diff --git a/src/eval.c b/src/eval.c
index 302d51565..fd12e40ad 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -136,7 +136,7 @@ void sha1hex(char *digest, char *script, size_t len) {
digest[40] = '\0';
}
-/* server.breakpoint()
+/* Adds server.breakpoint() function used by lua debugger.
*
* Allows to stop execution during a debugging session from within
* the Lua code implementation, like if a breakpoint was set in the code
@@ -151,7 +151,7 @@ int luaServerBreakpointCommand(lua_State *lua) {
return 1;
}
-/* server.debug()
+/* Adds server.debug() function used by lua debugger
*
* Log a string message into the output console.
* Can take multiple arguments that will be separated by commas.
@@ -168,7 +168,7 @@ int luaServerDebugCommand(lua_State *lua) {
return 0;
}
-/* server.replicate_commands()
+/* Adds server.replicate_commands()
*
* DEPRECATED: Now do nothing and always return true.
* Turn on single commands replication if the script never called
@@ -208,7 +208,8 @@ void scriptingInit(int setup) {
luaRegisterServerAPI(lua);
- /* register debug commands */
+ /* register debug commands. we only need to add it under 'server' as 'redis' is effectively aliased to 'server'
+ * table at this point. */
lua_getglobal(lua, "server");
/* server.breakpoint */
@@ -235,7 +236,7 @@ void scriptingInit(int setup) {
{
char *errh_func = "local dbg = debug\n"
"debug = nil\n"
- "function __redis__err__handler(err)\n"
+ "function __server__err__handler(err)\n"
" local i = dbg.getinfo(2,'nSl')\n"
" if i and i.what == 'C' then\n"
" i = dbg.getinfo(3,'nSl')\n"
@@ -251,6 +252,9 @@ void scriptingInit(int setup) {
"end\n";
luaL_loadbuffer(lua, errh_func, strlen(errh_func), "@err_handler_def");
lua_pcall(lua, 0, 0, 0);
+ /* Duplicate the function with __redis__err_handler name for backwards compatibility */
+ lua_getglobal(lua, "__server__err__handler");
+ lua_setglobal(lua, "__redis__err__handler");
}
/* Create the (non connected) client that we use to execute server commands
@@ -577,7 +581,7 @@ void evalGenericCommand(client *c, int evalsha) {
evalCalcFunctionName(evalsha, c->argv[1]->ptr, funcname);
/* Push the pcall error handler function on the stack. */
- lua_getglobal(lua, "__redis__err__handler");
+ lua_getglobal(lua, "__server__err__handler");
/* Try to lookup the Lua function */
lua_getfield(lua, LUA_REGISTRYINDEX, funcname);
@@ -1525,7 +1529,8 @@ void ldbServer(lua_State *lua, sds *argv, int argc) {
lua_getglobal(lua, "server");
lua_pushstring(lua, "call");
lua_gettable(lua, -2); /* Stack: server, server.call */
- for (j = 1; j < argc; j++) lua_pushlstring(lua, argv[j], sdslen(argv[j]));
+ for (j = 1; j < argc; j++)
+ lua_pushlstring(lua, argv[j], sdslen(argv[j]));
ldb.step = 1; /* Force server.call() to log. */
lua_pcall(lua, argc - 1, 1, 0); /* Stack: server, result */
ldb.step = 0; /* Disable logging. */
diff --git a/src/function_lua.c b/src/function_lua.c
index 685485e37..fa9983bf7 100644
--- a/src/function_lua.c
+++ b/src/function_lua.c
@@ -427,7 +427,7 @@ int luaEngineInitEngine(void) {
/* Register the library commands table and fields and store it to registry */
lua_newtable(lua_engine_ctx->lua); /* load library globals */
- lua_newtable(lua_engine_ctx->lua); /* load library `redis` table */
+ lua_newtable(lua_engine_ctx->lua); /* load library `server` table */
lua_pushstring(lua_engine_ctx->lua, "register_function");
lua_pushcfunction(lua_engine_ctx->lua, luaRegisterFunction);
diff --git a/src/rand.h b/src/rand.h
index dec746508..16b1d26f8 100644
--- a/src/rand.h
+++ b/src/rand.h
@@ -33,6 +33,6 @@
int32_t serverLrand48(void);
void serverSrand48(int32_t seedval);
-#define REDIS_LRAND48_MAX INT32_MAX
+#define SERVER_LRAND48_MAX INT32_MAX
#endif
diff --git a/src/script_lua.c b/src/script_lua.c
index ce13b7127..e378157d8 100644
--- a/src/script_lua.c
+++ b/src/script_lua.c
@@ -56,10 +56,11 @@ static char *libraries_allow_list[] = {
};
/* Lua API globals */
-static char *redis_api_allow_list[] = {
+static char *server_api_allow_list[] = {
SERVER_API_NAME,
REDIS_API_NAME,
- "__redis__err__handler", /* error handler for eval, currently located on globals.
