修复热点数据从文件系统转移到内存时可能不完整的Bug/实现部分Partial Content功能

internal/caches/partial_ranges.go

@@ -0,0 +1,143 @@
+// Copyright 2022 Liuxiangchao iwind.liu@gmail.com. All rights reserved.
+
+package caches
+
+import (
+	"encoding/json"
+)
+
+// PartialRanges 内容分区范围定义
+type PartialRanges struct {
+	ranges [][2]int64
+}
+
+// NewPartialRanges 获取新对象
+func NewPartialRanges() *PartialRanges {
+	return &PartialRanges{ranges: [][2]int64{}}
+}
+
+// NewPartialRangesFromJSON 从JSON中解析范围
+func NewPartialRangesFromJSON(data []byte) (*PartialRanges, error) {
+	var rs = [][2]int64{}
+	err := json.Unmarshal(data, &rs)
+	if err != nil {
+		return nil, err
+	}
+	var r = NewPartialRanges()
+	r.ranges = rs
+	return r, nil
+}
+
+// Add 添加新范围
+func (this *PartialRanges) Add(begin int64, end int64) {
+	if begin > end {
+		begin, end = end, begin
+	}
+
+	var nr = [2]int64{begin, end}
+
+	var count = len(this.ranges)
+	if count == 0 {
+		this.ranges = [][2]int64{nr}
+		return
+	}
+
+	// insert
+	// TODO 将来使用二分法改进
+	var index = -1
+	for i, r := range this.ranges {
+		if r[0] > begin || (r[0] == begin && r[1] >= end) {
+			index = i
+			this.ranges = append(this.ranges, [2]int64{})
+			copy(this.ranges[index+1:], this.ranges[index:])
+			this.ranges[index] = nr
+			break
+		}
+	}
+
+	if index == -1 {
+		index = count
+		this.ranges = append(this.ranges, nr)
+	}
+
+	this.merge(index)
+}
+
+// Ranges 获取所有范围
+func (this *PartialRanges) Ranges() [][2]int64 {
+	return this.ranges
+}
+
+// Contains 检查是否包含某个范围
+func (this *PartialRanges) Contains(begin int64, end int64) bool {
+	if len(this.ranges) == 0 {
+		return true
+	}
+
+	// TODO 使用二分法查找改进性能
+	for _, r2 := range this.ranges {
+		if r2[0] <= begin && r2[1] >= end {
+			return true
+		}
+	}
+
+	return false
+}
+
+// AsJSON 转换为JSON
+func (this *PartialRanges) AsJSON() ([]byte, error) {
+	return json.Marshal(this.ranges)
+}
+
+func (this *PartialRanges) merge(index int) {
+	// forward
+	var lastIndex = index
+	for i := index; i >= 1; i-- {
+		var curr = this.ranges[i]
+		var prev = this.ranges[i-1]
+		var w1 = this.w(curr)
+		var w2 = this.w(prev)
+		if w1+w2 >= this.max(curr[1], prev[1])-this.min(curr[0], prev[0])-1 {
+			prev = [2]int64{this.min(curr[0], prev[0]), this.max(curr[1], prev[1])}
+			this.ranges[i-1] = prev
+			this.ranges = append(this.ranges[:i], this.ranges[i+1:]...)
+			lastIndex = i - 1
+		} else {
+			break
+		}
+	}
+
+	// backward
+	index = lastIndex
+	for index < len(this.ranges)-1 {
+		var curr = this.ranges[index]
+		var next = this.ranges[index+1]
+		var w1 = this.w(curr)
+		var w2 = this.w(next)
+		if w1+w2 >= this.max(curr[1], next[1])-this.min(curr[0], next[0])-1 {
+			curr = [2]int64{this.min(curr[0], next[0]), this.max(curr[1], next[1])}
+			this.ranges = append(this.ranges[:index], this.ranges[index+1:]...)
+			this.ranges[index] = curr
+		} else {
+			break
+		}
+	}
+}
+
+func (this *PartialRanges) w(r [2]int64) int64 {
+	return r[1] - r[0]
+}
+
+func (this *PartialRanges) min(n1 int64, n2 int64) int64 {
+	if n1 <= n2 {
+		return n1
+	}
+	return n2
+}
+
+func (this *PartialRanges) max(n1 int64, n2 int64) int64 {
+	if n1 >= n2 {
+		return n1
+	}
+	return n2
+}

