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+/* 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/. */
+
+var {classes: Cc, interfaces: Ci, utils: Cu, results: Cr} = Components;
+
+this.EXPORTED_SYMBOLS = ["CommonUtils"];
+
+Cu.import("resource://gre/modules/Promise.jsm");
+Cu.import("resource://gre/modules/Services.jsm");
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+Cu.import("resource://gre/modules/osfile.jsm")
+Cu.import("resource://gre/modules/Log.jsm");
+
+this.CommonUtils = {
+ /*
+ * Set manipulation methods. These should be lifted into toolkit, or added to
+ * `Set` itself.
+ */
+
+ /**
+ * Return elements of `a` or `b`.
+ */
+ union: function (a, b) {
+ let out = new Set(a);
+ for (let x of b) {
+ out.add(x);
+ }
+ return out;
+ },
+
+ /**
+ * Return elements of `a` that are not present in `b`.
+ */
+ difference: function (a, b) {
+ let out = new Set(a);
+ for (let x of b) {
+ out.delete(x);
+ }
+ return out;
+ },
+
+ /**
+ * Return elements of `a` that are also in `b`.
+ */
+ intersection: function (a, b) {
+ let out = new Set();
+ for (let x of a) {
+ if (b.has(x)) {
+ out.add(x);
+ }
+ }
+ return out;
+ },
+
+ /**
+ * Return true if `a` and `b` are the same size, and
+ * every element of `a` is in `b`.
+ */
+ setEqual: function (a, b) {
+ if (a.size != b.size) {
+ return false;
+ }
+ for (let x of a) {
+ if (!b.has(x)) {
+ return false;
+ }
+ }
+ return true;
+ },
+
+ /**
+ * Encode byte string as base64URL (RFC 4648).
+ *
+ * @param bytes
+ * (string) Raw byte string to encode.
+ * @param pad
+ * (bool) Whether to include padding characters (=). Defaults
+ * to true for historical reasons.
+ */
+ encodeBase64URL: function encodeBase64URL(bytes, pad=true) {
+ let s = btoa(bytes).replace(/\+/g, "-").replace(/\//g, "_");
+
+ if (!pad) {
+ return s.replace(/=+$/, "");
+ }
+
+ return s;
+ },
+
+ /**
+ * Create a nsIURI instance from a string.
+ */
+ makeURI: function makeURI(URIString) {
+ if (!URIString)
+ return null;
+ try {
+ return Services.io.newURI(URIString, null, null);
+ } catch (e) {
+ let log = Log.repository.getLogger("Common.Utils");
+ log.debug("Could not create URI", e);
+ return null;
+ }
+ },
+
+ /**
+ * Execute a function on the next event loop tick.
+ *
+ * @param callback
+ * Function to invoke.
+ * @param thisObj [optional]
+ * Object to bind the callback to.
+ */
+ nextTick: function nextTick(callback, thisObj) {
+ if (thisObj) {
+ callback = callback.bind(thisObj);
+ }
+ Services.tm.currentThread.dispatch(callback, Ci.nsIThread.DISPATCH_NORMAL);
+ },
+
+ /**
+ * Return a promise resolving on some later tick.
+ *
+ * This a wrapper around Promise.resolve() that prevents stack
+ * accumulation and prevents callers from accidentally relying on
+ * same-tick promise resolution.
+ */
+ laterTickResolvingPromise: function (value, prototype) {
+ let deferred = Promise.defer(prototype);
+ this.nextTick(deferred.resolve.bind(deferred, value));
+ return deferred.promise;
+ },
+
+ /**
+ * Spin the event loop and return once the next tick is executed.
+ *
+ * This is an evil function and should not be used in production code. It
+ * exists in this module for ease-of-use.
+ */
+ waitForNextTick: function waitForNextTick() {
+ let cb = Async.makeSyncCallback();
+ this.nextTick(cb);
+ Async.waitForSyncCallback(cb);
+
+ return;
+ },
+
+ /**
+ * Return a timer that is scheduled to call the callback after waiting the
+ * provided time or as soon as possible. The timer will be set as a property
+ * of the provided object with the given timer name.
