CocoaPods - 源码篇

前言

由于项目里业务线很多，集成了很多第三方pod库 和 私有pod库，整个pod project体积非常大。默认的Xcode 编译行为寻找依赖的project进行编译，并且是并行的。



我们做了如下改动，加快主工程编译速度：

.去除了主工程对 Pods target的依赖编译
.取消上面两个勾选
.在 Manage Scheme 里勾选了Pods project，以便于可以手动选择 Pods project进行编译

如果对Pods库更改了，我们可以手动选择 Pods Scheme 进行编译，然后再编译主工程，这样避免Pods不必要编译。

问题

每次pod install之后，pods scheme 自动消失了，我们找到 xcschememanagement.plist文件

cd demo/Pods/Pods.xcodeproj/xcuserdata/Green.xcuserdatad/xcschemescat xcschememanagement.plist# 输出<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"><plist version="1.0"><dict><key>SchemeUserState</key><dict>    <key>Pods.xcscheme</key>    <dict>        <key>isShown</key>        <false/>    </dict>...

可以看到：Pods.xcscheme isShown 是 false，这样导致scheme 中没有Pods。

Pod Install 剖析

我们来看看 CocoaPods 源码

cd /Library/Ruby/Gems/2.0.0/gems/#这里有很多版本，我们只看0.38.2

当我们执行 pod install，其实调用到Installer对象，

#文件位置：`cocoapods-0.38.2/lib/cocoapods/command/project.rb`#初始化 Installer 对象       def run_install_with_update(update)    installer = Installer.new(config.sandbox, config.podfile, config.lockfile)    installer.update = update    #install 方法    installer.install!  endend

install!

#文件位置：`cocoapods-0.38.2/lib/cocoapods/installer.rb`文件，  #install 方法def install!  prepare  resolve_dependencies  #下载依赖  download_dependencies  determine_dependency_product_types  verify_no_duplicate_framework_names  verify_no_static_framework_transitive_dependencies  verify_framework_usage  #合成 pods project  generate_pods_project  integrate_user_project if config.integrate_targets?  perform_post_install_actionsend

download_dependencies

#下载pods 资源def download_dependencies  UI.section 'Downloading dependencies' do    create_file_accessors    install_pod_sources    run_podfile_pre_install_hooks    clean_pod_sources  endend

generate_pods_project

#合成 pods projectdef generate_pods_project  UI.section 'Generating Pods project' do    prepare_pods_project    install_file_references    install_libraries    set_target_dependencies    #执行Podfile 的post_install 代码块    run_podfile_post_install_hooks    #重新写入pod project，就是在这里修改了所有`pod.xcscheme` 的`isShown`为false    write_pod_project    share_development_pod_schemes    write_lockfiles  endend

run post_install

#执行Podfile 的post_install 代码块def run_podfile_post_install_hooks  UI.message '- Running post install hooks' do    executed = run_podfile_post_install_hook    UI.message '- Podfile' if executed  endenddef run_podfile_post_install_hook    #执行 post_install，这个代码块（block）可以在Podfile里指定  podfile.post_install!(self)rescue => e  raise Informative, 'An error occurred while processing the post-install ' \    'hook of the Podfile.' \    "\n\n#{e.message}\n\n#{e.backtrace * "\n"}"end

post_install

我们经常在 Podfile 里设置 @post_install 代码块:

#文件位置：`cocoapods-core-0.38.2/lib/cocoapods-core/podfile/dsl.rb` 文件  def post_install(&block)    @post_install_callback = block  end    

write_pod_project

# 重新写入pod project，就是在这里修改了所有`pod.xcscheme` 的`isShown`为falsedef write_pod_project  UI.message "- Writing Xcode project file to #{UI.path sandbox.project_path}" do    pods_project.pods.remove_from_project if pods_project.pods.empty?    pods_project.development_pods.remove_from_project if pods_project.development_pods.empty?    pods_project.sort(:groups_position => :below)    ##重新创建schemes 文件，这里更改了isShown    pods_project.recreate_user_schemes(false)    pods_project.predictabilize_uuids if config.deterministic_uuids?    pods_project.save  endend  