internal/caches/partial_ranges_test.go

@@ -0,0 +1,124 @@
+// Copyright 2022 Liuxiangchao iwind.liu@gmail.com. All rights reserved.
+
+package caches_test
+
+import (
+	"github.com/TeaOSLab/EdgeNode/internal/caches"
+	"github.com/iwind/TeaGo/assert"
+	"github.com/iwind/TeaGo/logs"
+	"testing"
+)
+
+func TestNewPartialRanges(t *testing.T) {
+	var r = caches.NewPartialRanges()
+	r.Add(1, 100)
+	r.Add(50, 300)
+
+	r.Add(30, 80)
+	r.Add(30, 100)
+	r.Add(30, 400)
+	r.Add(1000, 10000)
+	r.Add(200, 1000)
+	r.Add(200, 10040)
+
+	logs.PrintAsJSON(r.Ranges())
+}
+
+func TestNewPartialRanges1(t *testing.T) {
+	var a = assert.NewAssertion(t)
+
+	var r = caches.NewPartialRanges()
+	r.Add(1, 100)
+	r.Add(1, 101)
+	r.Add(1, 102)
+	r.Add(2, 103)
+	r.Add(200, 300)
+	r.Add(1, 1000)
+
+	var rs = r.Ranges()
+	logs.PrintAsJSON(rs, t)
+	a.IsTrue(len(rs) == 1)
+	if len(rs) == 1 {
+		a.IsTrue(rs[0][0] == 1)
+		a.IsTrue(rs[0][1] == 1000)
+	}
+}
+
+func TestNewPartialRanges2(t *testing.T) {
+	// low -> high
+	var r = caches.NewPartialRanges()
+	r.Add(1, 100)
+	r.Add(1, 101)
+	r.Add(1, 102)
+	r.Add(2, 103)
+	r.Add(200, 300)
+	r.Add(301, 302)
+	r.Add(303, 304)
+	r.Add(250, 400)
+
+	var rs = r.Ranges()
+	logs.PrintAsJSON(rs, t)
+}
+
+func TestNewPartialRanges3(t *testing.T) {
+	// high -> low
+	var r = caches.NewPartialRanges()
+	r.Add(301, 302)
+	r.Add(303, 304)
+	r.Add(200, 300)
+	r.Add(250, 400)
+
+	var rs = r.Ranges()
+	logs.PrintAsJSON(rs, t)
+}
+
+func TestNewPartialRanges4(t *testing.T) {
+	// nearby
+	var r = caches.NewPartialRanges()
+	r.Add(301, 302)
+	r.Add(303, 304)
+	r.Add(305, 306)
+
+	r.Add(417, 417)
+	r.Add(410, 415)
+	r.Add(400, 409)
+
+	var rs = r.Ranges()
+	logs.PrintAsJSON(rs, t)
+	t.Log(r.Contains(400, 416))
+}
+
+func TestNewPartialRanges5(t *testing.T) {
+	var r = caches.NewPartialRanges()
+	for j := 0; j < 1000; j++ {
+		r.Add(int64(j), int64(j+100))
+	}
+	logs.PrintAsJSON(r.Ranges(), t)
+}
+
+func TestNewPartialRanges_AsJSON(t *testing.T) {
+	var r = caches.NewPartialRanges()
+	for j := 0; j < 1000; j++ {
+		r.Add(int64(j), int64(j+100))
+	}
+	data, err := r.AsJSON()
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Log(string(data))
+
+	r2, err := caches.NewPartialRangesFromJSON(data)
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Log(r2.Ranges())
+}
+
+func BenchmarkNewPartialRanges(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		var r = caches.NewPartialRanges()
+		for j := 0; j < 1000; j++ {
+			r.Add(int64(j), int64(j+100))
+		}
+	}
+}

internal/caches/reader_file.go

@@ -32,6 +32,10 @@ func NewFileReader(fp *os.File) *FileReader {
 }
 
 func (this *FileReader) Init() error {
+	return this.InitAutoDiscard(true)
+}
+
+func (this *FileReader) InitAutoDiscard(autoDiscard bool) error {
 	if this.openFile != nil {
 		this.meta = this.openFile.meta
 		this.header = this.openFile.header
@@ -39,11 +43,13 @@ func (this *FileReader) Init() error {
 
 	isOk := false
 
-	defer func() {
-		if !isOk {
-			_ = this.discard()
-		}
-	}()
+	if autoDiscard {
+		defer func() {
+			if !isOk {
+				_ = this.discard()
+			}
+		}()
+	}
 
 	var buf = this.meta
 	if len(buf) == 0 {
@@ -78,13 +84,13 @@ func (this *FileReader) Init() error {
 	this.headerOffset = int64(SizeMeta) + int64(urlLength)
 
 	// body
+	this.bodyOffset = this.headerOffset + int64(headerSize)
 	bodySize := int(binary.BigEndian.Uint64(buf[SizeExpiresAt+SizeStatus+SizeURLLength+SizeHeaderLength : SizeExpiresAt+SizeStatus+SizeURLLength+SizeHeaderLength+SizeBodyLength]))
 	if bodySize == 0 {
 		isOk = true
 		return nil
 	}
 	this.bodySize = int64(bodySize)
-	this.bodyOffset = this.headerOffset + int64(headerSize)
 
