From fd4612fab021659cd42be70d3c0938d620a09b73 Mon Sep 17 00:00:00 2001
From: Derek Collison <derek.collison@gmail.com>
Date: Tue, 20 Nov 2012 08:15:28 -0800
Subject: [PATCH] Properly handle unsub and pub/msg split buffer scenarios

---
 server/parser.go | 34 +++++++++++++++++++++++++---------
 1 file changed, 25 insertions(+), 9 deletions(-)

diff --git a/server/parser.go b/server/parser.go
index d286902b..5645ceff 100644
--- a/server/parser.go
+++ b/server/parser.go
@@ -4,7 +4,6 @@ package server
 
 import (
 	"fmt"
-//	"log"
 )
 
 type pubArg struct {
@@ -59,8 +58,6 @@ func (c *client) parse(buf []byte) error {
 	var i int
 	var b byte
 
-//	log.Printf("parse: len = %d, cap = %d\n", len(buf), cap(buf))
-//	log.Printf("Parse bytes: '%s'\n", buf)
 	c.nr++
 	c.nb += len(buf)
 
@@ -111,14 +108,13 @@ func (c *client) parse(buf []byte) error {
 				var arg []byte
 				if c.argBuf != nil {
 					arg = c.argBuf
-					c.argBuf = nil
 				} else {
 					arg = buf[c.as : i-c.drop]
 				}
+				c.drop, c.as, c.state = 0, i+1, MSG_PAYLOAD
 				if err := c.processPub(arg); err != nil {
 					return err
 				}
-				c.drop, c.as, c.state = 0, i+1, MSG_PAYLOAD
 			default:
 				if c.argBuf != nil {
 					c.argBuf = append(c.argBuf, b)
@@ -128,7 +124,7 @@ func (c *client) parse(buf []byte) error {
 			if c.msgBuf != nil {
 				if len(c.msgBuf) >= c.pa.size {
 					c.processMsg(c.msgBuf)
-					c.msgBuf, c.state = nil, MSG_END
+					c.argBuf, c.msgBuf, c.state = nil, nil, MSG_END
 				} else {
 					c.msgBuf = append(c.msgBuf, b)
 				}
@@ -327,15 +323,22 @@ func (c *client) parse(buf []byte) error {
 			goto parseErr
 		}
 	}
-	// Check for split buffer scenarios
-	if (c.state == SUB_ARG || c.state == PUB_ARG) && c.argBuf == nil {
+	// Check for split buffer scenarios for SUB and UNSUB and PUB
+	if (c.state == SUB_ARG || c.state == UNSUB_ARG || c.state == PUB_ARG) && c.argBuf == nil {
 		c.argBuf = c.scratch[:0]
 		c.argBuf = append(c.argBuf, buf[c.as:(i+1)-c.drop]...)
 		// FIXME, check max len
 	}
+	// Check for split msg
 	if c.state == MSG_PAYLOAD && c.msgBuf == nil {
+		// We need to clone the pubArg if it is still referencing the
+		// read buffer and we are not able to process the msg.
+		if c.argBuf == nil {
+			c.clonePubArg()
+		}
 		// FIXME: copy better here? Make whole buf if large?
-		c.msgBuf = c.scratch[:0]
+		//c.msgBuf = c.scratch[:0]
+		c.msgBuf = c.scratch[len(c.argBuf):len(c.argBuf)]
 		c.msgBuf = append(c.msgBuf, (buf[c.as:])...)
 	}
 	return nil
@@ -343,3 +346,16 @@ func (c *client) parse(buf []byte) error {
 parseErr:
 	return fmt.Errorf("Parse Error [%d]: '%s'", c.state, buf[i:])
 }
+
+
+// clonePubArg is used when the split buffer scenario has the pubArg in the existing read buffer, but
+// we need to hold onto it into the next read.
+func (c *client) clonePubArg() {
+	c.argBuf = c.scratch[:0]
+	c.argBuf = append(c.argBuf, c.pa.subject...)
+	c.argBuf = append(c.argBuf, c.pa.reply...)
+	c.argBuf = append(c.argBuf, c.pa.szb...)
+	c.pa.subject = c.argBuf[:len(c.pa.subject)]
+	c.pa.reply = c.argBuf[len(c.pa.subject) : len(c.pa.subject)+len(c.pa.reply)]
+	c.pa.szb = c.argBuf[len(c.pa.subject)+len(c.pa.reply):]
+}