
/**
* Return a shallow clone of the enumerable properties of an object.
*/
var clone = SharedAll.clone;
/**
* Extract a shortened version of an object, fit for logging.
*
* This function returns a copy of the original object in which all
* long strings, Arrays, TypedArrays, ArrayBuffers are removed and
* replaced with placeholders. Use this function to sanitize objects
* if you wish to log them or to keep them in memory.
*
* @param {*} obj The obj to shorten.
* @return {*} array A shorter object, fit for logging.
*/
function summarizeObject(obj) {
if (!obj) {
return null;
}
if (typeof obj == "string") {
if (obj.length > 1024) {
return {"Long string": obj.length};
}
return obj;
}
if (typeof obj == "object") {
if (Array.isArray(obj)) {
if (obj.length > 32) {
return {"Long array": obj.length};
}
return obj.map(summarizeObject);
}
if ("byteLength" in obj) {
// Assume TypedArray or ArrayBuffer
return {"Binary Data": obj.byteLength};
}
let result = {};
for (let k of Object.keys(obj)) {
result[k] = summarizeObject(obj[k]);
}
return result;
}
return obj;
}
// In order to expose Scheduler to the unfiltered Cu.import return value variant
// on B2G we need to save it to `this`. This does not make it public;
// EXPORTED_SYMBOLS still controls that in all cases.
var Scheduler = this.Scheduler = {
/**
* |true| once we have sent at least one message to the worker.
* This field is unaffected by resetting the worker.
*/
launched: false,
/**
* |true| once shutdown has begun i.e. we should reject any
* message, including resets.
*/
shutdown: false,
/**
* A promise resolved once all currently pending operations are complete.
*
* This promise is never rejected and the result is always undefined.
*/
queue: Promise.resolve(),
/**
* A promise resolved once all currently pending `kill` operations
* are complete.
*
* This promise is never rejected and the result is always undefined.
*/
_killQueue: Promise.resolve(),
/**
* Miscellaneous debugging information
*/
Debugging: {
/**
* The latest message sent and still waiting for a reply.
*/
latestSent: undefined,
/**
* The latest reply received, or null if we are waiting for a reply.
*/
latestReceived: undefined,
/**
* Number of messages sent to the worker. This includes the
* initial SET_DEBUG, if applicable.
*/
messagesSent: 0,
/**
* Total number of messages ever queued, including the messages
* sent.
*/
messagesQueued: 0,
/**
* Number of messages received from the worker.
*/
messagesReceived: 0,
},
/**
* A timer used to automatically shut down the worker after some time.
*/
resetTimer: null,
/**
* The worker to which to send requests.
*
* If the worker has never been created or has been reset, this is a
* fresh worker, initialized with osfile_async_worker.js.
*
* @type {PromiseWorker}
*/
get worker() {
if (!this._worker) {
// Either the worker has never been created or it has been
// reset. In either case, it is time to instantiate the worker.
this._worker = new BasePromiseWorker("resource://gre/modules/osfile/osfile_async_worker.js");
this._worker.log = LOG;
this._worker.ExceptionHandlers["OS.File.Error"] = OSError.fromMsg;
}
return this._worker;
},
_worker: null,
/**
* Prepare to kill the OS.File worker after a few seconds.
*/
restartTimer: function(arg) {
let delay = Services.prefs.getIntPref("osfile.reset_worker_delay", 0);
if (!delay) {
// Don't auto-shutdown if we don't have a delay preference set.
return;
}
if (this.resetTimer) {
clearTimeout(this.resetTimer);
}
this.resetTimer = setTimeout(
() => Scheduler.kill({reset: true, shutdown: false}),
delay
);
},
/**
* Shutdown OS.File.
*
* @param {*} options
* - {boolean} shutdown If |true|, reject any further request. Otherwise,
* further requests will resurrect the worker.
* - {boolean} reset If |true|, instruct the worker to shutdown if this
* would not cause leaks. Otherwise, assume that the worker will be shutdown
* through some other mean.
*/
kill: function({shutdown, reset}) {
// Grab the kill queue to make sure that we
// cannot be interrupted by another call to `kill`.
let killQueue = this._killQueue;
// Deactivate the queue, to ensure that no message is sent
// to an obsolete worker (we reactivate it in the `finally`).
// This needs to be done right now so that we maintain relative
// ordering with calls to post(), etc.
let deferred = Promise.defer();
let savedQueue = this.queue;
this.queue = deferred.promise;
return this._killQueue = Task.spawn(function*() {
yield killQueue;
// From this point, and until the end of the Task, we are the
// only call to `kill`, regardless of any `yield`.
yield savedQueue;
try {
// Enter critical section: no yield in this block
// (we want to make sure that we remain the only
// request in the queue).
if (!this.launched || this.shutdown || !this._worker) {
// Nothing to kill
this.shutdown = this.shutdown || shutdown;
this._worker = null;
return null;
}
// Exit critical section
let message = ["Meta_shutdown", [reset]];
Scheduler.latestReceived = [];
Scheduler.latestSent = [Date.now(),
Task.Debugging.generateReadableStack(new Error().stack),
...message];
// Wait for result
let resources;
try {
resources = yield this._worker.post(...message);
Scheduler.latestReceived = [Date.now(), message];
} catch (ex) {
LOG("Could not dispatch Meta_reset", ex);
// It's most likely a programmer error, but we'll assume that
// the worker has been shutdown, as it's less risky than the
// opposite stance.