 	// read header
 	if this.openFileCache != nil && len(this.header) == 0 {

internal/caches/reader_file_test.go

@@ -54,6 +54,30 @@ func TestFileReader(t *testing.T) {
 	}
 }
 
+func TestFileReader_ReadHeader(t *testing.T) {
+	var path = "/Users/WorkSpace/EdgeProject/EdgeCache/p43/12/6b/126bbed90fc80f2bdfb19558948b0d49.cache"
+	fp, err := os.Open(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		_ = fp.Close()
+	}()
+	var reader = NewFileReader(fp)
+	err = reader.Init()
+	if err != nil {
+		t.Fatal(err)
+	}
+	var buf = make([]byte, 16*1024)
+	err = reader.ReadHeader(buf, func(n int) (goNext bool, err error) {
+		t.Log("header:", string(buf[:n]))
+		return
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
 func TestFileReader_Range(t *testing.T) {
 	storage := NewFileStorage(&serverconfigs.HTTPCachePolicy{
 		Id:   1,

internal/caches/storage_file.go

@@ -325,11 +325,11 @@ func (this *FileStorage) openReader(key string, allowMemory bool, useStale bool)
 }
 
 // OpenWriter 打开缓存文件等待写入
-func (this *FileStorage) OpenWriter(key string, expiredAt int64, status int, size int64) (Writer, error) {
+func (this *FileStorage) OpenWriter(key string, expiredAt int64, status int, size int64, isPartial bool) (Writer, error) {
 	// 先尝试内存缓存
 	// 我们限定仅小文件优先存在内存中
-	if this.memoryStorage != nil && size > 0 && size < 32*1024*1024 {
-		writer, err := this.memoryStorage.OpenWriter(key, expiredAt, status, size)
+	if !isPartial && this.memoryStorage != nil && size > 0 && size < 32*1024*1024 {
+		writer, err := this.memoryStorage.OpenWriter(key, expiredAt, status, size, false)
 		if err == nil {
 			return writer, nil
 		}
@@ -361,13 +361,13 @@ func (this *FileStorage) OpenWriter(key string, expiredAt int64, status int, siz
 	if this.policy.MaxKeys > 0 && count > this.policy.MaxKeys {
 		return nil, NewCapacityError("write file cache failed: too many keys in cache storage")
 	}
-	capacityBytes := this.diskCapacityBytes()
+	var capacityBytes = this.diskCapacityBytes()
 	if capacityBytes > 0 && capacityBytes <= this.totalSize {
 		return nil, NewCapacityError("write file cache failed: over disk size, current total size: " + strconv.FormatInt(this.totalSize, 10) + " bytes, capacity: " + strconv.FormatInt(capacityBytes, 10))
 	}
 
-	hash := stringutil.Md5(key)
-	dir := this.cacheConfig.Dir + "/p" + strconv.FormatInt(this.policy.Id, 10) + "/" + hash[:2] + "/" + hash[2:4]
+	var hash = stringutil.Md5(key)
+	var dir = this.cacheConfig.Dir + "/p" + strconv.FormatInt(this.policy.Id, 10) + "/" + hash[:2] + "/" + hash[2:4]
 	_, err = os.Stat(dir)
 	if err != nil {
 		if !os.IsNotExist(err) {
@@ -387,6 +387,9 @@ func (this *FileStorage) OpenWriter(key string, expiredAt int64, status int, siz
 		return nil, ErrFileIsWriting
 	}
 	var tmpPath = cachePath + ".tmp"
+	if isPartial {
+		tmpPath = cachePath
+	}
 
 	// 先删除
 	err = this.list.Remove(hash)
@@ -421,70 +424,96 @@ func (this *FileStorage) OpenWriter(key string, expiredAt int64, status int, siz
 		return nil, ErrFileIsWriting
 	}
 
-	err = writer.Truncate(0)
-	if err != nil {
-		return nil, err
-	}
-
-	// 写入过期时间
-	bytes4 := make([]byte, 4)
-	{
-		binary.BigEndian.PutUint32(bytes4, uint32(expiredAt))
-		_, err = writer.Write(bytes4)
-		if err != nil {
-			return nil, err
+	// 是否已经有内容
+	var isNewCreated = true
+	var partialBodyOffset int64
+	if isPartial {
+		partialFP, err := os.OpenFile(tmpPath, os.O_RDONLY, 0444)
+		if err == nil {
+			var partialReader = NewFileReader(partialFP)
+			err = partialReader.InitAutoDiscard(false)
+			if err == nil && partialReader.bodyOffset > 0 {
+				isNewCreated = false
+				partialBodyOffset = partialReader.bodyOffset
+			}
+			_ = partialReader.Close()
 		}
 	}
 
-	// 写入状态码
-	if status > 999 || status < 100 {
-		status = 200
-	}
-	_, err = writer.WriteString(strconv.Itoa(status))
-	if err != nil {
-		return nil, err
-	}
-
-	// 写入URL长度
-	{
-		binary.BigEndian.PutUint32(bytes4, uint32(len(key)))
-		_, err = writer.Write(bytes4)
+	if isNewCreated {
+		err = writer.Truncate(0)
 		if err != nil {
 			return nil, err
 		}
-	}
 
