vendor: 引入 Lua 3.2 官方源码 + 移植评估 (lua_3.2 分支)

- 前 lua_State 时代 API(全局单例状态机), 与项目多实例+管道模式抽象冲突
- 评估结论: 不建议移植, 详见 doc/ADAPTATION-lua32.md

lib/lua/lbuffer.c

@@ -0,0 +1,75 @@
+/*
+** $Id: lbuffer.c,v 1.9 1999/02/26 15:48:55 roberto Exp $
+** Auxiliary functions for building Lua libraries
+** See Copyright Notice in lua.h
+*/
+
+
+#include <stdio.h>
+
+#include "lauxlib.h"
+#include "lmem.h"
+#include "lstate.h"
+
+
+/*-------------------------------------------------------
+**  Auxiliary buffer
+-------------------------------------------------------*/
+
+
+#define EXTRABUFF	32
+
+
+#define openspace(size)  if (L->Mbuffnext+(size) > L->Mbuffsize) Openspace(size)
+
+static void Openspace (int size) {
+  lua_State *l = L;  /* to optimize */
+  size += EXTRABUFF;
+  l->Mbuffsize = l->Mbuffnext+size;
+  luaM_growvector(l->Mbuffer, l->Mbuffnext, size, char, arrEM, MAX_INT);
+}
+
+
+char *luaL_openspace (int size) {
+  openspace(size);
+  return L->Mbuffer+L->Mbuffnext;
+}
+
+
+void luaL_addchar (int c) {
+  openspace(1);
+  L->Mbuffer[L->Mbuffnext++] = (char)c;
+}
+
+
+void luaL_resetbuffer (void) {
+  L->Mbuffnext = L->Mbuffbase;
+}
+
+
+void luaL_addsize (int n) {
+  L->Mbuffnext += n;
+}
+
+int luaL_getsize (void) {
+  return L->Mbuffnext-L->Mbuffbase;
+}
+
+int luaL_newbuffer (int size) {
+  int old = L->Mbuffbase;
+  openspace(size);
+  L->Mbuffbase = L->Mbuffnext;
+  return old;
+}
+
+
+void luaL_oldbuffer (int old) {
+  L->Mbuffnext = L->Mbuffbase;
+  L->Mbuffbase = old;
+}
+
+
+char *luaL_buffer (void) {
+  return L->Mbuffer+L->Mbuffbase;
+}
+