resources = {openedFiles: [], openedDirectoryIterators: [], killed: true};
Scheduler.latestReceived = [Date.now(), message, ex];
}
let {openedFiles, openedDirectoryIterators, killed} = resources;
if (!reset
&& (openedFiles && openedFiles.length
|| ( openedDirectoryIterators && openedDirectoryIterators.length))) {
// The worker still holds resources. Report them.
let msg = "";
if (openedFiles.length > 0) {
msg += "The following files are still open:\n" +
openedFiles.join("\n");
}
if (openedDirectoryIterators.length > 0) {
msg += "The following directory iterators are still open:\n" +
openedDirectoryIterators.join("\n");
}
LOG("WARNING: File descriptors leaks detected.\n" + msg);
}
// Make sure that we do not leave an invalid |worker| around.
if (killed || shutdown) {
this._worker = null;
}
this.shutdown = shutdown;
return resources;
} finally {
// Resume accepting messages. If we have set |shutdown| to |true|,
// any pending/future request will be rejected. Otherwise, any
// pending/future request will spawn a new worker if necessary.
deferred.resolve();
}
}.bind(this));
},
/**
* Push a task at the end of the queue.
*
* @param {function} code A function returning a Promise.
* This function will be executed once all the previously
* pushed tasks have completed.
* @return {Promise} A promise with the same behavior as
* the promise returned by |code|.
*/
push: function(code) {
let promise = this.queue.then(code);
// By definition, |this.queue| can never reject.
this.queue = promise.then(null, () => undefined);
// Fork |promise| to ensure that uncaught errors are reported
return promise.then(null, null);
},
/**
* Post a message to the worker thread.
*
* @param {string} method The name of the method to call.
* @param {...} args The arguments to pass to the method. These arguments
* must be clonable.
* @return {Promise} A promise conveying the result/error caused by
* calling |method| with arguments |args|.
*/
post: function post(method, args = undefined, closure = undefined) {
if (this.shutdown) {
LOG("OS.File is not available anymore. The following request has been rejected.",
method, args);
return Promise.reject(new Error("OS.File has been shut down. Rejecting post to " + method));
}
let firstLaunch = !this.launched;
this.launched = true;
if (firstLaunch && SharedAll.Config.DEBUG) {
// If we have delayed sending SET_DEBUG, do it now.
this.worker.post("SET_DEBUG", [true]);
Scheduler.Debugging.messagesSent++;
}
Scheduler.Debugging.messagesQueued++;
return this.push(Task.async(function*() {
if (this.shutdown) {
LOG("OS.File is not available anymore. The following request has been rejected.",
method, args);
throw new Error("OS.File has been shut down. Rejecting request to " + method);
}
// Update debugging information. As |args| may be quite
// expensive, we only keep a shortened version of it.
Scheduler.Debugging.latestReceived = null;
Scheduler.Debugging.latestSent = [Date.now(), method, summarizeObject(args)];
// Don't kill the worker just yet
Scheduler.restartTimer();
let reply;
try {
try {
Scheduler.Debugging.messagesSent++;
Scheduler.Debugging.latestSent = Scheduler.Debugging.latestSent.slice(0, 2);
reply = yield this.worker.post(method, args, closure);
Scheduler.Debugging.latestReceived = [Date.now(), summarizeObject(reply)];
return reply;
} finally {
Scheduler.Debugging.messagesReceived++;
}
} catch (error) {
Scheduler.Debugging.latestReceived = [Date.now(), error.message, error.fileName, error.lineNumber];
throw error;
} finally {
Scheduler.restartTimer();
}
}.bind(this)));
}
};
const PREF_OSFILE_LOG = "toolkit.osfile.log";
const PREF_OSFILE_LOG_REDIRECT = "toolkit.osfile.log.redirect";
/**
* Listen to PREF_OSFILE_LOG changes and update gShouldLog flag
* appropriately.
*/
Services.prefs.addObserver(PREF_OSFILE_LOG,
function prefObserver(aSubject, aTopic, aData) {
SharedAll.Config.DEBUG = Services.prefs.getBoolPref(PREF_OSFILE_LOG, SharedAll.Config.DEBUG);
if (Scheduler.launched) {
// Don't start the worker just to set this preference.
Scheduler.post("SET_DEBUG", [SharedAll.Config.DEBUG]);
}
}, false);
SharedAll.Config.DEBUG = Services.prefs.getBoolPref(PREF_OSFILE_LOG, false);
Services.prefs.addObserver(PREF_OSFILE_LOG_REDIRECT,
function prefObserver(aSubject, aTopic, aData) {
SharedAll.Config.TEST = Services.prefs.getBoolPref(PREF_OSFILE_LOG_REDIRECT, OS.Shared.TEST);
}, false);
SharedAll.Config.TEST = Services.prefs.getBoolPref(PREF_OSFILE_LOG_REDIRECT, false);
/**
* If |true|, use the native implementaiton of OS.File methods
* whenever possible. Otherwise, force the use of the JS version.
