gecko-dev/toolkit/components/osfile/osfile_win_allthreads.jsm

198 lines
6.6 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 Win 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.Shared.Win.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_win_allthreads.jsm must be loaded after osfile_shared_allthreads.jsm");
}
if (exports.OS.Shared.Win) {
// Avoid double inclusion
return;
}
exports.OS.Shared.Win = {};
let LOG = OS.Shared.LOG.bind(OS.Shared, "Win", "allthreads");
// Open libc
let libc = ctypes.open("kernel32.dll");
if (!libc) {
throw new Error("Could not open kernel32.dll");
}
exports.OS.Shared.Win.libc = libc;
// Define declareFFI
let declareFFI = OS.Shared.declareFFI.bind(null, libc);
exports.OS.Shared.Win.declareFFI = declareFFI;
// Define Error
let FormatMessage = libc.declare("FormatMessageW", ctypes.winapi_abi,
/*return*/ ctypes.uint32_t,
/*flags*/ ctypes.uint32_t,
/*source*/ ctypes.voidptr_t,
/*msgid*/ ctypes.uint32_t,
/*langid*/ ctypes.uint32_t,
/*buf*/ ctypes.jschar.ptr,
/*size*/ ctypes.uint32_t,
/*Arguments*/ctypes.voidptr_t
);
/**
* 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
* |winLastError|, 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.Win|.
*
* @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, lastError) {
operation = operation || "unknown operation";
exports.OS.Shared.Error.call(this, operation);
this.winLastError = lastError || ctypes.winLastError;
};
OSError.prototype = new exports.OS.Shared.Error();
OSError.prototype.toString = function toString() {
let buf = new (ctypes.ArrayType(ctypes.jschar, 1024))();
let result = FormatMessage(
exports.OS.Constants.Win.FORMAT_MESSAGE_FROM_SYSTEM |
exports.OS.Constants.Win.FORMAT_MESSAGE_IGNORE_INSERTS,
null,
/* The error number */ this.winLastError,
/* Default language */ 0,
/* Output buffer*/ buf,
/* Minimum size of buffer */ 1024,
/* Format args*/ null
);
if (!result) {
buf = "additional error " +
ctypes.winLastError +
" while fetching system error message";
}
return "Win error " + this.winLastError + " during operation "
+ this.operation + " (" + buf.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.winLastError == exports.OS.Constants.Win.ERROR_FILE_EXISTS ||
this.winLastError == exports.OS.Constants.Win.ERROR_ALREADY_EXISTS;
}
});
/**
* |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.winLastError == exports.OS.Constants.Win.ERROR_FILE_NOT_FOUND;
}
});
/**
* |true| if the error was raised because a directory is not empty
* does not exist, |false| otherwise.
*/
Object.defineProperty(OSError.prototype, "becauseNotEmpty", {
get: function becauseNotEmpty() {
return this.winLastError == OS.Constants.Win.ERROR_DIR_NOT_EMPTY;
}
});
/**
* |true| if the error was raised because a file or directory
* is closed, |false| otherwise.
*/
Object.defineProperty(OSError.prototype, "becauseClosed", {
get: function becauseClosed() {
return this.winLastError == exports.OS.Constants.Win.INVALID_HANDLE_VALUE;
}
});
/**
* 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,
winLastError: error.winLastError
};
};
/**
* Deserialize a message back to an instance of OSError
*/
OSError.fromMsg = function fromMsg(msg) {
return new OSError(msg.operation, msg.winLastError);
};
exports.OS.Shared.Win.Error = OSError;
// Special constants that need to be defined on all platforms
Object.defineProperty(exports.OS.Shared, "POS_START", { value: exports.OS.Constants.Win.FILE_BEGIN });
Object.defineProperty(exports.OS.Shared, "POS_CURRENT", { value: exports.OS.Constants.Win.FILE_CURRENT });
Object.defineProperty(exports.OS.Shared, "POS_END", { value: exports.OS.Constants.Win.FILE_END });
// Special types that need to be defined for communication
// between threads
let Types = exports.OS.Shared.Type;
/**
* Native paths
*
* Under Windows, expressed as wide strings
*/
Types.path = Types.wstring.withName("[in] path");
Types.out_path = Types.out_wstring.withName("[out] path");
// Special constructors that need to be defined on all threads
OSError.closed = function closed(operation) {
return new OSError(operation, exports.OS.Constants.Win.INVALID_HANDLE_VALUE);
};
})(this);