зеркало из https://github.com/mozilla/gecko-dev.git
967 строки
30 KiB
JavaScript
967 строки
30 KiB
JavaScript
/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this file,
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* You can obtain one at http://mozilla.org/MPL/2.0/. */
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{
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if (typeof Components != "undefined") {
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this.EXPORTED_SYMBOLS = ["OS"];
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}
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(function(exports) {
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"use strict";
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/*
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* This block defines |OS.Shared.Type|. However, |OS| can exist already
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* (in particular, if this code is executed in a worker thread, it is
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* defined).
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*/
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if (!exports.OS) {
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exports.OS = {};
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}
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if (!exports.OS.Shared) {
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exports.OS.Shared = {};
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}
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if (exports.OS.Shared.Type) {
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return; // Avoid double-initialization
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}
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// Import components after having initialized |exports.OS|, to ensure
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// that everybody uses the same definition of |OS|.
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if (typeof Components != "undefined") {
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const Cu = Components.utils;
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Cu.import("resource://gre/modules/ctypes.jsm");
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Components.classes["@mozilla.org/net/osfileconstantsservice;1"].
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getService(Components.interfaces.nsIOSFileConstantsService).init();
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if (typeof exports.OS.Shared.DEBUG !== "undefined") {
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return; // Avoid reading and attaching an observer more than once.
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}
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Cu.import("resource://gre/modules/Services.jsm");
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const PREF_OSFILE_LOG = "toolkit.osfile.log";
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/**
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* Safely read a PREF_OSFILE_LOG preference.
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* Returns a value read or, in case of an error, oldPref or false.
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*
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* @param bool oldPref
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* An optional value that the DEBUG flag was set to previously.
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*/
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let readDebugPref = function readDebugPref(oldPref) {
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let pref;
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try {
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pref = Services.prefs.getBoolPref(PREF_OSFILE_LOG);
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} catch (x) {
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// In case of an error when reading a pref keep it as is.
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pref = oldPref;
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}
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// If neither pref nor oldPref were set, default it to false.
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return pref || false;
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};
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/**
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* A variable controlling if osfile logs should be printed.
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*/
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exports.OS.Shared.DEBUG = readDebugPref(exports.OS.Shared.DEBUG);
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/**
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* Listen to PREF_OSFILE_LOG changes and update the shared DEBUG flag
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* appropriately.
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*/
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Services.prefs.addObserver(PREF_OSFILE_LOG,
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function prefObserver(aSubject, aTopic, aData) {
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exports.OS.Shared.DEBUG = readDebugPref(exports.OS.Shared.DEBUG);
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}, false);
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}
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// Define a lazy getter for a property
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let defineLazyGetter = function defineLazyGetter(object, name, getter) {
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Object.defineProperty(object, name, {
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configurable: true,
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get: function lazy() {
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delete this[name];
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let value = getter.call(this);
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Object.defineProperty(object, name, {
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value: value
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});
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return value;
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}
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});
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};
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exports.OS.Shared.defineLazyGetter = defineLazyGetter;
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let LOG;
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if (typeof console != "undefined" && console.log) {
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LOG = console.log.bind(console, "OS");
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} else {
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LOG = function() {
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let text = "OS";
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for (let i = 0; i < arguments.length; ++i) {
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text += (" " + arguments[i]);
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}
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dump(text + "\n");
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};
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}
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/**
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* Returns |arg.toString()| if available, otherwise
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* applies JSON.stringify.
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* Return itself otherwise.
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*
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* @param arg An argument to be stringified if possible.
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*/
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let stringifyArg = function stringifyArg(arg) {
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if (typeof arg === "string") {
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return arg;
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}
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if (arg && typeof arg === "object") {
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let argToString = arg.toString();
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/**
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* The only way to detect whether this object has a non-default
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* implementation of |toString| is to check whether it returns
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* '[object Object]'. Unfortunately, we cannot simply compare |arg.toString|
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* and |Object.prototype.toString| as |arg| typically comes from another
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* compartment.
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*/
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if (argToString === "[object Object]") {
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return JSON.stringify(arg);
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} else {
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return argToString;
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}
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}
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return arg;
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};
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/**
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* A Shared LOG utility function that only logs when DEBUG is set.
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*
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* @params {string|object}
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* An arbitrary number of arguments to be logged.
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*/
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exports.OS.Shared.LOG = function (...args) {
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// If DEBUG is falsy, do nothing.
