X-Git-Url: https://git.saurik.com/redis.git/blobdiff_plain/7585836e6eb1c0199e8d9ea2c3f7a0f67b03c00b..9514aa325192d4d59497fab560ce781b3ed90bbb:/src/scripting.c

diff --git a/src/scripting.c b/src/scripting.c
index 42ba3bf9..08151710 100644
--- a/src/scripting.c
+++ b/src/scripting.c
@@ -1,13 +1,348 @@
 #include "redis.h"
 #include "sha1.h"
+#include "rand.h"
 
 #include <lua.h>
 #include <lauxlib.h>
 #include <lualib.h>
+#include <ctype.h>
+#include <math.h>
+
+char *redisProtocolToLuaType_Int(lua_State *lua, char *reply);
+char *redisProtocolToLuaType_Bulk(lua_State *lua, char *reply);
+char *redisProtocolToLuaType_Status(lua_State *lua, char *reply);
+char *redisProtocolToLuaType_Error(lua_State *lua, char *reply);
+char *redisProtocolToLuaType_MultiBulk(lua_State *lua, char *reply);
+int redis_math_random (lua_State *L);
+int redis_math_randomseed (lua_State *L);
+
+/* 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
+ * clients, it is trvial to implement the redis() lua function.
+ *
+ * Basically we take the arguments, execute the Redis command in the context
+ * of a non connected client, then take the generated reply and convert it
+ * into a suitable Lua type. With this trick the scripting feature does not
+ * need the introduction of a full Redis internals API. Basically the script
+ * 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.
+ * The reply string can be altered during the parsing as it is discared
+ * after the conversion is completed.
+ *
+ * Errors are returned as a table with a single 'err' field set to the
+ * error string.
+ */
+
+char *redisProtocolToLuaType(lua_State *lua, char* reply) {
+    char *p = reply;
+
+    switch(*p) {
+    case ':':
+        p = redisProtocolToLuaType_Int(lua,reply);
+        break;
+    case '$':
+        p = redisProtocolToLuaType_Bulk(lua,reply);
+        break;
+    case '+':
+        p = redisProtocolToLuaType_Status(lua,reply);
+        break;
+    case '-':
+        p = redisProtocolToLuaType_Error(lua,reply);
+        break;
+    case '*':
+        p = redisProtocolToLuaType_MultiBulk(lua,reply);
+        break;
+    }
+    return p;
+}
+
+char *redisProtocolToLuaType_Int(lua_State *lua, char *reply) {
+    char *p = strchr(reply+1,'\r');
+    long long value;
+
+    string2ll(reply+1,p-reply-1,&value);
+    lua_pushnumber(lua,(lua_Number)value);
+    return p+2;
+}
+
+char *redisProtocolToLuaType_Bulk(lua_State *lua, char *reply) {
+    char *p = strchr(reply+1,'\r');
+    long long bulklen;
+
+    string2ll(reply+1,p-reply-1,&bulklen);
+    if (bulklen == -1) {
+        lua_pushboolean(lua,0);
+        return p+2;
+    } else {
+        lua_pushlstring(lua,p+2,bulklen);
+        return p+2+bulklen+2;
+    }
+}
+
+char *redisProtocolToLuaType_Status(lua_State *lua, char *reply) {
+    char *p = strchr(reply+1,'\r');
+
+    lua_newtable(lua);
+    lua_pushstring(lua,"ok");
+    lua_pushlstring(lua,reply+1,p-reply-1);
+    lua_settable(lua,-3);
+    return p+2;
+}
+
+char *redisProtocolToLuaType_Error(lua_State *lua, char *reply) {
+    char *p = strchr(reply+1,'\r');
+
+    lua_newtable(lua);
+    lua_pushstring(lua,"err");
+    lua_pushlstring(lua,reply+1,p-reply-1);
+    lua_settable(lua,-3);
+    return p+2;
+}
+
+char *redisProtocolToLuaType_MultiBulk(lua_State *lua, char *reply) {
+    char *p = strchr(reply+1,'\r');
+    long long mbulklen;
+    int j = 0;
+
+    string2ll(reply+1,p-reply-1,&mbulklen);
+    p += 2;
+    if (mbulklen == -1) {
+        lua_pushboolean(lua,0);
+        return p;
+    }
+    lua_newtable(lua);
+    for (j = 0; j < mbulklen; j++) {
+        lua_pushnumber(lua,j+1);
+        p = redisProtocolToLuaType(lua,p);
+        lua_settable(lua,-3);
+    }
+    return p;
+}
+
+void luaPushError(lua_State *lua, char *error) {
+    lua_newtable(lua);
+    lua_pushstring(lua,"err");
+    lua_pushstring(lua, error);
+    lua_settable(lua,-3);
+}
+
+int luaRedisCommand(lua_State *lua) {
+    int j, argc = lua_gettop(lua);
+    struct redisCommand *cmd;
+    robj **argv;
+    redisClient *c = server.lua_client;
