feat: use lru.Cache and cache trees

* drop objectCache in favor for lru.Cache
* cache repo trees

Author: aymanbagabas

commit_submodule.go

@@ -8,6 +8,8 @@ import (
 	"bufio"
 	"bytes"
 	"strings"
+
+	"github.com/golang/groupcache/lru"
 )
 
 // Submodule contains information of a Git submodule.
@@ -21,7 +23,7 @@ type Submodule struct {
 }
 
 // Submodules contains information of submodules.
-type Submodules = *objectCache
+type Submodules = *lru.Cache
 
 // Submodules returns submodules found in this commit.
 func (c *Commit) Submodules() (Submodules, error) {
@@ -39,7 +41,7 @@ func (c *Commit) Submodules() (Submodules, error) {
 		}
 
 		scanner := bufio.NewScanner(bytes.NewReader(p))
-		c.submodules = newObjectCache()
+		c.submodules = lru.New(0)
 		var inSection bool
 		var path string
 		var url string
@@ -72,7 +74,7 @@ func (c *Commit) Submodules() (Submodules, error) {
 					return
 				}
 
-				c.submodules.Set(path, mod)
+				c.submodules.Add(path, mod)
 				inSection = false
 			}
 		}

go.mod

@@ -3,6 +3,7 @@ module github.com/gogs/git-module
 go 1.13
 
 require (
+	github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da
 	github.com/mcuadros/go-version v0.0.0-20190308113854-92cdf37c5b75
 	github.com/stretchr/testify v1.7.2
 	golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e

go.sum

@@ -1,5 +1,7 @@
 github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da h1:oI5xCqsCo564l8iNU+DwB5epxmsaqB+rhGL0m5jtYqE=
+github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da/go.mod h1:cIg4eruTrX1D+g88fzRXU5OdNfaM+9IcxsU14FzY7Hc=
 github.com/mcuadros/go-version v0.0.0-20190308113854-92cdf37c5b75 h1:Pijfgr7ZuvX7QIQiEwLdRVr3RoMG+i0SbBO1Qu+7yVk=
 github.com/mcuadros/go-version v0.0.0-20190308113854-92cdf37c5b75/go.mod h1:76rfSfYPWj01Z85hUf/ituArm797mNKcvINh1OlsZKo=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=

repo.go

@@ -15,14 +15,17 @@ import (
 	"strconv"
 	"strings"
 	"time"
+
+	"github.com/golang/groupcache/lru"
 )
 
 // Repository contains information of a Git repository.
 type Repository struct {
 	path string
 
-	cachedCommits *objectCache
-	cachedTags    *objectCache
+	cachedCommits *lru.Cache
+	cachedTags    *lru.Cache
+	cachedTrees   *lru.Cache
 }
 
 // Path returns the path of the repository.
@@ -84,9 +87,18 @@ func Init(path string, opts ...InitOptions) error {
 	return err
 }
 
+// OpenOptions contains optional arguments for opening a repository.
+type OpenOptions struct {
+	MaxCacheEntries int
+}
+
 // Open opens the repository at the given path. It returns an os.ErrNotExist if
 // the path does not exist.
-func Open(repoPath string) (*Repository, error) {
+func Open(repoPath string, opts ...OpenOptions) (*Repository, error) {
+	var opt OpenOptions
+	if len(opts) > 0 {
+		opt = opts[0]
+	}
 	repoPath, err := filepath.Abs(repoPath)
 	if err != nil {
 		return nil, err
@@ -96,8 +108,9 @@ func Open(repoPath string) (*Repository, error) {
 
 	return &Repository{
 		path:          repoPath,
-		cachedCommits: newObjectCache(),
-		cachedTags:    newObjectCache(),
+		cachedCommits: lru.New(opt.MaxCacheEntries),
+		cachedTags:    lru.New(opt.MaxCacheEntries),
+		cachedTrees:   lru.New(opt.MaxCacheEntries),
 	}, nil
 }
 

repo_commit.go

@@ -112,7 +112,7 @@ func (r *Repository) CatFileCommit(rev string, opts ...CatFileCommitOptions) (*C
 	c.repo = r
 	c.ID = MustIDFromString(commitID)
 
-	r.cachedCommits.Set(commitID, c)
+	r.cachedCommits.Add(commitID, c)
 	return c, nil
 }
 

repo_tag.go

@@ -94,7 +94,7 @@ func (r *Repository) getTag(timeout time.Duration, id *SHA1) (*Tag, error) {
 		return nil, fmt.Errorf("unsupported tag type: %s", typ)
 	}
 
-	r.cachedTags.Set(id.String(), tag)
+	r.cachedTags.Add(id.String(), tag)
 	return tag, nil
 }
 

repo_tree.go

@@ -97,25 +97,30 @@ type LsTreeOptions struct {
 }
 
 // LsTree returns the tree object in the repository by given revision.
-func (r *Repository) LsTree(rev string, opts ...LsTreeOptions) (*Tree, error) {
+func (r *Repository) LsTree(treeID string, opts ...LsTreeOptions) (*Tree, error) {
 	var opt LsTreeOptions
 	if len(opts) > 0 {
 		opt = opts[0]
 	}
 
+	cache, ok := r.cachedTrees.Get(treeID)
+	if ok {
+		log("Cached tree hit: %s", treeID)
+		return cache.(*Tree), nil
+	}
 	var err error
-	rev, err = r.RevParse(rev, RevParseOptions{Timeout: opt.Timeout}) //nolint
+	treeID, err = r.RevParse(treeID, RevParseOptions{Timeout: opt.Timeout}) //nolint
 	if err != nil {
 		return nil, err
 	}
 	t := &Tree{
-		id:   MustIDFromString(rev),
+		id:   MustIDFromString(treeID),
 		repo: r,
 	}
 
 	stdout, err := NewCommand("ls-tree").
 		AddOptions(opt.CommandOptions).
-		AddArgs(rev).
+		AddArgs(treeID).
 		RunInDirWithTimeout(opt.Timeout, r.path)
 	if err != nil {
 		return nil, err
@@ -126,5 +131,6 @@ func (r *Repository) LsTree(rev string, opts ...LsTreeOptions) (*Tree, error) {
 		return nil, err
 	}
 
+	r.cachedTrees.Add(treeID, t)
 	return t, nil
 }

utils.go

@@ -8,37 +8,8 @@ import (
 	"fmt"
 	"os"
 	"strings"
-	"sync"
 )
 
-// objectCache provides thread-safe cache operations. TODO(@unknwon): Use
-// sync.Map once requires Go 1.13.
-type objectCache struct {
-	lock  sync.RWMutex
-	cache map[string]interface{}
-}
-
-func newObjectCache() *objectCache {
-	return &objectCache{
-		cache: make(map[string]interface{}),
-	}
-}
-
-func (oc *objectCache) Set(id string, obj interface{}) {
-	oc.lock.Lock()
-	defer oc.lock.Unlock()
-
-	oc.cache[id] = obj
-}
-
-func (oc *objectCache) Get(id string) (interface{}, bool) {
-	oc.lock.RLock()
-	defer oc.lock.RUnlock()
-
-	obj, has := oc.cache[id]
-	return obj, has
-}
-
 // isDir returns true if given path is a directory, or returns false when it's a
 // file or does not exist.
 func isDir(dir string) bool {