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if (!exports.OS.Shared.DEBUG) {
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return;
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}
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let logFunc = LOG;
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if (exports.OS.Shared.TEST && Services) {
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// If TEST is true and the file is loaded in the main thread,
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// use Services.console for logging and listening to.
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logFunc = function logFunc(...args) {
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let message = ["TEST", "OS"].concat(args).join(" ");
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Services.console.logStringMessage(message + "\n");
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};
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}
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logFunc.apply(null, [stringifyArg(arg) for (arg of args)]);
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};
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/**
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* An OS error.
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*
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* This class is provided mostly for type-matching. If you need more
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* details about an error, you should use the platform-specific error
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* codes provided by subclasses of |OS.Shared.Error|.
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*
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* @param {string} operation The operation that failed.
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*
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* @constructor
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*/
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function OSError(operation) {
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Error.call(this);
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this.operation = operation;
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}
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exports.OS.Shared.Error = OSError;
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/**
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* Abstraction above js-ctypes types.
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*
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* Use values of this type to register FFI functions. In addition to the
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* usual features of js-ctypes, values of this type perform the necessary
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* transformations to ensure that C errors are handled nicely, to connect
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* resources with their finalizer, etc.
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*
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* @param {string} name The name of the type. Must be unique.
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* @param {CType} implementation The js-ctypes implementation of the type.
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*
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* @constructor
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*/
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function Type(name, implementation) {
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if (!(typeof name == "string")) {
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throw new TypeError("Type expects as first argument a name, got: "
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+ name);
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}
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if (!(implementation instanceof ctypes.CType)) {
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throw new TypeError("Type expects as second argument a ctypes.CType"+
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", got: " + implementation);
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}
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Object.defineProperty(this, "name", { value: name });
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Object.defineProperty(this, "implementation", { value: implementation });
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}
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Type.prototype = {
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/**
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* Serialize a value of |this| |Type| into a format that can
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* be transmitted as a message (not necessarily a string).
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*
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* In the default implementation, the method returns the
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* value unchanged.
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*/
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toMsg: function default_toMsg(value) {
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return value;
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},
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/**
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* Deserialize a message to a value of |this| |Type|.
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*
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* In the default implementation, the method returns the
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* message unchanged.
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*/
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fromMsg: function default_fromMsg(msg) {
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return msg;
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},
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/**
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* Import a value from C.
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*
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* In this default implementation, return the value
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* unchanged.
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*/
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importFromC: function default_importFromC(value) {
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return value;
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},
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/**
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* A pointer/array used to pass data to the foreign function.
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*/
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get in_ptr() {
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delete this.in_ptr;
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let ptr_t = new PtrType(
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"[in] " + this.name + "*",
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this.implementation.ptr,
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this);
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Object.defineProperty(this, "in_ptr",
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{
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get: function() {
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return ptr_t;
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}
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});
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return ptr_t;
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},
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/**
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* A pointer/array used to receive data from the foreign function.
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*/
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get out_ptr() {
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delete this.out_ptr;
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let ptr_t = new PtrType(
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"[out] " + this.name + "*",
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this.implementation.ptr,
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this);
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Object.defineProperty(this, "out_ptr",
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{
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get: function() {
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return ptr_t;
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}
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});
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return ptr_t;
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},
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/**
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* A pointer/array used to both pass data to the foreign function
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* and receive data from the foreign function.
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*
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* Whenever possible, prefer using |in_ptr| or |out_ptr|, which
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* are generally faster.
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*/
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get inout_ptr() {
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delete this.inout_ptr;
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let ptr_t = new PtrType(
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"[inout] " + this.name + "*",
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this.implementation.ptr,
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this);
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Object.defineProperty(this, "inout_ptr",
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{
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get: function() {
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return ptr_t;
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}
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});
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return ptr_t;
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},
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/**
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* Attach a finalizer to a type.
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*/
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releaseWith: function releaseWith(finalizer) {
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let parent = this;
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let type = this.withName("[auto " + this.name + ", " + finalizer + "] ");
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type.importFromC = function importFromC(value, operation) {
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return ctypes.CDataFinalizer(
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parent.importFromC(value, operation),
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finalizer);
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};
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return type;
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},
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/**
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* Return an alias to a type with a different name.
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*/
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withName: function withName(name) {
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return Object.create(this, {name: {value: name}});
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},
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/**
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* Cast a C value to |this| type.