+    sds reply;
+
+    /* Build the arguments vector */
+    argv = zmalloc(sizeof(robj*)*argc);
+    for (j = 0; j < argc; j++) {
+        if (!lua_isstring(lua,j+1)) break;
+        argv[j] = createStringObject((char*)lua_tostring(lua,j+1),
+                                     lua_strlen(lua,j+1));
+    }
+    
+    /* Check if one of the arguments passed by the Lua script
+     * is not a string or an integer (lua_isstring() return true for
+     * integers as well). */
+    if (j != argc) {
+        j--;
+        while (j >= 0) {
+            decrRefCount(argv[j]);
+            j--;
+        }
+        zfree(argv);
+        luaPushError(lua,
+            "Lua redis() command arguments must be strings or integers");
+        return 1;
+    }
+
+    /* Setup our fake client for command execution */
+    c->argv = argv;
+    c->argc = argc;
+
+    /* Command lookup */
+    cmd = lookupCommand(argv[0]->ptr);
+    if (!cmd || ((cmd->arity > 0 && cmd->arity != argc) ||
+                   (argc < -cmd->arity)))
+    {
+        if (cmd)
+            luaPushError(lua,
+                "Wrong number of args calling Redis command From Lua script");
+        else
+            luaPushError(lua,"Unknown Redis command called from Lua script");
+        goto cleanup;
+    }
+
+    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;
+    }
+
+    if (cmd->flags & REDIS_CMD_RANDOM) server.lua_random_dirty = 1;
+
+    /* Run the command */
+    cmd->proc(c);
+
+    /* 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
+     * output buffers. */
+    reply = sdsempty();
+    if (c->bufpos) {
+        reply = sdscatlen(reply,c->buf,c->bufpos);
+        c->bufpos = 0;
+    }
+    while(listLength(c->reply)) {
+        robj *o = listNodeValue(listFirst(c->reply));
+
+        reply = sdscatlen(reply,o->ptr,sdslen(o->ptr));
+        listDelNode(c->reply,listFirst(c->reply));
+    }
+    redisProtocolToLuaType(lua,reply);
+    sdsfree(reply);
+
+cleanup:
+    /* Clean up. Command code may have changed argv/argc so we use the
+     * argv/argc of the client instead of the local variables. */
+    for (j = 0; j < c->argc; j++)
+        decrRefCount(c->argv[j]);
+    zfree(c->argv);
+
+    return 1;
+}
+
+int luaLogCommand(lua_State *lua) {
+    int j, argc = lua_gettop(lua);
+    int level;
+    sds log;
+
+    if (argc < 2) {
+        luaPushError(lua, "redis.log() requires two arguments or more.");
+        return 1;
+    } else if (!lua_isnumber(lua,-argc)) {
+        luaPushError(lua, "First argument must be a number (log level).");
+        return 1;
+    }
+    level = lua_tonumber(lua,-argc);
+    if (level < REDIS_DEBUG || level > REDIS_WARNING) {
+        luaPushError(lua, "Invalid debug level.");
+        return 1;
+    }
+
+    /* Glue together all the arguments */
+    log = sdsempty();
+    for (j = 1; j < argc; j++) {
+        size_t len;
+        char *s;
+
+        s = (char*)lua_tolstring(lua,(-argc)+j,&len);
+        if (s) {
+            if (j != 1) log = sdscatlen(log," ",1);
+            log = sdscatlen(log,s,len);
+        }
+    }
+    redisLogRaw(level,log);
+    sdsfree(log);
+    return 0;
+}
+
+void luaMaskCountHook(lua_State *lua, lua_Debug *ar) {
+    long long elapsed;
+    REDIS_NOTUSED(ar);
+
+    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.");
+        lua_error(lua);
+    }
+}
+
+void luaLoadLib(lua_State *lua, const char *libname, lua_CFunction luafunc) {
+  lua_pushcfunction(lua, luafunc);
+  lua_pushstring(lua, libname);
+  lua_call(lua, 1, 0);
+}
+
+void luaLoadLibraries(lua_State *lua) {
+    luaLoadLib(lua, "", luaopen_base);
+    luaLoadLib(lua, LUA_TABLIBNAME, luaopen_table);
+    luaLoadLib(lua, LUA_STRLIBNAME, luaopen_string);
+    luaLoadLib(lua, LUA_MATHLIBNAME, luaopen_math);
+    luaLoadLib(lua, LUA_DBLIBNAME, luaopen_debug); 
+
+#if 0 /* Stuff that we don't load currently, for sandboxing concerns. */
+    luaLoadLib(lua, LUA_LOADLIBNAME, luaopen_package);
+    luaLoadLib(lua, LUA_OSLIBNAME, luaopen_os);
+#endif
+}
 
