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Diffstat (limited to 'mobile/android/modules/AndroidLog.jsm')
| -rw-r--r-- | mobile/android/modules/AndroidLog.jsm | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/mobile/android/modules/AndroidLog.jsm b/mobile/android/modules/AndroidLog.jsm new file mode 100644 index 000000000..be6cca4e8 --- /dev/null +++ b/mobile/android/modules/AndroidLog.jsm @@ -0,0 +1,92 @@ +/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- + * 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/. */ +"use strict"; + +/** + * Native Android logging for JavaScript. Lets you specify a priority and tag + * in addition to the message being logged. Resembles the android.util.Log API + * <http://developer.android.com/reference/android/util/Log.html>. + * + * // Import it as a JSM: + * let Log = Cu.import("resource://gre/modules/AndroidLog.jsm", {}).AndroidLog; + * + * // Or require it in a chrome worker: + * importScripts("resource://gre/modules/workers/require.js"); + * let Log = require("resource://gre/modules/AndroidLog.jsm"); + * + * // Use Log.i, Log.v, Log.d, Log.w, and Log.e to log verbose, debug, info, + * // warning, and error messages, respectively. + * Log.v("MyModule", "This is a verbose message."); + * Log.d("MyModule", "This is a debug message."); + * Log.i("MyModule", "This is an info message."); + * Log.w("MyModule", "This is a warning message."); + * Log.e("MyModule", "This is an error message."); + * + * // Bind a function with a tag to replace a bespoke dump/log/debug function: + * let debug = Log.d.bind(null, "MyModule"); + * debug("This is a debug message."); + * // Outputs "D/GeckoMyModule(#####): This is a debug message." + * + * // Or "bind" the module object to a tag to automatically tag messages: + * Log = Log.bind("MyModule"); + * Log.d("This is a debug message."); + * // Outputs "D/GeckoMyModule(#####): This is a debug message." + * + * Note: the module automatically prepends "Gecko" to the tag you specify, + * since all tags used by Fennec code should start with that string; and it + * truncates tags longer than MAX_TAG_LENGTH characters (not including "Gecko"). + */ + +if (typeof Components != "undefined") { + // Specify exported symbols for JSM module loader. + this.EXPORTED_SYMBOLS = ["AndroidLog"]; + Components.utils.import("resource://gre/modules/ctypes.jsm"); +} + +// From <https://android.googlesource.com/platform/system/core/+/master/include/android/log.h>. +const ANDROID_LOG_VERBOSE = 2; +const ANDROID_LOG_DEBUG = 3; +const ANDROID_LOG_INFO = 4; +const ANDROID_LOG_WARN = 5; +const ANDROID_LOG_ERROR = 6; + +// android.util.Log.isLoggable throws IllegalArgumentException if a tag length +// exceeds 23 characters, and we prepend five characters ("Gecko") to every tag, +// so we truncate tags exceeding 18 characters (although __android_log_write +// itself and other android.util.Log methods don't seem to mind longer tags). +const MAX_TAG_LENGTH = 18; + +var liblog = ctypes.open("liblog.so"); // /system/lib/liblog.so +var __android_log_write = liblog.declare("__android_log_write", + ctypes.default_abi, + ctypes.int, // return value: num bytes logged + ctypes.int, // priority (ANDROID_LOG_* constant) + ctypes.char.ptr, // tag + ctypes.char.ptr); // message + +var AndroidLog = { + MAX_TAG_LENGTH: MAX_TAG_LENGTH, + v: (tag, msg) => __android_log_write(ANDROID_LOG_VERBOSE, "Gecko" + tag.substring(0, MAX_TAG_LENGTH), msg), + d: (tag, msg) => __android_log_write(ANDROID_LOG_DEBUG, "Gecko" + tag.substring(0, MAX_TAG_LENGTH), msg), + i: (tag, msg) => __android_log_write(ANDROID_LOG_INFO, "Gecko" + tag.substring(0, MAX_TAG_LENGTH), msg), + w: (tag, msg) => __android_log_write(ANDROID_LOG_WARN, "Gecko" + tag.substring(0, MAX_TAG_LENGTH), msg), + e: (tag, msg) => __android_log_write(ANDROID_LOG_ERROR, "Gecko" + tag.substring(0, MAX_TAG_LENGTH), msg), + + bind: function(tag) { + return { + MAX_TAG_LENGTH: MAX_TAG_LENGTH, + v: AndroidLog.v.bind(null, tag), + d: AndroidLog.d.bind(null, tag), + i: AndroidLog.i.bind(null, tag), + w: AndroidLog.w.bind(null, tag), + e: AndroidLog.e.bind(null, tag), + }; + }, +}; + +if (typeof Components == "undefined") { + // Specify exported symbols for require.js module loader. + module.exports = AndroidLog; +} |