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*
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* Throw an error if the value cannot be casted.
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*/
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cast: function cast(value) {
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return ctypes.cast(value, this.implementation);
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},
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/**
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* Return the number of bytes in a value of |this| type.
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*
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* This may not be defined, e.g. for |void_t|, array types
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* without length, etc.
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*/
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get size() {
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return this.implementation.size;
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}
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};
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/**
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* Utility function used to determine whether an object is a typed array
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*/
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let isTypedArray = function isTypedArray(obj) {
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return typeof obj == "object"
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&& "byteOffset" in obj;
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};
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exports.OS.Shared.isTypedArray = isTypedArray;
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/**
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* A |Type| of pointers.
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*
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* @param {string} name The name of this type.
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* @param {CType} implementation The type of this pointer.
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* @param {Type} targetType The target type.
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*/
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function PtrType(name, implementation, targetType) {
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Type.call(this, name, implementation);
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if (targetType == null || !targetType instanceof Type) {
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throw new TypeError("targetType must be an instance of Type");
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}
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/**
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* The type of values targeted by this pointer type.
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*/
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Object.defineProperty(this, "targetType", {
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value: targetType
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});
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}
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PtrType.prototype = Object.create(Type.prototype);
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/**
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* Convert a value to a pointer.
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*
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* Protocol:
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* - |null| returns |null|
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* - a string returns |{string: value}|
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* - a typed array returns |{ptr: address_of_buffer}|
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* - a C array returns |{ptr: address_of_buffer}|
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* everything else raises an error
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*/
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PtrType.prototype.toMsg = function ptr_toMsg(value) {
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if (value == null) {
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return null;
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}
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if (typeof value == "string") {
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return { string: value };
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}
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let normalized;
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if (isTypedArray(value)) { // Typed array
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normalized = Types.uint8_t.in_ptr.implementation(value.buffer);
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if (value.byteOffset != 0) {
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normalized = exports.OS.Shared.offsetBy(normalized, value.byteOffset);
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}
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} else if ("addressOfElement" in value) { // C array
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normalized = value.addressOfElement(0);
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} else if ("isNull" in value) { // C pointer
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normalized = value;
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} else {
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throw new TypeError("Value " + value +
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" cannot be converted to a pointer");
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}
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let cast = Types.uintptr_t.cast(normalized);
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return {ptr: cast.value.toString()};
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};
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/**
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* Convert a message back to a pointer.
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*/
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PtrType.prototype.fromMsg = function ptr_fromMsg(msg) {
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if (msg == null) {
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return null;
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}
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if ("string" in msg) {
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return msg.string;
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}
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if ("ptr" in msg) {
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let address = ctypes.uintptr_t(msg.ptr);
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return this.cast(address);
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}
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throw new TypeError("Message " + msg.toSource() +
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" does not represent a pointer");
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};
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exports.OS.Shared.Type = Type;
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let Types = Type;
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/*
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* Some values are large integers on 64 bit platforms. Unfortunately,
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* in practice, 64 bit integers cannot be manipulated in JS. We
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* therefore project them to regular numbers whenever possible.
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*/
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let projectLargeInt = function projectLargeInt(x) {
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return parseInt(x.toString(), 10);
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};
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let projectLargeUInt = function projectLargeUInt(x) {
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return parseInt(x.toString(), 10);
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};
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let projectValue = function projectValue(x) {
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if (!(x instanceof ctypes.CData)) {
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return x;
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}
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if (!("value" in x)) { // Sanity check
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throw new TypeError("Number " + x.toSource() + " has no field |value|");
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}
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return x.value;
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};
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function projector(type, signed) {
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exports.OS.Shared.LOG("Determining best projection for", type,
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"(size: ", type.size, ")", signed?"signed":"unsigned");
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if (type instanceof Type) {
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type = type.implementation;
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}
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if (!type.size) {
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throw new TypeError("Argument is not a proper C type");
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}
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// Determine if type is projected to Int64/Uint64
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if (type.size == 8 // Usual case
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// The following cases have special treatment in js-ctypes
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// Regardless of their size, the value getter returns
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// a Int64/Uint64
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|| type == ctypes.size_t // Special cases
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|| type == ctypes.ssize_t
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|| type == ctypes.intptr_t
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|| type == ctypes.uintptr_t
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|| type == ctypes.off_t) {
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if (signed) {
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exports.OS.Shared.LOG("Projected as a large signed integer");
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return projectLargeInt;
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} else {
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exports.OS.Shared.LOG("Projected as a large unsigned integer");
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return projectLargeUInt;
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}
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}
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exports.OS.Shared.LOG("Projected as a regular number");
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return projectValue;
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};
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exports.OS.Shared.projectValue = projectValue;
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/**
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* Get the appropriate type for an unsigned int of the given size.