 void scriptingInit(void) {
     lua_State *lua = lua_open();
-    luaL_openlibs(lua);
+    luaLoadLibraries(lua);
+
+    /* Initialize a dictionary we use to map SHAs to scripts.
+     * This is useful for replication, as we need to replicate EVALSHA
+     * as EVAL, so we need to remember the associated script. */
+    server.lua_scripts = dictCreate(&dbDictType,NULL);
+
+    /* Register the redis commands table and fields */
+    lua_newtable(lua);
+
+    /* redis.call */
+    lua_pushstring(lua,"call");
+    lua_pushcfunction(lua,luaRedisCommand);
+    lua_settable(lua,-3);
+
+    /* redis.log and log levels. */
+    lua_pushstring(lua,"log");
+    lua_pushcfunction(lua,luaLogCommand);
+    lua_settable(lua,-3);
+
+    lua_pushstring(lua,"LOG_DEBUG");
+    lua_pushnumber(lua,REDIS_DEBUG);
+    lua_settable(lua,-3);
+
+    lua_pushstring(lua,"LOG_VERBOSE");
+    lua_pushnumber(lua,REDIS_VERBOSE);
+    lua_settable(lua,-3);
+
+    lua_pushstring(lua,"LOG_NOTICE");
+    lua_pushnumber(lua,REDIS_NOTICE);
+    lua_settable(lua,-3);
+
+    lua_pushstring(lua,"LOG_WARNING");
+    lua_pushnumber(lua,REDIS_WARNING);
+    lua_settable(lua,-3);
+
+    /* Finally set the table as 'redis' global var. */
+    lua_setglobal(lua,"redis");
+
+    /* Replace math.random and math.randomseed with our implementations. */
+    lua_getglobal(lua,"math");
+
+    lua_pushstring(lua,"random");
+    lua_pushcfunction(lua,redis_math_random);
+    lua_settable(lua,-3);
+
+    lua_pushstring(lua,"randomseed");
+    lua_pushcfunction(lua,redis_math_randomseed);
+    lua_settable(lua,-3);
+
+    lua_setglobal(lua,"math");
+
+    /* 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;
+
     server.lua = lua;
 }
 
@@ -32,17 +367,62 @@ void hashScript(char *digest, char *script, size_t len) {
 }
 
 void luaReplyToRedisReply(redisClient *c, lua_State *lua) {
-    int t = lua_type(lua,1);
+    int t = lua_type(lua,-1);
 