+ "__redis__err__handler", /* Backwards compatible error handler */
+ "__server__err__handler", /* error handler for eval, currently located on globals.
Should move to registry. */
NULL,
};
@@ -117,7 +118,7 @@ static char *lua_builtins_removed_after_initialization_allow_list[] = {
* after that the global table is locked so not need to check anything.*/
static char **allow_lists[] = {
libraries_allow_list,
- redis_api_allow_list,
+ server_api_allow_list,
lua_builtins_allow_list,
lua_builtins_not_documented_allow_list,
lua_builtins_removed_after_initialization_allow_list,
@@ -135,8 +136,8 @@ static char *deny_list[] = {
NULL,
};
-static int redis_math_random(lua_State *L);
-static int redis_math_randomseed(lua_State *L);
+static int server_math_random(lua_State *L);
+static int server_math_randomseed(lua_State *L);
static void redisProtocolToLuaType_Int(void *ctx, long long val, const char *proto, size_t proto_len);
static void
redisProtocolToLuaType_BulkString(void *ctx, const char *str, size_t len, const char *proto, size_t proto_len);
@@ -159,7 +160,8 @@ static void redisProtocolToLuaType_VerbatimString(void *ctx,
const char *proto,
size_t proto_len);
static void redisProtocolToLuaType_Attribute(struct ReplyParser *parser, void *ctx, size_t len, const char *proto);
-static void luaReplyToRedisReply(client *c, client *script_client, lua_State *lua);
+
+static void luaReplyToServerReply(client *c, client *script_client, lua_State *lua);
/*
* Save the give pointer on Lua registry, used to save the Lua context and
@@ -204,7 +206,7 @@ void *luaGetFromRegistry(lua_State *lua, const char *name) {
/* Take a server reply in the RESP format and convert it into a
* Lua type. Thanks to this function, and the introduction of not connected
- * clients, it is trivial to implement the redis() lua function.
+ * clients, it is trivial to implement the server() lua function.
*
* Basically we take the arguments, execute the command in the context
* of a non connected client, then take the generated reply and convert it
@@ -610,7 +612,7 @@ int luaError(lua_State *lua) {
/* Reply to client 'c' converting the top element in the Lua stack to a
* server reply. As a side effect the element is consumed from the stack. */
-static void luaReplyToRedisReply(client *c, client *script_client, lua_State *lua) {
+static void luaReplyToServerReply(client *c, client *script_client, lua_State *lua) {
int t = lua_type(lua, -1);
if (!lua_checkstack(lua, 4)) {
@@ -733,9 +735,9 @@ static void luaReplyToRedisReply(client *c, client *script_client, lua_State *lu
lua_pushnil(lua); /* Use nil to start iteration. */
while (lua_next(lua, -2)) {
/* Stack now: table, key, value */
- lua_pushvalue(lua, -2); /* Dup key before consuming. */
- luaReplyToRedisReply(c, script_client, lua); /* Return key. */
- luaReplyToRedisReply(c, script_client, lua); /* Return value. */
+ lua_pushvalue(lua, -2); /* Dup key before consuming. */
+ luaReplyToServerReply(c, script_client, lua); /* Return key. */
+ luaReplyToServerReply(c, script_client, lua); /* Return value. */
/* Stack now: table, key. */
maplen++;
}
@@ -756,9 +758,9 @@ static void luaReplyToRedisReply(client *c, client *script_client, lua_State *lu
lua_pushnil(lua); /* Use nil to start iteration. */
while (lua_next(lua, -2)) {
/* Stack now: table, key, true */
- lua_pop(lua, 1); /* Discard the boolean value. */
- lua_pushvalue(lua, -1); /* Dup key before consuming. */
- luaReplyToRedisReply(c, script_client, lua); /* Return key. */
+ lua_pop(lua, 1); /* Discard the boolean value. */
+ lua_pushvalue(lua, -1); /* Dup key before consuming. */
+ luaReplyToServerReply(c, script_client, lua); /* Return key. */
/* Stack now: table, key. */
setlen++;
}
@@ -780,7 +782,7 @@ static void luaReplyToRedisReply(client *c, client *script_client, lua_State *lu
lua_pop(lua, 1);
break;
}
- luaReplyToRedisReply(c, script_client, lua);
+ luaReplyToServerReply(c, script_client, lua);
mbulklen++;
}
setDeferredArrayLen(c, replylen, mbulklen);
@@ -793,7 +795,7 @@ static void luaReplyToRedisReply(client *c, client *script_client, lua_State *lu
/* ---------------------------------------------------------------------------
* Lua server.* functions implementations.
