[Tarantool-patches] [PATCH 1/5] uuid: introduce and use luaL_pushuuidstr()
Vladislav Shpilevoy
v.shpilevoy at tarantool.org
Wed Jul 28 00:24:11 MSK 2021
The function safely pushes tt_uuid as a string on a Lua stack.
Safety means that it does not use tt_uuid_str() which stores the
result into the global static buffer and can not be used in Lua
context.
The static buffer is not safe to use in Lua and Lua C because
during a static string push onto a Lua stack the GC might be
started and it can spoil the buffer.
Part of #6259
---
src/box/lua/net_box.c | 4 +---
src/lua/utils.c | 13 +++++++++++++
src/lua/utils.h | 3 +++
3 files changed, 17 insertions(+), 3 deletions(-)
diff --git a/src/box/lua/net_box.c b/src/box/lua/net_box.c
index 3f43872ca..d1c7bedf6 100644
--- a/src/box/lua/net_box.c
+++ b/src/box/lua/net_box.c
@@ -422,7 +422,6 @@ netbox_decode_greeting(lua_State *L)
struct greeting greeting;
size_t len;
const char *buf = NULL;
- char uuid_buf[UUID_STR_LEN + 1];
if (lua_isstring(L, 1))
buf = lua_tolstring(L, 1, &len);
@@ -443,8 +442,7 @@ netbox_decode_greeting(lua_State *L)
lua_pushlstring(L, greeting.salt, greeting.salt_len);
lua_setfield(L, -2, "salt");
- tt_uuid_to_string(&greeting.uuid, uuid_buf);
- lua_pushstring(L, uuid_buf);
+ luaL_pushuuidstr(L, &greeting.uuid);
lua_setfield(L, -2, "uuid");
return 1;
diff --git a/src/lua/utils.c b/src/lua/utils.c
index 34cec0eed..bcd647827 100644
--- a/src/lua/utils.c
+++ b/src/lua/utils.c
@@ -37,6 +37,7 @@
#include <trivia/util.h>
#include <diag.h>
#include <fiber.h>
+#include "uuid/tt_uuid.h"
int luaL_nil_ref = LUA_REFNIL;
@@ -107,6 +108,18 @@ luaL_pushuuid(struct lua_State *L)
return luaL_pushcdata(L, CTID_UUID);
}
+void
+luaL_pushuuidstr(struct lua_State *L, const struct tt_uuid *uuid)
+{
+ /*
+ * Do not use a global buffer. It might be overwritten if GC starts
+ * working.
+ */
+ char str[UUID_STR_LEN + 1];
+ tt_uuid_to_string(uuid, str);
+ lua_pushlstring(L, str, UUID_STR_LEN);
+}
+
int
luaL_iscdata(struct lua_State *L, int idx)
{
diff --git a/src/lua/utils.h b/src/lua/utils.h
index 947d9240b..804fc9548 100644
--- a/src/lua/utils.h
+++ b/src/lua/utils.h
@@ -73,6 +73,9 @@ extern uint32_t CTID_UUID;
struct tt_uuid *
luaL_pushuuid(struct lua_State *L);
+void
+luaL_pushuuidstr(struct lua_State *L, const struct tt_uuid *uuid);
+
/** \cond public */
/**
--
2.24.3 (Apple Git-128)
More information about the Tarantool-patches
mailing list