-	// 写入Header Length
-	{
-		binary.BigEndian.PutUint32(bytes4, uint32(0))
-		_, err = writer.Write(bytes4)
+		// 写入过期时间
+		bytes4 := make([]byte, 4)
+		{
+			binary.BigEndian.PutUint32(bytes4, uint32(expiredAt))
+			_, err = writer.Write(bytes4)
+			if err != nil {
+				return nil, err
+			}
+		}
+
+		// 写入状态码
+		if status > 999 || status < 100 {
+			status = 200
+		}
+		_, err = writer.WriteString(strconv.Itoa(status))
 		if err != nil {
 			return nil, err
 		}
-	}
 
-	// 写入Body Length
-	{
-		b := make([]byte, SizeBodyLength)
-		binary.BigEndian.PutUint64(b, uint64(0))
-		_, err = writer.Write(b)
+		// 写入URL长度
+		{
+			binary.BigEndian.PutUint32(bytes4, uint32(len(key)))
+			_, err = writer.Write(bytes4)
+			if err != nil {
+				return nil, err
+			}
+		}
+
+		// 写入Header Length
+		{
+			binary.BigEndian.PutUint32(bytes4, uint32(0))
+			_, err = writer.Write(bytes4)
+			if err != nil {
+				return nil, err
+			}
+		}
+
+		// 写入Body Length
+		{
+			b := make([]byte, SizeBodyLength)
+			binary.BigEndian.PutUint64(b, uint64(0))
+			_, err = writer.Write(b)
+			if err != nil {
+				return nil, err
+			}
+		}
+
+		// 写入URL
+		_, err = writer.WriteString(key)
 		if err != nil {
 			return nil, err
 		}
 	}
 
-	// 写入URL
-	_, err = writer.WriteString(key)
-	if err != nil {
-		return nil, err
-	}
-
 	isOk = true
-	return NewFileWriter(writer, key, expiredAt, func() {
-		sharedWritingFileKeyLocker.Lock()
-		delete(sharedWritingFileKeyMap, key)
-		sharedWritingFileKeyLocker.Unlock()
-	}), nil
+	if isPartial {
+		return NewPartialFileWriter(writer, key, expiredAt, isNewCreated, isPartial, partialBodyOffset, func() {
+			sharedWritingFileKeyLocker.Lock()
+			delete(sharedWritingFileKeyMap, key)
+			sharedWritingFileKeyLocker.Unlock()
+		}), nil
+	} else {
+		return NewFileWriter(writer, key, expiredAt, func() {
+			sharedWritingFileKeyLocker.Lock()
+			delete(sharedWritingFileKeyMap, key)
+			sharedWritingFileKeyLocker.Unlock()
+		}), nil
+	}
 }
 
 // AddToList 添加到List
@@ -930,6 +959,9 @@ func (this *FileStorage) hotLoop() {
 
 			err = reader.ReadBody(buf, func(n int) (goNext bool, err error) {
 				_, err = writer.Write(buf[:n])
+				if err == nil {
+					goNext = true
+				}
 				return
 			})
 			if err != nil {

internal/caches/storage_file_test.go

@@ -62,7 +62,7 @@ func TestFileStorage_OpenWriter(t *testing.T) {
 
 	header := []byte("Header")
 	body := []byte("This is Body")
-	writer, err := storage.OpenWriter("my-key", time.Now().Unix()+86400, 200, -1)
+	writer, err := storage.OpenWriter("my-key", time.Now().Unix()+86400, 200, -1, false)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -87,6 +87,41 @@ func TestFileStorage_OpenWriter(t *testing.T) {
 	t.Log("ok")
 }
 
+func TestFileStorage_OpenWriter_Partial(t *testing.T) {
+	var storage = NewFileStorage(&serverconfigs.HTTPCachePolicy{
+		Id:   2,
+		IsOn: true,
+		Options: map[string]interface{}{
+			"dir": Tea.Root + "/caches",
+		},
+	})
+	err := storage.Init()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	writer, err := storage.OpenWriter("my-key", time.Now().Unix()+86400, 200, -1, true)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	_, err = writer.WriteHeader([]byte("Content-Type:text/html; charset=utf-8"))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = writer.WriteAt([]byte("Hello, World"), 0)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = writer.Close()
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Log(writer)
+}
+
 func TestFileStorage_OpenWriter_HTTP(t *testing.T) {
 	storage := NewFileStorage(&serverconfigs.HTTPCachePolicy{
 		Id:   1,
@@ -104,7 +139,7 @@ func TestFileStorage_OpenWriter_HTTP(t *testing.T) {
 		t.Log(time.Since(now).Seconds()*1000, "ms")
 	}()
 