*/
var nativeWheneverAvailable = true;
const PREF_OSFILE_NATIVE = "toolkit.osfile.native";
Services.prefs.addObserver(PREF_OSFILE_NATIVE,
function prefObserver(aSubject, aTopic, aData) {
nativeWheneverAvailable = Services.prefs.getBoolPref(PREF_OSFILE_NATIVE, nativeWheneverAvailable);
}, false);
// Update worker's DEBUG flag if it's true.
// Don't start the worker just for this, though.
if (SharedAll.Config.DEBUG && Scheduler.launched) {
Scheduler.post("SET_DEBUG", [true]);
}
// Observer topics used for monitoring shutdown
const WEB_WORKERS_SHUTDOWN_TOPIC = "web-workers-shutdown";
// Preference used to configure test shutdown observer.
const PREF_OSFILE_TEST_SHUTDOWN_OBSERVER =
"toolkit.osfile.test.shutdown.observer";
AsyncShutdown.webWorkersShutdown.addBlocker(
"OS.File: flush pending requests, warn about unclosed files, shut down service.",
Task.async(function*() {
// Give clients a last chance to enqueue requests.
yield Barriers.shutdown.wait({crashAfterMS: null});
// Wait until all requests are complete and kill the worker.
yield Scheduler.kill({reset: false, shutdown: true});
}),
() => {
let details = Barriers.getDetails();
details.clients = Barriers.shutdown.state;
return details;
}
);
// Attaching an observer for PREF_OSFILE_TEST_SHUTDOWN_OBSERVER to enable or
// disable the test shutdown event observer.
// Note: By default the PREF_OSFILE_TEST_SHUTDOWN_OBSERVER is unset.
// Note: This is meant to be used for testing purposes only.
Services.prefs.addObserver(PREF_OSFILE_TEST_SHUTDOWN_OBSERVER,
function prefObserver() {
// The temporary phase topic used to trigger the unclosed
// phase warning.
let TOPIC = Services.prefs.getCharPref(PREF_OSFILE_TEST_SHUTDOWN_OBSERVER,
"");
if (TOPIC) {
// Generate a phase, add a blocker.
// Note that this can work only if AsyncShutdown itself has been
// configured for testing by the testsuite.
let phase = AsyncShutdown._getPhase(TOPIC);
phase.addBlocker(
"(for testing purposes) OS.File: warn about unclosed files",
() => Scheduler.kill({shutdown: false, reset: false})
);
}
}, false);
/**
* Representation of a file, with asynchronous methods.
*
* @param {*} fdmsg The _message_ representing the platform-specific file
* handle.
*
* @constructor
*/
var File = function File(fdmsg) {
// FIXME: At the moment, |File| does not close on finalize
// (see bug 777715)
this._fdmsg = fdmsg;
this._closeResult = null;
this._closed = null;
};
File.prototype = {
/**
* Close a file asynchronously.
*
* This method is idempotent.
*
* @return {promise}
* @resolves {null}
* @rejects {OS.File.Error}
*/
close: function close() {
if (this._fdmsg != null) {
let msg = this._fdmsg;
this._fdmsg = null;
return this._closeResult =
Scheduler.post("File_prototype_close", [msg], this);
}
return this._closeResult;
},
/**
* Fetch information about the file.
*
* @return {promise}
* @resolves {OS.File.Info} The latest information about the file.
* @rejects {OS.File.Error}
*/
stat: function stat() {
return Scheduler.post("File_prototype_stat", [this._fdmsg], this).then(
File.Info.fromMsg
);
},
/**
* Write bytes from a buffer to this file.
*
* Note that, by default, this function may perform several I/O
* operations to ensure that the buffer is fully written.
*
* @param {Typed array | C pointer} buffer The buffer in which the
* the bytes are stored. The buffer must be large enough to
* accomodate |bytes| bytes. Using the buffer before the operation
* is complete is a BAD IDEA.
* @param {*=} options Optionally, an object that may contain the
* following fields:
* - {number} bytes The number of |bytes| to write from the buffer. If
* unspecified, this is |buffer.byteLength|. Note that |bytes| is required
* if |buffer| is a C pointer.
*
* @return {number} The number of bytes actually written.
*/
write: function write(buffer, options = {}) {
// If |buffer| is a typed array and there is no |bytes| options,
// we need to extract the |byteLength| now, as it will be lost
// by communication.
// Options might be a nullish value, so better check for that before using
// the |in| operator.
if (isTypedArray(buffer) && !(options && "bytes" in options)) {
// Preserve reference to option |outExecutionDuration|, if it is passed.
options = clone(options, ["outExecutionDuration"]);
options.bytes = buffer.byteLength;
}
return Scheduler.post("File_prototype_write",
[this._fdmsg,
Type.void_t.in_ptr.toMsg(buffer),
options],
buffer/*Ensure that |buffer| is not gc-ed*/);
},
/**
* Read bytes from this file to a new buffer.
*
* @param {number=} bytes If unspecified, read all the remaining bytes from
* this file. If specified, read |bytes| bytes, or less if the file does not
* contain that many bytes.
* @param {JSON} options
* @return {promise}
* @resolves {Uint8Array} An array containing the bytes read.