     switch(t) {
     case LUA_TSTRING:
-        addReplyBulkCBuffer(c,(char*)lua_tostring(lua,1),lua_strlen(lua,1));
+        addReplyBulkCBuffer(c,(char*)lua_tostring(lua,-1),lua_strlen(lua,-1));
         break;
     case LUA_TBOOLEAN:
-        addReply(c,lua_toboolean(lua,1) ? shared.cone : shared.czero);
+        addReply(c,lua_toboolean(lua,-1) ? shared.cone : shared.nullbulk);
         break;
     case LUA_TNUMBER:
-        addReplyLongLong(c,(long long)lua_tonumber(lua,1));
+        addReplyLongLong(c,(long long)lua_tonumber(lua,-1));
+        break;
+    case LUA_TTABLE:
+        /* We need to check if it is an array, an error, or a status reply.
+         * Error are returned as a single element table with 'err' field.
+         * Status replies are returned as single elment table with 'ok' field */
+        lua_pushstring(lua,"err");
+        lua_gettable(lua,-2);
+        t = lua_type(lua,-1);
+        if (t == LUA_TSTRING) {
+            sds err = sdsnew(lua_tostring(lua,-1));
+            sdsmapchars(err,"\r\n","  ",2);
+            addReplySds(c,sdscatprintf(sdsempty(),"-%s\r\n",err));
+            sdsfree(err);
+            lua_pop(lua,2);
+            return;
+        }
+
+        lua_pop(lua,1);
+        lua_pushstring(lua,"ok");
+        lua_gettable(lua,-2);
+        t = lua_type(lua,-1);
+        if (t == LUA_TSTRING) {
+            sds ok = sdsnew(lua_tostring(lua,-1));
+            sdsmapchars(ok,"\r\n","  ",2);
+            addReplySds(c,sdscatprintf(sdsempty(),"+%s\r\n",ok));
+            sdsfree(ok);
+            lua_pop(lua,1);
+        } else {
+            void *replylen = addDeferredMultiBulkLength(c);
+            int j = 1, mbulklen = 0;
+
+            lua_pop(lua,1); /* Discard the 'ok' field value we popped */
+            while(1) {
+                lua_pushnumber(lua,j++);
+                lua_gettable(lua,-2);
+                t = lua_type(lua,-1);
+                if (t == LUA_TNIL) {
+                    lua_pop(lua,1);
+                    break;
+                }
+                luaReplyToRedisReply(c, lua);
+                mbulklen++;
+            }
+            setDeferredMultiBulkLength(c,replylen,mbulklen);
+        }
         break;
     default:
         addReply(c,shared.nullbulk);
@@ -50,19 +430,76 @@ void luaReplyToRedisReply(redisClient *c, lua_State *lua) {
     lua_pop(lua,1);
 }
 
-void evalCommand(redisClient *c) {
+/* Set an array of Redis String Objects as a Lua array (table) stored into a
+ * global variable. */
+void luaSetGlobalArray(lua_State *lua, char *var, robj **elev, int elec) {
+    int j;
+
+    lua_newtable(lua);
+    for (j = 0; j < elec; j++) {
+        lua_pushlstring(lua,(char*)elev[j]->ptr,sdslen(elev[j]->ptr));
+        lua_rawseti(lua,-2,j+1);
+    }
+    lua_setglobal(lua,var);
+}
+
+void evalGenericCommand(redisClient *c, int evalsha) {
     lua_State *lua = server.lua;
     char funcname[43];
+    long long numkeys;
+
+    /* We want the same PRNG sequence at every call so that our PRNG is
+     * not affected by external state. */
+    redisSrand48(0);
+
+    /* We set this flag to zero to remember that so far no random command
+     * was called. This way we can allow the user to call commands like
+     * SRANDMEMBER or RANDOMKEY from Lua scripts as far as no write command
+     * is called (otherwise the replication and AOF would end with non
+     * deterministic sequences).
+     *
+     * 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;
+
+    /* Get the number of arguments that are keys */
+    if (getLongLongFromObjectOrReply(c,c->argv[2],&numkeys,NULL) != REDIS_OK)
+        return;
+    if (numkeys > (c->argc - 3)) {
+        addReplyError(c,"Number of keys can't be greater than number of args");
+        return;
+    }
 
     /* We obtain the script SHA1, then check if this function is already
      * defined into the Lua state */
     funcname[0] = 'f';
     funcname[1] = '_';
-    hashScript(funcname+2,c->argv[1]->ptr,sdslen(c->argv[1]->ptr));
+    if (!evalsha) {
+        /* Hash the code if this is an EVAL call */
+        hashScript(funcname+2,c->argv[1]->ptr,sdslen(c->argv[1]->ptr));
+    } else {
+        /* We already have the SHA if it is a EVALSHA */
+        int j;
+        char *sha = c->argv[1]->ptr;
+
+        for (j = 0; j < 40; j++)
+            funcname[j+2] = tolower(sha[j]);
+        funcname[42] = '\0';
+    }
+
     lua_getglobal(lua, funcname);
     if (lua_isnil(lua,1)) {
-        /* Function not defined... let's define it. */
-        sds funcdef = sdsempty();
+        sds funcdef;
+      
+        /* 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 ");
@@ -70,14 +507,16 @@ void evalCommand(redisClient *c) {
         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);
+        /* 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));
@@ -85,16 +524,123 @@ void evalCommand(redisClient *c) {
             return;
         }
         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]);
+            redisAssert(retval == DICT_OK);
+            incrRefCount(c->argv[1]);
+        }
     }
+
+    /* Populate the argv and keys table accordingly to the arguments that
+     * EVAL received. */
+    luaSetGlobalArray(lua,"KEYS",c->argv+3,numkeys);
+    luaSetGlobalArray(lua,"ARGV",c->argv+3+numkeys,c->argc-3-numkeys);
+
+    /* Select the right DB in the context of the Lua client */
+    selectDb(server.lua_client,c->db->id);
     