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*
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* This function is useful to define types such as |mode_t| whose
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* actual width depends on the OS/platform.
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*
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* @param {number} size The number of bytes requested.
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*/
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Types.uintn_t = function uintn_t(size) {
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switch (size) {
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case 1: return Types.uint8_t;
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case 2: return Types.uint16_t;
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case 4: return Types.uint32_t;
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case 8: return Types.uint64_t;
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default:
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throw new Error("Cannot represent unsigned integers of " + size + " bytes");
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}
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};
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/**
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* Get the appropriate type for an signed int of the given size.
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*
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* This function is useful to define types such as |mode_t| whose
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* actual width depends on the OS/platform.
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*
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* @param {number} size The number of bytes requested.
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*/
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Types.intn_t = function intn_t(size) {
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switch (size) {
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case 1: return Types.int8_t;
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case 2: return Types.int16_t;
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case 4: return Types.int32_t;
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case 8: return Types.int64_t;
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default:
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throw new Error("Cannot represent integers of " + size + " bytes");
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}
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};
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/**
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* Actual implementation of common C types.
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*/
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/**
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* The void value.
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*/
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Types.void_t =
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new Type("void",
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ctypes.void_t);
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/**
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* Shortcut for |void*|.
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*/
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Types.voidptr_t =
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new PtrType("void*",
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ctypes.voidptr_t,
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Types.void_t);
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// void* is a special case as we can cast any pointer to/from it
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// so we have to shortcut |in_ptr|/|out_ptr|/|inout_ptr| and
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// ensure that js-ctypes' casting mechanism is invoked directly
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["in_ptr", "out_ptr", "inout_ptr"].forEach(function(key) {
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Object.defineProperty(Types.void_t, key,
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{
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value: Types.voidptr_t
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});
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});
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/**
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* A Type of integers.
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*
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* @param {string} name The name of this type.
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* @param {CType} implementation The underlying js-ctypes implementation.
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* @param {bool} signed |true| if this is a type of signed integers,
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* |false| otherwise.
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*
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* @constructor
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*/
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function IntType(name, implementation, signed) {
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Type.call(this, name, implementation);
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this.importFromC = projector(implementation, signed);
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this.project = this.importFromC;
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};
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IntType.prototype = Object.create(Type.prototype);
|
|
IntType.prototype.toMsg = function toMsg(value) {
|
|
if (typeof value == "number") {
|
|
return value;
|
|
}
|
|
return this.project(value);
|
|
};
|
|
|
|
/**
|
|
* A C char (one byte)
|
|
*/
|
|
Types.char =
|
|
new Type("char",
|
|
ctypes.char);
|
|
|
|
/**
|
|
* A C wide char (two bytes)
|
|
*/
|
|
Types.jschar =
|
|
new Type("jschar",
|
|
ctypes.jschar);
|
|
|
|
/**
|
|
* Base string types.
|
|
*/
|
|
Types.cstring = Types.char.in_ptr.withName("[in] C string");
|
|
Types.wstring = Types.jschar.in_ptr.withName("[in] wide string");
|
|
Types.out_cstring = Types.char.out_ptr.withName("[out] C string");
|
|
Types.out_wstring = Types.jschar.out_ptr.withName("[out] wide string");
|
|
|
|
/**
|
|
* A C integer (8-bits).
|
|
*/
|
|
Types.int8_t =
|
|
new IntType("int8_t", ctypes.int8_t, true);
|
|
|
|
Types.uint8_t =
|
|
new IntType("uint8_t", ctypes.uint8_t, false);
|
|
|
|
/**
|
|
* A C integer (16-bits).
|
|
*
|
|
* Also known as WORD under Windows.
|
|
*/
|
|
Types.int16_t =
|
|
new IntType("int16_t", ctypes.int16_t, true);
|
|
|
|
Types.uint16_t =
|
|
new IntType("uint16_t", ctypes.uint16_t, false);
|
|
|
|
/**
|
|
* A C integer (32-bits).
|
|
*
|
|
* Also known as DWORD under Windows.
