casual search

storage/spider/ha_spider.cc

@@ -153,6 +153,7 @@ ha_spider::ha_spider(
 #ifdef HANDLER_HAS_DIRECT_AGGREGATE
   result_list.direct_aggregate = FALSE;
 #endif
+  result_list.casual_read = NULL;
   DBUG_VOID_RETURN;
 }
 
@@ -256,6 +257,7 @@ ha_spider::ha_spider(
 #ifdef HANDLER_HAS_DIRECT_AGGREGATE
   result_list.direct_aggregate = FALSE;
 #endif
+  result_list.casual_read = NULL;
   ref_length = sizeof(SPIDER_POSITION);
   DBUG_VOID_RETURN;
 }
@@ -1670,6 +1672,7 @@ int ha_spider::reset()
     }
 */
     memset(need_mons, 0, sizeof(int) * share->link_count);
+    memset(result_list.casual_read, 0, sizeof(int) * share->link_count);
     rm_bulk_tmp_table();
     for (roop_count = share->link_count - 1; roop_count >= 0; roop_count--)
     {
@@ -2132,6 +2135,9 @@ int ha_spider::index_read_map_internal(
 #ifndef WITHOUT_SPIDER_BG_SEARCH
     if (result_list.bgs_phase > 0)
     {
+      if ((error_num = spider_check_and_init_casual_read(trx->thd, this,
+        roop_count)))
+        DBUG_RETURN(error_num);
       if ((error_num = spider_bg_conn_search(this, roop_count, roop_start,
         TRUE, FALSE, (roop_count != link_ok))))
       {
@@ -2616,6 +2622,9 @@ int ha_spider::index_read_last_map_internal(
 #ifndef WITHOUT_SPIDER_BG_SEARCH
     if (result_list.bgs_phase > 0)
     {
+      if ((error_num = spider_check_and_init_casual_read(trx->thd, this,
+        roop_count)))
+        DBUG_RETURN(error_num);
       if ((error_num = spider_bg_conn_search(this, roop_count, roop_start,
         TRUE, FALSE, (roop_count != link_ok))))
       {
@@ -3074,6 +3083,9 @@ int ha_spider::index_first_internal(
 #ifndef WITHOUT_SPIDER_BG_SEARCH
       if (result_list.bgs_phase > 0)
       {
+        if ((error_num = spider_check_and_init_casual_read(trx->thd, this,
+          roop_count)))
+          DBUG_RETURN(error_num);
         if ((error_num = spider_bg_conn_search(this, roop_count, roop_start,
           TRUE, FALSE, (roop_count != link_ok))))
         {
@@ -3450,6 +3462,9 @@ int ha_spider::index_last_internal(
 #ifndef WITHOUT_SPIDER_BG_SEARCH
       if (result_list.bgs_phase > 0)
       {
+        if ((error_num = spider_check_and_init_casual_read(trx->thd, this,
+          roop_count)))
+          DBUG_RETURN(error_num);
         if ((error_num = spider_bg_conn_search(this, roop_count, roop_start,
           TRUE, FALSE, (roop_count != link_ok))))
         {
@@ -3885,6 +3900,9 @@ int ha_spider::read_range_first_internal(
 #ifndef WITHOUT_SPIDER_BG_SEARCH
     if (result_list.bgs_phase > 0)
     {
+      if ((error_num = spider_check_and_init_casual_read(trx->thd, this,
+        roop_count)))
+        DBUG_RETURN(error_num);
       if ((error_num = spider_bg_conn_search(this, roop_count, roop_start,
         TRUE, FALSE, (roop_count != link_ok))))
       {
@@ -4467,6 +4485,9 @@ int ha_spider::read_multi_range_first_internal(
 #ifndef WITHOUT_SPIDER_BG_SEARCH
         if (result_list.bgs_phase > 0)
         {
+          if ((error_num = spider_check_and_init_casual_read(trx->thd, this,
+            roop_count)))
+            DBUG_RETURN(error_num);
           error_num = spider_bg_conn_search(this, roop_count, roop_start,
             TRUE, FALSE, (roop_count != link_ok));
           if (
@@ -5239,6 +5260,9 @@ int ha_spider::read_multi_range_first_internal(
 #ifndef WITHOUT_SPIDER_BG_SEARCH
         if (result_list.bgs_phase > 0)
         {
+          if ((error_num = spider_check_and_init_casual_read(trx->thd, this,
+            roop_count)))
+            DBUG_RETURN(error_num);
           if ((error_num = spider_bg_conn_search(this, roop_count, roop_start,
             TRUE, FALSE, (roop_count != link_ok))))
           {
@@ -5813,6 +5837,9 @@ int ha_spider::read_multi_range_next(
 #ifndef WITHOUT_SPIDER_BG_SEARCH
         if (result_list.bgs_phase > 0)
         {
+          if ((error_num = spider_check_and_init_casual_read(trx->thd, this,
+            roop_count)))
+            DBUG_RETURN(error_num);
           error_num = spider_bg_conn_search(this, roop_count, roop_start,
             TRUE, FALSE, (roop_count != link_ok));
           if (
@@ -6595,6 +6622,9 @@ int ha_spider::read_multi_range_next(
 #ifndef WITHOUT_SPIDER_BG_SEARCH
         if (result_list.bgs_phase > 0)
         {
+          if ((error_num = spider_check_and_init_casual_read(trx->thd, this,
+            roop_count)))
+            DBUG_RETURN(error_num);
           if ((error_num = spider_bg_conn_search(this, roop_count, roop_start,
             TRUE, FALSE, (roop_count != link_ok))))
           {
@@ -7213,6 +7243,9 @@ int ha_spider::rnd_next_internal(
 #ifndef WITHOUT_SPIDER_BG_SEARCH
       if (result_list.bgs_phase > 0)
       {
+        if ((error_num = spider_check_and_init_casual_read(trx->thd, this,
+          roop_count)))
+          DBUG_RETURN(error_num);
         if ((error_num = spider_bg_conn_search(this, roop_count, roop_start,
           TRUE, FALSE, (roop_count != link_ok))))
         {
@@ -7796,6 +7829,9 @@ int ha_spider::ft_read_internal(
 #ifndef WITHOUT_SPIDER_BG_SEARCH
       if (result_list.bgs_phase > 0)
       {
+        if ((error_num = spider_check_and_init_casual_read(trx->thd, this,
+          roop_count)))
+          DBUG_RETURN(error_num);
         if ((error_num = spider_bg_conn_search(this, roop_count, roop_start,
           TRUE, FALSE, (roop_count != link_ok))))
         {
@@ -8689,6 +8725,14 @@ int ha_spider::pre_records()
   {
     DBUG_RETURN(0);
   }
+  THD *thd = trx->thd;
+  if (
+    spider_param_sync_autocommit(thd) &&
+    (!thd_test_options(thd, OPTION_NOT_AUTOCOMMIT | OPTION_BEGIN))
+  ) {
+    result_list.casual_read[search_link_idx] =
+      spider_param_casual_read(thd, share->casual_read);
+  }
   if ((error_num = spider_db_show_records(this, search_link_idx, TRUE)))
   {
     DBUG_RETURN(check_error_mode(error_num));
@@ -8708,6 +8752,17 @@ ha_rows ha_spider::records()
     use_pre_records = FALSE;
     DBUG_RETURN(0);
   }
+  if (!use_pre_records)
+  {
+    THD *thd = trx->thd;
+    if (
+      spider_param_sync_autocommit(thd) &&
+      (!thd_test_options(thd, OPTION_NOT_AUTOCOMMIT | OPTION_BEGIN))
+    ) {
+      result_list.casual_read[search_link_idx] =
+        spider_param_casual_read(thd, share->casual_read);
+    }
+  }
   if ((error_num = spider_db_show_records(this, search_link_idx, FALSE)))
   {
     use_pre_records = FALSE;