+    /* Set an hook in order to be able to stop the script execution if it
+     * 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) {
+        lua_sethook(lua,luaMaskCountHook,LUA_MASKCOUNT,100000);
+        server.lua_time_start = ustime()/1000;
+    } else {
+        lua_sethook(lua,luaMaskCountHook,0,0);
+    }
+
     /* 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)) {
+        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_pop(lua,1);
+        lua_gc(lua,LUA_GCCOLLECT,0);
         return;
     }
+    selectDb(c,server.lua_client->db->id); /* set DB ID from Lua client */
     luaReplyToRedisReply(c,lua);
+    lua_gc(lua,LUA_GCSTEP,1);
+
+    /* If we have slaves attached we want to replicate this command as
+     * EVAL instead of EVALSHA. We do this also in the AOF as currently there
+     * is no easy way to propagate a command in a different way in the AOF
+     * and in the replication link.
+     *
+     * IMPROVEMENT POSSIBLE:
+     * 1) Replicate this command as EVALSHA in the AOF.
+     * 2) Remember what slave already received a given script, and replicate
+     *    the EVALSHA against this slaves when possible.
+     */
+    if (evalsha) {
+        robj *script = dictFetchValue(server.lua_scripts,c->argv[1]->ptr);
+
+        redisAssert(script != NULL);
+        rewriteClientCommandArgument(c,0,
+            resetRefCount(createStringObject("EVAL",4)));
+        rewriteClientCommandArgument(c,1,script);
+    }
+}
+
+void evalCommand(redisClient *c) {
+    evalGenericCommand(c,0);
+}
+
+void evalShaCommand(redisClient *c) {
+    if (sdslen(c->argv[1]->ptr) != 40) {
+        /* We know that a match is not possible if the provided SHA is
+         * not the right length. So we return an error ASAP, this way
+         * evalGenericCommand() can be implemented without string length
+         * sanity check */
+        addReply(c, shared.noscripterr);
+        return;
+    }
+    evalGenericCommand(c,1);
+}
+
+/* We replace math.random() with our implementation that is not affected
+ * by specific libc random() implementations and will output the same sequence
+ * (for the same seed) in every arch. */
+
+/* The following implementation is the one shipped with Lua itself but with
+ * rand() replaced by redisLrand48(). */
+int redis_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)(redisLrand48()%REDIS_LRAND48_MAX) /
+                                (lua_Number)REDIS_LRAND48_MAX;
+  switch (lua_gettop(L)) {  /* check number of arguments */
+    case 0: {  /* no arguments */
+      lua_pushnumber(L, r);  /* Number between 0 and 1 */
+      break;
+    }
+    case 1: {  /* only upper limit */
+      int u = luaL_checkint(L, 1);
+      luaL_argcheck(L, 1<=u, 1, "interval is empty");
+      lua_pushnumber(L, floor(r*u)+1);  /* int between 1 and `u' */
+      break;
+    }
+    case 2: {  /* lower and upper limits */
+      int l = luaL_checkint(L, 1);
+      int u = luaL_checkint(L, 2);
+      luaL_argcheck(L, l<=u, 2, "interval is empty");
+      lua_pushnumber(L, floor(r*(u-l+1))+l);  /* int between `l' and `u' */
+      break;
+    }
+    default: return luaL_error(L, "wrong number of arguments");
+  }
+  return 1;
+}
+
+int redis_math_randomseed (lua_State *L) {
+  redisSrand48(luaL_checkint(L, 1));
+  return 0;
 }