char *redisProtocolToLuaType_MultiBulk(lua_State *lua, char *reply);
int redis_math_random (lua_State *L);
int redis_math_randomseed (lua_State *L);
+void sha1hex(char *digest, char *script, size_t len);
/* Take a Redis reply in the Redis protocol format and convert it into a
* Lua type. Thanks to this function, and the introduction of not connected
* is like a normal client that bypasses all the slow I/O paths.
*
* Note: in this function we do not do any sanity check as the reply is
- * generated by Redis directly. This allows use to go faster.
+ * generated by Redis directly. This allows us to go faster.
* The reply string can be altered during the parsing as it is discared
* after the conversion is completed.
*
lua_settable(lua,-3);
}
-int luaRedisCommand(lua_State *lua) {
+/* Sort the array currently in the stack. We do this to make the output
+ * of commands like KEYS or SMEMBERS something deterministic when called
+ * from Lua (to play well with AOf/replication).
+ *
+ * The array is sorted using table.sort itself, and assuming all the
+ * list elements are strings. */
+void luaSortArray(lua_State *lua) {
+ /* Initial Stack: array */
+ lua_getglobal(lua,"table");
+ lua_pushstring(lua,"sort");
+ lua_gettable(lua,-2); /* Stack: array, table, table.sort */
+ lua_pushvalue(lua,-3); /* Stack: array, table, table.sort, array */
+ if (lua_pcall(lua,1,0,0)) {
+ /* Stack: array, table, error */
+
+ /* We are not interested in the error, we assume that the problem is
+ * that there are 'false' elements inside the array, so we try
+ * again with a slower function but able to handle this case, that
+ * is: table.sort(table, __redis__compare_helper) */
+ lua_pop(lua,1); /* Stack: array, table */
+ lua_pushstring(lua,"sort"); /* Stack: array, table, sort */
+ lua_gettable(lua,-2); /* Stack: array, table, table.sort */
+ lua_pushvalue(lua,-3); /* Stack: array, table, table.sort, array */
+ lua_getglobal(lua,"__redis__compare_helper");
+ /* Stack: array, table, table.sort, array, __redis__compare_helper */
+ lua_call(lua,2,0);
+ }
+ /* Stack: array (sorted), table */
+ lua_pop(lua,1); /* Stack: array (sorted) */
+}
+
+int luaRedisGenericCommand(lua_State *lua, int raise_error) {
int j, argc = lua_gettop(lua);
struct redisCommand *cmd;
robj **argv;
goto cleanup;
}
+ /* There are commands that are not allowed inside scripts. */
if (cmd->flags & REDIS_CMD_NOSCRIPT) {
luaPushError(lua, "This Redis command is not allowed from scripts");
goto cleanup;
}
- if (cmd->flags & REDIS_CMD_WRITE && server.lua_random_dirty) {
- luaPushError(lua,
- "Write commands not allowed after non deterministic commands");
- goto cleanup;
+ /* Write commands are forbidden against read-only slaves, or if a
+ * command marked as non-deterministic was already called in the context
+ * of this script. */
+ if (cmd->flags & REDIS_CMD_WRITE) {
+ if (server.lua_random_dirty) {
+ luaPushError(lua,
+ "Write commands not allowed after non deterministic commands");
+ goto cleanup;
+ } else if (server.masterhost && server.repl_slave_ro &&
+ !(server.lua_caller->flags & REDIS_MASTER))
+ {
+ luaPushError(lua, shared.roslaveerr->ptr);
+ goto cleanup;
+ } else if (server.stop_writes_on_bgsave_err &&
+ server.saveparamslen > 0 &&
+ server.lastbgsave_status == REDIS_ERR)
+ {
+ luaPushError(lua, shared.bgsaveerr->ptr);
+ goto cleanup;
+ }
+ }
+
+ /* If we reached the memory limit configured via maxmemory, commands that
+ * could enlarge the memory usage are not allowed, but only if this is the
+ * first write in the context of this script, otherwise we can't stop
+ * in the middle. */
+ if (server.maxmemory && server.lua_write_dirty == 0 &&
+ (cmd->flags & REDIS_CMD_DENYOOM))
+ {
+ if (freeMemoryIfNeeded() == REDIS_ERR) {
+ luaPushError(lua, shared.oomerr->ptr);
+ goto cleanup;
+ }
}
if (cmd->flags & REDIS_CMD_RANDOM) server.lua_random_dirty = 1;
+ if (cmd->flags & REDIS_CMD_WRITE) server.lua_write_dirty = 1;
/* Run the command */
- cmd->proc(c);
+ c->cmd = cmd;
+ call(c,REDIS_CALL_SLOWLOG | REDIS_CALL_STATS);
/* Convert the result of the Redis command into a suitable Lua type.