*/
read: function read(nbytes, options = {}) {
let promise = Scheduler.post("File_prototype_read",
[this._fdmsg,
nbytes, options]);
return promise.then(
function onSuccess(data) {
return new Uint8Array(data.buffer, data.byteOffset, data.byteLength);
});
},
/**
* Return the current position in the file, as bytes.
*
* @return {promise}
* @resolves {number} The current position in the file,
* as a number of bytes since the start of the file.
*/
getPosition: function getPosition() {
return Scheduler.post("File_prototype_getPosition",
[this._fdmsg]);
},
/**
* Set the current position in the file, as bytes.
*
* @param {number} pos A number of bytes.
* @param {number} whence The reference position in the file,
* which may be either POS_START (from the start of the file),
* POS_END (from the end of the file) or POS_CUR (from the
* current position in the file).
*
* @return {promise}
*/
setPosition: function setPosition(pos, whence) {
return Scheduler.post("File_prototype_setPosition",
[this._fdmsg, pos, whence]);
},
/**
* Flushes the file's buffers and causes all buffered data
* to be written.
* Disk flushes are very expensive and therefore should be used carefully,
* sparingly and only in scenarios where it is vital that data survives
* system crashes. Even though the function will be executed off the
* main-thread, it might still affect the overall performance of any running
* application.
*
* @return {promise}
*/
flush: function flush() {
return Scheduler.post("File_prototype_flush",
[this._fdmsg]);
},
/**
* Set the file's access permissions. This does nothing on Windows.
*
* This operation is likely to fail if applied to a file that was
* not created by the currently running program (more precisely,
* if it was created by a program running under a different OS-level
* user account). It may also fail, or silently do nothing, if the
* filesystem containing the file does not support access permissions.
*
* @param {*=} options Object specifying the requested permissions:
*
* - {number} unixMode The POSIX file mode to set on the file. If omitted,
* the POSIX file mode is reset to the default used by |OS.file.open|. If
* specified, the permissions will respect the process umask as if they
* had been specified as arguments of |OS.File.open|, unless the
* |unixHonorUmask| parameter tells otherwise.
* - {bool} unixHonorUmask If omitted or true, any |unixMode| value is
* modified by the process umask, as |OS.File.open| would have done. If
* false, the exact value of |unixMode| will be applied.
*/
setPermissions: function setPermissions(options = {}) {
return Scheduler.post("File_prototype_setPermissions",
[this._fdmsg, options]);
}
};
/**
* Set the last access and modification date of the file.
* The time stamp resolution is 1 second at best, but might be worse
* depending on the platform.
*
* @return {promise}
* @rejects {TypeError}
* @rejects {OS.File.Error}
*/
File.prototype.setDates = function(accessDate, modificationDate) {
return Scheduler.post("File_prototype_setDates",
[this._fdmsg, accessDate, modificationDate], this);
};
/**
* Open a file asynchronously.
*
* @return {promise}
* @resolves {OS.File}
* @rejects {OS.Error}
*/
File.open = function open(path, mode, options) {
return Scheduler.post(
"open", [Type.path.toMsg(path), mode, options],
path
).then(
function onSuccess(msg) {
return new File(msg);
}
);
};
/**
* Creates and opens a file with a unique name. By default, generate a random HEX number and use it to create a unique new file name.
*
* @param {string} path The path to the file.
* @param {*=} options Additional options for file opening. This
* implementation interprets the following fields:
*
* - {number} humanReadable If |true|, create a new filename appending a decimal number. ie: filename-1.ext, filename-2.ext.
* If |false| use HEX numbers ie: filename-A65BC0.ext
* - {number} maxReadableNumber Used to limit the amount of tries after a failed
* file creation. Default is 20.
*
* @return {Object} contains A file object{file} and the path{path}.
* @throws {OS.File.Error} If the file could not be opened.
*/
File.openUnique = function openUnique(path, options) {
return Scheduler.post(
"openUnique", [Type.path.toMsg(path), options],
path
).then(
function onSuccess(msg) {
return {
path: msg.path,
file: new File(msg.file)
};
}
);
};
/**
* Get the information on the file.
*
* @return {promise}
* @resolves {OS.File.Info}
* @rejects {OS.Error}
*/
File.stat = function stat(path, options) {
return Scheduler.post(
"stat", [Type.path.toMsg(path), options],
path).then(File.Info.fromMsg);
};
/**
* Set the last access and modification date of the file.
* The time stamp resolution is 1 second at best, but might be worse
* depending on the platform.
*
* @return {promise}
* @rejects {TypeError}
* @rejects {OS.File.Error}
*/
File.setDates = function setDates(path, accessDate, modificationDate) {
return Scheduler.post("setDates",
[Type.path.toMsg(path), accessDate, modificationDate],
this);
};
/**
* Set the file's access permissions. This does nothing on Windows.
*
* This operation is likely to fail if applied to a file that was
* not created by the currently running program (more precisely,
* if it was created by a program running under a different OS-level
* user account). It may also fail, or silently do nothing, if the
* filesystem containing the file does not support access permissions.
*
* @param {string} path The path to the file.
