修复并发下，写缓存文件可能冲突的问题

internal/caches/storage_file.go

@@ -47,6 +47,9 @@ const (
 	HotItemSize = 1024
 )
 
+var sharedWritingKeyMap = map[string]zero.Zero{} // key => bool
+var sharedWritingKeyLocker = sync.Mutex{}
+
 // FileStorage 文件缓存
 //   文件结构：
 //    [expires time] | [ status ] | [url length] | [header length] | [body length] | [url] [header data] [body data]
@@ -56,10 +59,9 @@ type FileStorage struct {
 	memoryStorage *MemoryStorage                      // 一级缓存
 	totalSize     int64
 
-	list          ListInterface
-	writingKeyMap map[string]zero.Zero // key => bool
-	locker        sync.RWMutex
-	purgeTicker   *utils.Ticker
+	list        ListInterface
+	locker      sync.RWMutex
+	purgeTicker *utils.Ticker
 
 	hotMap       map[string]*HotItem // key => count
 	hotMapLocker sync.Mutex
@@ -69,10 +71,9 @@ type FileStorage struct {
 
 func NewFileStorage(policy *serverconfigs.HTTPCachePolicy) *FileStorage {
 	return &FileStorage{
-		policy:        policy,
-		writingKeyMap: map[string]zero.Zero{},
-		hotMap:        map[string]*HotItem{},
-		lastHotSize:   -1,
+		policy:      policy,
+		hotMap:      map[string]*HotItem{},
+		lastHotSize: -1,
 	}
 }
 
@@ -314,21 +315,20 @@ func (this *FileStorage) OpenWriter(key string, expiredAt int64, status int) (Wr
 	}
 
 	// 是否正在写入
-	var isWriting = false
-	this.locker.Lock()
-	_, ok := this.writingKeyMap[key]
-	this.locker.Unlock()
+	var isOk = false
+	sharedWritingKeyLocker.Lock()
+	_, ok := sharedWritingKeyMap[key]
 	if ok {
+		sharedWritingKeyLocker.Unlock()
 		return nil, ErrFileIsWriting
 	}
-	this.locker.Lock()
-	this.writingKeyMap[key] = zero.New()
-	this.locker.Unlock()
+	sharedWritingKeyMap[key] = zero.New()
+	sharedWritingKeyLocker.Unlock()
 	defer func() {
-		if !isWriting {
-			this.locker.Lock()
-			delete(this.writingKeyMap, key)
-			this.locker.Unlock()
+		if !isOk {
+			sharedWritingKeyLocker.Lock()
+			delete(sharedWritingKeyMap, key)
+			sharedWritingKeyLocker.Unlock()
 		}
 	}()
 
@@ -358,21 +358,27 @@ func (this *FileStorage) OpenWriter(key string, expiredAt int64, status int) (Wr
 		}
 	}
 
+	// 检查缓存是否已经生成
+	var cachePath = dir + "/" + hash + ".cache"
+	stat, err := os.Stat(cachePath)
+	if err == nil && time.Now().Sub(stat.ModTime()) <= 1*time.Second {
+		// 防止并发连续写入
+		return nil, ErrFileIsWriting
+	}
+	var tmpPath = cachePath + ".tmp"
+
 	// 先删除
 	err = this.list.Remove(hash)
 	if err != nil {
 		return nil, err
 	}
 
-	path := dir + "/" + hash + ".cache.tmp"
-	writer, err := os.OpenFile(path, os.O_CREATE|os.O_SYNC|os.O_WRONLY, 0666)
+	writer, err := os.OpenFile(tmpPath, os.O_CREATE|os.O_SYNC|os.O_WRONLY, 0666)
 	if err != nil {
 		return nil, err
 	}
-	isWriting = true
 
-	isOk := false
-	removeOnFailure := true
+	var removeOnFailure = true
 	defer func() {
 		if err != nil {
 			isOk = false
@@ -382,7 +388,7 @@ func (this *FileStorage) OpenWriter(key string, expiredAt int64, status int) (Wr
 		if !isOk {
 			_ = writer.Close()
 			if removeOnFailure {
-				_ = os.Remove(path)
+				_ = os.Remove(tmpPath)
 			}
 		}
 	}()
@@ -453,11 +459,10 @@ func (this *FileStorage) OpenWriter(key string, expiredAt int64, status int) (Wr
 	}
 
 	isOk = true
-
 	return NewFileWriter(writer, key, expiredAt, func() {
-		this.locker.Lock()
-		delete(this.writingKeyMap, key)
-		this.locker.Unlock()
+		sharedWritingKeyLocker.Lock()
+		delete(sharedWritingKeyMap, key)
+		sharedWritingKeyLocker.Unlock()
 	}), nil
 }
 