* The first thing we need is to create a single string from the client
reply = sdscatlen(reply,o->ptr,sdslen(o->ptr));
listDelNode(c->reply,listFirst(c->reply));
}
+ if (raise_error && reply[0] != '-') raise_error = 0;
redisProtocolToLuaType(lua,reply);
+ /* Sort the output array if needed, assuming it is a non-null multi bulk
+ * reply as expected. */
+ if ((cmd->flags & REDIS_CMD_SORT_FOR_SCRIPT) &&
+ (reply[0] == '*' && reply[1] != '-')) {
+ /* Skip this step if command is SORT but output was already sorted */
+ if (cmd->proc != sortCommand || server.sort_dontsort)
+ luaSortArray(lua);
+ }
sdsfree(reply);
cleanup:
decrRefCount(c->argv[j]);
zfree(c->argv);
+ if (raise_error) {
+ /* If we are here we should have an error in the stack, in the
+ * form of a table with an "err" field. Extract the string to
+ * return the plain error. */
+ lua_pushstring(lua,"err");
+ lua_gettable(lua,-2);
+ return lua_error(lua);
+ }
+ return 1;
+}
+
+int luaRedisCallCommand(lua_State *lua) {
+ return luaRedisGenericCommand(lua,1);
+}
+
+int luaRedisPCallCommand(lua_State *lua) {
+ return luaRedisGenericCommand(lua,0);
+}
+
+/* This adds redis.sha1hex(string) to Lua scripts using the same hashing
+ * function used for sha1ing lua scripts. */
+int luaRedisSha1hexCommand(lua_State *lua) {
+ int argc = lua_gettop(lua);
+ char digest[41];
+ size_t len;
+ char *s;
+
+ if (argc != 1) {
+ luaPushError(lua, "wrong number of arguments");
+ return 1;
+ }
+
+ s = (char*)lua_tolstring(lua,1,&len);
+ sha1hex(digest,s,len);
+ lua_pushstring(lua,digest);
return 1;
}
void luaMaskCountHook(lua_State *lua, lua_Debug *ar) {
long long elapsed;
REDIS_NOTUSED(ar);
+ REDIS_NOTUSED(lua);
elapsed = (ustime()/1000) - server.lua_time_start;
- if (elapsed >= server.lua_time_limit) {
- redisLog(REDIS_NOTICE,"Lua script aborted for max execution time after %lld milliseconds of running time.",elapsed);
- lua_pushstring(lua,"Script aborted for max execution time.");
+ if (elapsed >= server.lua_time_limit && server.lua_timedout == 0) {
+ redisLog(REDIS_WARNING,"Lua slow script detected: still in execution after %lld milliseconds. You can try killing the script using the SCRIPT KILL command.",elapsed);
+ server.lua_timedout = 1;
+ /* Once the script timeouts we reenter the event loop to permit others
+ * to call SCRIPT KILL or SHUTDOWN NOSAVE if needed. For this reason
+ * we need to mask the client executing the script from the event loop.
