bench-forgejo/modules/git/repo_branch_nogogit.go
zeripath 9e6e1dc950
Improve checkBranchName (#17901)
The current implementation of checkBranchName is highly inefficient
involving opening the repository, the listing all of the branch names
checking them individually before then using using opened repo to get
the tags.

This PR avoids this by simply walking the references from show-ref
instead of opening the repository (in the nogogit case).

Signed-off-by: Andrew Thornton <art27@cantab.net>
2021-12-08 19:08:16 +00:00

172 lines
4.2 KiB
Go

// Copyright 2015 The Gogs Authors. All rights reserved.
// Copyright 2018 The Gitea Authors. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
//go:build !gogit
// +build !gogit
package git
import (
"bufio"
"bytes"
"context"
"io"
"strings"
"code.gitea.io/gitea/modules/log"
)
// IsObjectExist returns true if given reference exists in the repository.
func (repo *Repository) IsObjectExist(name string) bool {
if name == "" {
return false
}
wr, rd, cancel := repo.CatFileBatchCheck(repo.Ctx)
defer cancel()
_, err := wr.Write([]byte(name + "\n"))
if err != nil {
log.Debug("Error writing to CatFileBatchCheck %v", err)
return false
}
sha, _, _, err := ReadBatchLine(rd)
return err == nil && bytes.HasPrefix(sha, []byte(strings.TrimSpace(name)))
}
// IsReferenceExist returns true if given reference exists in the repository.
func (repo *Repository) IsReferenceExist(name string) bool {
if name == "" {
return false
}
wr, rd, cancel := repo.CatFileBatchCheck(repo.Ctx)
defer cancel()
_, err := wr.Write([]byte(name + "\n"))
if err != nil {
log.Debug("Error writing to CatFileBatchCheck %v", err)
return false
}
_, _, _, err = ReadBatchLine(rd)
return err == nil
}
// IsBranchExist returns true if given branch exists in current repository.
func (repo *Repository) IsBranchExist(name string) bool {
if name == "" {
return false
}
return repo.IsReferenceExist(BranchPrefix + name)
}
// GetBranchNames returns branches from the repository, skipping skip initial branches and
// returning at most limit branches, or all branches if limit is 0.
func (repo *Repository) GetBranchNames(skip, limit int) ([]string, int, error) {
return callShowRef(repo.Ctx, repo.Path, BranchPrefix, "--heads", skip, limit)
}
// WalkReferences walks all the references from the repository
func WalkReferences(ctx context.Context, repoPath string, walkfn func(string) error) (int, error) {
return walkShowRef(ctx, repoPath, "", 0, 0, walkfn)
}
// callShowRef return refs, if limit = 0 it will not limit
func callShowRef(ctx context.Context, repoPath, prefix, arg string, skip, limit int) (branchNames []string, countAll int, err error) {
countAll, err = walkShowRef(ctx, repoPath, arg, skip, limit, func(branchName string) error {
branchName = strings.TrimPrefix(branchName, prefix)
branchNames = append(branchNames, branchName)
return nil
})
return
}
func walkShowRef(ctx context.Context, repoPath, arg string, skip, limit int, walkfn func(string) error) (countAll int, err error) {
stdoutReader, stdoutWriter := io.Pipe()
defer func() {
_ = stdoutReader.Close()
_ = stdoutWriter.Close()
}()
go func() {
stderrBuilder := &strings.Builder{}
args := []string{"show-ref"}
if arg != "" {
args = append(args, arg)
}
err := NewCommandContext(ctx, args...).RunInDirPipeline(repoPath, stdoutWriter, stderrBuilder)
if err != nil {
if stderrBuilder.Len() == 0 {
_ = stdoutWriter.Close()
return
}
_ = stdoutWriter.CloseWithError(ConcatenateError(err, stderrBuilder.String()))
} else {
_ = stdoutWriter.Close()
}
}()
i := 0
bufReader := bufio.NewReader(stdoutReader)
for i < skip {
_, isPrefix, err := bufReader.ReadLine()
if err == io.EOF {
return i, nil
}
if err != nil {
return 0, err
}
if !isPrefix {
i++
}
}
for limit == 0 || i < skip+limit {
// The output of show-ref is simply a list:
// <sha> SP <ref> LF
_, err := bufReader.ReadSlice(' ')
for err == bufio.ErrBufferFull {
// This shouldn't happen but we'll tolerate it for the sake of peace
_, err = bufReader.ReadSlice(' ')
}
if err == io.EOF {
return i, nil
}
if err != nil {
return 0, err
}
branchName, err := bufReader.ReadString('\n')
if err == io.EOF {
// This shouldn't happen... but we'll tolerate it for the sake of peace
return i, nil
}
if err != nil {
return i, err
}
if len(branchName) > 0 {
branchName = branchName[:len(branchName)-1]
}
err = walkfn(branchName)
if err != nil {
return i, err
}
i++
}
// count all refs
for limit != 0 {
_, isPrefix, err := bufReader.ReadLine()
if err == io.EOF {
return i, nil
}
if err != nil {
return 0, err
}
if !isPrefix {
i++
}
}
return i, nil
}