* ------------------------------------------------------------------------- */
-void freeLuaRedisArgv(robj **argv, int argc, int argv_len);
+void freeLuaServerArgv(robj **argv, int argc, int argv_len);
/* Cached argv array across calls. */
static robj **lua_argv = NULL;
@@ -803,7 +805,7 @@ static int lua_argv_size = 0;
static robj *lua_args_cached_objects[LUA_CMD_OBJCACHE_SIZE];
static size_t lua_args_cached_objects_len[LUA_CMD_OBJCACHE_SIZE];
-static robj **luaArgsToRedisArgv(lua_State *lua, int *argc, int *argv_len) {
+static robj **luaArgsToServerArgv(lua_State *lua, int *argc, int *argv_len) {
int j;
/* Require at least one argument */
*argc = lua_gettop(lua);
@@ -864,7 +866,7 @@ static robj **luaArgsToRedisArgv(lua_State *lua, int *argc, int *argv_len) {
* is not a string or an integer (lua_isstring() return true for
* integers as well). */
if (j != *argc) {
- freeLuaRedisArgv(lua_argv, j, lua_argv_size);
+ freeLuaServerArgv(lua_argv, j, lua_argv_size);
luaPushError(lua, "Command arguments must be strings or integers");
return NULL;
}
@@ -872,7 +874,7 @@ static robj **luaArgsToRedisArgv(lua_State *lua, int *argc, int *argv_len) {
return lua_argv;
}
-void freeLuaRedisArgv(robj **argv, int argc, int argv_len) {
+void freeLuaServerArgv(robj **argv, int argc, int argv_len) {
int j;
for (j = 0; j < argc; j++) {
robj *o = argv[j];
@@ -899,7 +901,7 @@ void freeLuaRedisArgv(robj **argv, int argc, int argv_len) {
}
}
-static int luaRedisGenericCommand(lua_State *lua, int raise_error) {
+static int luaServerGenericCommand(lua_State *lua, int raise_error) {
int j;
scriptRunCtx *rctx = luaGetFromRegistry(lua, REGISTRY_RUN_CTX_NAME);
serverAssert(rctx); /* Only supported inside script invocation */
@@ -907,7 +909,7 @@ static int luaRedisGenericCommand(lua_State *lua, int raise_error) {
client *c = rctx->c;
sds reply;
- c->argv = luaArgsToRedisArgv(lua, &c->argc, &c->argv_len);
+ c->argv = luaArgsToServerArgv(lua, &c->argc, &c->argv_len);
if (c->argv == NULL) {
return raise_error ? luaError(lua) : 1;
}
@@ -915,7 +917,7 @@ static int luaRedisGenericCommand(lua_State *lua, int raise_error) {
static int inuse = 0; /* Recursive calls detection. */
/* By using Lua debug hooks it is possible to trigger a recursive call
- * to luaRedisGenericCommand(), which normally should never happen.
+ * to luaServerGenericCommand(), which normally should never happen.