+ * If we don't do that the client may disconnect and could no longer be
+ * here when the EVAL command will return. */
+ aeDeleteFileEvent(server.el, server.lua_caller->fd, AE_READABLE);
+ }
+ if (server.lua_timedout)
+ aeProcessEvents(server.el, AE_FILE_EVENTS|AE_DONT_WAIT);
+ if (server.lua_kill) {
+ redisLog(REDIS_WARNING,"Lua script killed by user with SCRIPT KILL.");
+ lua_pushstring(lua,"Script killed by user with SCRIPT KILL...");
lua_error(lua);
}
}
}
LUALIB_API int (luaopen_cjson) (lua_State *L);
+LUALIB_API int (luaopen_struct) (lua_State *L);
+LUALIB_API int (luaopen_cmsgpack) (lua_State *L);
void luaLoadLibraries(lua_State *lua) {
luaLoadLib(lua, "", luaopen_base);
luaLoadLib(lua, LUA_STRLIBNAME, luaopen_string);
luaLoadLib(lua, LUA_MATHLIBNAME, luaopen_math);
luaLoadLib(lua, LUA_DBLIBNAME, luaopen_debug);
- luaLoadLib(lua, "cjson", luaopen_cjson);
+ luaLoadLib(lua, "cjson", luaopen_cjson);
+ luaLoadLib(lua, "struct", luaopen_struct);
+ luaLoadLib(lua, "cmsgpack", luaopen_cmsgpack);
#if 0 /* Stuff that we don't load currently, for sandboxing concerns. */
luaLoadLib(lua, LUA_LOADLIBNAME, luaopen_package);
#endif
}
+/* Remove a functions that we don't want to expose to the Redis scripting
+ * environment. */
+void luaRemoveUnsupportedFunctions(lua_State *lua) {
+ lua_pushnil(lua);
+ lua_setglobal(lua,"loadfile");
+}
+
+/* This function installs metamethods in the global table _G that prevent
+ * the creation of globals accidentally.
+ *
+ * It should be the last to be called in the scripting engine initialization
+ * sequence, because it may interact with creation of globals. */
+void scriptingEnableGlobalsProtection(lua_State *lua) {
+ char *s[32];
+ sds code = sdsempty();
+ int j = 0;
+
+ /* strict.lua from: http://metalua.luaforge.net/src/lib/strict.lua.html.
+ * Modified to be adapted to Redis. */
+ s[j++]="local mt = {}\n";
+ s[j++]="setmetatable(_G, mt)\n";
+ s[j++]="mt.__newindex = function (t, n, v)\n";
+ s[j++]=" if debug.getinfo(2) then\n";
+ s[j++]=" local w = debug.getinfo(2, \"S\").what\n";
+ s[j++]=" if w ~= \"main\" and w ~= \"C\" then\n";
+ s[j++]=" error(\"Script attempted to create global variable '\"..tostring(n)..\"'\", 2)\n";
+ s[j++]=" end\n";
+ s[j++]=" end\n";
+ s[j++]=" rawset(t, n, v)\n";
+ s[j++]="end\n";
+ s[j++]="mt.__index = function (t, n)\n";
+ s[j++]=" if debug.getinfo(2) and debug.getinfo(2, \"S\").what ~= \"C\" then\n";
+ s[j++]=" error(\"Script attempted to access unexisting global variable '\"..tostring(n)..\"'\", 2)\n";
+ s[j++]=" end\n";
+ s[j++]=" return rawget(t, n)\n";
+ s[j++]="end\n";
+ s[j++]=NULL;
+
+ for (j = 0; s[j] != NULL; j++) code = sdscatlen(code,s[j],strlen(s[j]));
+ luaL_loadbuffer(lua,code,sdslen(code),"@enable_strict_lua");
+ lua_pcall(lua,0,0,0);
+ sdsfree(code);
+}
+
+/* Initialize the scripting environment.
+ * It is possible to call this function to reset the scripting environment
+ * assuming that we call scriptingRelease() before.
+ * See scriptingReset() for more information. */
void scriptingInit(void) {
lua_State *lua = lua_open();
+
luaLoadLibraries(lua);
+ luaRemoveUnsupportedFunctions(lua);
/* Initialize a dictionary we use to map SHAs to scripts.
