From c5ebfa0c6793562d7392ffc68b1318d250f47a02 Mon Sep 17 00:00:00 2001
From: Mike Pall <mike>
Date: Wed, 29 May 2013 20:17:26 +0200
Subject: [PATCH] Refactor string buffer growth helpers.

---
 src/lj_buf.c | 36 ++++++++++++++++++++++++------------
 src/lj_buf.h | 14 +++++++-------
 src/lj_str.c |  2 --
 3 files changed, 31 insertions(+), 21 deletions(-)

diff --git a/src/lj_buf.c b/src/lj_buf.c
index 1786c10d..1f6e97bf 100644
--- a/src/lj_buf.c
+++ b/src/lj_buf.c
@@ -3,8 +3,6 @@
 ** Copyright (C) 2005-2013 Mike Pall. See Copyright Notice in luajit.h
 */
 
-#include <stdio.h>
-
 #define lj_buf_c
 #define LUA_CORE
 
@@ -18,23 +16,37 @@
 
 /* -- Buffer management --------------------------------------------------- */
 
-LJ_NOINLINE void LJ_FASTCALL lj_buf_grow(SBuf *sb, char *en)
+static void buf_grow(SBuf *sb, MSize sz)
 {
-  lua_State *L = sbufL(sb);
-  char *b = sbufB(sb);
-  MSize sz = (MSize)(en - b);
-  MSize osz = (MSize)(sbufE(sb) - b), nsz = osz;
-  MSize n = (MSize)(sbufP(sb) - b);
-  if (LJ_UNLIKELY(sz > LJ_MAX_MEM))
-    lj_err_mem(L);
+  MSize osz = sbufsz(sb), len = sbuflen(sb), nsz = osz;
+  char *b;
   if (nsz < LJ_MIN_SBUF) nsz = LJ_MIN_SBUF;
   while (nsz < sz) nsz += nsz;
-  b = (char *)lj_mem_realloc(L, b, osz, nsz);
+  b = (char *)lj_mem_realloc(sbufL(sb), sbufB(sb), osz, nsz);
   setmref(sb->b, b);
-  setmref(sb->p, b + n);
+  setmref(sb->p, b + len);
   setmref(sb->e, b + nsz);
 }
 
+LJ_NOINLINE char *LJ_FASTCALL lj_buf_need2(SBuf *sb, MSize sz)
+{
+  lua_assert(sz > sbufsz(sb));
+  if (LJ_UNLIKELY(sz > LJ_MAX_MEM))
+    lj_err_mem(sbufL(sb));
+  buf_grow(sb, sz);
+  return sbufB(sb);
+}
+
+LJ_NOINLINE char *LJ_FASTCALL lj_buf_more2(SBuf *sb, MSize sz)
+{
+  MSize len = sbuflen(sb);
+  lua_assert(sz > sbufleft(sb));
+  if (LJ_UNLIKELY(sz > LJ_MAX_MEM || len + sz > LJ_MAX_MEM))
+    lj_err_mem(sbufL(sb));
+  buf_grow(sb, len + sz);
+  return sbufP(sb);
+}
+
 void LJ_FASTCALL lj_buf_shrink(lua_State *L, SBuf *sb)
 {
   char *b = sbufB(sb);
diff --git a/src/lj_buf.h b/src/lj_buf.h
index 5f78c4a9..7a123e83 100644
--- a/src/lj_buf.h
+++ b/src/lj_buf.h
@@ -17,11 +17,13 @@
 #define sbufL(sb)	(mref((sb)->L, lua_State))
 #define sbufsz(sb)	((MSize)(sbufE((sb)) - sbufB((sb))))
 #define sbuflen(sb)	((MSize)(sbufP((sb)) - sbufB((sb))))
+#define sbufleft(sb)	((MSize)(sbufE((sb)) - sbufP((sb))))
 #define setsbufP(sb, q)	(setmref((sb)->p, (q)))
 #define setsbufL(sb, l)	(setmref((sb)->L, (l)))
 
 /* Buffer management */
-LJ_FUNC void LJ_FASTCALL lj_buf_grow(SBuf *sb, char *en);
+LJ_FUNC char *LJ_FASTCALL lj_buf_need2(SBuf *sb, MSize sz);
+LJ_FUNC char *LJ_FASTCALL lj_buf_more2(SBuf *sb, MSize sz);
 LJ_FUNC void LJ_FASTCALL lj_buf_shrink(lua_State *L, SBuf *sb);
 LJ_FUNC char * LJ_FASTCALL lj_buf_tmp(lua_State *L, MSize sz);
 
@@ -51,17 +53,15 @@ static LJ_AINLINE void lj_buf_free(global_State *g, SBuf *sb)
 
 static LJ_AINLINE char *lj_buf_need(SBuf *sb, MSize sz)
 {
-  char *en = sbufB(sb) + sz;
-  if (LJ_UNLIKELY(en > sbufE(sb)))
-    lj_buf_grow(sb, en);
+  if (LJ_UNLIKELY(sz > sbufsz(sb)))
+    return lj_buf_need2(sb, sz);
   return sbufB(sb);
 }
 
 static LJ_AINLINE char *lj_buf_more(SBuf *sb, MSize sz)
 {
-  char *en = sbufP(sb) + sz;
-  if (LJ_UNLIKELY(en > sbufE(sb)))
-    lj_buf_grow(sb, en);
+  if (LJ_UNLIKELY(sz > sbufleft(sb)))
+    return lj_buf_more2(sb, sz);
   return sbufP(sb);
 }
 
diff --git a/src/lj_str.c b/src/lj_str.c
index 24d96067..5fdd1672 100644
--- a/src/lj_str.c
+++ b/src/lj_str.c
@@ -3,8 +3,6 @@
 ** Copyright (C) 2005-2013 Mike Pall. See Copyright Notice in luajit.h
 */
 
-#include <stdio.h>
-
 #define lj_str_c
 #define LUA_CORE