-	writer, err := storage.OpenWriter("my-http-response", time.Now().Unix()+86400, 200, -1)
+	writer, err := storage.OpenWriter("my-http-response", time.Now().Unix()+86400, 200, -1, false)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -177,10 +212,11 @@ func TestFileStorage_Concurrent_Open_DifferentFile(t *testing.T) {
 		go func(i int) {
 			defer wg.Done()
 
-			writer, err := storage.OpenWriter("abc"+strconv.Itoa(i), time.Now().Unix()+3600, 200, -1)
+			writer, err := storage.OpenWriter("abc"+strconv.Itoa(i), time.Now().Unix()+3600, 200, -1, false)
 			if err != nil {
 				if err != ErrFileIsWriting {
-					t.Fatal(err)
+					t.Error(err)
+					return
 				}
 				return
 			}
@@ -188,7 +224,8 @@ func TestFileStorage_Concurrent_Open_DifferentFile(t *testing.T) {
 
 			_, err = writer.Write([]byte("Hello,World"))
 			if err != nil {
-				t.Fatal(err)
+				t.Error(err)
+				return
 			}
 
 			// 故意造成慢速写入
@@ -196,7 +233,8 @@ func TestFileStorage_Concurrent_Open_DifferentFile(t *testing.T) {
 
 			err = writer.Close()
 			if err != nil {
-				t.Fatal(err)
+				t.Error(err)
+				return
 			}
 		}(i)
 	}
@@ -229,10 +267,11 @@ func TestFileStorage_Concurrent_Open_SameFile(t *testing.T) {
 		go func(i int) {
 			defer wg.Done()
 
-			writer, err := storage.OpenWriter("abc"+strconv.Itoa(0), time.Now().Unix()+3600, 200, -1)
+			writer, err := storage.OpenWriter("abc"+strconv.Itoa(0), time.Now().Unix()+3600, 200, -1, false)
 			if err != nil {
 				if err != ErrFileIsWriting {
-					t.Fatal(err)
+					t.Error(err)
+					return
 				}
 				return
 			}
@@ -241,7 +280,8 @@ func TestFileStorage_Concurrent_Open_SameFile(t *testing.T) {
 			t.Log("writing")
 			_, err = writer.Write([]byte("Hello,World"))
 			if err != nil {
-				t.Fatal(err)
+				t.Error(err)
+				return
 			}
 
 			// 故意造成慢速写入
@@ -249,7 +289,8 @@ func TestFileStorage_Concurrent_Open_SameFile(t *testing.T) {
 
 			err = writer.Close()
 			if err != nil {
-				t.Fatal(err)
+				t.Error(err)
+				return
 			}
 		}(i)
 	}

internal/caches/storage_interface.go

@@ -13,7 +13,7 @@ type StorageInterface interface {
 	OpenReader(key string, useStale bool) (reader Reader, err error)
 
 	// OpenWriter 打开缓存写入器等待写入
-	OpenWriter(key string, expiredAt int64, status int, size int64) (Writer, error)
+	OpenWriter(key string, expiredAt int64, status int, size int64, isPartial bool) (Writer, error)
 
 	// Delete 删除某个键值对应的缓存
 	Delete(key string) error

internal/caches/storage_memory.go

@@ -145,7 +145,11 @@ func (this *MemoryStorage) OpenReader(key string, useStale bool) (Reader, error)
 }
 
 // OpenWriter 打开缓存写入器等待写入
-func (this *MemoryStorage) OpenWriter(key string, expiredAt int64, status int, size int64) (Writer, error) {
+func (this *MemoryStorage) OpenWriter(key string, expiredAt int64, status int, size int64, isPartial bool) (Writer, error) {
+	// TODO 内存缓存暂时不支持分块内容存储
+	if isPartial {
+		return nil, ErrFileIsWriting
+	}
 	return this.openWriter(key, expiredAt, status, size, true)
 }
 
@@ -387,7 +391,7 @@ func (this *MemoryStorage) flushItem(key string) {
 		return
 	}
 
-	writer, err := this.parentStorage.OpenWriter(key, item.ExpiredAt, item.Status, -1)
+	writer, err := this.parentStorage.OpenWriter(key, item.ExpiredAt, item.Status, -1, false)
 	if err != nil {
 		if !CanIgnoreErr(err) {
 			remotelogs.Error("CACHE", "flush items failed: open writer failed: "+err.Error())

internal/caches/storage_memory_test.go

@@ -15,7 +15,7 @@ import (
 func TestMemoryStorage_OpenWriter(t *testing.T) {
 	storage := NewMemoryStorage(&serverconfigs.HTTPCachePolicy{}, nil)
 
-	writer, err := storage.OpenWriter("abc", time.Now().Unix()+60, 200, -1)
+	writer, err := storage.OpenWriter("abc", time.Now().Unix()+60, 200, -1, false)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -62,7 +62,7 @@ func TestMemoryStorage_OpenWriter(t *testing.T) {
 		}
 	}
 