* @param {*=} options Object specifying the requested permissions:
*
* - {number} unixMode The POSIX file mode to set on the file. If omitted,
* the POSIX file mode is reset to the default used by |OS.file.open|. If
* specified, the permissions will respect the process umask as if they
* had been specified as arguments of |OS.File.open|, unless the
* |unixHonorUmask| parameter tells otherwise.
* - {bool} unixHonorUmask If omitted or true, any |unixMode| value is
* modified by the process umask, as |OS.File.open| would have done. If
* false, the exact value of |unixMode| will be applied.
*/
File.setPermissions = function setPermissions(path, options = {}) {
return Scheduler.post("setPermissions",
[Type.path.toMsg(path), options]);
};
/**
* Fetch the current directory
*
* @return {promise}
* @resolves {string} The current directory, as a path usable with OS.Path
* @rejects {OS.Error}
*/
File.getCurrentDirectory = function getCurrentDirectory() {
return Scheduler.post(
"getCurrentDirectory"
).then(Type.path.fromMsg);
};
/**
* Change the current directory
*
* @param {string} path The OS-specific path to the current directory.
* You should use the methods of OS.Path and the constants of OS.Constants.Path
* to build OS-specific paths in a portable manner.
*
* @return {promise}
* @resolves {null}
* @rejects {OS.Error}
*/
File.setCurrentDirectory = function setCurrentDirectory(path) {
return Scheduler.post(
"setCurrentDirectory", [Type.path.toMsg(path)], path
);
};
/**
* Copy a file to a destination.
*
* @param {string} sourcePath The platform-specific path at which
* the file may currently be found.
* @param {string} destPath The platform-specific path at which the
* file should be copied.
* @param {*=} options An object which may contain the following fields:
*
* @option {bool} noOverwrite - If true, this function will fail if
* a file already exists at |destPath|. Otherwise, if this file exists,
* it will be erased silently.
*
* @rejects {OS.File.Error} In case of any error.
*
* General note: The behavior of this function is defined only when
* it is called on a single file. If it is called on a directory, the
* behavior is undefined and may not be the same across all platforms.
*
* General note: The behavior of this function with respect to metadata
* is unspecified. Metadata may or may not be copied with the file. The
* behavior may not be the same across all platforms.
*/
File.copy = function copy(sourcePath, destPath, options) {
return Scheduler.post("copy", [Type.path.toMsg(sourcePath),
Type.path.toMsg(destPath), options], [sourcePath, destPath]);
};
/**
* Move a file to a destination.
*
* @param {string} sourcePath The platform-specific path at which
* the file may currently be found.
* @param {string} destPath The platform-specific path at which the
* file should be moved.
* @param {*=} options An object which may contain the following fields:
*
* @option {bool} noOverwrite - If set, this function will fail if
* a file already exists at |destPath|. Otherwise, if this file exists,
* it will be erased silently.
*
* @returns {Promise}
* @rejects {OS.File.Error} In case of any error.
*
* General note: The behavior of this function is defined only when
* it is called on a single file. If it is called on a directory, the
* behavior is undefined and may not be the same across all platforms.
*
* General note: The behavior of this function with respect to metadata
* is unspecified. Metadata may or may not be moved with the file. The
* behavior may not be the same across all platforms.
*/
File.move = function move(sourcePath, destPath, options) {
return Scheduler.post("move", [Type.path.toMsg(sourcePath),
Type.path.toMsg(destPath), options], [sourcePath, destPath]);
};
/**
* Create a symbolic link to a source.
*
* @param {string} sourcePath The platform-specific path to which
* the symbolic link should point.
* @param {string} destPath The platform-specific path at which the
* symbolic link should be created.
*
* @returns {Promise}
* @rejects {OS.File.Error} In case of any error.
*/
if (!SharedAll.Constants.Win) {
File.unixSymLink = function unixSymLink(sourcePath, destPath) {
return Scheduler.post("unixSymLink", [Type.path.toMsg(sourcePath),
Type.path.toMsg(destPath)], [sourcePath, destPath]);
};
}
/**
* Gets the number of bytes available on disk to the current user.
*
* @param {string} Platform-specific path to a directory on the disk to
* query for free available bytes.
*
* @return {number} The number of bytes available for the current user.
* @throws {OS.File.Error} In case of any error.
*/
File.getAvailableFreeSpace = function getAvailableFreeSpace(sourcePath) {
return Scheduler.post("getAvailableFreeSpace",
[Type.path.toMsg(sourcePath)], sourcePath
).then(Type.uint64_t.fromMsg);
};
/**
* Remove an empty directory.
*
* @param {string} path The name of the directory to remove.
* @param {*=} options Additional options.
* - {bool} ignoreAbsent If |true|, do not fail if the
* directory does not exist yet.
*/
File.removeEmptyDir = function removeEmptyDir(path, options) {
return Scheduler.post("removeEmptyDir",
[Type.path.toMsg(path), options], path);
};
/**
* Remove an existing file.
*
* @param {string} path The name of the file.
* @param {*=} options Additional options.
* - {bool} ignoreAbsent If |false|, throw an error if the file does
* not exist. |true| by default.
*
* @throws {OS.File.Error} In case of I/O error.
