How B2G talk to lower layer

2018-09-05

Android hardware abstraction layer (HAL)

gecko/hal/gonk/GonkHal.cpp
gecko/dom/system/gonk/GonkGPSGelocationProvider.cpp
gecko/dom/camera/GonkCameraManager.cpp
Use hw_get_module Android HAL layer Interface
http://emb.hqyj.com/Column/Column733.htm

Unix domain socket

rilproxy/src/rilproxy.c
Use socket_local_server connect to rilproxy socket

Remote Procedure Call(RPC) / binder

gecko/dom/system/gonk/AudioManager.cpp
gecko/media/libsydneyaudio/src/gonk/AudioSystem.h
frameworks/base/media/libmedia/AudioSystem.cpp
Use binder = sm->getService()
https://blog.csdn.net/freekiteyu/article/details/70082302

Use ‘proc’ , ‘system’ file system

gecko/hal/gonk/GonkHal.cpp
Use fopen to open battery file node

Shared library

gecko/dom/wifi/libhardware_legacy.js
ctypes.open(“libhardware_legacy.so”);
https://developer.mozilla.org/zh-CN/docs/Mozilla/js-ctypes/Using_js-ctypes

System call

gecko/hal/gonk/GonkHal.cpp
Use syscall of Linux

gecko/hal/linux/LinuxPower.cpp
Use reboot of Linux
https://blog.csdn.net/qingkongyeyue/article/details/71597783

展开全文 >>

ES6 let/const/解构赋值/模版字符串

2018-04-19

let

它声明的变量只在let命令所在的代码块内有效。代码块由{}表示。
相较于var不存在变量提升。(undefined, ReferenceError)
let命令声明变量之前，该变量都是不可用的。(暂时性死区)
块级作用域内不允许重复声明

const

声明一个只读常量。
声明需要立即初始化。
只在声明的块级作用域内有效
存在暂时性死区
块级作用域内不允许重复声明

解构赋值

解构成功
1
let [a, b, c] = [1, 2, 3];
解构不成功

1	let [bar, foo] = [1];

不完全解构

1	let [x, y] = [1, 2, 3];

只要某种数据结构具有 Iterator 接口，都可以采用数组形式的解构赋值。

允许默认值

1 2	let [x, y = 'b'] = ['a', undefined]; // x='a', y='b', 必须严格等于undfined

对象解构：对象的属性没有次序，变量必须与属性同名，才能取到正确的值
用途：
- 交换变量的值
- 从函数返回多个值
- 函数参数的定义
- 提取 JSON 数据
- 函数参数的默认值
- 遍历 Map 结构
- 输入模块的指定方法
字符串拓展
模板字符串（template string）是增强版的字符串，用反引号（`）标识。它可以当作普通字符串使用，也可以用来定义多行字符串，或者在字符串中嵌入变量。
1
2
3
4
5
$('#result').append(`
There are <b>${basket.count}</b> items
in your basket, <em>${basket.onSale}</em>
are on sale!
`);
charAt()/at() 前者不能识别大于码点大于0xffff的字符，后者可以。
includes()/startsWith()/endsWith() 作用与indexOf类似，判断是否包含字符串/以目标字串开始/以目标字串结束

展开全文 >>

What is HTML5

2018-04-17

HTML5：HTML5 是定义 HTML 标准的最新的版本。该术语表示两个不同的概念：

它是一个新版本的HTML语言，具有新的元素，属性和行为，
它有更大的技术集，允许更多样化和强大的网站和应用程序。这个集合有时称为HTML5和朋友，通常缩写为HTML5

文件类型声明只有<!DOCTYPE HTML>
相对之前版本新增、移除一些标签（移除center、font 等,新增nav、footer等）
Accessibility（无障碍）
新的API:
- Geolocation: navigator.geolocation.getCurrentPosition(callback)
- Drag and Drop
- Local Storage
- Web Workers: 是运行在后台的 JavaScript，独立于其他脚本，不会影响页面的性能。
- SSE: SSE（Server-Sent Events，服务器发送事件）就是浏览器向服务器发送一个HTTP请求，然后服务器不断单向地向浏览器推送“信息”。
- Canvas/WebGL
- Audio/Video