-	writer, err = storage.OpenWriter("abc", time.Now().Unix()+60, 200, -1)
+	writer, err = storage.OpenWriter("abc", time.Now().Unix()+60, 200, -1, false)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -103,7 +103,7 @@ func TestMemoryStorage_OpenReaderLock(t *testing.T) {
 func TestMemoryStorage_Delete(t *testing.T) {
 	storage := NewMemoryStorage(&serverconfigs.HTTPCachePolicy{}, nil)
 	{
-		writer, err := storage.OpenWriter("abc", time.Now().Unix()+60, 200, -1)
+		writer, err := storage.OpenWriter("abc", time.Now().Unix()+60, 200, -1, false)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -111,7 +111,7 @@ func TestMemoryStorage_Delete(t *testing.T) {
 		t.Log(len(storage.valuesMap))
 	}
 	{
-		writer, err := storage.OpenWriter("abc1", time.Now().Unix()+60, 200, -1)
+		writer, err := storage.OpenWriter("abc1", time.Now().Unix()+60, 200, -1, false)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -126,7 +126,7 @@ func TestMemoryStorage_Stat(t *testing.T) {
 	storage := NewMemoryStorage(&serverconfigs.HTTPCachePolicy{}, nil)
 	expiredAt := time.Now().Unix() + 60
 	{
-		writer, err := storage.OpenWriter("abc", expiredAt, 200, -1)
+		writer, err := storage.OpenWriter("abc", expiredAt, 200, -1, false)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -139,7 +139,7 @@ func TestMemoryStorage_Stat(t *testing.T) {
 		})
 	}
 	{
-		writer, err := storage.OpenWriter("abc1", expiredAt, 200, -1)
+		writer, err := storage.OpenWriter("abc1", expiredAt, 200, -1, false)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -163,7 +163,7 @@ func TestMemoryStorage_CleanAll(t *testing.T) {
 	storage := NewMemoryStorage(&serverconfigs.HTTPCachePolicy{}, nil)
 	expiredAt := time.Now().Unix() + 60
 	{
-		writer, err := storage.OpenWriter("abc", expiredAt, 200, -1)
+		writer, err := storage.OpenWriter("abc", expiredAt, 200, -1, false)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -175,7 +175,7 @@ func TestMemoryStorage_CleanAll(t *testing.T) {
 		})
 	}
 	{
-		writer, err := storage.OpenWriter("abc1", expiredAt, 200, -1)
+		writer, err := storage.OpenWriter("abc1", expiredAt, 200, -1, false)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -198,7 +198,7 @@ func TestMemoryStorage_Purge(t *testing.T) {
 	storage := NewMemoryStorage(&serverconfigs.HTTPCachePolicy{}, nil)
 	expiredAt := time.Now().Unix() + 60
 	{
-		writer, err := storage.OpenWriter("abc", expiredAt, 200, -1)
+		writer, err := storage.OpenWriter("abc", expiredAt, 200, -1, false)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -210,7 +210,7 @@ func TestMemoryStorage_Purge(t *testing.T) {
 		})
 	}
 	{
-		writer, err := storage.OpenWriter("abc1", expiredAt, 200, -1)
+		writer, err := storage.OpenWriter("abc1", expiredAt, 200, -1, false)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -241,7 +241,7 @@ func TestMemoryStorage_Expire(t *testing.T) {
 	for i := 0; i < 1000; i++ {
 		expiredAt := time.Now().Unix() + int64(rands.Int(0, 60))
 		key := "abc" + strconv.Itoa(i)
-		writer, err := storage.OpenWriter(key, expiredAt, 200, -1)
+		writer, err := storage.OpenWriter(key, expiredAt, 200, -1, false)
 		if err != nil {
 			t.Fatal(err)
 		}

internal/caches/writer.go

@@ -8,6 +8,9 @@ type Writer interface {
 	// Write 写入Body数据
 	Write(data []byte) (n int, err error)
 
+	// WriteAt 在指定位置写入数据
+	WriteAt(data []byte, offset int64) error
+
 	// HeaderSize 写入的Header数据大小
 	HeaderSize() int64
 

internal/caches/writer_file.go

@@ -2,6 +2,7 @@ package caches
 
 import (
 	"encoding/binary"
+	"errors"
 	"github.com/iwind/TeaGo/types"
 	"io"
 	"os"
@@ -65,6 +66,13 @@ func (this *FileWriter) Write(data []byte) (n int, err error) {
 	return
 }
 
