Reduce recvBuffer's implementation's buffer size limits

internal/multiplex/datagramBufferedPipe.go

@@ -13,7 +13,8 @@ import (
 // instead of byte-oriented. The integrity of datagrams written into this buffer is preserved.
 // it won't get chopped up into individual bytes
 type datagramBufferedPipe struct {
-	pLens     []int
+	pLens []int
+	// lazily allocated
 	buf       *bytes.Buffer
 	closed    bool
 	rwCond    *sync.Cond
@@ -114,7 +115,7 @@ func (d *datagramBufferedPipe) Write(f Frame) (toBeClosed bool, err error) {
 		if d.closed {
 			return true, io.ErrClosedPipe
 		}
-		if d.buf.Len() <= BUF_SIZE_LIMIT {
+		if d.buf.Len() <= recvBufferSizeLimit {
 			// if d.buf gets too large, write() will panic. We don't want this to happen
 			break
 		}

internal/multiplex/recvBuffer.go

@@ -21,3 +21,8 @@ type recvBuffer interface {
 	// has been written for a while. After that duration it should return ErrTimeout
 	SetWriteToTimeout(d time.Duration)
 }
+
+// size we want the amount of unread data in buffer to grow before recvBuffer.Write blocks.
+// If the buffer grows larger than what the system's memory can offer at the time of recvBuffer.Write,
+// a panic will happen.
+const recvBufferSizeLimit = defaultSendRecvBufSize << 12

internal/multiplex/streamBufferedPipe.go

@@ -9,8 +9,6 @@ import (
 	"time"
 )
 
-const BUF_SIZE_LIMIT = 1 << 20 * 500
-
 // The point of a streamBufferedPipe is that Read() will block until data is available
 type streamBufferedPipe struct {
 	// only alloc when on first Read or Write
@@ -105,7 +103,7 @@ func (p *streamBufferedPipe) Write(input []byte) (int, error) {
 		if p.closed {
 			return 0, io.ErrClosedPipe
 		}
-		if p.buf.Len() <= BUF_SIZE_LIMIT {
+		if p.buf.Len() <= recvBufferSizeLimit {
 			// if p.buf gets too large, write() will panic. We don't want this to happen
 			break
 		}