* This is useful for replication, as we need to replicate EVALSHA
/* redis.call */
lua_pushstring(lua,"call");
- lua_pushcfunction(lua,luaRedisCommand);
+ lua_pushcfunction(lua,luaRedisCallCommand);
+ lua_settable(lua,-3);
+
+ /* redis.pcall */
+ lua_pushstring(lua,"pcall");
+ lua_pushcfunction(lua,luaRedisPCallCommand);
lua_settable(lua,-3);
/* redis.log and log levels. */
lua_pushnumber(lua,REDIS_WARNING);
lua_settable(lua,-3);
+ /* redis.sha1hex */
+ lua_pushstring(lua, "sha1hex");
+ lua_pushcfunction(lua, luaRedisSha1hexCommand);
+ lua_settable(lua, -3);
+
/* Finally set the table as 'redis' global var. */
lua_setglobal(lua,"redis");
lua_setglobal(lua,"math");
+ /* Add a helper funciton that we use to sort the multi bulk output of non
+ * deterministic commands, when containing 'false' elements. */
+ {
+ char *compare_func = "function __redis__compare_helper(a,b)\n"
+ " if a == false then a = '' end\n"
+ " if b == false then b = '' end\n"
+ " return a<b\n"
+ "end\n";
+ luaL_loadbuffer(lua,compare_func,strlen(compare_func),"@cmp_func_def");
+ lua_pcall(lua,0,0,0);
+ }
+
/* Create the (non connected) client that we use to execute Redis commands
- * inside the Lua interpreter */
- server.lua_client = createClient(-1);
- server.lua_client->flags |= REDIS_LUA_CLIENT;
+ * inside the Lua interpreter.
+ * Note: there is no need to create it again when this function is called
+ * by scriptingReset(). */
+ if (server.lua_client == NULL) {
+ server.lua_client = createClient(-1);
+ server.lua_client->flags |= REDIS_LUA_CLIENT;
+ }
+
+ /* Lua beginners ofter don't use "local", this is likely to introduce
+ * subtle bugs in their code. To prevent problems we protect accesses
+ * to global variables. */
+ scriptingEnableGlobalsProtection(lua);
server.lua = lua;
}
-/* Hash the scripit into a SHA1 digest. We use this as Lua function name.
- * Digest should point to a 41 bytes buffer: 40 for SHA1 converted into an
+/* Release resources related to Lua scripting.
+ * This function is used in order to reset the scripting environment. */
+void scriptingRelease(void) {
+ dictRelease(server.lua_scripts);
+ lua_close(server.lua);
+}
+
+void scriptingReset(void) {
+ scriptingRelease();
+ scriptingInit();
+}
+
+/* Perform the SHA1 of the input string. We use this both for hasing script
+ * bodies in order to obtain the Lua function name, and in the implementation
+ * of redis.sha1().
+ *
+ * 'digest' should point to a 41 bytes buffer: 40 for SHA1 converted into an
* hexadecimal number, plus 1 byte for null term. */
-void hashScript(char *digest, char *script, size_t len) {
+void sha1hex(char *digest, char *script, size_t len) {
SHA1_CTX ctx;
unsigned char hash[20];
char *cset = "0123456789abcdef";
lua_setglobal(lua,var);
}
+/* Define a lua function with the specified function name and body.
+ * The function name musts be a 2 characters long string, since all the
+ * functions we defined in the Lua context are in the form:
+ *
+ * f_<hex sha1 sum>
+ *
+ * On success REDIS_OK is returned, and nothing is left on the Lua stack.