展开全文 >>

Algorithms part 1

2018-01-12

数据结构：便于算法操作的组织数据的方法
基础编程模型
数据抽象
抽象数据类型
- 背包
- 队列
- 栈
经典的 union-find 抽象数据结构

欧几里得算法（找最大公约数）

自然语言描述：

1	计算两个非负整数p和q的最大公约数：若q是0，则最大公约数为p。否则将p除以q得到余数r，p和q的最大公约数即为q和r的最大公约数。

JavaScript语言描述

// p, q 为非负整数
function gcd(p, q) {
  if (q === 0) {
    return p;
  }
  
  let r = p % q;
  return gcd(q, r);
}

展开全文 >>

Professional Javascript part 1

2018-01-11

JS组成

ECMAScript，提供核心语言功能
DOM，提供访问和操作网页内容的方法和接口
BOM，提供和浏览器交互的方法

script 标签

延时脚本，defer属性：可以让脚本在文档完全呈现之后再执行，总是按照顺序执行。
异步脚本，async属性：表示当前脚本不必等待其他脚本，也不必阻塞文档的呈现，且不保证异步的脚本按照它们在页面中出现的顺序执行。

文档模式

HTML5: <!DOCTYPE html>
其他模式

语法

区分大小写
标识符：第一个字符必须是一个字母／下划线／美元符号，采用驼峰大小写格式
严格模式：
1
'use strict';

数据类型

Undefined
Null
Boolean
string
Number
Object

展开全文 >>

Gaia Makefile

2017-12-04

Makefile

https://github.com/zwts/gaia/blob/v2.2/Makefile

Makefile 基础语法入门：
http://www.ruanyifeng.com/blog/2015/02/make.html

注释内容

Global configrations
1. GAIA_DOMAIN
2. SYSTEM
3. ADB
4. DEBUG
5. REPORTER
6. MOZPREFOUT: File path to output mozperf data. Empty mean stdout.
7. MARIONETTE_RUNNER_HOST
8. COVERAGE
9. GAIA_APP_CONFIG
Lint code
1. make hint
2. make gjslint
3. make lint
B2G Desktop
1. USE_LOCAL_XULRUNNER_SDK
2. XULRUNNER_DIRECTORY