recreate_user_schemes

  #重新创建schemes 文件def recreate_user_schemes(visible = true)  schemes_dir = XCScheme.user_data_dir(path)  FileUtils.rm_rf(schemes_dir)  FileUtils.mkdir_p(schemes_dir)  xcschememanagement = {}  xcschememanagement['SchemeUserState'] = {}  xcschememanagement['SuppressBuildableAutocreation'] = {}  targets.each do |target|    scheme = XCScheme.new    scheme.add_build_target(target)    scheme.save_as(path, target.name, false)    xcschememanagement['SchemeUserState']["#{target.name}.xcscheme"] = {}    #就是在这里修改的。    xcschememanagement['SchemeUserState']["#{target.name}.xcscheme"]['isShown'] = visible  end  xcschememanagement_path = schemes_dir + 'xcschememanagement.plist'  Xcodeproj.write_plist(xcschememanagement, xcschememanagement_path)end

这样我们找到了根本问题，其实还是底层做了限制，每次 pod install 会重新生成 scheme 文件，并且每个 pod target 的 isShown 都是 false 。

Podfile 剖析

Podfile 其实是个 Ruby 类，对应 Cocoapods 的 Podfile class，我们可以看看Podfile class源码:

# 文件位置：/Library/Ruby/Gems/2.0.0/gems/cocoapods-core-0.38.2/lib/cocoapods-core/podfile/dsl.rbmodule Pod  class Podfile module DSL ...

platform

指定 Pods target 的 platform

# @!group Target configuration#   These settings are used to control the  CocoaPods generated project.##   This starts out simply with stating what `platform` you are working  on. `xcodeproj` allows you to state specifically which project to link with.# Specifies the platform for which a static library should be built.## CocoaPods provides a default deployment target if one is not specified.# The current default values are `4.3` for iOS, `10.6` for OS X and `2.0` for watchOS.## If the deployment target requires it (iOS < `4.3`), `armv6` architecture will be added to `ARCHS`.## @param    [Symbol] name#           the name of platform, can be either `:osx` for OS X, `:ios`#           for iOS or `:watchos` for watchOS.## @param    [String, Version] target#           The optional deployment.  If not provided a default value#           according to the platform name will be assigned.## @example  Specifying the platform##           platform :ios, "4.0"#           platform :ios## @return   [void]def platform(name, target = nil)  # Support for deprecated options parameter  target = target[:deployment_target] if target.is_a?(Hash)  current_target_definition.set_platform(name, target)end

xcodeproj

指定 Pods libraries 可以被哪个 project 链接。

# @Specifies the Xcode project that contains the target that the Pods library should be linked with.# # @param    [String] path#           the path of the project to link with## @param    [Hash{String => symbol}] build_configurations#           a hash where the keys are the name of the build#           configurations in your Xcode project and the values are#           Symbols that specify if the configuration should be based on#           the `:debug` or `:release` configuration. If no explicit#           mapping is specified for a configuration in your project, it#           will default to `:release`.## @example  Specifying the user project##           # Look for target to link with in an Xcode project called#           # `MyProject.xcodeproj`.#           xcodeproj 'MyProject'##           target :test do#             # This Pods library links with a target in another project.#             xcodeproj 'TestProject'#           end## @example  Using custom build configurations##           xcodeproj 'TestProject', 'Mac App Store' => :release, 'Test' => :debug### @return   [void]def xcodeproj(path, build_configurations = {})  current_target_definition.user_project_path = path  current_target_definition.build_configurations = build_configurationsend

inhibit_all_warnings

指定 是否需要忽略警告

# @Inhibits **all** the warnings from the CocoaPods libraries.### This attribute is inherited by child target definitions.## If you would like to inhibit warnings per Pod you can use the following syntax:##     pod 'SSZipArchive', :inhibit_warnings => truedef inhibit_all_warnings!  current_target_definition.inhibit_all_warnings = trueend

