First working implementation of the hierarchical router.

server/modules/include/shardrouter.h

@@ -171,6 +171,7 @@ struct router_client_session {
         int              rses_versno;    /*< even = no active update, else odd. not used 4/14 */
         bool             rses_closed;    /*< true when closeSession is called      */
 	    DCB*			 rses_client_dcb;
+            DCB* dummy_dcb; /* DCB used to send the client write messages from the router itself */
 	    MYSQL_session*   rses_mysql_session;
 	/** Properties listed by their type */
 	rses_property_t* rses_properties[RSES_PROP_TYPE_COUNT];
@@ -185,7 +186,6 @@ struct router_client_session {
         SUBSERVICE*     *subservice;
         int             n_subservice;
         bool            hash_init;
-        GWBUF*          queue;
         SESSION*        session;
 #if defined(SS_DEBUG)
         skygw_chk_t      rses_chk_tail;

server/modules/routing/dbshard/shardrouter.c

@@ -66,6 +66,10 @@ extern __thread log_info_t tls_log_info;
 
 static char *version_str = "V1.0.0";
 static int filterReply (FILTER* instance, void *session, GWBUF *reply);
+static void dummyDiagnostic(FILTER *instance, void *session, DCB *dcb)
+{
+    return;
+}
 static void dummySetUpstream(FILTER *instance, void *fsession, UPSTREAM *downstream)
 {
     return;
@@ -79,7 +83,7 @@ static FILTER_OBJECT dummyObject = {
     dummySetUpstream,
     NULL,
     filterReply,
-    NULL,
+    dummyDiagnostic,
 };
 
 static ROUTER* createInstance(SERVICE *service, char **options);
@@ -252,6 +256,7 @@ hashcmpfun(
 
     return strcmp(i1, i2);
 }
+/*
 
 static void*
 hstrdup(void* fval)
@@ -266,6 +271,7 @@ hfree(void* fval)
     free(fval);
     return NULL;
 }
+*/
 
 bool
 parse_mapping_response(ROUTER_CLIENT_SES* rses, char* target, GWBUF* buf)
@@ -434,11 +440,13 @@ filterReply (FILTER* instance, void *session, GWBUF *reply)
     SUBSERVICE* subsvc;
     int i,rv = 1;
     bool mapped = true;
+    sescmd_cursor_t* scur;
     
     if(!rses_begin_locked_router_action(rses))
     {
         return 0;
     }
+    
     subsvc = get_subsvc_from_ses(rses,session);
     subsvc_clear_state(subsvc,SUBSVC_WAITING_RESULT|SUBSVC_QUERY_ACTIVE);
     if(!rses->hash_init)
@@ -453,28 +461,60 @@ filterReply (FILTER* instance, void *session, GWBUF *reply)
                 mapped = false;
                 break;
             }
+        
         }
+        
+        gwbuf_free(reply);
+        
         if(mapped)
         {
             rses->hash_init = true;            
+        }
         
-            if(rses->queue){
+        goto retblock;   
-                GWBUF* tmp = rses->queue;
-                rses->queue = NULL;
-                rses_end_locked_router_action(rses);                
-                rv = routeQuery((ROUTER*)rses->router, (void*)rses, tmp);
-                return rv;
-            }
-        }
     }
     
     
+        scur = subsvc->scur;
+       
+        if(sescmd_cursor_is_active(scur)) 
+        {
+            if(!sescmd_cursor_next(scur))
+            {
+                sescmd_cursor_set_active(scur,false);
+            }
+            else
+            {
+                execute_sescmd_in_backend(subsvc);
+                goto retblock;
+            }
+        }
     
     rv = SESSION_ROUTE_REPLY(rses->session, reply);
     
+    retblock:
     rses_end_locked_router_action(rses);
     return rv;
 }
+
+/**
+ * This function reads the DCB's readqueue and sends it as a reply to the session
+ * who owns the DCB. 
+ * @param dcb The dummy DCB
+ * @return 1 on success, 0 on failure
+ */
+int fakeRead(DCB* dcb)
+{
+    if(dcb->dcb_readqueue)
+    {
+        GWBUF* tmp = dcb->dcb_readqueue;
+        dcb->dcb_readqueue = NULL;
+        return SESSION_ROUTE_REPLY(dcb->session, tmp);
+    }
+    return 1;
+}
+
+
 /**
  * Implementation of the mandatory version entry point
  *
@@ -715,7 +755,10 @@ newSession(
     client_rses->rses_autocommit_enabled = true;
     client_rses->rses_transaction_active = false;
     client_rses->session = session;
-
+    client_rses->dummy_dcb = dcb_alloc(DCB_ROLE_REQUEST_HANDLER);
+    client_rses->dummy_dcb->func.read = fakeRead;
+    client_rses->dummy_dcb->state = DCB_STATE_POLLING;
+    client_rses->dummy_dcb->session = session;
     spinlock_init(&client_rses->rses_lock);
 