+ */
+ namedTimer: function namedTimer(callback, wait, thisObj, name) {
+ if (!thisObj || !name) {
+ throw "You must provide both an object and a property name for the timer!";
+ }
+
+ // Delay an existing timer if it exists
+ if (name in thisObj && thisObj[name] instanceof Ci.nsITimer) {
+ thisObj[name].delay = wait;
+ return;
+ }
+
+ // Create a special timer that we can add extra properties
+ let timer = Object.create(Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer));
+
+ // Provide an easy way to clear out the timer
+ timer.clear = function() {
+ thisObj[name] = null;
+ timer.cancel();
+ };
+
+ // Initialize the timer with a smart callback
+ timer.initWithCallback({
+ notify: function notify() {
+ // Clear out the timer once it's been triggered
+ timer.clear();
+ callback.call(thisObj, timer);
+ }
+ }, wait, timer.TYPE_ONE_SHOT);
+
+ return thisObj[name] = timer;
+ },
+
+ encodeUTF8: function encodeUTF8(str) {
+ try {
+ str = this._utf8Converter.ConvertFromUnicode(str);
+ return str + this._utf8Converter.Finish();
+ } catch (ex) {
+ return null;
+ }
+ },
+
+ decodeUTF8: function decodeUTF8(str) {
+ try {
+ str = this._utf8Converter.ConvertToUnicode(str);
+ return str + this._utf8Converter.Finish();
+ } catch (ex) {
+ return null;
+ }
+ },
+
+ byteArrayToString: function byteArrayToString(bytes) {
+ return bytes.map(byte => String.fromCharCode(byte)).join("");
+ },
+
+ stringToByteArray: function stringToByteArray(bytesString) {
+ return Array.prototype.slice.call(bytesString).map(c => c.charCodeAt(0));
+ },
+
+ bytesAsHex: function bytesAsHex(bytes) {
+ return Array.prototype.slice.call(bytes).map(c => ("0" + c.charCodeAt(0).toString(16)).slice(-2)).join("");
+ },
+
+ stringAsHex: function stringAsHex(str) {
+ return CommonUtils.bytesAsHex(CommonUtils.encodeUTF8(str));
+ },
+
+ stringToBytes: function stringToBytes(str) {
+ return CommonUtils.hexToBytes(CommonUtils.stringAsHex(str));
+ },
+
+ hexToBytes: function hexToBytes(str) {
+ let bytes = [];
+ for (let i = 0; i < str.length - 1; i += 2) {
+ bytes.push(parseInt(str.substr(i, 2), 16));
+ }
+ return String.fromCharCode.apply(String, bytes);
+ },
+
+ hexAsString: function hexAsString(hex) {
+ return CommonUtils.decodeUTF8(CommonUtils.hexToBytes(hex));
+ },
+
+ /**
+ * Base32 encode (RFC 4648) a string
+ */
+ encodeBase32: function encodeBase32(bytes) {
+ const key = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";
+ let quanta = Math.floor(bytes.length / 5);
+ let leftover = bytes.length % 5;
+
+ // Pad the last quantum with zeros so the length is a multiple of 5.
+ if (leftover) {
+ quanta += 1;
+ for (let i = leftover; i < 5; i++)
+ bytes += "\0";
+ }
+
+ // Chop the string into quanta of 5 bytes (40 bits). Each quantum
+ // is turned into 8 characters from the 32 character base.