*/
File.remove = function remove(path, options) {
return Scheduler.post("remove",
[Type.path.toMsg(path), options], path);
};
/**
* Create a directory and, optionally, its parent directories.
*
* @param {string} path The name of the directory.
* @param {*=} options Additional options.
*
* - {string} from If specified, the call to |makeDir| creates all the
* ancestors of |path| that are descendants of |from|. Note that |path|
* must be a descendant of |from|, and that |from| and its existing
* subdirectories present in |path| must be user-writeable.
* Example:
* makeDir(Path.join(profileDir, "foo", "bar"), { from: profileDir });
* creates directories profileDir/foo, profileDir/foo/bar
* - {bool} ignoreExisting If |false|, throw an error if the directory
* already exists. |true| by default. Ignored if |from| is specified.
* - {number} unixMode Under Unix, if specified, a file creation mode,
* as per libc function |mkdir|. If unspecified, dirs are
* created with a default mode of 0700 (dir is private to
* the user, the user can read, write and execute). Ignored under Windows
* or if the file system does not support file creation modes.
* - {C pointer} winSecurity Under Windows, if specified, security
* attributes as per winapi function |CreateDirectory|. If
* unspecified, use the default security descriptor, inherited from
* the parent directory. Ignored under Unix or if the file system
* does not support security descriptors.
*/
File.makeDir = function makeDir(path, options) {
return Scheduler.post("makeDir",
[Type.path.toMsg(path), options], path);
};
/**
* Return the contents of a file
*
* @param {string} path The path to the file.
* @param {number=} bytes Optionally, an upper bound to the number of bytes
* to read. DEPRECATED - please use options.bytes instead.
* @param {JSON} options Additional options.
* - {boolean} sequential A flag that triggers a population of the page cache
* with data from a file so that subsequent reads from that file would not
* block on disk I/O. If |true| or unspecified, inform the system that the
* contents of the file will be read in order. Otherwise, make no such
* assumption. |true| by default.
* - {number} bytes An upper bound to the number of bytes to read.
* - {string} compression If "lz4" and if the file is compressed using the lz4
* compression algorithm, decompress the file contents on the fly.
*
* @resolves {Uint8Array} A buffer holding the bytes
* read from the file.
*/
File.read = function read(path, bytes, options = {}) {
if (typeof bytes == "object") {
// Passing |bytes| as an argument is deprecated.
// We should now be passing it as a field of |options|.
options = bytes || {};
} else {
options = clone(options, ["outExecutionDuration"]);
if (typeof bytes != "undefined") {
options.bytes = bytes;
}
}
if (options.compression || !nativeWheneverAvailable) {
// We need to use the JS implementation.
let promise = Scheduler.post("read",
[Type.path.toMsg(path), bytes, options], path);
return promise.then(
function onSuccess(data) {
if (typeof data == "string") {
return data;
}
return new Uint8Array(data.buffer, data.byteOffset, data.byteLength);
});
}
// Otherwise, use the native implementation.
return Scheduler.push(() => Native.read(path, options));
};
/**
* Find outs if a file exists.
*
* @param {string} path The path to the file.
*
* @return {bool} true if the file exists, false otherwise.
*/
File.exists = function exists(path) {
return Scheduler.post("exists",
[Type.path.toMsg(path)], path);
};
/**
* Write a file, atomically.
*
* By opposition to a regular |write|, this operation ensures that,
* until the contents are fully written, the destination file is
* not modified.
*
* Limitation: In a few extreme cases (hardware failure during the
* write, user unplugging disk during the write, etc.), data may be
* corrupted. If your data is user-critical (e.g. preferences,
* application data, etc.), you may wish to consider adding options
* |tmpPath| and/or |flush| to reduce the likelihood of corruption, as
* detailed below. Note that no combination of options can be
* guaranteed to totally eliminate the risk of corruption.
*
* @param {string} path The path of the file to modify.
* @param {Typed Array | C pointer} buffer A buffer containing the bytes to write.
* @param {*=} options Optionally, an object determining the behavior
* of this function. This object may contain the following fields:
* - {number} bytes The number of bytes to write. If unspecified,
* |buffer.byteLength|. Required if |buffer| is a C pointer.
* - {string} tmpPath If |null| or unspecified, write all data directly
* to |path|. If specified, write all data to a temporary file called
* |tmpPath| and, once this write is complete, rename the file to
* replace |path|. Performing this additional operation is a little
* slower but also a little safer.
* - {bool} noOverwrite - If set, this function will fail if a file already
* exists at |path|.
* - {bool} flush - If |false| or unspecified, return immediately once the
* write is complete. If |true|, before writing, force the operating system
* to write its internal disk buffers to the disk. This is considerably slower
* (not just for the application but for the whole system) but also safer:
* if the system shuts down improperly (typically due to a kernel freeze
* or a power failure) or if the device is disconnected before the buffer
* is flushed, the file has more chances of not being corrupted.
* - {string} backupTo - If specified, backup the destination file as |backupTo|.
* Note that this function renames the destination file before overwriting it.
* If the process or the operating system freezes or crashes
* during the short window between these operations,
* the destination file will have been moved to its backup.
*
* @return {promise}
* @resolves {number} The number of bytes actually written.
