< 笔记 > Git

06 Git 分支管理

By Kevin Song

• 06-01 创建与合并分支
• 06-02 解决冲突
• 06-03 分支管理策略
• 06-04 存储工作区
• 06-05 Feature分支
• 06-06 多人协作

分支作用：

• 主分支不能一直在修改（会导致项目中其他人不能干活）
• 主分支不能一次性推送（会导致一个篮子里鸡蛋都碎了）
• 创建一个新分支
  
  • 在新分支中工作
  • 随时提交
  • 开发完合并到Master Branch

06-01 创建与合并分支

1 . 创建分支

$ git branch dev

2 . 切换分支

$ git checkout devSwitched to branch 'dev'

第一第二步可以合并成一句：

$ git checkout -b devSwitched to a new branch 'dev'

3 . 查看当前分支

• 当前分支前有星号

$ git branch* dev  master

4 . 修改readme.txt文件并提交到当前分支

Creating a new branch is quick.

$ git add readme.txt $ git commit -m "branch test"[dev fec145a] branch test 1 file changed, 1 insertion(+)

5 . 切换回master分支

$ git checkout masterSwitched to branch 'master'

6 . 合并dev分支到master分支

$ git merge devUpdating d17efd8..fec145aFast-forward readme.txt |    1 + 1 file changed, 1 insertion(+)

7 . 删除dev分支

$ git branch -d devDeleted branch dev (was fec145a).

06-02 解决冲突

两个分支的同一个文件做了不同修改导致 冲突

feature1分支修改readme.txt

$ git checkout -b feature1Switched to a new branch 'feature1'

Creating a new branch is quick AND simple.

$ git add readme.txt $ git commit -m "AND simple"[feature1 75a857c] AND simple 1 file changed, 1 insertion(+), 1 deletion(-)

master分支修改readme.txt

$ git checkout masterSwitched to branch 'master'Your branch is ahead of 'origin/master' by 1 commit.

Creating a new branch is quick & simple.

$ git add readme.txt $ git commit -m "& simple"[master 400b400] & simple 1 file changed, 1 insertion(+), 1 deletion(-)

master分支和feature1分支各自都分别有新的提交

此时合并会产生冲突

$ git merge feature1Auto-merging readme.txtCONFLICT (content): Merge conflict in readme.txtAutomatic merge failed; fix conflicts and then commit the result.

直接查看readme.txt的内容：

Git is a distributed version control system.Git is free software distributed under the GPL.Git has a mutable index called stage.Git tracks changes of files.<<<<<<< HEADCreating a new branch is quick & simple.=======Creating a new branch is quick AND simple.>>>>>>> feature1

修改如下后保存：

Creating a new branch is quick and simple.

再提交：

$ git add readme.txt $ git commit -m "conflict fixed"[master 59bc1cb] conflict fixed

git log 可以看到分支的合并情况：

$ git log --graph --pretty=oneline --abbrev-commit*   59bc1cb conflict fixed|\| * 75a857c AND simple* | 400b400 & simple|/* fec145a branch test...

删除feature1分支：

$ git branch -d feature1Deleted branch feature1 (was 75a857c).

06-03 分支管理策略

合并分支默认使用Fast forward 模式

Fast Forward 缺点：删除分支后，会丢掉分支信息

禁用Fast forward模式

1 . 创建并切换dev分支：

$ git checkout -b devSwitched to a new branch 'dev'

2 . 修改readme.txt文件，并提交一个新的commit：

$ git add readme.txt $ git commit -m "add merge"[dev 6224937] add merge 1 file changed, 1 insertion(+)

3 . 切换回master：

$ git checkout masterSwitched to branch 'master'

4 . 合并dev分支

• –no-ff参数：禁用Fast forward
• -m参数：添加commit描述

$ git merge --no-ff -m "merge with no-ff" devMerge made by the 'recursive' strategy. readme.txt |    1 + 1 file changed, 1 insertion(+)

分支策略

• master分支：只用来发布新版本，不用来开发
  
  • dev分支：用来开发
    
    • 每个人在dev分支上开发，每个人都有自己的分支，时不时往dev分支上合并

06-04 存储工作区

git stash存储当前工作区

$ git stashSaved working directory and index state WIP on dev: 6224937 add mergeHEAD is now at 6224937 add merge

git stash list查看存储的工作区：

$ git stash liststash@{0}: WIP on dev: 6224937 add merge

恢复方法一：git stash apply

• stash内容不删除
• git stash drop手动删除

恢复方法二：git stash pop

• stash内容恢复后删除

$ git stash pop# On branch dev# Changes to be committed:#   (use "git reset HEAD <file>..." to unstage)##       new file:   hello.py## Changes not staged for commit:#   (use "git add <file>..." to update what will be committed)#   (use "git checkout -- <file>..." to discard changes in working directory)##       modified:   readme.txt#Dropped refs/stash@{0} (f624f8e5f082f2df2bed8a4e09c12fd2943bdd40)

06-05 Feature分支

新建一个新功能分支，开发完再合并到master branch

$ git checkout -b feature-vulcanSwitched to a new branch 'feature-vulcan'

开发完毕

$ git add vulcan.py$ git status# On branch feature-vulcan# Changes to be committed:#   (use "git reset HEAD <file>..." to unstage)##       new file:   vulcan.py#$ git commit -m "add feature vulcan"[feature-vulcan 756d4af] add feature vulcan 1 file changed, 2 insertions(+) create mode 100644 vulcan.py

切回dev，准备合并：

$ git checkout dev

突然要销毁该分支

$ git branch -d feature-vulcanerror: The branch 'feature-vulcan' is not fully merged.If you are sure you want to delete it, run 'git branch -D feature-vulcan'.