     client_rses->subservice = calloc(router->n_services, sizeof(SUBSERVICE*));
@@ -735,6 +778,11 @@ newSession(
             goto errorblock;
         }
         
+        /* TODO: add NULL value checks */
+        
+        subsvc->scur = calloc(1,sizeof(sescmd_cursor_t));
+        subsvc->scur->scmd_cur_rses = client_rses;
+        subsvc->scur->scmd_cur_ptr_property = client_rses->rses_properties;
         subsvc->service = router->services[i];
         subsvc->dcb =dcb_clone(client_rses->rses_client_dcb);
         subsvc->session = session_alloc(subsvc->service,subsvc->dcb);
@@ -762,6 +810,14 @@ newSession(
      */
     atomic_add(&client_rses->rses_versno, 2);
     ss_dassert(client_rses->rses_versno == 2);
+
+    client_rses->dbhash = hashtable_alloc(100, hashkeyfun, hashcmpfun);
+    hashtable_memory_fns(client_rses->dbhash, (HASHMEMORYFN) strdup,
+                         (HASHMEMORYFN) strdup,
+                         (HASHMEMORYFN) free,
+                         (HASHMEMORYFN) free);
+    gen_tablelist(router, client_rses);
+
     /**
      * Add this session to end of the list of active sessions in router.
      */
@@ -943,262 +999,13 @@ get_shard_route_target(skygw_query_type_t qtype,
 }
 