*/
File.writeAtomic = function writeAtomic(path, buffer, options = {}) {
// Copy |options| to avoid modifying the original object but preserve the
// reference to |outExecutionDuration| option if it is passed.
options = clone(options, ["outExecutionDuration"]);
// As options.tmpPath is a path, we need to encode it as |Type.path| message
if ("tmpPath" in options) {
options.tmpPath = Type.path.toMsg(options.tmpPath);
};
if (isTypedArray(buffer) && (!("bytes" in options))) {
options.bytes = buffer.byteLength;
};
let promise = Scheduler.post("writeAtomic",
[Type.path.toMsg(path),
Type.void_t.in_ptr.toMsg(buffer),
options], [options, buffer, path]);
return promise;
};
File.removeDir = function(path, options = {}) {
return Scheduler.post("removeDir",
[Type.path.toMsg(path), options], path);
};
/**
* Information on a file, as returned by OS.File.stat or
* OS.File.prototype.stat
*
* @constructor
*/
File.Info = function Info(value) {
// Note that we can't just do this[k] = value[k] because our
// prototype defines getters for all of these fields.
for (let k in value) {
if (k != "creationDate") {
Object.defineProperty(this, k, {value: value[k]});
}
}
Object.defineProperty(this, "_deprecatedCreationDate", {value: value["creationDate"]});
};
File.Info.prototype = SysAll.AbstractInfo.prototype;
// Deprecated
Object.defineProperty(File.Info.prototype, "creationDate", {
get: function creationDate() {
let {Deprecated} = Cu.import("resource://gre/modules/Deprecated.jsm", {});
Deprecated.warning("Field 'creationDate' is deprecated.", "https://developer.mozilla.org/en-US/docs/JavaScript_OS.File/OS.File.Info#Cross-platform_Attributes");
return this._deprecatedCreationDate;
}
});
File.Info.fromMsg = function fromMsg(value) {
return new File.Info(value);
};
/**
* Get worker's current DEBUG flag.
* Note: This is used for testing purposes.
*/
File.GET_DEBUG = function GET_DEBUG() {
return Scheduler.post("GET_DEBUG");
};
/**
* Iterate asynchronously through a directory
*
* @constructor
*/
var DirectoryIterator = function DirectoryIterator(path, options) {
/**
* Open the iterator on the worker thread
*
* @type {Promise}
* @resolves {*} A message accepted by the methods of DirectoryIterator
* in the worker thread
* @rejects {StopIteration} If all entries have already been visited
* or the iterator has been closed.
*/
this.__itmsg = Scheduler.post(
"new_DirectoryIterator", [Type.path.toMsg(path), options],
path
);
this._isClosed = false;
};
DirectoryIterator.prototype = {
iterator: function () {
return this;
},
__iterator__: function () {
return this;
},
// Once close() is called, _itmsg should reject with a
// StopIteration. However, we don't want to create the promise until
// it's needed because it might never be used. In that case, we
// would get a warning on the console.
get _itmsg() {
if (!this.__itmsg) {
this.__itmsg = Promise.reject(StopIteration);
}
return this.__itmsg;
},
/**
* Determine whether the directory exists.
*
* @resolves {boolean}
*/
exists: function exists() {
return this._itmsg.then(
function onSuccess(iterator) {
return Scheduler.post("DirectoryIterator_prototype_exists", [iterator]);
}
);
},
/**
* Get the next entry in the directory.
*
* @return {Promise}
* @resolves {OS.File.Entry}
* @rejects {StopIteration} If all entries have already been visited.
*/
next: function next() {
let self = this;
let promise = this._itmsg;
// Get the iterator, call _next
promise = promise.then(
function withIterator(iterator) {
return self._next(iterator);
});
return promise;
},
/**
* Get several entries at once.
*
* @param {number=} length If specified, the number of entries
* to return. If unspecified, return all remaining entries.
* @return {Promise}
* @resolves {Array} An array containing the |length| next entries.
*/
nextBatch: function nextBatch(size) {
if (this._isClosed) {
return Promise.resolve([]);
}
let promise = this._itmsg;
promise = promise.then(
function withIterator(iterator) {
return Scheduler.post("DirectoryIterator_prototype_nextBatch", [iterator, size]);
});
promise = promise.then(
function withEntries(array) {
return array.map(DirectoryIterator.Entry.fromMsg);
});
return promise;
},
/**
* Apply a function to all elements of the directory sequentially.
*
* @param {Function} cb This function will be applied to all entries
* of the directory. It receives as arguments
* - the OS.File.Entry corresponding to the entry;
* - the index of the entry in the enumeration;
* - the iterator itself - return |iterator.close()| to stop the loop.
*
* If the callback returns a promise, iteration waits until the
* promise is resolved before proceeding.
*
* @return {Promise} A promise resolved once the loop has reached
* its end.