正文

MAKEFLAGS=-r
- -r禁止使用build-in规则
- https://www.gnu.org/software/make/manual/make.html#Implicit-Rules
REBUILD
- GAIA_DISTRIBUTION_DIR
- LOCALE_BASEDIR
- LOCALES_FILE
- 上述参数定义/改变的情况下，需要rebuild(具体rebuild操作gaia/build/rebuild.js)
WGET_OPTS?=-c -nv wget参数
DEVICE_DEBUG?=0 是否默认打开设备可调试
NO_LOCK_SCREEN?=0 是否默认打开锁屏
SCREEN_TIMEOUT?=-1 是否打开屏幕超时
PRODUCTION?=0 区别编译user/userdebug/eng版本，PRODUCTION is also set for user and userdebug B2G builds(PRODUCTION=1)
GAIA_OPTIMIZE?=0
webpp-optimize will do below things：
1. Inline embeded html from into html and commented(<!–CONTENT–>).
2. Concat l10n resource to json files and put them as link and attach to html.
3. Aggregate and uglify all JS files used in html to one JS file.
4. Optimize inline JS/CSS content.
GAIA_DEV_PIXELS_PER_PX?=1
P?=1 Parallel build for multicores CPU
GAIA_DPPX Alias of GAIA_DEV_PIXELS_PER_PX
DOGFOOD?=0dogfood测试，零时版本？会影响：
- PRODUCTION
- GAIA_APP_TARGET=dogfood
- BUILD_CONFIG
NODE_MODULES_SRC
- git-gaia-node-modules
- modules.tar
NODE_MODULES_CACHEDIR=modules_tar_cachedir
GAIA_DEVICE_TYPE?=phone device type customization
1. phone - default
2. tablet
3. tv
TEST_AGENT_PORT?=8789 use for:
1. .PHONY: test-agent-server(.PHONY 声明伪目标，每次都执行，而不去监测是否存在目标文件)
2. .PHONY: test-agent-test
GAIA_APP_TARGET?=engineering
use for build app list:
1. 路径为gaia/build/config/phone/app-engineer.list
2. GAIA_APP_CONFIG=$(GAIA_DIR)$(SEP)build$(SEP)config$(SEP)$(GAIA_DEVICE_TYPE)$(SEP)apps-$(GAIA_APP_TARGET).list (Makefile line:350)
DESKTOP?=$(DEBUG) Enable compatibility to run in Firefox Desktop
NOFTU?=0 Disable first time experience screen 去掉开机设置向导相关内容
NOFTUPING?=0 Disable first time ping
FTU_PING_URL?=https://fxos.telemetry.mozilla.org/submit/telemetry if NOFTUPING = 0
REMOTE_DEBUGGER?=0 Automatically enable remote debugger
BUILD_DEBUG?=0 Debug mode for build process
RAPTOR?=0 Are we building for RAPTOR?
Raptor是一种可视化的程序设计环境，为程序和算法设计的基础课程的教学提供实验环境。使用RAPTOR设计的程序和算法可以直接转换成为C++、C#、Java等高级程序语言
SHARE_PERF_USAGE?=1 Share performance and usage data
PROFILE_FOLDER
1. profile(default)
2. profile-debug(firefox Desktop/debug mode)
3. profile-test(test-integration)
STAGE_DIR gaia/build_stage
LOCAL_DOMAINS
ADB?=adb 定义adb工具
SCHEME [skim] app://
SYSTEM system application url: app://system.gaiamobile.org
BUILD_APP_NAME
正在编译的APP名字,可以在编译的时候在参数中用APP=ftu来指定
BUILDAPP?=desktop BUILDAPP variable defines the target b2g platform (eg desktop, device)
and exports it for the gaia-marionette script
https://www.blackglory.me/experience-firefox-os/
npm_config_loglevel=warn Ensure that NPM only logs warnings and errors
REPORTER
- mocha-tbpl-reporter
- spec
MARIONETTE_RUNNER_HOST
- marionette-socket-host
- marionette-b2gdesktop-host
MAKECMDGOALS make 在执行时会设置一个特殊变量 – “MAKECMDGOALS” ，该变量记录了命令行参数指定的终极目标列表，没有通过参数指定终极目标时此变量为空。该变量仅限于用在特殊场合(比如判断)，在 Makefile 中最好不要对它进行重新定义。
- demo
- dogfood
- production
- test-integration
GAIA_PORT?=:8080 In debug mode the offline cache is not used (even if it is generated) and
Gaia is loaded by a built-in web server via port GAIA_PORT.
SHELL := /bin/bash Force bash for all shell commands since we depend on bash-specific syntax
GAIA_DIR := $(CURDIR) CURDIR是make的内嵌变量，自动设置为当前目录
SYS=$(shell uname -s)
ARCH?=$(shell uname -m) what OS are we on?

Configuration for pre-built or already downloaded b2g (or alternative)

USE_LOCAL_XULRUNNER_SDK
XULRUNNER_DIRECTORY
XPCSHELL_GUESS Some guesswork to figure out where the xpcshell binary really is

XPCSHELL_GUESS = $(firstword $(wildcard \
    $(XULRUNNER_DIRECTORY)/B2G.app/Contents/MacOS/xpcshell \
    $(XULRUNNER_DIRECTORY)/bin/XUL.framework/Versions/Current/xpcshell \
    $(XULRUNNER_DIRECTORY)/bin/xpcshell* \
    $(XULRUNNER_DIRECTORY)/b2g/xpcshell* \
  ))

XPCSHELLSDK
XPCSHELL_GUESS => xpcshell
XULRUNNERSDK
XPCSHELLSDK/run-mozilla.sh

Configuration for a downloaded b2g desktop

B2G_SDK_VERSION
B2G_SDK_DATE
XULRUNNER_BASE_DIR b2g_sdk
XULRUNNER_DIRECTORY

GAIA_DISTRIBUTION_DIR

1 2	GAIA_DISTRIBUTION_DIR := $(shell pushd $(GAIA_DISTRIBUTION_DIR) > /dev/null; \ pwd -W \| sed 's\|/\|\\\\\|g'; popd > /dev/null;)

