first commit

av/pktque/buf.go

@@ -0,0 +1,73 @@
+package pktque
+
+import (
+	"github.com/deepch/vdk/av"
+)
+
+type Buf struct {
+	Head, Tail BufPos
+	pkts       []av.Packet
+	Size       int
+	Count      int
+}
+
+func NewBuf() *Buf {
+	return &Buf{
+		pkts: make([]av.Packet, 64),
+	}
+}
+
+func (self *Buf) Pop() av.Packet {
+	if self.Count == 0 {
+		panic("pktque.Buf: Pop() when count == 0")
+	}
+
+	i := int(self.Head) & (len(self.pkts) - 1)
+	pkt := self.pkts[i]
+	self.pkts[i] = av.Packet{}
+	self.Size -= len(pkt.Data)
+	self.Head++
+	self.Count--
+
+	return pkt
+}
+
+func (self *Buf) grow() {
+	newpkts := make([]av.Packet, len(self.pkts)*2)
+	for i := self.Head; i.LT(self.Tail); i++ {
+		newpkts[int(i)&(len(newpkts)-1)] = self.pkts[int(i)&(len(self.pkts)-1)]
+	}
+	self.pkts = newpkts
+}
+
+func (self *Buf) Push(pkt av.Packet) {
+	if self.Count == len(self.pkts) {
+		self.grow()
+	}
+	self.pkts[int(self.Tail)&(len(self.pkts)-1)] = pkt
+	self.Tail++
+	self.Count++
+	self.Size += len(pkt.Data)
+}
+
+func (self *Buf) Get(pos BufPos) av.Packet {
+	return self.pkts[int(pos)&(len(self.pkts)-1)]
+}
+
+func (self *Buf) IsValidPos(pos BufPos) bool {
+	return pos.GE(self.Head) && pos.LT(self.Tail)
+}
+
+type BufPos int
+
+func (self BufPos) LT(pos BufPos) bool {
+	return self-pos < 0
+}
+
+func (self BufPos) GE(pos BufPos) bool {
+	return self-pos >= 0
+}
+
+func (self BufPos) GT(pos BufPos) bool {
+	return self-pos > 0
+}