+ * On error REDIS_ERR is returned and an appropriate error is set in the
+ * client context. */
+int luaCreateFunction(redisClient *c, lua_State *lua, char *funcname, robj *body) {
+ sds funcdef = sdsempty();
+
+ funcdef = sdscat(funcdef,"function ");
+ funcdef = sdscatlen(funcdef,funcname,42);
+ funcdef = sdscatlen(funcdef,"() ",3);
+ funcdef = sdscatlen(funcdef,body->ptr,sdslen(body->ptr));
+ funcdef = sdscatlen(funcdef," end",4);
+
+ if (luaL_loadbuffer(lua,funcdef,sdslen(funcdef),"@user_script")) {
+ addReplyErrorFormat(c,"Error compiling script (new function): %s\n",
+ lua_tostring(lua,-1));
+ lua_pop(lua,1);
+ sdsfree(funcdef);
+ return REDIS_ERR;
+ }
+ sdsfree(funcdef);
+ if (lua_pcall(lua,0,0,0)) {
+ addReplyErrorFormat(c,"Error running script (new function): %s\n",
+ lua_tostring(lua,-1));
+ lua_pop(lua,1);
+ return REDIS_ERR;
+ }
+
+ /* We also save a SHA1 -> Original script map in a dictionary
+ * so that we can replicate / write in the AOF all the
+ * EVALSHA commands as EVAL using the original script. */
+ {
+ int retval = dictAdd(server.lua_scripts,
+ sdsnewlen(funcname+2,40),body);
+ redisAssertWithInfo(c,NULL,retval == DICT_OK);
+ incrRefCount(body);
+ }
+ return REDIS_OK;
+}
+
void evalGenericCommand(redisClient *c, int evalsha) {
lua_State *lua = server.lua;
char funcname[43];
long long numkeys;
+ int delhook = 0;
/* We want the same PRNG sequence at every call so that our PRNG is
* not affected by external state. */
* Thanks to this flag we'll raise an error every time a write command
* is called after a random command was used. */
server.lua_random_dirty = 0;
+ server.lua_write_dirty = 0;
/* Get the number of arguments that are keys */
if (getLongLongFromObjectOrReply(c,c->argv[2],&numkeys,NULL) != REDIS_OK)
funcname[1] = '_';
if (!evalsha) {
/* Hash the code if this is an EVAL call */
- hashScript(funcname+2,c->argv[1]->ptr,sdslen(c->argv[1]->ptr));
+ sha1hex(funcname+2,c->argv[1]->ptr,sdslen(c->argv[1]->ptr));
} else {
/* We already have the SHA if it is a EVALSHA */
int j;
funcname[42] = '\0';
}
+ /* Try to lookup the Lua function */
lua_getglobal(lua, funcname);
if (lua_isnil(lua,1)) {
- sds funcdef;
-
+ lua_pop(lua,1); /* remove the nil from the stack */
/* Function not defined... let's define it if we have the
* body of the funciton. If this is an EVALSHA call we can just
* return an error. */
if (evalsha) {
addReply(c, shared.noscripterr);
- lua_pop(lua,1); /* remove the nil from the stack */
- return;
- }
- funcdef = sdsempty();
-
- lua_pop(lua,1); /* remove the nil from the stack */
- funcdef = sdscat(funcdef,"function ");
- funcdef = sdscatlen(funcdef,funcname,42);
- funcdef = sdscatlen(funcdef," ()\n",4);
- funcdef = sdscatlen(funcdef,c->argv[1]->ptr,sdslen(c->argv[1]->ptr));
- funcdef = sdscatlen(funcdef,"\nend\n",5);
- /* printf("Defining:\n%s\n",funcdef); */
-
- if (luaL_loadbuffer(lua,funcdef,sdslen(funcdef),"func definition")) {
- addReplyErrorFormat(c,"Error compiling script (new function): %s\n",
- lua_tostring(lua,-1));
- lua_pop(lua,1);
- sdsfree(funcdef);
- return;
- }
- sdsfree(funcdef);
- if (lua_pcall(lua,0,0,0)) {
- addReplyErrorFormat(c,"Error running script (new function): %s\n",
- lua_tostring(lua,-1));
- lua_pop(lua,1);
return;
}
+ if (luaCreateFunction(c,lua,funcname,c->argv[1]) == REDIS_ERR) return;
+ /* Now the following is guaranteed to return non nil */
lua_getglobal(lua, funcname);
-
- /* We also save a SHA1 -> Original script map in a dictionary
- * so that we can replicate / write in the AOF all the
- * EVALSHA commands as EVAL using the original script. */
- {
- int retval = dictAdd(server.lua_scripts,
- sdsnewlen(funcname+2,40),c->argv[1]);
- redisAssertWithInfo(c,NULL,retval == DICT_OK);
- incrRefCount(c->argv[1]);
- }
+ redisAssert(!lua_isnil(lua,1));
}
/* Populate the argv and keys table accordingly to the arguments that
* is running for too much time.