* To make this function reentrant is futile and makes it slower, but
* we should at least detect such a misuse, and abort. */
if (inuse) {
@@ -978,7 +980,8 @@ static int luaRedisGenericCommand(lua_State *lua, int raise_error) {
redisProtocolToLuaType(lua, reply);
/* If the debugger is active, log the reply from the server. */
- if (ldbIsEnabled()) ldbLogRespReply(reply);
+ if (ldbIsEnabled())
+ ldbLogRespReply(reply);
if (reply != c->buf) sdsfree(reply);
c->reply_bytes = 0;
@@ -986,7 +989,7 @@ static int luaRedisGenericCommand(lua_State *lua, int raise_error) {
cleanup:
/* Clean up. Command code may have changed argv/argc so we use the
* argv/argc of the client instead of the local variables. */
- freeLuaRedisArgv(c->argv, c->argc, c->argv_len);
+ freeLuaServerArgv(c->argv, c->argc, c->argv_len);
c->argc = c->argv_len = 0;
c->user = NULL;
c->argv = NULL;
@@ -1032,12 +1035,12 @@ static int luaRedisPcall(lua_State *lua) {
/* server.call() */
static int luaRedisCallCommand(lua_State *lua) {
- return luaRedisGenericCommand(lua, 1);
+ return luaServerGenericCommand(lua, 1);
}
/* server.pcall() */
static int luaRedisPCallCommand(lua_State *lua) {
- return luaRedisGenericCommand(lua, 0);
+ return luaServerGenericCommand(lua, 0);
}
/* This adds server.sha1hex(string) to Lua scripts using the same hashing
@@ -1137,7 +1140,7 @@ static int luaRedisAclCheckCmdPermissionsCommand(lua_State *lua) {
int raise_error = 0;
int argc, argv_len;
- robj **argv = luaArgsToRedisArgv(lua, &argc, &argv_len);
+ robj **argv = luaArgsToServerArgv(lua, &argc, &argv_len);
/* Require at least one argument */
if (argv == NULL) return luaError(lua);
@@ -1156,7 +1159,7 @@ static int luaRedisAclCheckCmdPermissionsCommand(lua_State *lua) {
}
}
- freeLuaRedisArgv(argv, argc, argv_len);
+ freeLuaServerArgv(argv, argc, argv_len);
if (raise_error)
return luaError(lua);
else
@@ -1432,44 +1435,61 @@ void luaRegisterLogFunction(lua_State *lua) {
lua_settable(lua, -3);
}
+/*
+ * Adds server.* functions/fields to lua such as server.call etc.
+ * This function only handles fields common between Functions and LUA scripting.
+ * scriptingInit() and functionsInit() may add additional fields specific to each.
+ */
void luaRegisterServerAPI(lua_State *lua) {
+ /* In addition to registering server.call/pcall API, we will throw a custom message when a script accesses
+ * undefined global variable. LUA stores global variables in the global table, accessible to us on stack at virtual
+ * index = LUA_GLOBALSINDEX. We will set __index handler in global table's metatable to a custom C function to
+ * achieve this - handled by luaSetAllowListProtection. Refer to https://www.lua.org/pil/13.4.1.html for
+ * documentation on __index and https://www.lua.org/pil/contents.html#13 for documentation on metatables. We need to
+ * pass global table to lua invocations as parameters. To achieve this, lua_pushvalue invocation brings global
+ * variable table to the top of the stack by pushing value from global index onto the stack. And lua_pop invocation
+ * after luaSetAllowListProtection removes it - resetting the stack to its original state. */
lua_pushvalue(lua, LUA_GLOBALSINDEX);
luaSetAllowListProtection(lua);
lua_pop(lua, 1);
+ /* Add default C functions provided in deps/lua codebase to handle basic data types such as table, string etc. */
luaLoadLibraries(lua);
+ /* Before Redis OSS 7, Lua used to return error messages as strings from pcall function. With Valkey (or Redis OSS 7), Lua now returns
+ * error messages as tables. To keep backwards compatibility, we wrap the Lua pcall function with our own
+ * implementation of C function that converts table to string. */
lua_pushcfunction(lua, luaRedisPcall);
lua_setglobal(lua, "pcall");
- /* Register the commands table and fields */
+ /* Create a top level table object on the stack to temporarily hold fields for 'server' table. We will name it as
+ * 'server' and send it to LUA at the very end. Also add 'call' and 'pcall' functions to the table. */
lua_newtable(lua);
-
- /* server.call */
lua_pushstring(lua, "call");
lua_pushcfunction(lua, luaRedisCallCommand);
lua_settable(lua, -3);
-
- /* server.pcall */
lua_pushstring(lua, "pcall");
lua_pushcfunction(lua, luaRedisPCallCommand);
lua_settable(lua, -3);