+ let ret = "";
+ for (let i = 0; i < bytes.length; i += 5) {
+ let c = Array.prototype.slice.call(bytes.slice(i, i + 5)).map(byte => byte.charCodeAt(0));
+ ret += key[c[0] >> 3]
+ + key[((c[0] << 2) & 0x1f) | (c[1] >> 6)]
+ + key[(c[1] >> 1) & 0x1f]
+ + key[((c[1] << 4) & 0x1f) | (c[2] >> 4)]
+ + key[((c[2] << 1) & 0x1f) | (c[3] >> 7)]
+ + key[(c[3] >> 2) & 0x1f]
+ + key[((c[3] << 3) & 0x1f) | (c[4] >> 5)]
+ + key[c[4] & 0x1f];
+ }
+
+ switch (leftover) {
+ case 1:
+ return ret.slice(0, -6) + "======";
+ case 2:
+ return ret.slice(0, -4) + "====";
+ case 3:
+ return ret.slice(0, -3) + "===";
+ case 4:
+ return ret.slice(0, -1) + "=";
+ default:
+ return ret;
+ }
+ },
+
+ /**
+ * Base32 decode (RFC 4648) a string.
+ */
+ decodeBase32: function decodeBase32(str) {
+ const key = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";
+
+ let padChar = str.indexOf("=");
+ let chars = (padChar == -1) ? str.length : padChar;
+ let bytes = Math.floor(chars * 5 / 8);
+ let blocks = Math.ceil(chars / 8);
+
+ // Process a chunk of 5 bytes / 8 characters.
+ // The processing of this is known in advance,
+ // so avoid arithmetic!
+ function processBlock(ret, cOffset, rOffset) {
+ let c, val;
+
+ // N.B., this relies on
+ // undefined | foo == foo.
+ function accumulate(val) {
+ ret[rOffset] |= val;
+ }
+
+ function advance() {
+ c = str[cOffset++];
+ if (!c || c == "" || c == "=") // Easier than range checking.
+ throw "Done"; // Will be caught far away.
+ val = key.indexOf(c);
+ if (val == -1)
+ throw "Unknown character in base32: " + c;
+ }
+
+ // Handle a left shift, restricted to bytes.
+ function left(octet, shift) {
+ return (octet << shift) & 0xff;
+ }
+
+ advance();
+ accumulate(left(val, 3));
+ advance();
+ accumulate(val >> 2);
+ ++rOffset;
+ accumulate(left(val, 6));
+ advance();
+ accumulate(left(val, 1));
+ advance();
+ accumulate(val >> 4);
+ ++rOffset;
+ accumulate(left(val, 4));
+ advance();
+ accumulate(val >> 1);
+ ++rOffset;
+ accumulate(left(val, 7));
+ advance();
+ accumulate(left(val, 2));
+ advance();
+ accumulate(val >> 3);
+ ++rOffset;
+ accumulate(left(val, 5));
+ advance();
+ accumulate(val);
+ ++rOffset;
+ }
+
+ // Our output. Define to be explicit (and maybe the compiler will be smart).
+ let ret = new Array(bytes);
+ let i = 0;
+ let cOff = 0;
+ let rOff = 0;
+
+ for (; i < blocks; ++i) {
+ try {
+ processBlock(ret, cOff, rOff);
+ } catch (ex) {
+ // Handle the detection of padding.
+ if (ex == "Done")
+ break;
+ throw ex;
+ }
+ cOff += 8;
+ rOff += 5;
+ }
+
+ // Slice in case our shift overflowed to the right.
+ return CommonUtils.byteArrayToString(ret.slice(0, bytes));
+ },
+
+ /**
+ * Trim excess padding from a Base64 string and atob().
+ *
+ * See bug 562431 comment 4.
+ */
+ safeAtoB: function safeAtoB(b64) {
+ let len = b64.length;
+ let over = len % 4;
+ return over ? atob(b64.substr(0, len - over)) : atob(b64);
+ },
+
+ /**
+ * Parses a JSON file from disk using OS.File and promises.
+ *
+ * @param path the file to read. Will be passed to `OS.File.read()`.
+ * @return a promise that resolves to the JSON contents of the named file.
+ */
+ readJSON: function(path) {
+ return OS.File.read(path, { encoding: "utf-8" }).then((data) => {
+ return JSON.parse(data);
+ });
+ },
+
+ /**
+ * Write a JSON object to the named file using OS.File and promises.