+// WriteAt 在指定位置写入数据
+func (this *FileWriter) WriteAt(data []byte, offset int64) error {
+	_ = data
+	_ = offset
+	return errors.New("not supported")
+}
+
 // WriteBodyLength 写入Body长度数据
 func (this *FileWriter) WriteBodyLength(bodyLength int64) error {
 	bytes8 := make([]byte, 8)

internal/caches/writer_memory.go

@@ -1,6 +1,7 @@
 package caches
 
 import (
+	"errors"
 	"github.com/cespare/xxhash"
 	"sync"
 	"time"
@@ -55,6 +56,13 @@ func (this *MemoryWriter) Write(data []byte) (n int, err error) {
 	return len(data), nil
 }
 
+// WriteAt 在指定位置写入数据
+func (this *MemoryWriter) WriteAt(b []byte, offset int64) error {
+	_ = b
+	_ = offset
+	return errors.New("not supported")
+}
+
 // HeaderSize 数据尺寸
 func (this *MemoryWriter) HeaderSize() int64 {
 	return this.headerSize

internal/caches/writer_partial_file.go

@@ -0,0 +1,173 @@
+// Copyright 2022 Liuxiangchao iwind.liu@gmail.com. All rights reserved.
+
+package caches
+
+import (
+	"encoding/binary"
+	"github.com/iwind/TeaGo/types"
+	"io"
+	"os"
+	"strings"
+	"sync"
+)
+
+type PartialFileWriter struct {
+	rawWriter  *os.File
+	key        string
+	headerSize int64
+	bodySize   int64
+	expiredAt  int64
+	endFunc    func()
+	once       sync.Once
+
+	isNew      bool
+	isPartial  bool
+	bodyOffset int64
+}
+
+func NewPartialFileWriter(rawWriter *os.File, key string, expiredAt int64, isNew bool, isPartial bool, bodyOffset int64, endFunc func()) *PartialFileWriter {
+	return &PartialFileWriter{
+		key:        key,
+		rawWriter:  rawWriter,
+		expiredAt:  expiredAt,
+		endFunc:    endFunc,
+		isNew:      isNew,
+		isPartial:  isPartial,
+		bodyOffset: bodyOffset,
+	}
+}
+
+// WriteHeader 写入数据
+func (this *PartialFileWriter) WriteHeader(data []byte) (n int, err error) {
+	if !this.isNew {
+		return
+	}
+	n, err = this.rawWriter.Write(data)
+	this.headerSize += int64(n)
+	if err != nil {
+		_ = this.Discard()
+	}
+	return
+}
+
+// WriteHeaderLength 写入Header长度数据
+func (this *PartialFileWriter) WriteHeaderLength(headerLength int) error {
+	bytes4 := make([]byte, 4)
+	binary.BigEndian.PutUint32(bytes4, uint32(headerLength))
+	_, err := this.rawWriter.Seek(SizeExpiresAt+SizeStatus+SizeURLLength, io.SeekStart)
+	if err != nil {
+		_ = this.Discard()
+		return err
+	}
+	_, err = this.rawWriter.Write(bytes4)
+	if err != nil {
+		_ = this.Discard()
+		return err
+	}
+	return nil
+}
+
+// Write 写入数据
+func (this *PartialFileWriter) Write(data []byte) (n int, err error) {
+	n, err = this.rawWriter.Write(data)
+	this.bodySize += int64(n)
+	if err != nil {
+		_ = this.Discard()
+	}
+	return
+}
+
+// WriteAt 在指定位置写入数据
+func (this *PartialFileWriter) WriteAt(data []byte, offset int64) error {
+	if this.bodyOffset == 0 {
+		this.bodyOffset = SizeMeta + int64(len(this.key)) + this.headerSize
+	}
+	_, err := this.rawWriter.WriteAt(data, this.bodyOffset+offset)
+	return err
+}
+
+// WriteBodyLength 写入Body长度数据
+func (this *PartialFileWriter) WriteBodyLength(bodyLength int64) error {
+	bytes8 := make([]byte, 8)
+	binary.BigEndian.PutUint64(bytes8, uint64(bodyLength))
+	_, err := this.rawWriter.Seek(SizeExpiresAt+SizeStatus+SizeURLLength+SizeHeaderLength, io.SeekStart)
+	if err != nil {
+		_ = this.Discard()
+		return err
+	}
+	_, err = this.rawWriter.Write(bytes8)
+	if err != nil {
+		_ = this.Discard()
+		return err
+	}
+	return nil
+}
+
+// Close 关闭
+func (this *PartialFileWriter) Close() error {
+	defer this.once.Do(func() {
+		this.endFunc()
+	})
+
+	var path = this.rawWriter.Name()
+
+	if this.isNew {
+		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
+		}
+	}
+
+	err := this.rawWriter.Close()
+	if err != nil {
+		_ = os.Remove(path)
+	} else if !this.isPartial {
+		err = os.Rename(path, strings.Replace(path, ".tmp", "", 1))
+		if err != nil {
+			_ = os.Remove(path)
+		}
+	}
+
+	return err
+}
+
+// Discard 丢弃
+func (this *PartialFileWriter) Discard() error {
+	defer this.once.Do(func() {
+		this.endFunc()
+	})
+
+	_ = this.rawWriter.Close()
+
+	err := os.Remove(this.rawWriter.Name())
+	return err
+}
+
+func (this *PartialFileWriter) HeaderSize() int64 {
+	return this.headerSize
+}
+
+func (this *PartialFileWriter) BodySize() int64 {
+	return this.bodySize
+}
+
+func (this *PartialFileWriter) ExpiredAt() int64 {
+	return this.expiredAt
+}
+
+func (this *PartialFileWriter) Key() string {
+	return this.key
+}
+
+// ItemType 获取内容类型
+func (this *PartialFileWriter) ItemType() ItemType {
+	return ItemTypeFile
+}

