SORT is now more deterministic: does not accept to compare by score items that have...

[redis.git] / src / scripting.c

diff --git a/src/scripting.c b/src/scripting.c
index 0b548873fd8fbac94e9b4b2f04a05f803db3af73..2eac840c52e5707829a57f5deab6950d9bf086cc 100644 (file)
--- a/src/scripting.c
+++ b/src/scripting.c
@@ -27,7 +27,7 @@ int redis_math_randomseed (lua_State *L);
  * 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
  * 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.
  *
  * The reply string can be altered during the parsing as it is discared
  * after the conversion is completed.
  *


@@ -128,6 +128,37 @@ void luaPushError(lua_State *lua, char *error) {
     lua_settable(lua,-3);
 }
 
     lua_settable(lua,-3);
 }
 

+/* 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;
 int luaRedisGenericCommand(lua_State *lua, int raise_error) {
     int j, argc = lua_gettop(lua);
     struct redisCommand *cmd;


@@ -187,6 +218,7 @@ int luaRedisGenericCommand(lua_State *lua, int raise_error) {
     }
 
     if (cmd->flags & REDIS_CMD_RANDOM) server.lua_random_dirty = 1;
     }
 
     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);
 
     /* Run the command */
     cmd->proc(c);


@@ -207,6 +239,14 @@ int luaRedisGenericCommand(lua_State *lua, int raise_error) {
     }
     if (raise_error && reply[0] != '-') raise_error = 0;
     redisProtocolToLuaType(lua,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:
     sdsfree(reply);
 
 cleanup:


@@ -277,11 +317,22 @@ void luaMaskCountHook(lua_State *lua, lua_Debug *ar) {
 
     elapsed = (ustime()/1000) - server.lua_time_start;
     if (elapsed >= server.lua_time_limit && server.lua_timedout == 0) {
 
     elapsed = (ustime()/1000) - server.lua_time_start;
     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 shut down the server using the SHUTDOWN command.",elapsed);
+        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;
         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_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);
+    }

 }
 
 void luaLoadLib(lua_State *lua, const char *libname, lua_CFunction luafunc) {
 }
 
 void luaLoadLib(lua_State *lua, const char *libname, lua_CFunction luafunc) {


@@ -369,6 +420,18 @@ void scriptingInit(void) {
 
     lua_setglobal(lua,"math");
 
 
     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.
      * Note: there is no need to create it again when this function is called
     /* Create the (non connected) client that we use to execute Redis commands
      * inside the Lua interpreter.
      * Note: there is no need to create it again when this function is called


@@ -504,9 +567,9 @@ int luaCreateFunction(redisClient *c, lua_State *lua, char *funcname, robj *body
 
     funcdef = sdscat(funcdef,"function ");
     funcdef = sdscatlen(funcdef,funcname,42);
 
     funcdef = sdscat(funcdef,"function ");
     funcdef = sdscatlen(funcdef,funcname,42);

-    funcdef = sdscatlen(funcdef," ()\n",4);
+    funcdef = sdscatlen(funcdef,"() ",3);

     funcdef = sdscatlen(funcdef,body->ptr,sdslen(body->ptr));
     funcdef = sdscatlen(funcdef,body->ptr,sdslen(body->ptr));

-    funcdef = sdscatlen(funcdef,"\nend\n",5);
+    funcdef = sdscatlen(funcdef," end",4);

 
     if (luaL_loadbuffer(lua,funcdef,sdslen(funcdef),"func definition")) {
         addReplyErrorFormat(c,"Error compiling script (new function): %s\n",
 
     if (luaL_loadbuffer(lua,funcdef,sdslen(funcdef),"func definition")) {
         addReplyErrorFormat(c,"Error compiling script (new function): %s\n",


@@ -553,6 +616,7 @@ void evalGenericCommand(redisClient *c, int evalsha) {
      * 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;
      * 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)
 
     /* Get the number of arguments that are keys */
     if (getLongLongFromObjectOrReply(c,c->argv[2],&numkeys,NULL) != REDIS_OK)


@@ -610,7 +674,6 @@ void evalGenericCommand(redisClient *c, int evalsha) {
      * make the Lua script execution slower. */
     if (server.lua_time_limit > 0 && server.masterhost == NULL) {
         lua_sethook(lua,luaMaskCountHook,LUA_MASKCOUNT,100000);
      * make the Lua script execution slower. */
     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);
     }
     } else {
         lua_sethook(lua,luaMaskCountHook,0,0);
     }


@@ -618,8 +681,18 @@ void evalGenericCommand(redisClient *c, int evalsha) {
     /* 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. */
     /* 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. */

+    server.lua_caller = c;
+    server.lua_time_start = ustime()/1000;
+    server.lua_kill = 0;

     if (lua_pcall(lua,0,1,0)) {
     if (lua_pcall(lua,0,1,0)) {

-        server.lua_timedout = 0;
+        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));
         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));


@@ -628,6 +701,7 @@ void evalGenericCommand(redisClient *c, int evalsha) {
         return;
     }
     server.lua_timedout = 0;
         return;
     }
     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);
     selectDb(c,server.lua_client->db->id); /* set DB ID from Lua client */
     luaReplyToRedisReply(c,lua);
     lua_gc(lua,LUA_GCSTEP,1);


@@ -743,6 +817,15 @@ void scriptCommand(redisClient *c) {
         }
         addReplyBulkCBuffer(c,funcname+2,40);
         sdsfree(sha);
         }
         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.");
     }
     } else {
         addReplyError(c, "Unknown SCRIPT subcommand or wrong # of args.");
     }