+ *
+ * @param contents a JS object. Will be serialized.
+ * @param path the path of the file to write.
+ * @return a promise, as produced by OS.File.writeAtomic.
+ */
+ writeJSON: function(contents, path) {
+ let data = JSON.stringify(contents);
+ return OS.File.writeAtomic(path, data, {encoding: "utf-8", tmpPath: path + ".tmp"});
+ },
+
+
+ /**
+ * Ensure that the specified value is defined in integer milliseconds since
+ * UNIX epoch.
+ *
+ * This throws an error if the value is not an integer, is negative, or looks
+ * like seconds, not milliseconds.
+ *
+ * If the value is null or 0, no exception is raised.
+ *
+ * @param value
+ * Value to validate.
+ */
+ ensureMillisecondsTimestamp: function ensureMillisecondsTimestamp(value) {
+ if (!value) {
+ return;
+ }
+
+ if (!/^[0-9]+$/.test(value)) {
+ throw new Error("Timestamp value is not a positive integer: " + value);
+ }
+
+ let intValue = parseInt(value, 10);
+
+ if (!intValue) {
+ return;
+ }
+
+ // Catch what looks like seconds, not milliseconds.
+ if (intValue < 10000000000) {
+ throw new Error("Timestamp appears to be in seconds: " + intValue);
+ }
+ },
+
+ /**
+ * Read bytes from an nsIInputStream into a string.
+ *
+ * @param stream
+ * (nsIInputStream) Stream to read from.
+ * @param count
+ * (number) Integer number of bytes to read. If not defined, or
+ * 0, all available input is read.
+ */
+ readBytesFromInputStream: function readBytesFromInputStream(stream, count) {
+ let BinaryInputStream = Components.Constructor(
+ "@mozilla.org/binaryinputstream;1",
+ "nsIBinaryInputStream",
+ "setInputStream");
+ if (!count) {
+ count = stream.available();
+ }
+
+ return new BinaryInputStream(stream).readBytes(count);
+ },
+
+ /**
+ * Generate a new UUID using nsIUUIDGenerator.
+ *
+ * Example value: "1e00a2e2-1570-443e-bf5e-000354124234"
+ *
+ * @return string A hex-formatted UUID string.
+ */
+ generateUUID: function generateUUID() {
+ let uuid = Cc["@mozilla.org/uuid-generator;1"]
+ .getService(Ci.nsIUUIDGenerator)
+ .generateUUID()
+ .toString();
+
+ return uuid.substring(1, uuid.length - 1);
+ },
+
+ /**
+ * Obtain an epoch value from a preference.
+ *
+ * This reads a string preference and returns an integer. The string
+ * preference is expected to contain the integer milliseconds since epoch.
+ * For best results, only read preferences that have been saved with
+ * setDatePref().
+ *
+ * We need to store times as strings because integer preferences are only
+ * 32 bits and likely overflow most dates.
+ *
+ * If the pref contains a non-integer value, the specified default value will
+ * be returned.
+ *
+ * @param branch
+ * (Preferences) Branch from which to retrieve preference.
+ * @param pref
+ * (string) The preference to read from.
+ * @param def
+ * (Number) The default value to use if the preference is not defined.
+ * @param log
+ * (Log.Logger) Logger to write warnings to.
+ */
+ getEpochPref: function getEpochPref(branch, pref, def=0, log=null) {
+ if (!Number.isInteger(def)) {
+ throw new Error("Default value is not a number: " + def);
+ }
+
+ let valueStr = branch.get(pref, null);
+
+ if (valueStr !== null) {
+ let valueInt = parseInt(valueStr, 10);
+ if (Number.isNaN(valueInt)) {
+ if (log) {
+ log.warn("Preference value is not an integer. Using default. " +
+ pref + "=" + valueStr + " -> " + def);
+ }
+
+ return def;
+ }
+
+ return valueInt;
+ }
+
+ return def;
+ },
+
+ /**
+ * Obtain a Date from a preference.