internal/caches/writer_partial_file_test.go

@@ -0,0 +1,50 @@
+// Copyright 2022 Liuxiangchao iwind.liu@gmail.com. All rights reserved.
+
+package caches_test
+
+import (
+	"github.com/TeaOSLab/EdgeNode/internal/caches"
+	"github.com/iwind/TeaGo/types"
+	"io/ioutil"
+	"os"
+	"testing"
+	"time"
+)
+
+func TestPartialFileWriter_SeekOffset(t *testing.T) {
+	var path = "/tmp/test@partial.cache"
+	_ = os.Remove(path)
+
+	var reader = func() {
+		data, err := ioutil.ReadFile(path)
+		if err != nil {
+			t.Fatal(err)
+		}
+		t.Log("["+types.String(len(data))+"]", string(data))
+	}
+
+	fp, err := os.OpenFile(path, os.O_CREATE|os.O_WRONLY, 0666)
+	if err != nil {
+		t.Fatal(err)
+	}
+	var writer = caches.NewPartialFileWriter(fp, "test", time.Now().Unix()+86500, true, true, 0, func() {
+		t.Log("end")
+	})
+	_, err = writer.WriteHeader([]byte("header"))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// 移动位置
+	err = writer.WriteAt([]byte("HELLO"), 100)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = writer.Close()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	reader()
+}

internal/nodes/api_stream.go

@@ -182,7 +182,7 @@ func (this *APIStream) handleWriteCache(message *pb.NodeStreamMessage) error {
 	}
 
 	expiredAt := time.Now().Unix() + msg.LifeSeconds
-	writer, err := storage.OpenWriter(msg.Key, expiredAt, 200, int64(len(msg.Value)))
+	writer, err := storage.OpenWriter(msg.Key, expiredAt, 200, int64(len(msg.Value)), false)
 	if err != nil {
 		this.replyFail(message.RequestId, "prepare writing failed: "+err.Error())
 		return err
@@ -462,7 +462,7 @@ func (this *APIStream) handlePreheatCache(message *pb.NodeStreamMessage) error {
 			}
 
 			expiredAt := time.Now().Unix() + 8600
-			writer, err := storage.OpenWriter(key, expiredAt, 200, resp.ContentLength) // TODO 可以设置缓存过期时间
+			writer, err := storage.OpenWriter(key, expiredAt, 200, resp.ContentLength, false) // TODO 可以设置缓存过期时间
 			if err != nil {
 				locker.Lock()
 				errorMessages = append(errorMessages, "open cache writer failed: "+key+": "+err.Error())

internal/nodes/http_writer.go

@@ -243,7 +243,7 @@ func (this *HTTPWriter) PrepareCache(resp *http.Response, size int64) {
 
 	var expiredAt = utils.UnixTime() + life
 	var cacheKey = this.req.cacheKey
-	cacheWriter, err := storage.OpenWriter(cacheKey, expiredAt, this.StatusCode(), size)
+	cacheWriter, err := storage.OpenWriter(cacheKey, expiredAt, this.StatusCode(), size, false)
 	if err != nil {
 		if !caches.CanIgnoreErr(err) {
 			remotelogs.Error("HTTP_WRITER", "write cache failed: "+err.Error())
@@ -310,6 +310,7 @@ func (this *HTTPWriter) PrepareWebP(resp *http.Response, size int64) {
 				return
 			}
 			this.Header().Del("Content-Encoding")
+			this.Header().Del("Content-Length")
 			this.rawReader = reader
 		case "": // 空
 		default:
@@ -559,7 +560,7 @@ func (this *HTTPWriter) Close() {
 		if this.cacheWriter != nil {
 			var cacheKey = this.cacheWriter.Key() + webpSuffix
 
-			webpCacheWriter, _ = this.cacheStorage.OpenWriter(cacheKey, this.cacheWriter.ExpiredAt(), this.StatusCode(), -1)
+			webpCacheWriter, _ = this.cacheStorage.OpenWriter(cacheKey, this.cacheWriter.ExpiredAt(), this.StatusCode(), -1, false)
 			if webpCacheWriter != nil {
 				// 写入Header
 				for k, v := range this.Header() {