问题
I am new to git and I want to execute manifest file manually after doing repo init, instead of doing repo sync. To measure the time difference between normal git commands and repo sync in different cases. But I am not sure which git command to does repo uses.
I know that repo is just an wrapper for git for large codebase.
I just want to know what will be the exact command for git clone If I have the following Variables.
- name - path - revision - upstream - remote
I know how to form a url for git clone but not sure about revision and upstream.
回答1:
Here's a sample manifest default.xml:
<manifest>
<remote name="aosp"
fetch="https://android.googlesource.com/"/>
<remote name="test"
fetch="https://github.com/test/"/>
<default revision="master"
remote="test"
sync-j="4" />
<project name="platform/tools/motodev" path="tools/motodev" revision="69989786cefbde82527960a1e100ec9afba46a98" upstream="master" remote="aosp"/>
</manifest>
Create a parent directory for testing
mkdir repotest
cd repotest
Create a git repository for the manifest
mkdir local_manifest
cd local_manifest
git init
# Create the default.xml file
git add default.xml
git commit -m "Local Manifest"
cd ..
Download the repo tool
mkdir -p .bin
PATH="${HOME}/repotest/.bin:${PATH}"
curl https://storage.googleapis.com/git-repo-downloads/repo > .bin/repo
chmod a+rx .bin/repo
Init based on the local manifest
mkdir test
cd test
repo init -u ~/repotest/local_manifest/
Modify source code of repo to get more debugging output (in addition to --trace and GIT_TRACE=1)
nano .repo/repo/git_command.py
# Remove stderr argument from the subprocess.Popen call (line no: ~292)
# Also comment the line at line no: ~331 which includes the use of the above removed argument stderr
# Save the file and exit
Sync
export GIT_TRACE=1
repo --trace sync &> ../log
cd ..
Filter the log
grep "built-in:\|curl\|export" < log > temp
awk -F '[0-9][0-9]:[0-9][0-9]:[0-9][0-9].[0-9]+ git.c:' '{print $1}' > trim1 < temp
awk -F 'trace: built-in:' '{print $2}' > trim2 < temp
paste -d' ' trim1 trim2 > filtered_log
Filtered Log shows the sequence of git commands being executed
git version
git describe HEAD
git config --file /home/test/repotest/test/.repo/manifests.git/config --null --list
git config --file /home/test/repotest/test/.repo/repo/.git/config --null --list
: export GIT_DIR=/home/test/repotest/test/.repo/manifests.git
git fetch origin --tags '+refs/tags/*:refs/tags/*' '+refs/heads/*:refs/remotes/origin/*' +refs/heads/master:refs/remotes/origin/master
git upload-pack /home/test/repotest/local_manifest/
git rev-list --objects --stdin --not --all --quiet --alternate-refs
git gc --auto
git symbolic-ref -m 'manifest set to refs/heads/master' refs/remotes/m/master refs/remotes/origin/master
: export GIT_DIR=/home/test/repotest/test/.repo/project-objects/platform/tools/motodev.git
git init
git config --file /home/test/repotest/test/.repo/projects/tools/motodev.git/config --null --list
git config --file /home/test/repotest/test/.repo/projects/tools/motodev.git/config --replace-all filter.lfs.smudge 'git-lfs smudge --skip -- %f'
git config --file /home/test/repotest/test/.repo/projects/tools/motodev.git/config --replace-all filter.lfs.process 'git-lfs filter-process --skip'
git config --file /home/test/repotest/test/.repo/projects/tools/motodev.git/config --unset-all core.bare
git config --file /home/test/repotest/test/.repo/projects/tools/motodev.git/config --replace-all remote.aosp.url https://android.googlesource.com/platform/tools/motodev
git config --file /home/test/repotest/test/.repo/projects/tools/motodev.git/config --replace-all remote.aosp.projectname platform/tools/motodev
git config --file /home/test/repotest/test/.repo/projects/tools/motodev.git/config --replace-all remote.aosp.fetch '+refs/heads/*:refs/remotes/aosp/*'
curl --fail --output /home/test/repotest/test/.repo/projects/tools/motodev.git/clone.bundle.tmp --netrc --location https://android.googlesource.com/platform/tools/motodev/clone.bundle
: export GIT_DIR=/home/test/repotest/test/.repo/projects/tools/motodev.git
git fetch /home/test/repotest/test/.repo/projects/tools/motodev.git/clone.bundle '+refs/heads/*:refs/remotes/aosp/*' '+refs/tags/*:refs/tags/*'
git index-pack --fix-thin --stdin
git rev-list --objects --stdin --not --all --quiet --alternate-refs
git gc --auto
git fetch aosp --tags '+refs/tags/*:refs/tags/*' '+refs/heads/*:refs/remotes/aosp/*' +refs/heads/master:refs/remotes/aosp/master
git fetch-pack --stateless-rpc --stdin --lock-pack --thin --no-progress https://android.googlesource.com/platform/tools/motodev/
git unpack-objects -q --pack_header=2,2
git rev-list --objects --stdin --not --all --quiet --alternate-refs
git gc --auto
git update-ref -m 'manifest set to 69989786cefbde82527960a1e100ec9afba46a98' --no-deref refs/remotes/m/master 69989786cefbde82527960a1e100ec9afba46a98^0
git gc --auto
git read-tree --reset -u -v HEAD
Now that's a lot of commands. (Observation: repo uses curl to download the repositories).
As suggested by User ElpieKay, for the above manifest file, an approximation of git commands would be:
git clone https://android.googlesource.com/platform/tools/motodev -b master -- tools/motodev
cd tools/motodev
git checkout 69989786cefbde82527960a1e100ec9afba46a98
To compare the performance of the repo tool and git, you can do :
# For repo tool
repo --time sync
# For git commands
export GIT_TRACE_PERFORMANCE=1
git clone $remote -b $upstream -- $path
cd $path
git checkout $revision
or using time command to get the total execution time of the git commands
time -p sh -c 'git clone $remote -b $upstream -- $path ; cd $path ; git checkout $revision'
Note: remote has an attribute fetch whose value is the url prefix of the server. The prefix and name form the actual url to the remote repository - User ElpieKay
More on the Debugging Variables used in git:
GIT_TRACE_PERFORMANCE
controls logging of performance data. The output shows how long each particular git invocation takes.
GIT_TRACE
controls general traces, which don’t fit into any specific category. This includes the expansion of aliases, and delegation to other sub-programs.
来源：https://stackoverflow.com/questions/59463893/what-will-be-the-alternative-for-repo-sync-command