+ *
+ * This is a wrapper around getEpochPref. It converts the value to a Date
+ * instance and performs simple range checking.
+ *
+ * The range checking ensures the date is newer than the oldestYear
+ * parameter.
+ *
+ * @param branch
+ * (Preferences) Branch from which to read preference.
+ * @param pref
+ * (string) The preference from which to read.
+ * @param def
+ * (Number) The default value (in milliseconds) if the preference is
+ * not defined or invalid.
+ * @param log
+ * (Log.Logger) Logger to write warnings to.
+ * @param oldestYear
+ * (Number) Oldest year to accept in read values.
+ */
+ getDatePref: function getDatePref(branch, pref, def=0, log=null,
+ oldestYear=2010) {
+
+ let valueInt = this.getEpochPref(branch, pref, def, log);
+ let date = new Date(valueInt);
+
+ if (valueInt == def || date.getFullYear() >= oldestYear) {
+ return date;
+ }
+
+ if (log) {
+ log.warn("Unexpected old date seen in pref. Returning default: " +
+ pref + "=" + date + " -> " + def);
+ }
+
+ return new Date(def);
+ },
+
+ /**
+ * Store a Date in a preference.
+ *
+ * This is the opposite of getDatePref(). The same notes apply.
+ *
+ * If the range check fails, an Error will be thrown instead of a default
+ * value silently being used.
+ *
+ * @param branch
+ * (Preference) Branch from which to read preference.
+ * @param pref
+ * (string) Name of preference to write to.
+ * @param date
+ * (Date) The value to save.
+ * @param oldestYear
+ * (Number) The oldest year to accept for values.
+ */
+ setDatePref: function setDatePref(branch, pref, date, oldestYear=2010) {
+ if (date.getFullYear() < oldestYear) {
+ throw new Error("Trying to set " + pref + " to a very old time: " +
+ date + ". The current time is " + new Date() +
+ ". Is the system clock wrong?");
+ }
+
+ branch.set(pref, "" + date.getTime());
+ },
+
+ /**
+ * Convert a string between two encodings.
+ *
+ * Output is only guaranteed if the input stream is composed of octets. If
+ * the input string has characters with values larger than 255, data loss
+ * will occur.
+ *
+ * The returned string is guaranteed to consist of character codes no greater
+ * than 255.
+ *
+ * @param s
+ * (string) The source string to convert.
+ * @param source
+ * (string) The current encoding of the string.
+ * @param dest
+ * (string) The target encoding of the string.
+ *
+ * @return string
+ */
+ convertString: function convertString(s, source, dest) {
+ if (!s) {
+ throw new Error("Input string must be defined.");
+ }
+
+ let is = Cc["@mozilla.org/io/string-input-stream;1"]
+ .createInstance(Ci.nsIStringInputStream);
+ is.setData(s, s.length);
+
+ let listener = Cc["@mozilla.org/network/stream-loader;1"]
+ .createInstance(Ci.nsIStreamLoader);
+
+ let result;
+
+ listener.init({
+ onStreamComplete: function onStreamComplete(loader, context, status,
+ length, data) {
+ result = String.fromCharCode.apply(this, data);
+ },
+ });
+
+ let converter = this._converterService.asyncConvertData(source, dest,
+ listener, null);
+ converter.onStartRequest(null, null);
+ converter.onDataAvailable(null, null, is, 0, s.length);
+ converter.onStopRequest(null, null, null);
+
+ return result;
+ },
+};
+
+XPCOMUtils.defineLazyGetter(CommonUtils, "_utf8Converter", function() {
+ let converter = Cc["@mozilla.org/intl/scriptableunicodeconverter"]
+ .createInstance(Ci.nsIScriptableUnicodeConverter);
+ converter.charset = "UTF-8";
+ return converter;
+});
+
+XPCOMUtils.defineLazyGetter(CommonUtils, "_converterService", function() {
+ return Cc["@mozilla.org/streamConverters;1"]
+ .getService(Ci.nsIStreamConverterService);
+});
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