gecko/toolkit/components/osfile/osfile_unix_allthreads.jsm
2012-08-16 22:05:30 -04:00

163 lines
5.2 KiB
JavaScript

/* 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/. */
/**
* This module defines the thread-agnostic components of the Unix version
* of OS.File. It depends on the thread-agnostic cross-platform components
* of OS.File.
*
* It serves the following purposes:
* - open libc;
* - define OS.Unix.Error;
* - define a few constants and types that need to be defined on all platforms.
*
* This module can be:
* - opened from the main thread as a jsm module;
* - opened from a chrome worker through importScripts.
*/
if (typeof Components != "undefined") {
// Module is opened as a jsm module
var EXPORTED_SYMBOLS = ["OS"];
Components.utils.import("resource://gre/modules/ctypes.jsm");
Components.utils.import("resource://gre/modules/osfile/osfile_shared_allthreads.jsm");
} else {
// File is included from a chrome worker
importScripts("resource://gre/modules/osfile/osfile_shared_allthreads.jsm");
}
(function(exports) {
"use strict";
if (!exports.OS || !exports.OS.Shared) {
throw new Error("osfile_unix_allthreads.jsm must be loaded after osfile_shared_allthreads.jsm");
}
if (exports.OS.Shared.Unix) {
// Avoid double inclusion
return;
}
exports.OS.Shared.Unix = {};
let LOG = OS.Shared.LOG.bind(OS.Shared, "Unix", "allthreads");
// Open libc
let libc;
let libc_candidates = [ "libsystem.B.dylib",
"libc.so.6",
"libc.so" ];
for (let i = 0; i < libc_candidates.length; ++i) {
try {
libc = ctypes.open(libc_candidates[i]);
break;
} catch (x) {
LOG("Could not open libc "+libc_candidates[i]);
}
}
if (!libc) {
throw new Error("Could not open any libc.");
}
exports.OS.Shared.Unix.libc = libc;
// Define declareFFI
let declareFFI = OS.Shared.declareFFI.bind(null, libc);
exports.OS.Shared.Unix.declareFFI = declareFFI;
// Define Error
let strerror = libc.declare("strerror",
ctypes.default_abi,
/*return*/ ctypes.char.ptr,
/*errnum*/ ctypes.int);
/**
* A File-related error.
*
* To obtain a human-readable error message, use method |toString|.
* To determine the cause of the error, use the various |becauseX|
* getters. To determine the operation that failed, use field
* |operation|.
*
* Additionally, this implementation offers a field
* |unixErrno|, which holds the OS-specific error
* constant. If you need this level of detail, you may match the value
* of this field against the error constants of |OS.Constants.libc|.
*
* @param {string=} operation The operation that failed. If unspecified,
* the name of the calling function is taken to be the operation that
* failed.
* @param {number=} lastError The OS-specific constant detailing the
* reason of the error. If unspecified, this is fetched from the system
* status.
*
* @constructor
* @extends {OS.Shared.Error}
*/
let OSError = function OSError(operation, errno) {
operation = operation || "unknown operation";
exports.OS.Shared.Error.call(this, operation);
this.unixErrno = errno || ctypes.errno;
};
OSError.prototype = new exports.OS.Shared.Error();
OSError.prototype.toString = function toString() {
return "Unix error " + this.unixErrno +
" during operation " + this.operation +
" (" + strerror(this.unixErrno).readString() + ")";
};
/**
* |true| if the error was raised because a file or directory
* already exists, |false| otherwise.
*/
Object.defineProperty(OSError.prototype, "becauseExists", {
get: function becauseExists() {
return this.unixErrno == OS.Constants.libc.EEXISTS;
}
});
/**
* |true| if the error was raised because a file or directory
* does not exist, |false| otherwise.
*/
Object.defineProperty(OSError.prototype, "becauseNoSuchFile", {
get: function becauseNoSuchFile() {
return this.unixErrno == OS.Constants.libc.ENOENT;
}
});
/**
* Serialize an instance of OSError to something that can be
* transmitted across threads (not necessarily a string).
*/
OSError.toMsg = function toMsg(error) {
return {
operation: error.operation,
unixErrno: error.unixErrno
};
};
/**
* Deserialize a message back to an instance of OSError
*/
OSError.fromMsg = function fromMsg(msg) {
return new OSError(msg.operation, msg.unixErrno);
};
exports.OS.Shared.Unix.Error = OSError;
// Special constants that need to be defined on all platforms
Object.defineProperty(exports.OS.Shared, "POS_START", { value: exports.OS.Constants.libc.SEEK_SET });
Object.defineProperty(exports.OS.Shared, "POS_CURRENT", { value: exports.OS.Constants.libc.SEEK_CUR });
Object.defineProperty(exports.OS.Shared, "POS_END", { value: exports.OS.Constants.libc.SEEK_END });
// Special types that need to be defined for communication
// between threads
let Types = exports.OS.Shared.Type;
/**
* Native paths
*
* Under Unix, expressed as C strings
*/
Types.path = Types.cstring.withName("[in] path");
Types.out_path = Types.out_cstring.withName("[out] path");
})(this);