use_frameworks

指定是否使用 framework

# @Use frameworks instead of static libraries for Pods.## ------## This attribute is inherited by child target definitions.#    def use_frameworks!(flag = true)  current_target_definition.use_frameworks!(flag)end

workspace

指定 合成的 workspace 路径

# @!group Workspace##   This group list the options to configure workspace and to set global settings.# Specifies the Xcode workspace that should contain all the projects.## -----## If no explicit Xcode workspace is specified and only **one** project# exists in the same directory as the Podfile, then the name of that project is used as the workspace’s name.## @param    [String] path#           path of the workspace.## @example  Specifying a workspace##           workspace 'MyWorkspace'## @return   [void]def workspace(path)  set_hash_value('workspace', path.to_s)end

source

指定 specs 仓库源

# @!group Sources##   The Podfile retrieves specs from a given list of sources (repositories).##   Sources are __global__ and they are not stored per target definition.# Specifies the location of specs## -----## Use this method to specify sources. The order of the sources is# relevant. CocoaPods will use the highest version of a Pod of the first# source which includes the Pod (regardless whether other sources have a# higher version).## @param    [String] source#           The URL of a specs repository.## @example  Specifying to first use the Artsy repository and then the#           CocoaPods Master Repository##           source 'https://github.com/artsy/Specs.git'#           source 'https://github.com/CocoaPods/Specs.git'## @return   [void]def source(source)  hash_sources = get_hash_value('sources') || []  hash_sources << source  set_hash_value('sources', hash_sources.uniq)end

post_install

设置 installer 之后的执行的代码块

# This hook allows you to make any last changes to the generated Xcode# project before it is written to disk, or any other tasks you might want to perform.## It receives the [`Pod::Installer`](http://rubydoc.info/gems/cocoapods/Pod/Installer/) as its only argument.## @example  Customising the build settings of all targets##   post_install do |installer|#     installer.pods_project.targets.each do |target|#       target.build_configurations.each do |config|#         config.build_settings['GCC_ENABLE_OBJC_GC'] = 'supported'#       end#     end#   end## @return   [void]#def post_install(&block)  @post_install_callback = blockend

Podfile 自定义

我们在Podfile中增加如下代码：

#设置 Podfile 对象 @post_install_callback 成员self.post_install do |installer|$KDPod_Projectbegin    $KDPod_Project=installer.project    rescue    puts "installer.project is delete"    $KDPod_Project=installer.pods_projectendinstaller.use_default_plugins = false$KDPod_Project.targets.each do |target|    #设置ORGANIZATIONNAME 、 CLASSPREFIX    #target.project.root_object.attributes['ORGANIZATIONNAME']='xxxxx.xxx'    #target.project.root_object.attributes['CLASSPREFIX']='xxxx'    target.build_configurations.each do |config|        #设置target的编译后生成目录        config.build_settings['CONFIGURATION_TEMP_DIR'] = './build'        config.build_settings['ONLY_ACTIVE_ARCH'] = 'NO'    endend# 延迟执行def kdperformSelector(time)    before=Time.now    fork do        sleep(1) until Time.now-before >= time        yield    endend#延迟3秒 更改pods scheme visabledkdperformSelector(3){    ##update pod visabled    $schemes_dir = Xcodeproj::XCScheme.user_data_dir($KDPod_Project.path)    $xcschememanagement_path = $schemes_dir + 'xcschememanagement.plist'    $xcschememanagement_content = Xcodeproj.read_plist($xcschememanagement_path)    #设置 isShown 属性    $xcschememanagement_content['SchemeUserState']["Pods.xcscheme"]['isShown'] = true    FileUtils.rm_rf($xcschememanagement_path)    Xcodeproj.write_plist($xcschememanagement_content,$xcschememanagement_path)    #    puts $xcschememanagement_content    #    $KDPod_Project.recreate_user_schemes(true)    $KDPod_Project.save    puts "KDPod_Project.save"}end

我们新for一个进程，在 download_dependencies 之后 延迟了3秒执行更新 pods.xschemeisShown 属性。
这样就可以显示Pods Scheme了。

这里只是做个例子，重要的是，了解了源码，我们就可以对project进行其他配置。