* We set the hook only if the time limit is enabled as the hook will
* make the Lua script execution slower. */
- if (server.lua_time_limit > 0) {
+ server.lua_caller = c;
+ server.lua_time_start = ustime()/1000;
+ server.lua_kill = 0;
+ if (server.lua_time_limit > 0 && server.masterhost == NULL) {
lua_sethook(lua,luaMaskCountHook,LUA_MASKCOUNT,100000);
- server.lua_time_start = ustime()/1000;
- } else {
- lua_sethook(lua,luaMaskCountHook,0,0);
+ delhook = 1;
}
/* At this point whatever this script was never seen before or if it was
* already defined, we can call it. We have zero arguments and expect
* a single return value. */
if (lua_pcall(lua,0,1,0)) {
+ if (delhook) lua_sethook(lua,luaMaskCountHook,0,0); /* Disable hook */
+ if (server.lua_timedout) {
+ server.lua_timedout = 0;
+ /* Restore the readable handler that was unregistered when the
+ * script timeout was detected. */
+ aeCreateFileEvent(server.el,c->fd,AE_READABLE,
+ readQueryFromClient,c);
+ }
+ server.lua_caller = NULL;
selectDb(c,server.lua_client->db->id); /* set DB ID from Lua client */
addReplyErrorFormat(c,"Error running script (call to %s): %s\n",
funcname, lua_tostring(lua,-1));
lua_gc(lua,LUA_GCCOLLECT,0);
return;
}
+ if (delhook) lua_sethook(lua,luaMaskCountHook,0,0); /* Disable hook */
+ server.lua_timedout = 0;
+ server.lua_caller = NULL;
selectDb(c,server.lua_client->db->id); /* set DB ID from Lua client */
luaReplyToRedisReply(c,lua);
lua_gc(lua,LUA_GCSTEP,1);
redisSrand48(luaL_checkint(L, 1));
return 0;
}
+
+/* ---------------------------------------------------------------------------
+ * SCRIPT command for script environment introspection and control
+ * ------------------------------------------------------------------------- */
+
+void scriptCommand(redisClient *c) {
+ if (c->argc == 2 && !strcasecmp(c->argv[1]->ptr,"flush")) {
+ scriptingReset();
+ addReply(c,shared.ok);
+ server.dirty++; /* Replicating this command is a good idea. */
+ } else if (c->argc >= 2 && !strcasecmp(c->argv[1]->ptr,"exists")) {
+ int j;
+
+ addReplyMultiBulkLen(c, c->argc-2);
+ for (j = 2; j < c->argc; j++) {
+ if (dictFind(server.lua_scripts,c->argv[j]->ptr))
+ addReply(c,shared.cone);
+ else
+ addReply(c,shared.czero);
+ }
+ } else if (c->argc == 3 && !strcasecmp(c->argv[1]->ptr,"load")) {
+ char funcname[43];
+ sds sha;
+
+ funcname[0] = 'f';
+ funcname[1] = '_';
+ sha1hex(funcname+2,c->argv[2]->ptr,sdslen(c->argv[2]->ptr));
+ sha = sdsnewlen(funcname+2,40);
+ if (dictFind(server.lua_scripts,sha) == NULL) {
+ if (luaCreateFunction(c,server.lua,funcname,c->argv[2])
+ == REDIS_ERR) {
+ sdsfree(sha);
+ return;
+ }
+ }
+ addReplyBulkCBuffer(c,funcname+2,40);
+ sdsfree(sha);
+ } else if (c->argc == 2 && !strcasecmp(c->argv[1]->ptr,"kill")) {
+ if (server.lua_caller == NULL) {
+ addReplyError(c,"No scripts in execution right now.");
+ } else if (server.lua_write_dirty) {
+ addReplyError(c, "Sorry the script already executed write commands against the dataset. You can either wait the script termination or kill the server in an hard way using the SHUTDOWN NOSAVE command.");
+ } else {
+ server.lua_kill = 1;
+ addReply(c,shared.ok);
+ }
+ } else {
+ addReplyError(c, "Unknown SCRIPT subcommand or wrong # of args.");
+ }
+}
projects / redis.git / blobdiff