SETTINGS_PATH build/config/custom-settings.json
KEYBOARD_LAYOUTS_PATH build/config/keyboard-layouts.json
CONTACTS_IMPORT_SERVICES_PATH build/config/communications_services.json
EMAIL_SERVICES_PATH
GAIA_APP_SRCDIRS
GAIA_LOCALES_PATH locales
LOCALES_FILE shared/resources/languages.json
GAIA_LOCALE_SRCDIRS $(GAIA_DIR)$(SEP)shared $(GAIA_APPDIRS)
GAIA_DEFAULT_LOCALE en-US
GAIA_PRETRANSLATE
GAIA_CONCAT_LOCALES
MD5SUM md5sum -b
SED_INPLACE_NO_SUFFIX sed -i
DOWNLOAD_CMD wget $(WGET_OPTS)
TAR_WILDCARDS tar –wildcards
Test agent
- TEST_AGENT_CONFIG
- TEST_AGENT_COVERAGE
- TEST_COMMON
- NODEJS
- NPM
Marionette testing variables
- make sure we’re python 2.7.x
- MARIONETTE_HOST ?= localhost
- MARIONETTE_PORT ?= 2828
BUILD_CONFIG
Generate profile
- target: PROFILE_FOLDER
- need:
  - profile-dir: @test -d $(PROFILE_FOLDER) || mkdir -p $(PROFILE_FOLDER)
  - build-app @$(call run-js-command,update-webapps-json)
  - test-agent-config
  - contacts
  - extensions
  - b2g_sdk
  - .git/hooks/pre-commit

展开全文 >>

FFOS Part 3

2017-12-01

Gecko

XPCOM

Cross Platform Component Object Model; A framework which allows developers to break up monolithic software projects into smaller modularized pieces
Provide:
1. component management
2. object message passing
3. memory management
nsISupports(?)
CID: 128-bit number that uniquely identifies a class or component.{ 0x777f7150, 0x4a2b, 0x4301, 0xad, 0x10, 0x5e, 0xab, 0x25, 0xb3, 0x22, 0xaa}
IID: 128-bit number that uniquely identifies an interface
Contract ID: human readable string used to access a component."@mozilla.org/network/ldap-operation;1"
Expections(?): All interface methods should return an nsresult error value

Create XPCOM Component

https://developer.mozilla.org/en-US/docs/Mozilla/Tech/XPCOM/Guide/Creating_components

XPConnect

The bridge between XPCOM and JS(?)

XPIDL

An Interface Description Language used to specify XPCOM interface classes
Some examples are in the gecko/xpcom/base and geckoxpcom/ds directories

xpidl

A tool
For generating XPCOM interface information
1. c++ headers
2. type library files(.xpt): type library is the binary representation of interfaces.类型lib库(.xpt文件)，是用接口类文件生成的二进制的文件。

xptcall

A small low level XPCOM method call library.
The code is at: gecko/xpcom/reflect/xptcall
xptcall exists for two reasons:
1. To support invoking arbitrary methods on XPCOM interfaces.
2. To support dynamically impersonating any XPCOM interface.

Non-blocking IO(?)

There is an IO thread in gecko. You can check RilClient in gecko/ipc/ril/Ril.cpp

Code Directory Structure

https://developer.mozilla.org/en-US/docs/Mozilla/Developer_guide/Source_Code/Directory_structure

展开全文 >>

FFOS Part 2

2017-11-30

Gaia

XUL

XML User Interface Language, a cross-platform language for description applications’ user interface.
https://developer.mozilla.org/en-US/docs/XUL_Tutorial

XULRunner

XULRunner deploys XUL applications.
https://developer.mozilla.org/en-US/docs/XULRunner

shell.xul

An entry point of Gaia, brings system APP up.
gecko/b2g/chrome/content/shell.xul

System app

System app is the parent frame that create and destroy iframes to launch or stop other web apps.

API: mozSettings

get
set
observer

How app to launch

Get app reference from mozApps API, and call app.launch()
Gecko receives request, then fire mozChromeEvent to System with launching APP detail
System handle event, then insert iframe into it’s DOM
App load index.html in iframe

Write test case in Gaia

https://github.com/mozilla-b2g/gaia/#tests
Unit Tests, https://developer.mozilla.org/en/Mozilla/Boot_to_Gecko/Gaia_Unit_Tests
Integration Test, https://developer.mozilla.org/en-US/docs/Mozilla/Firefox_OS/Automated_testing/Gaia_integration_tests
Provide APIs: suite(), test(), setup(), teardown()

展开全文 >>

Android hardware abstraction layer (HAL)

Unix domain socket

Remote Procedure Call(RPC) / binder

Use ‘proc’ , ‘system’ file system

Shared library

System call

let

const

解构赋值

字符串拓展

欧几里得算法（找最大公约数）

JS组成

script 标签

文档模式

语法

数据类型

Makefile

Gecko

Gaia