rtmp: simplify recv call in C_RTMPSockBuf_Fill

rtmp/rtmp.go

@@ -615,10 +615,9 @@ func C_ReadN(r *C_RTMP, buffer *byte, n int) int {
 		}
 
 		if nRead > 0 {
-			memmove(unsafe.Pointer(ptr), unsafe.Pointer(r.m_sb.sb_start), uintptr(nRead))
-			r.m_sb.sb_start = (*byte)(incBytePtr(unsafe.Pointer(r.m_sb.sb_start),
-				nRead))
-			r.m_sb.sb_size -= int32(nRead)
+			memmove(unsafe.Pointer(ptr), unsafe.Pointer(&r.m_sb.sb_buf[r.m_sb.sb_start]), uintptr(nRead))
+			r.m_sb.sb_start += nRead
+			r.m_sb.sb_size -= nRead
 			nBytes = nRead
 			r.m_nBytesIn += int32(nRead)
 			if r.m_bSendCounter && r.m_nBytesIn > (r.m_nBytesInSent+r.m_nClientBW/10) {
@@ -1797,15 +1796,11 @@ func C_CloseInternal(r *C_RTMP, reconnect int32) {
 // rtmp.c +4253
 func C_RTMPSockBuf_Fill(sb *C_RTMPSockBuf) int {
 	if sb.sb_size == 0 {
-		sb.sb_start = &sb.sb_buf[0]
+		sb.sb_start = 0
 	}
 
-	nBytes := C.long(unsafe.Sizeof(sb.sb_buf)) - 1 - C.long(sb.sb_size) -
-		C.long(uintptr(unsafe.Pointer(sb.sb_start))-uintptr(unsafe.Pointer(
-			&sb.sb_buf[0])))
-
-	nBytes, err := C.recv(C.int(sb.sb_socket), unsafe.Pointer(uintptr(unsafe.Pointer(
-		sb.sb_start))+uintptr(int(sb.sb_size))), C.size_t(nBytes), 0)
+	nBytes := C.long((len(sb.sb_buf) - 1) - (sb.sb_size + sb.sb_start))
+	nBytes, err := C.recv(C.int(sb.sb_socket), unsafe.Pointer(&sb.sb_buf[sb.sb_start+sb.sb_size]), C.size_t(nBytes), 0)
 	if nBytes == -1 {
 		log.Printf("C_RTMPSockBuf_Fill: recv error: %v", err)
 		if err == syscall.EWOULDBLOCK || err == syscall.EAGAIN {
@@ -1813,7 +1808,7 @@ func C_RTMPSockBuf_Fill(sb *C_RTMPSockBuf) int {
 			nBytes = 0
 		}
 	} else {
-		sb.sb_size += int32(nBytes)
+		sb.sb_size += int(nBytes)
 	}
 
 	return int(nBytes)

rtmp/rtmp_headers.go

@@ -137,8 +137,8 @@ type C_RTMPPacket struct {
 // rtmp.h +127
 type C_RTMPSockBuf struct {
 	sb_socket   int32
-	sb_size     int32
-	sb_start    *byte
+	sb_size     int
+	sb_start    int
 	sb_buf      [RTMP_BUFFER_CACHE_SIZE]byte // port const
 	sb_timedout bool
 }