实现WAF

internal/grids/item.go

@@ -0,0 +1,88 @@
+package grids
+
+import (
+	"bytes"
+	"compress/gzip"
+	"github.com/dchest/siphash"
+	"github.com/iwind/TeaGo/logs"
+	"sync/atomic"
+	"unsafe"
+)
+
+type ItemType = int8
+
+const (
+	ItemInt64     = 1
+	ItemBytes     = 2
+	ItemInterface = 3
+)
+
+func HashKey(key []byte) uint64 {
+	return siphash.Hash(0, 0, key)
+}
+
+type Item struct {
+	Key            []byte
+	ExpireAt       int64
+	Type           ItemType
+	ValueInt64     int64
+	ValueBytes     []byte
+	ValueInterface interface{}
+	IsCompressed   bool
+
+	// linked list
+	Prev *Item
+	Next *Item
+
+	size int64
+}
+
+func NewItem(key []byte, dataType ItemType) *Item {
+	return &Item{
+		Key:  key,
+		Type: dataType,
+	}
+}
+
+func (this *Item) HashKey() uint64 {
+	return HashKey(this.Key)
+}
+
+func (this *Item) IncreaseInt64(delta int64) {
+	atomic.AddInt64(&this.ValueInt64, delta)
+}
+
+func (this *Item) Bytes() []byte {
+	if this.IsCompressed {
+		reader, err := gzip.NewReader(bytes.NewBuffer(this.ValueBytes))
+		if err != nil {
+			logs.Error(err)
+			return this.ValueBytes
+		}
+
+		buf := make([]byte, 256)
+		dataBuf := bytes.NewBuffer([]byte{})
+		for {
+			n, err := reader.Read(buf)
+			if n > 0 {
+				dataBuf.Write(buf[:n])
+			}
+			if err != nil {
+				break
+			}
+		}
+		return dataBuf.Bytes()
+	}
+	return this.ValueBytes
+}
+
+func (this *Item) String() string {
+	return string(this.Bytes())
+}
+
+func (this *Item) Size() int64 {
+	if this.size == 0 {
+		this.size = int64(int(unsafe.Sizeof(*this)) + len(this.Key) + len(this.ValueBytes))
+	}
+	return this.size
+}