 /**
- * Check if the query is a DROP TABLE... query and
+ * This function creates a custom SHOW DATABASES response by iterating through
- * if it targets a temporary table, remove it from the hashtable.
+ * the database names in the session's hashtable. This generates a complete list
- * @param instance Router instance
+ * of all available databases in all of the clusters.
- * @param router_session Router client session
+ * @param router The router instance
- * @param querybuf GWBUF containing the query
+ * @param client Router client session
- * @param type The type of the query resolved so far
+ * @return Pointer to the generated response
  */
-void
-check_drop_tmp_table(
-                     ROUTER* instance,
-                     void* router_session,
-                     GWBUF* querybuf,
-                     skygw_query_type_t type)
-{
-
-    int tsize = 0, klen = 0, i;
-    char** tbl = NULL;
-    char *hkey, *dbname;
-
-    ROUTER_CLIENT_SES* router_cli_ses = (ROUTER_CLIENT_SES *) router_session;
-    rses_property_t* rses_prop_tmp;
-
-    rses_prop_tmp = router_cli_ses->rses_properties[RSES_PROP_TYPE_TMPTABLES];
-    dbname = router_cli_ses->rses_mysql_session->db;
-
-    if(is_drop_table_query(querybuf))
-    {
-        tbl = skygw_get_table_names(querybuf, &tsize, false);
-        if(tbl != NULL)
-        {
-            for(i = 0; i < tsize; i++)
-            {
-                klen = strlen(dbname) + strlen(tbl[i]) + 2;
-                hkey = calloc(klen, sizeof(char));
-                strcpy(hkey, dbname);
-                strcat(hkey, ".");
-                strcat(hkey, tbl[i]);
-
-                if(rses_prop_tmp &&
-                   rses_prop_tmp->rses_prop_data.temp_tables)
-                {
-                    if(hashtable_delete(rses_prop_tmp->rses_prop_data.temp_tables,
-                                        (void *) hkey))
-                    {
-                        LOGIF(LT, (skygw_log_write(LOGFILE_TRACE,
-                                                   "Temporary table dropped: %s", hkey)));
-                    }
-                }
-                free(tbl[i]);
-                free(hkey);
-            }
-
-            free(tbl);
-        }
-    }
-}
-
-/**
- * Check if the query targets a temporary table.
- * @param instance Router instance
- * @param router_session Router client session
- * @param querybuf GWBUF containing the query
- * @param type The type of the query resolved so far
- * @return The type of the query
- */
-skygw_query_type_t
-is_read_tmp_table(
-                  ROUTER* instance,
-                  void* router_session,
-                  GWBUF* querybuf,
-                  skygw_query_type_t type)
-{
-
-    bool target_tmp_table = false;
-    int tsize = 0, klen = 0, i;
-    char** tbl = NULL;
-    char *hkey, *dbname;
-
-    ROUTER_CLIENT_SES* router_cli_ses = (ROUTER_CLIENT_SES *) router_session;
-    skygw_query_type_t qtype = type;
-    rses_property_t* rses_prop_tmp;
-
-    rses_prop_tmp = router_cli_ses->rses_properties[RSES_PROP_TYPE_TMPTABLES];
-    dbname = router_cli_ses->rses_mysql_session->db;
-
-    if(QUERY_IS_TYPE(qtype, QUERY_TYPE_READ) ||
-       QUERY_IS_TYPE(qtype, QUERY_TYPE_LOCAL_READ) ||
-       QUERY_IS_TYPE(qtype, QUERY_TYPE_USERVAR_READ) ||
-       QUERY_IS_TYPE(qtype, QUERY_TYPE_SYSVAR_READ) ||
-       QUERY_IS_TYPE(qtype, QUERY_TYPE_GSYSVAR_READ))
-    {
-        tbl = skygw_get_table_names(querybuf, &tsize, false);
-
-        if(tbl != NULL && tsize > 0)
-        {
-            /** Query targets at least one table */
-            for(i = 0; i < tsize && !target_tmp_table && tbl[i]; i++)
-            {
-                klen = strlen(dbname) + strlen(tbl[i]) + 2;
-                hkey = calloc(klen, sizeof(char));
-                strcpy(hkey, dbname);
-                strcat(hkey, ".");
-                strcat(hkey, tbl[i]);
-
-                if(rses_prop_tmp &&
-                   rses_prop_tmp->rses_prop_data.temp_tables)
-                {
-
-                    if((target_tmp_table =
-                        (bool) hashtable_fetch(rses_prop_tmp->rses_prop_data.temp_tables, (void *) hkey)))
-                    {
-                        /**Query target is a temporary table*/
-                        qtype = QUERY_TYPE_READ_TMP_TABLE;
-                        LOGIF(LT,
-                              (skygw_log_write(LOGFILE_TRACE,
-                                               "Query targets a temporary table: %s", hkey)));
-                    }
-                }
-
-                free(hkey);
-            }
-
-        }
-    }
-
-
-    if(tbl != NULL)
-    {
-        for(i = 0; i < tsize; i++)
-        {
-            free(tbl[i]);
-        }
-        free(tbl);
-    }
-
-    return qtype;
-}
-
-/** 
- * If query is of type QUERY_TYPE_CREATE_TMP_TABLE then find out 
- * the database and table name, create a hashvalue and 
- * add it to the router client session's property. If property 
- * doesn't exist then create it first.
- * @param instance Router instance
- * @param router_session Router client session
- * @param querybuf GWBUF containing the query