*/
forEach: function forEach(cb, options) {
if (this._isClosed) {
return Promise.resolve();
}
let self = this;
let position = 0;
let iterator;
// Grab iterator
let promise = this._itmsg.then(
function(aIterator) {
iterator = aIterator;
}
);
// Then iterate
let loop = function loop() {
if (self._isClosed) {
return Promise.resolve();
}
return self._next(iterator).then(
function onSuccess(value) {
return Promise.resolve(cb(value, position++, self)).then(loop);
},
function onFailure(reason) {
if (reason == StopIteration) {
return;
}
throw reason;
}
);
};
return promise.then(loop);
},
/**
* Auxiliary method: fetch the next item
*
* @rejects {StopIteration} If all entries have already been visited
* or the iterator has been closed.
*/
_next: function _next(iterator) {
if (this._isClosed) {
return this._itmsg;
}
let self = this;
let promise = Scheduler.post("DirectoryIterator_prototype_next", [iterator]);
promise = promise.then(
DirectoryIterator.Entry.fromMsg,
function onReject(reason) {
if (reason == StopIteration) {
self.close();
throw StopIteration;
}
throw reason;
});
return promise;
},
/**
* Close the iterator
*/
close: function close() {
if (this._isClosed) {
return Promise.resolve();
}
this._isClosed = true;
let self = this;
return this._itmsg.then(
function withIterator(iterator) {
// Set __itmsg to null so that the _itmsg getter returns a
// rejected StopIteration promise if it's ever used.
self.__itmsg = null;
return Scheduler.post("DirectoryIterator_prototype_close", [iterator]);
}
);
}
};
DirectoryIterator.Entry = function Entry(value) {
return value;
};
DirectoryIterator.Entry.prototype = Object.create(SysAll.AbstractEntry.prototype);
DirectoryIterator.Entry.fromMsg = function fromMsg(value) {
return new DirectoryIterator.Entry(value);
};
File.resetWorker = function() {
return Task.spawn(function*() {
let resources = yield Scheduler.kill({shutdown: false, reset: true});
if (resources && !resources.killed) {
throw new Error("Could not reset worker, this would leak file descriptors: " + JSON.stringify(resources));
}
});
};
// Constants
File.POS_START = SysAll.POS_START;
File.POS_CURRENT = SysAll.POS_CURRENT;
File.POS_END = SysAll.POS_END;
// Exports
File.Error = OSError;
File.DirectoryIterator = DirectoryIterator;
this.OS = {};
this.OS.File = File;
this.OS.Constants = SharedAll.Constants;
this.OS.Shared = {
LOG: SharedAll.LOG,
Type: SysAll.Type,
get DEBUG() {
return SharedAll.Config.DEBUG;
},
set DEBUG(x) {
return SharedAll.Config.DEBUG = x;
}
};
Object.freeze(this.OS.Shared);
this.OS.Path = Path;
// Returns a resolved promise when all the queued operation have been completed.
Object.defineProperty(OS.File, "queue", {
get: function() {
return Scheduler.queue;
}
});
// `true` if this is a content process, `false` otherwise.
// It would be nicer to go through `Services.appInfo`, but some tests need to be
// able to replace that field with a custom implementation before it is first
// called.
const isContent = Components.classes["@mozilla.org/xre/app-info;1"].getService(Ci.nsIXULRuntime).processType == Ci.nsIXULRuntime.PROCESS_TYPE_CONTENT;
/**
* Shutdown barriers, to let clients register to be informed during shutdown.
*/
var Barriers = {
shutdown: new AsyncShutdown.Barrier("OS.File: Waiting for clients before full shutdown"),
/**
* Return the shutdown state of OS.File
*/
getDetails: function() {
let result = {
launched: Scheduler.launched,
shutdown: Scheduler.shutdown,
worker: !!Scheduler._worker,
pendingReset: !!Scheduler.resetTimer,
latestSent: Scheduler.Debugging.latestSent,
latestReceived: Scheduler.Debugging.latestReceived,
messagesSent: Scheduler.Debugging.messagesSent,
messagesReceived: Scheduler.Debugging.messagesReceived,
messagesQueued: Scheduler.Debugging.messagesQueued,
DEBUG: SharedAll.Config.DEBUG,
};
// Convert dates to strings for better readability
for (let key of ["latestSent", "latestReceived"]) {
if (result[key] && typeof result[key][0] == "number") {
result[key][0] = Date(result[key][0]);
}
}
return result;
}
};
function setupShutdown(phaseName) {
Barriers[phaseName] = new AsyncShutdown.Barrier(`OS.File: Waiting for clients before ${phaseName}`),
File[phaseName] = Barriers[phaseName].client;
// Auto-flush OS.File during `phaseName`. This ensures that any I/O
// that has been queued *before* `phaseName` is properly completed.
// To ensure that I/O queued *during* `phaseName` change is completed,
// clients should register using AsyncShutdown.addBlocker.
AsyncShutdown[phaseName].addBlocker(
`OS.File: flush I/O queued before ${phaseName}`,
Task.async(function*() {
// Give clients a last chance to enqueue requests.
yield Barriers[phaseName].wait({crashAfterMS: null});
// Wait until all currently enqueued requests are completed.
yield Scheduler.queue;
}),
() => {
let details = Barriers.getDetails();
details.clients = Barriers[phaseName].state;
return details;
}
);
}
// profile-before-change only exists in the parent, and OS.File should
// not be used in the child process anyways.
if (!isContent) {
setupShutdown("profileBeforeChange")
}
File.shutdown = Barriers.shutdown.client;