byte-ring.go -> byte-slider.go

byte-slider.go

@@ -0,0 +1,31 @@
+// byte-slider.go
+package expr
+
+import "bytes"
+
+type ByteSlider struct {
+	buf    []byte
+	length int
+}
+
+func NewByteSlider(size int) *ByteSlider {
+	return &ByteSlider{
+		buf:    make([]byte, max(1, size)),
+		length: 0,
+	}
+}
+
+func (self *ByteSlider) PushEnd(b byte) {
+	if self.length == cap(self.buf) {
+		self.length--
+		for i := 0; i < self.length; i++ {
+			self.buf[i] = self.buf[i+1]
+		}
+	}
+	self.buf[self.length] = b
+	self.length++
+}
+
+func (self *ByteSlider) Equal(target []byte) bool {
+	return target != nil && bytes.Equal(self.buf, target)
+}