|
|
*/
|
|
Types.int32_t =
|
|
new IntType("int32_t", ctypes.int32_t, true);
|
|
|
|
Types.uint32_t =
|
|
new IntType("uint32_t", ctypes.uint32_t, false);
|
|
|
|
/**
|
|
* A C integer (64-bits).
|
|
*/
|
|
Types.int64_t =
|
|
new IntType("int64_t", ctypes.int64_t, true);
|
|
|
|
Types.uint64_t =
|
|
new IntType("uint64_t", ctypes.uint64_t, false);
|
|
|
|
/**
|
|
* A C integer
|
|
*
|
|
* Size depends on the platform.
|
|
*/
|
|
Types.int = Types.intn_t(ctypes.int.size).
|
|
withName("int");
|
|
|
|
Types.unsigned_int = Types.intn_t(ctypes.unsigned_int.size).
|
|
withName("unsigned int");
|
|
|
|
/**
|
|
* A C long integer.
|
|
*
|
|
* Size depends on the platform.
|
|
*/
|
|
Types.long =
|
|
Types.intn_t(ctypes.long.size).withName("long");
|
|
|
|
Types.unsigned_long =
|
|
Types.intn_t(ctypes.unsigned_long.size).withName("unsigned long");
|
|
|
|
/**
|
|
* An unsigned integer with the same size as a pointer.
|
|
*
|
|
* Used to cast a pointer to an integer, whenever necessary.
|
|
*/
|
|
Types.uintptr_t =
|
|
Types.uintn_t(ctypes.uintptr_t.size).withName("uintptr_t");
|
|
|
|
/**
|
|
* A boolean.
|
|
* Implemented as a C integer.
|
|
*/
|
|
Types.bool = Types.int.withName("bool");
|
|
Types.bool.importFromC = function projectBool(x) {
|
|
return !!(x.value);
|
|
};
|
|
|
|
/**
|
|
* A user identifier.
|
|
*
|
|
* Implemented as a C integer.
|
|
*/
|
|
Types.uid_t =
|
|
Types.int.withName("uid_t");
|
|
|
|
/**
|
|
* A group identifier.
|
|
*
|
|
* Implemented as a C integer.
|
|
*/
|
|
Types.gid_t =
|
|
Types.int.withName("gid_t");
|
|
|
|
/**
|
|
* An offset (positive or negative).
|
|
*
|
|
* Implemented as a C integer.
|
|
*/
|
|
Types.off_t =
|
|
new IntType("off_t", ctypes.off_t, true);
|
|
|
|
/**
|
|
* A size (positive).
|
|
*
|
|
* Implemented as a C size_t.
|
|
*/
|
|
Types.size_t =
|
|
new IntType("size_t", ctypes.size_t, false);
|
|
|
|
/**
|
|
* An offset (positive or negative).
|
|
* Implemented as a C integer.
|
|
*/
|
|
Types.ssize_t =
|
|
new IntType("ssize_t", ctypes.ssize_t, true);
|
|
|
|
/**
|
|
* Encoding/decoding strings
|
|
*/
|
|
Types.uencoder =
|
|
new Type("uencoder", ctypes.StructType("uencoder"));
|
|
Types.udecoder =
|
|
new Type("udecoder", ctypes.StructType("udecoder"));
|
|
|
|
/**
|
|
* Utility class, used to build a |struct| type
|
|
* from a set of field names, types and offsets.
|
|
*
|
|
* @param {string} name The name of the |struct| type.
|
|
* @param {number} size The total size of the |struct| type in bytes.
|
|
*/
|
|
function HollowStructure(name, size) {
|
|
if (!name) {
|
|
throw new TypeError("HollowStructure expects a name");
|
|
}
|
|
if (!size || size < 0) {
|
|
throw new TypeError("HollowStructure expects a (positive) size");
|
|
}
|
|
|
|
// A mapping from offsets in the struct to name/type pairs
|
|
// (or nothing if no field starts at that offset).
|
|
this.offset_to_field_info = [];
|
|
|
|
// The name of the struct
|
|
this.name = name;
|
|
|
|
// The size of the struct, in bytes
|
|
this.size = size;
|
|
|
|
// The number of paddings inserted so far.
|
|
// Used to give distinct names to padding fields.
|
|
this._paddings = 0;
|
|
}
|
|
HollowStructure.prototype = {
|
|
/**
|
|
* Add a field at a given offset.