删不了，只能强制删除

$ git branch -D feature-vulcanDeleted branch feature-vulcan (was 756d4af).

06-06 多人协作

git remote 查看远程仓库信息

$ git remoteorigin

git remote -v 查看详细远程仓库信息

$ git remote -vorigin  [e-mail]:KevinJtSong/learngit.git (fetch)origin  [e-mail]:KevinJtSong/learngit.git (push)

推送分支

推送master branch

$ git push origin master

推送dev branch

$ git push origin dev

分支种类

• master branch：时刻与远程同步
• dev branch：时刻与远程同步
• bug branch：只用于在本地修复bug，不需要推送
• feature

抓取分支

同事A克隆了仓库

$ git clone [e-mail]:michaelliao/learngit.gitCloning into 'learngit'...remote: Counting objects: 46, done.remote: Compressing objects: 100% (26/26), done.remote: Total 46 (delta 16), reused 45 (delta 15)Receiving objects: 100% (46/46), 15.69 KiB | 6 KiB/s, done.Resolving deltas: 100% (16/16), done.

同事A只能看到master branch

$ git branch* master

同事A要在dev分支上开发必须创建origin的dev分支到本地

$ git checkout -b dev origin/dev

同事A把dev分支push到远程：

$ git commit -m "add /usr/bin/env"[dev 291bea8] add /usr/bin/env 1 file changed, 1 insertion(+)$ git push origin devCounting objects: 5, done.Delta compression using up to 4 threads.Compressing objects: 100% (2/2), done.Writing objects: 100% (3/3), 349 bytes, done.Total 3 (delta 0), reused 0 (delta 0)To [e-mail]:KevinJtSong/learngit.git   fc38031..291bea8  dev -> dev

同事B对同样的文件作了修改，并试图推送：

$ git add hello.py $ git commit -m "add coding: utf-8"[dev bd6ae48] add coding: utf-8 1 file changed, 1 insertion(+)$ git push origin devTo [e-mail]:KevinJtSong/learngit.git ! [rejected]        dev -> dev (non-fast-forward)error: failed to push some refs to '[e-mail]:KevinJtSong/learngit.git'hint: Updates were rejected because the tip of your current branch is behindhint: its remote counterpart. Merge the remote changes (e.g. 'git pull')hint: before pushing again.hint: See the 'Note about fast-forwards' in 'git push --help' for details.

推送失败，必须先
用git pull把最新的提交从origin/dev抓下来，然后，在本地合并，解决冲突，再推送：

$ git pullremote: Counting objects: 5, done.remote: Compressing objects: 100% (2/2), done.remote: Total 3 (delta 0), reused 3 (delta 0)Unpacking objects: 100% (3/3), done.From github.com:michaelliao/learngit   fc38031..291bea8  dev        -> origin/devThere is no tracking information for the current branch.Please specify which branch you want to merge with.See git-pull(1) for details    git pull <remote> <branch>If you wish to set tracking information for this branch you can do so with:    git branch --set-upstream dev origin/<branch>

git pull也失败，原因是没有指定本地dev分支与远程origin/dev分支的链接，先设置dev和origin/dev的链接：

$ git branch --set-upstream dev origin/devBranch dev set up to track remote branch dev from origin.

再pull：

$ git pullAuto-merging hello.pyCONFLICT (content): Merge conflict in hello.pyAutomatic merge failed; fix conflicts and then commit the result.

这回git pull成功，但是合并有冲突，需要手动解决，解决的方法和分支管理中的解决冲突完全一样。解决后，提交，再push：

$ git commit -m "merge & fix hello.py"[dev adca45d] merge & fix hello.py$ git push origin devCounting objects: 10, done.Delta compression using up to 4 threads.Compressing objects: 100% (5/5), done.Writing objects: 100% (6/6), 747 bytes, done.Total 6 (delta 0), reused 0 (delta 0)To [e-mail]:michaelliao/learngit.git   291bea8..adca45d  dev -> dev

多人协作 工作模式

• 用git push origin branch-name推送自己的修改
• 如果推送失败，则因为远程分支比你的本地更新，需要先用git pull试图合并
• 如果合并有冲突，则解决冲突，并在本地提交
• 没有冲突或者解决掉冲突后，再用git push origin branch-name推送就能成功