- * @param type The type of the query resolved so far
- */
-void
-check_create_tmp_table(
-                       ROUTER* instance,
-                       void* router_session,
-                       GWBUF* querybuf,
-                       skygw_query_type_t type)
-{
-
-    int klen = 0;
-    char *hkey, *dbname;
-
-    ROUTER_CLIENT_SES* router_cli_ses = (ROUTER_CLIENT_SES *) router_session;
-    rses_property_t* rses_prop_tmp;
-    HASHTABLE* h;
-
-    rses_prop_tmp = router_cli_ses->rses_properties[RSES_PROP_TYPE_TMPTABLES];
-    dbname = router_cli_ses->rses_mysql_session->db;
-
-
-    if(QUERY_IS_TYPE(type, QUERY_TYPE_CREATE_TMP_TABLE))
-    {
-        bool is_temp = true;
-        char* tblname = NULL;
-
-        tblname = skygw_get_created_table_name(querybuf);
-
-        if(tblname && strlen(tblname) > 0)
-        {
-            klen = strlen(dbname) + strlen(tblname) + 2;
-            hkey = calloc(klen, sizeof(char));
-            strcpy(hkey, dbname);
-            strcat(hkey, ".");
-            strcat(hkey, tblname);
-        }
-        else
-        {
-            hkey = NULL;
-        }
-
-        if(rses_prop_tmp == NULL)
-        {
-            if((rses_prop_tmp =
-                (rses_property_t*) calloc(1, sizeof(rses_property_t))))
-            {
-#if defined(SS_DEBUG)
-                rses_prop_tmp->rses_prop_chk_top = CHK_NUM_ROUTER_PROPERTY;
-                rses_prop_tmp->rses_prop_chk_tail = CHK_NUM_ROUTER_PROPERTY;
-#endif
-                rses_prop_tmp->rses_prop_rsession = router_cli_ses;
-                rses_prop_tmp->rses_prop_refcount = 1;
-                rses_prop_tmp->rses_prop_next = NULL;
-                rses_prop_tmp->rses_prop_type = RSES_PROP_TYPE_TMPTABLES;
-                router_cli_ses->rses_properties[RSES_PROP_TYPE_TMPTABLES] = rses_prop_tmp;
-            }
-            else
-            {
-                LOGIF(LE, (skygw_log_write_flush(LOGFILE_ERROR, "Error : Call to malloc() failed.")));
-            }
-        }
-        if(rses_prop_tmp)
-        {
-            if(rses_prop_tmp->rses_prop_data.temp_tables == NULL)
-            {
-                h = hashtable_alloc(7, hashkeyfun, hashcmpfun);
-                hashtable_memory_fns(h, hstrdup, NULL, hfree, NULL);
-                if(h != NULL)
-                {
-                    rses_prop_tmp->rses_prop_data.temp_tables = h;
-                }
-                else
-                {
-                    LOGIF(LE, (skygw_log_write_flush(LOGFILE_ERROR, "Error : Failed to allocate a new hashtable.")));
-                }
-
-            }
-
-            if(hkey && rses_prop_tmp->rses_prop_data.temp_tables &&
-               hashtable_add(rses_prop_tmp->rses_prop_data.temp_tables,
-                             (void *) hkey,
-                             (void *) is_temp) == 0) /*< Conflict in hash table */
-            {
-                LOGIF(LT, (skygw_log_write(
-                                           LOGFILE_TRACE,
-                                           "Temporary table conflict in hashtable: %s",
-                                           hkey)));
-            }
-#if defined(SS_DEBUG)
-            {
-                bool retkey =
-                        hashtable_fetch(
-                                        rses_prop_tmp->rses_prop_data.temp_tables,
-                                        hkey);
-                if(retkey)
-                {
-                    LOGIF(LT, (skygw_log_write(
-                                               LOGFILE_TRACE,
-                                               "Temporary table added: %s",
-                                               hkey)));
-                }
-            }
-#endif
-        }
-
-        free(hkey);
-        free(tblname);
-    }
-}
-
 GWBUF*
 gen_show_dbs_response(ROUTER_INSTANCE* router, ROUTER_CLIENT_SES* client)
 {
@@ -1234,7 +1041,7 @@ gen_show_dbs_response(ROUTER_INSTANCE* router, ROUTER_CLIENT_SES* client)
         0x00, 0x00,
         0x00, 0x00};
 #endif
-
+/* The meanings of the "magic numbers" can be found in the COM_QUERY-response definition */
     coldef_len = sizeof(catalog) + strlen(schema) + 1 +
             strlen(table) + 1 +
             strlen(org_table) + 1 +
@@ -1362,20 +1169,16 @@ gen_show_dbs_response(ROUTER_INSTANCE* router, ROUTER_CLIENT_SES* client)
  * If routeQuery fails, it means that router session has failed.
  * In any tolerated failure, handleError is called and if necessary,
  * an error message is sent to the client.
- * 
- * For now, routeQuery don't tolerate errors, so any error will close
- * the session. vraa 14.6.14
  */
 static int
-routeQuery(
+routeQuery(ROUTER* instance,
-           ROUTER* instance,
            void* router_session,
            GWBUF* querybuf)
 {
     skygw_query_type_t qtype = QUERY_TYPE_UNKNOWN;
     mysql_server_cmd_t packet_type;
     uint8_t* packet;
-    int ret = 0;
+    int ret = 1;
     SUBSERVICE* target_subsvc;
     ROUTER_INSTANCE* inst = (ROUTER_INSTANCE *) instance;
     ROUTER_CLIENT_SES* router_cli_ses = (ROUTER_CLIENT_SES *) router_session;
@@ -1394,17 +1197,7 @@ routeQuery(
     }
     ss_dassert(!GWBUF_IS_TYPE_UNDEFINED(querybuf));
 
