优化缓存管理

internal/caches/reader_memory.go

@@ -0,0 +1,160 @@
+package caches
+
+import (
+	"errors"
+)
+
+type MemoryReader struct {
+	item *MemoryItem
+}
+
+func NewMemoryReader(item *MemoryItem) *MemoryReader {
+	return &MemoryReader{item: item}
+}
+
+func (this *MemoryReader) Init() error {
+	return nil
+}
+
+func (this *MemoryReader) Status() int {
+	return this.item.Status
+}
+
+func (this *MemoryReader) HeaderSize() int64 {
+	return int64(len(this.item.HeaderValue))
+}
+
+func (this *MemoryReader) BodySize() int64 {
+	return int64(len(this.item.BodyValue))
+}
+
+func (this *MemoryReader) ReadHeader(buf []byte, callback ReaderFunc) error {
+	l := len(buf)
+	if l == 0 {
+		return errors.New("using empty buffer")
+	}
+
+	size := len(this.item.HeaderValue)
+	offset := 0
+	for {
+		left := size - offset
+		if l <= left {
+			copy(buf, this.item.HeaderValue[offset:offset+l])
+			goNext, e := callback(l)
+			if e != nil {
+				return e
+			}
+			if !goNext {
+				break
+			}
+		} else {
+			copy(buf, this.item.HeaderValue[offset:])
+			_, e := callback(left)
+			if e != nil {
+				return e
+			}
+			break
+		}
+		offset += l
+		if offset >= size {
+			break
+		}
+	}
+
+	return nil
+}
+
+func (this *MemoryReader) ReadBody(buf []byte, callback ReaderFunc) error {
+	l := len(buf)
+	if l == 0 {
+		return errors.New("using empty buffer")
+	}
+
+	size := len(this.item.BodyValue)
+	offset := 0
+	for {
+		left := size - offset
+		if l <= left {
+			copy(buf, this.item.BodyValue[offset:offset+l])
+			goNext, e := callback(l)
+			if e != nil {
+				return e
+			}
+			if !goNext {
+				break
+			}
+		} else {
+			copy(buf, this.item.BodyValue[offset:])
+			_, e := callback(left)
+			if e != nil {
+				return e
+			}
+			break
+		}
+		offset += l
+		if offset >= size {
+			break
+		}
+	}
+	return nil
+}
+
+func (this *MemoryReader) ReadBodyRange(buf []byte, start int64, end int64, callback ReaderFunc) error {
+	offset := start
+	bodySize := int64(len(this.item.BodyValue))
+	if start < 0 {
+		offset = bodySize + end
+		end = bodySize - 1
+	} else if end < 0 {
+		offset = start
+		end = bodySize - 1
+	}
+
+	if end >= bodySize {
+		end = bodySize - 1
+	}
+
+	if offset < 0 || end < 0 || offset > end {
+		return ErrInvalidRange
+	}
+
+	newData := this.item.BodyValue[offset : end+1]
+
+	l := len(buf)
+	if l == 0 {
+		return errors.New("using empty buffer")
+	}
+
+	size := len(newData)
+	offset2 := 0
+	for {
+		left := size - offset2
+		if l <= left {
+			copy(buf, newData[offset2:offset2+l])
+			goNext, e := callback(l)
+			if e != nil {
+				return e
+			}
+			if !goNext {
+				break
+			}
+		} else {
+			copy(buf, newData[offset2:])
+			_, e := callback(left)
+			if e != nil {
+				return e
+			}
+			break
+		}
+		offset2 += l
+		if offset2 >= size {
+			break
+		}
+	}
+
+	return nil
+}
+
+func (this *MemoryReader) Close() error {
+	return nil
+}