|
|
*
|
|
* @param {number} offset The offset at which to insert the field.
|
|
* @param {string} name The name of the field.
|
|
* @param {CType|Type} type The type of the field.
|
|
*/
|
|
add_field_at: function add_field_at(offset, name, type) {
|
|
if (offset == null) {
|
|
throw new TypeError("add_field_at requires a non-null offset");
|
|
}
|
|
if (!name) {
|
|
throw new TypeError("add_field_at requires a non-null name");
|
|
}
|
|
if (!type) {
|
|
throw new TypeError("add_field_at requires a non-null type");
|
|
}
|
|
if (type instanceof Type) {
|
|
type = type.implementation;
|
|
}
|
|
if (this.offset_to_field_info[offset]) {
|
|
throw new Error("HollowStructure " + this.name +
|
|
" already has a field at offset " + offset);
|
|
}
|
|
if (offset + type.size > this.size) {
|
|
throw new Error("HollowStructure " + this.name +
|
|
" cannot place a value of type " + type +
|
|
" at offset " + offset +
|
|
" without exceeding its size of " + this.size);
|
|
}
|
|
let field = {name: name, type:type};
|
|
this.offset_to_field_info[offset] = field;
|
|
},
|
|
|
|
/**
|
|
* Create a pseudo-field that will only serve as padding.
|
|
*
|
|
* @param {number} size The number of bytes in the field.
|
|
* @return {Object} An association field-name => field-type,
|
|
* as expected by |ctypes.StructType|.
|
|
*/
|
|
_makePaddingField: function makePaddingField(size) {
|
|
let field = ({});
|
|
field["padding_" + this._paddings] =
|
|
ctypes.ArrayType(ctypes.uint8_t, size);
|
|
this._paddings++;
|
|
return field;
|
|
},
|
|
|
|
/**
|
|
* Convert this |HollowStructure| into a |Type|.
|
|
*/
|
|
getType: function getType() {
|
|
// Contents of the structure, in the format expected
|
|
// by ctypes.StructType.
|
|
let struct = [];
|
|
|
|
let i = 0;
|
|
while (i < this.size) {
|
|
let currentField = this.offset_to_field_info[i];
|
|
if (!currentField) {
|
|
// No field was specified at this offset, we need to
|
|
// introduce some padding.
|
|
|
|
// Firstly, determine how many bytes of padding
|
|
let padding_length = 1;
|
|
while (i + padding_length < this.size
|
|
&& !this.offset_to_field_info[i + padding_length]) {
|
|
++padding_length;
|
|
}
|
|
|
|
// Then add the padding
|
|
struct.push(this._makePaddingField(padding_length));
|
|
|
|
// And proceed
|
|
i += padding_length;
|
|
} else {
|
|
// We have a field at this offset.
|
|
|
|
// Firstly, ensure that we do not have two overlapping fields
|
|
for (let j = 1; j < currentField.type.size; ++j) {
|
|
let candidateField = this.offset_to_field_info[i + j];
|
|
if (candidateField) {
|
|
throw new Error("Fields " + currentField.name +
|
|
" and " + candidateField.name +
|
|
" overlap at position " + (i + j));
|
|
}
|
|
}
|
|
|
|
// Then add the field
|
|
let field = ({});
|
|
field[currentField.name] = currentField.type;
|
|
struct.push(field);
|
|
|
|
// And proceed
|
|
i += currentField.type.size;
|
|
}
|
|
}
|
|
let result = new Type(this.name, ctypes.StructType(this.name, struct));
|
|
if (result.implementation.size != this.size) {
|
|
throw new Error("Wrong size for type " + this.name +
|
|
": expected " + this.size +
|
|
", found " + result.implementation.size +
|
|
" (" + result.implementation.toSource() + ")");
|
|
}
|
|
return result;
|
|
}
|
|
};
|
|
exports.OS.Shared.HollowStructure = HollowStructure;
|
|
|
|
/**
|
|
* Declare a function through js-ctypes
|
|
*
|
|
* @param {ctypes.library} lib The ctypes library holding the function.
|
|
* @param {string} symbol The name of the function, as defined in the
|
|
* library.
|
|
* @param {ctypes.abi} abi The abi to use, or |null| for default.
|
|
* @param {Type} returnType The type of values returned by the function.
|
|
* @param {...Type} argTypes The type of arguments to the function.