-    if(router_cli_ses->dbhash == NULL && !router_cli_ses->hash_init)
+    
-    {
-        router_cli_ses->queue = querybuf;
-        router_cli_ses->dbhash = hashtable_alloc(100, hashkeyfun, hashcmpfun);
-        hashtable_memory_fns(router_cli_ses->dbhash, (HASHMEMORYFN) strdup,
-                             (HASHMEMORYFN) strdup,
-                             (HASHMEMORYFN) free,
-                             (HASHMEMORYFN) free);
-        gen_tablelist(inst, router_cli_ses);
-        return 1;
-    }
     packet = GWBUF_DATA(querybuf);
     packet_type = packet[4];
 
@@ -1491,60 +1284,8 @@ routeQuery(
                                              LOGFILE_ERROR,
                                              "Error : Changing database failed.")));
         }
-        /* ret = 1; */
-        /* goto retblock; */
     }
 
-    /**
-     * !!! Temporary tablen tutkiminen voi olla turhaa. Poista tarvittaessa.
-     */
-    /**
-     * Check if the query has anything to do with temporary tables.
-     */
-    qtype = is_read_tmp_table(instance, router_session, querybuf, qtype);
-    check_create_tmp_table(instance, router_session, querybuf, qtype);
-    check_drop_tmp_table(instance, router_session, querybuf, qtype);
-
-    /**
-     * !!! Transaktion tutkiminen voi olla turhaa paitsi jos haluataan 
-     * lokittaa. Poista tarvittaessa.
-     */
-    /**
-     * If autocommit is disabled or transaction is explicitly started
-     * transaction becomes active and master gets all statements until
-     * transaction is committed and autocommit is enabled again.
-     */
-    if(router_cli_ses->rses_autocommit_enabled &&
-       QUERY_IS_TYPE(qtype, QUERY_TYPE_DISABLE_AUTOCOMMIT))
-    {
-        router_cli_ses->rses_autocommit_enabled = false;
-
-        if(!router_cli_ses->rses_transaction_active)
-        {
-            router_cli_ses->rses_transaction_active = true;
-        }
-    }
-    else if(!router_cli_ses->rses_transaction_active &&
-            QUERY_IS_TYPE(qtype, QUERY_TYPE_BEGIN_TRX))
-    {
-        router_cli_ses->rses_transaction_active = true;
-    }
-    /** 
-     * Explicit COMMIT and ROLLBACK, implicit COMMIT.
-     */
-    if(router_cli_ses->rses_autocommit_enabled &&
-       router_cli_ses->rses_transaction_active &&
-       (QUERY_IS_TYPE(qtype, QUERY_TYPE_COMMIT) ||
-        QUERY_IS_TYPE(qtype, QUERY_TYPE_ROLLBACK)))
-    {
-        router_cli_ses->rses_transaction_active = false;
-    }
-    else if(!router_cli_ses->rses_autocommit_enabled &&
-            QUERY_IS_TYPE(qtype, QUERY_TYPE_ENABLE_AUTOCOMMIT))
-    {
-        router_cli_ses->rses_autocommit_enabled = true;
-        router_cli_ses->rses_transaction_active = false;
-    }
 
     if(LOG_IS_ENABLED(LOGFILE_TRACE))
     {
@@ -1583,7 +1324,10 @@ routeQuery(
        
         /* TODO: generate a fake response from the backend */
         route_target = TARGET_ANY;
-        
+        GWBUF* dbres = gen_show_dbs_response(inst,router_cli_ses);
+        poll_add_epollin_event_to_dcb(router_cli_ses->dummy_dcb,dbres);        
+        ret = 1;
+        goto retblock;
     }
 
     route_target = get_shard_route_target(qtype,
@@ -1962,7 +1706,7 @@ subsvc_clear_state(SUBSERVICE* svc,subsvc_state_t state)
 {
     
 
-    if(state == SUBSVC_WAITING_RESULT)
+    if(state & SUBSVC_WAITING_RESULT)
     {
         int prev1;
 
@@ -2647,6 +2391,10 @@ route_session_write(
                                            i+1 >= router_cli_ses->n_subservice ? "<" : "")));
             }
 
+            
+
+            
+           
             scur = subsvc->scur;
             
             /**