Performance improvement for last commit cache and show-ref (#15455)

* Improve performance when there are multiple commits in the last commit cache

* read refs directly if we can

Signed-off-by: Andrew Thornton <art27@cantab.net>

diff --git a/modules/git/commit_info_nogogit.go b/modules/git/commit_info_nogogit.go
index f14b7b82910fc42544f64965441060c676e73348..6dd7b11ba79c0fc1cf1de72d0d7931c74358b6ce 100644 (file)
--- a/modules/git/commit_info_nogogit.go
+++ b/modules/git/commit_info_nogogit.go
@@ -102,10 +102,13 @@ func (tes Entries) GetCommitsInfo(commit *Commit, treePath string, cache *LastCo
 }
 
 func getLastCommitForPathsByCache(commitID, treePath string, paths []string, cache *LastCommitCache) (map[string]*Commit, []string, error) {
+       wr, rd, cancel := CatFileBatch(cache.repo.Path)
+       defer cancel()
+
        var unHitEntryPaths []string
        var results = make(map[string]*Commit)
        for _, p := range paths {
-               lastCommit, err := cache.Get(commitID, path.Join(treePath, p))
+               lastCommit, err := cache.Get(commitID, path.Join(treePath, p), wr, rd)
                if err != nil {
                        return nil, nil, err
                }

diff --git a/modules/git/last_commit_cache_nogogit.go b/modules/git/last_commit_cache_nogogit.go
index 0e52d165386d081728e316f5f9d80d9cf662dc9b..0a1babb112148203e50da55d8f0211e620dee0c9 100644 (file)
--- a/modules/git/last_commit_cache_nogogit.go
+++ b/modules/git/last_commit_cache_nogogit.go
@@ -7,6 +7,8 @@
 package git
 
 import (
+       "bufio"
+       "io"
        "path"
 )
 
@@ -34,7 +36,7 @@ func NewLastCommitCache(repoPath string, gitRepo *Repository, ttl func() int64,
 }
 
 // Get get the last commit information by commit id and entry path
-func (c *LastCommitCache) Get(ref, entryPath string) (interface{}, error) {
+func (c *LastCommitCache) Get(ref, entryPath string, wr *io.PipeWriter, rd *bufio.Reader) (interface{}, error) {
        v := c.cache.Get(c.getCacheKey(c.repoPath, ref, entryPath))
        if vs, ok := v.(string); ok {
                log("LastCommitCache hit level 1: [%s:%s:%s]", ref, entryPath, vs)
@@ -46,7 +48,10 @@ func (c *LastCommitCache) Get(ref, entryPath string) (interface{}, error) {
                if err != nil {
                        return nil, err
                }
-               commit, err := c.repo.getCommit(id)
+               if _, err := wr.Write([]byte(vs + "\n")); err != nil {
+                       return nil, err
+               }
+               commit, err := c.repo.getCommitFromBatchReader(rd, id)
                if err != nil {
                        return nil, err
                }

diff --git a/modules/git/repo_commit_nogogit.go b/modules/git/repo_commit_nogogit.go
index 0a92de17037ef643362cbafa8de91bd0331292b4..df56b26b015941c76a01ac68256828363e3b4ee7 100644 (file)
--- a/modules/git/repo_commit_nogogit.go
+++ b/modules/git/repo_commit_nogogit.go
@@ -9,9 +9,10 @@ package git
 import (
        "bufio"
        "errors"
-       "fmt"
        "io"
        "io/ioutil"
+       "os"
+       "path/filepath"
        "strings"
 )
 
@@ -34,6 +35,18 @@ func (repo *Repository) ResolveReference(name string) (string, error) {
 
 // GetRefCommitID returns the last commit ID string of given reference (branch or tag).
 func (repo *Repository) GetRefCommitID(name string) (string, error) {
+       if strings.HasPrefix(name, "refs/") {
+               // We're gonna try just reading the ref file as this is likely to be quicker than other options
+               fileInfo, err := os.Lstat(filepath.Join(repo.Path, name))
+               if err == nil && fileInfo.Mode().IsRegular() && fileInfo.Size() == 41 {
+                       ref, err := ioutil.ReadFile(filepath.Join(repo.Path, name))
+
+                       if err == nil && SHAPattern.Match(ref[:40]) && ref[40] == '\n' {
+                               return string(ref[:40]), nil
+                       }
+               }
+       }
+
        stdout, err := NewCommand("show-ref", "--verify", "--hash", name).RunInDir(repo.Path)
        if err != nil {
                if strings.Contains(err.Error(), "not a valid ref") {
@@ -69,6 +82,11 @@ func (repo *Repository) getCommit(id SHA1) (*Commit, error) {
        }()
 
        bufReader := bufio.NewReader(stdoutReader)
+
+       return repo.getCommitFromBatchReader(bufReader, id)
+}
+
+func (repo *Repository) getCommitFromBatchReader(bufReader *bufio.Reader, id SHA1) (*Commit, error) {
        _, typ, size, err := ReadBatchLine(bufReader)
        if err != nil {
                if errors.Is(err, io.EOF) {
@@ -106,7 +124,6 @@ func (repo *Repository) getCommit(id SHA1) (*Commit, error) {
        case "commit":
                return CommitFromReader(repo, id, io.LimitReader(bufReader, size))
        default:
-               _ = stdoutReader.CloseWithError(fmt.Errorf("unknown typ: %s", typ))
                log("Unknown typ: %s", typ)
                return nil, ErrNotExist{
                        ID: id.String(),