|
|
*
|
|
* @return null if the function could not be defined (generally because
|
|
* it does not exist), or a JavaScript wrapper performing the call to C
|
|
* and any type conversion required.
|
|
*/// Note: Future versions will use a different implementation of this
|
|
// function on the main thread, osfile worker thread and regular worker
|
|
// thread
|
|
let declareFFI = function declareFFI(lib, symbol, abi,
|
|
returnType /*, argTypes ...*/) {
|
|
exports.OS.Shared.LOG("Attempting to declare FFI ", symbol);
|
|
// We guard agressively, to avoid any late surprise
|
|
if (typeof symbol != "string") {
|
|
throw new TypeError("declareFFI expects as first argument a string");
|
|
}
|
|
abi = abi || ctypes.default_abi;
|
|
if (Object.prototype.toString.call(abi) != "[object CABI]") {
|
|
// Note: This is the only known manner of checking whether an object
|
|
// is an abi.
|
|
throw new TypeError("declareFFI expects as second argument an abi or null");
|
|
}
|
|
if (!returnType.importFromC) {
|
|
throw new TypeError("declareFFI expects as third argument an instance of Type");
|
|
}
|
|
let signature = [symbol, abi];
|
|
let argtypes = [];
|
|
for (let i = 3; i < arguments.length; ++i) {
|
|
let current = arguments[i];
|
|
if (!current) {
|
|
throw new TypeError("Missing type for argument " + ( i - 3 ) +
|
|
" of symbol " + symbol);
|
|
}
|
|
if (!current.implementation) {
|
|
throw new TypeError("Missing implementation for argument " + (i - 3)
|
|
+ " of symbol " + symbol
|
|
+ " ( " + current.name + " )" );
|
|
}
|
|
signature.push(current.implementation);
|
|
}
|
|
try {
|
|
let fun = lib.declare.apply(lib, signature);
|
|
let result = function ffi(/*arguments*/) {
|
|
let result = fun.apply(fun, arguments);
|
|
return returnType.importFromC(result, symbol);
|
|
};
|
|
if (exports.OS.Shared.DEBUG) {
|
|
result.fun = fun; // Also return the raw FFI function.
|
|
}
|
|
exports.OS.Shared.LOG("Function", symbol, "declared");
|
|
return result;
|
|
} catch (x) {
|
|
// Note: Not being able to declare a function is normal.
|
|
// Some functions are OS (or OS version)-specific.
|
|
exports.OS.Shared.LOG("Could not declare function ", symbol, x);
|
|
return null;
|
|
}
|
|
};
|
|
exports.OS.Shared.declareFFI = declareFFI;
|
|
|
|
// A bogus array type used to perform pointer arithmetics
|
|
let gOffsetByType;
|
|
|
|
/**
|
|
* Advance a pointer by a number of items.
|
|
*
|
|
* This method implements adding an integer to a pointer in C.
|
|
*
|
|
* Example:
|
|
* // ptr is a uint16_t*,
|
|
* offsetBy(ptr, 3)
|
|
* // returns a uint16_t* with the address ptr + 3 * 2 bytes
|
|
*
|
|
* @param {C pointer} pointer The start pointer.
|
|
* @param {number} length The number of items to advance. Must not be
|
|
* negative.
|
|
*
|
|
* @return {C pointer} |pointer| advanced by |length| items
|
|
*/
|
|
exports.OS.Shared.offsetBy =
|
|
function offsetBy(pointer, length) {
|
|
if (length === undefined || length < 0) {
|
|
throw new TypeError("offsetBy expects a positive number");
|
|
}
|
|
if (!("isNull" in pointer)) {
|
|
throw new TypeError("offsetBy expects a pointer");
|
|
}
|
|
if (length == 0) {
|
|
return pointer;
|
|
}
|
|
let type = pointer.constructor;
|
|
let size = type.targetType.size;
|
|
if (size == 0 || size == null) {
|
|
throw new TypeError("offsetBy cannot be applied to a pointer without size");
|
|
}
|
|
let bytes = length * size;
|
|
if (!gOffsetByType || gOffsetByType.size <= bytes) {
|
|
gOffsetByType = ctypes.uint8_t.array(bytes * 2);
|
|
}
|
|
let addr = ctypes.cast(pointer, gOffsetByType.ptr).
|
|
contents.addressOfElement(bytes);
|
|
return ctypes.cast(addr, type);
|
|
};
|
|
|
|
// Encodings
|
|
|
|
})(this);
|
|
}
|