internal/caches/storage_file_test.go

@@ -270,7 +270,7 @@ func TestFileStorage_Read(t *testing.T) {
 		t.Fatal(err)
 	}
 	now := time.Now()
-	reader, err := storage.OpenReader("my-key")
+	reader, err := storage.OpenReader("my-key", false)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -306,7 +306,7 @@ func TestFileStorage_Read_HTTP_Response(t *testing.T) {
 		t.Fatal(err)
 	}
 	now := time.Now()
-	reader, err := storage.OpenReader("my-http-response")
+	reader, err := storage.OpenReader("my-http-response", false)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -360,7 +360,7 @@ func TestFileStorage_Read_NotFound(t *testing.T) {
 	}
 	now := time.Now()
 	buf := make([]byte, 6)
-	reader, err := storage.OpenReader("my-key-10000")
+	reader, err := storage.OpenReader("my-key-10000", false)
 	if err != nil {
 		if err == ErrNotFound {
 			t.Log("cache not fund")
@@ -506,7 +506,7 @@ func BenchmarkFileStorage_Read(b *testing.B) {
 		b.Fatal(err)
 	}
 	for i := 0; i < b.N; i++ {
-		reader, err := storage.OpenReader("my-key")
+		reader, err := storage.OpenReader("my-key", false)
 		if err != nil {
 			b.Fatal(err)
 		}

internal/caches/storage_memory_test.go

@@ -25,7 +25,7 @@ func TestMemoryStorage_OpenWriter(t *testing.T) {
 	t.Log(storage.valuesMap)
 
 	{
-		reader, err := storage.OpenReader("abc")
+		reader, err := storage.OpenReader("abc", false)
 		if err != nil {
 			if err == ErrNotFound {
 				t.Log("not found: abc")
@@ -52,7 +52,7 @@ func TestMemoryStorage_OpenWriter(t *testing.T) {
 	}
 
 	{
-		_, err := storage.OpenReader("abc 2")
+		_, err := storage.OpenReader("abc 2", false)
 		if err != nil {
 			if err == ErrNotFound {
 				t.Log("not found: abc2")
@@ -68,7 +68,7 @@ func TestMemoryStorage_OpenWriter(t *testing.T) {
 	}
 	_, _ = writer.Write([]byte("Hello123"))
 	{
-		reader, err := storage.OpenReader("abc")
+		reader, err := storage.OpenReader("abc", false)
 		if err != nil {
 			if err == ErrNotFound {
 				t.Log("not found: abc")
@@ -97,7 +97,7 @@ func TestMemoryStorage_OpenReaderLock(t *testing.T) {
 			IsDone: true,
 		},
 	}
-	_, _ = storage.OpenReader("test")
+	_, _ = storage.OpenReader("test", false)
 }
 
 func TestMemoryStorage_Delete(t *testing.T) {

internal/caches/writer_file.go

@@ -6,6 +6,7 @@ import (
 	"io"
 	"os"
 	"strings"
+	"sync"
 )
 
 type FileWriter struct {
@@ -15,6 +16,7 @@ type FileWriter struct {
 	bodySize   int64
 	expiredAt  int64
 	endFunc    func()
+	once       sync.Once
 }
 
 func NewFileWriter(rawWriter *os.File, key string, expiredAt int64, endFunc func()) *FileWriter {
@@ -82,18 +84,25 @@ func (this *FileWriter) WriteBodyLength(bodyLength int64) error {
 
 // Close 关闭
 func (this *FileWriter) Close() error {
-	defer this.endFunc()
+	defer this.once.Do(func() {
+		this.endFunc()
+	})
+
+	path := this.rawWriter.Name()
 
 	err := this.WriteHeaderLength(types.Int(this.headerSize))
 	if err != nil {
+		_ = this.rawWriter.Close()
+		_ = os.Remove(path)
 		return err
 	}
 	err = this.WriteBodyLength(this.bodySize)
 	if err != nil {
+		_ = this.rawWriter.Close()
+		_ = os.Remove(path)
 		return err
 	}
 
-	path := this.rawWriter.Name()
 	err = this.rawWriter.Close()
 	if err != nil {
 		_ = os.Remove(path)
@@ -109,7 +118,9 @@ func (this *FileWriter) Close() error {
 
 // Discard 丢弃
 func (this *FileWriter) Discard() error {
-	defer this.endFunc()
+	defer this.once.Do(func() {
+		this.endFunc()
+	})
 
 	_ = this.rawWriter.Close()