String buffers, part 1: object serialization.

Sponsored by fmad.io.

src/lib_buffer.c

@@ -0,0 +1,66 @@
+/*
+** Buffer library.
+** Copyright (C) 2005-2021 Mike Pall. See Copyright Notice in luajit.h
+*/
+
+#define lib_buffer_c
+#define LUA_LIB
+
+#include "lua.h"
+#include "lauxlib.h"
+#include "lualib.h"
+
+#include "lj_obj.h"
+
+#if LJ_HASBUFFER
+#include "lj_gc.h"
+#include "lj_buf.h"
+#include "lj_serialize.h"
+#include "lj_lib.h"
+
+/* ------------------------------------------------------------------------ */
+
+#define LJLIB_MODULE_buffer
+
+/* Note: this uses interim structs until the SBuf reorg. */
+
+LJLIB_CF(buffer_encode)
+{
+  cTValue *o = lj_lib_checkany(L, 1);
+  StrBuf sbuf;
+  sbuf.sb = lj_buf_tmp_(L);
+  lj_serialize_put(&sbuf, o);
+  setstrV(L, L->top++, lj_buf_str(L, sbuf.sb));
+  lj_gc_check(L);
+  return 1;
+}
+
+LJLIB_CF(buffer_decode)
+{
+  GCstr *str = lj_lib_checkstr(L, 1);
+  const char *p = strdata(str);
+  SBuf sb;
+  StrBuf sbuf;
+  setsbufL(&sb, L);
+  setmref(sb.b, p);
+  setmref(sb.p, p + str->len);
+  setmref(sb.e, p + str->len);
+  sbuf.sb = &sb;
+  sbuf.r = (char *)p;
+  setnilV(L->top++);
+  lj_serialize_get(&sbuf, L->top-1);
+  lj_gc_check(L);
+  return 1;
+}
+
+/* ------------------------------------------------------------------------ */
+
+#include "lj_libdef.h"
+
+int luaopen_string_buffer(lua_State *L)
+{
+  LJ_LIB_REG(L, NULL, buffer);
+  return 1;
+}
+
+#endif