+ /* Add server.log function and debug level constants. LUA scripts use it to print messages to server log. */
luaRegisterLogFunction(lua);
+ /* Add SERVER_VERSION_NUM, SERVER_VERSION and SERVER_NAME fields with appropriate values. */
luaRegisterVersion(lua);
- /* server.setresp */
+ /* Add server.setresp function to allow LUA scripts to change the RESP version for server.call and server.pcall
+ * invocations. */
lua_pushstring(lua, "setresp");
lua_pushcfunction(lua, luaSetResp);
lua_settable(lua, -3);
- /* server.sha1hex */
+ /* Add server.sha1hex function. */
lua_pushstring(lua, "sha1hex");
lua_pushcfunction(lua, luaRedisSha1hexCommand);
lua_settable(lua, -3);
- /* server.error_reply and server.status_reply */
+ /* Add server.error_reply and server.status_reply functions. */
lua_pushstring(lua, "error_reply");
lua_pushcfunction(lua, luaRedisErrorReplyCommand);
lua_settable(lua, -3);
@@ -1477,7 +1497,7 @@ void luaRegisterServerAPI(lua_State *lua) {
lua_pushcfunction(lua, luaRedisStatusReplyCommand);
lua_settable(lua, -3);
- /* server.set_repl and associated flags. */
+ /* Add server.set_repl function and associated flags. */
lua_pushstring(lua, "set_repl");
lua_pushcfunction(lua, luaRedisSetReplCommand);
lua_settable(lua, -3);
@@ -1502,7 +1522,7 @@ void luaRegisterServerAPI(lua_State *lua) {
lua_pushnumber(lua, PROPAGATE_AOF | PROPAGATE_REPL);
lua_settable(lua, -3);
- /* server.acl_check_cmd */
+ /* Add server.acl_check_cmd function. */
lua_pushstring(lua, "acl_check_cmd");
lua_pushcfunction(lua, luaRedisAclCheckCmdPermissionsCommand);
lua_settable(lua, -3);
@@ -1515,17 +1535,16 @@ void luaRegisterServerAPI(lua_State *lua) {
* This is not a deep copy but is enough for our purpose here. */
lua_getglobal(lua, SERVER_API_NAME);
lua_setglobal(lua, REDIS_API_NAME);
- /* Replace math.random and math.randomseed with our implementations. */
+
+ /* Replace math.random and math.randomseed with custom implementations. */
lua_getglobal(lua, "math");
-
lua_pushstring(lua, "random");
- lua_pushcfunction(lua, redis_math_random);
+ lua_pushcfunction(lua, server_math_random);
lua_settable(lua, -3);
-
lua_pushstring(lua, "randomseed");
- lua_pushcfunction(lua, redis_math_randomseed);
+ lua_pushcfunction(lua, server_math_randomseed);
lua_settable(lua, -3);
-
+ /* overwrite value of global variable 'math' with this modified math table present on top of stack. */
lua_setglobal(lua, "math");
}
@@ -1551,10 +1570,11 @@ static void luaCreateArray(lua_State *lua, robj **elev, int elec) {
/* The following implementation is the one shipped with Lua itself but with
* rand() replaced by serverLrand48(). */
-static int redis_math_random(lua_State *L) {
+static int server_math_random(lua_State *L) {
/* the `%' avoids the (rare) case of r==1, and is needed also because on
some systems (SunOS!) `rand()' may return a value larger than RAND_MAX */
- lua_Number r = (lua_Number)(serverLrand48() % REDIS_LRAND48_MAX) / (lua_Number)REDIS_LRAND48_MAX;
+ lua_Number r = (lua_Number)(serverLrand48() % SERVER_LRAND48_MAX) /
+ (lua_Number)SERVER_LRAND48_MAX;
switch (lua_gettop(L)) { /* check number of arguments */
case 0: { /* no arguments */
lua_pushnumber(L, r); /* Number between 0 and 1 */
@@ -1578,7 +1598,7 @@ static int redis_math_random(lua_State *L) {
return 1;
}
-static int redis_math_randomseed(lua_State *L) {
+static int server_math_randomseed(lua_State *L) {
serverSrand48(luaL_checkint(L, 1));
return 0;
}
@@ -1741,7 +1761,7 @@ void luaCallFunction(scriptRunCtx *run_ctx,
} else {
/* On success convert the Lua return value into RESP, and
* send it to * the client. */
- luaReplyToRedisReply(c, run_ctx->c, lua); /* Convert and consume the reply. */
+ luaReplyToServerReply(c, run_ctx->c, lua); /* Convert and consume the reply. */
}
/* Perform some cleanup that we need to do both on error and success. */
diff --git a/src/server.c b/src/server.c
index 866023a45..56a49c85a 100644
--- a/src/server.c
+++ b/src/server.c
@@ -2756,7 +2756,9 @@ void initServer(void) {
server.maxmemory_policy = MAXMEMORY_NO_EVICTION;
}
+ /* Initialize the LUA scripting engine. */
scriptingInit(1);
+ /* Initialize the functions engine based off of LUA initialization. */
if (functionsInit() == C_ERR) {
serverPanic("Functions initialization failed, check the server logs.");
exit(1);