storage/spider/spd_conn.cc

@@ -233,6 +233,7 @@ void spider_free_conn_from_trx(
       ) {
         /* conn_recycle_mode == 1 */
         *conn->conn_key = '0';
+        conn->casual_read_base_conn = NULL;
         if (
           conn->quick_target &&
           spider_db_free_result((ha_spider *) conn->quick_target, FALSE)
@@ -1100,6 +1101,91 @@ int spider_free_conn(
   DBUG_RETURN(0);
 }
 
+int spider_check_and_get_casual_read_conn(
+  THD *thd,
+  ha_spider *spider,
+  int link_idx
+) {
+  int error_num;
+  DBUG_ENTER("spider_check_and_get_casual_read_conn");
+  if (spider->result_list.casual_read[link_idx])
+  {
+    SPIDER_CONN *conn = spider->conns[link_idx];
+    if (conn->casual_read_query_id != thd->query_id)
+    {
+      conn->casual_read_query_id = thd->query_id;
+      conn->casual_read_current_id = 2;
+    }
+    if (spider->result_list.casual_read[link_idx] == 1)
+    {
+      spider->result_list.casual_read[link_idx] = conn->casual_read_current_id;
+      ++conn->casual_read_current_id;
+      if (conn->casual_read_current_id > 63)
+      {
+        conn->casual_read_current_id = 2;
+      }
+    }
+    char first_byte_bak = *spider->conn_keys[link_idx];
+    *spider->conn_keys[link_idx] =
+      '0' + spider->result_list.casual_read[link_idx];
+    if (
+      !(spider->conns[link_idx] =
+        spider_get_conn(spider->share, link_idx,
+          spider->conn_keys[link_idx], spider->trx,
+          spider, FALSE, TRUE, SPIDER_CONN_KIND_MYSQL,
+          &error_num))
+    ) {
+      *spider->conn_keys[link_idx] = first_byte_bak;
+      DBUG_RETURN(error_num);
+    }
+    *spider->conn_keys[link_idx] = first_byte_bak;
+    spider->conns[link_idx]->casual_read_base_conn = conn;
+    conn = spider->conns[link_idx];
+    spider_check_and_set_autocommit(thd, conn, NULL);
+  }
+  DBUG_RETURN(0);
+}
+
+int spider_check_and_init_casual_read(
+  THD *thd,
+  ha_spider *spider,
+  int link_idx
+) {
+  int error_num;
+  SPIDER_RESULT_LIST *result_list = &spider->result_list;
+  SPIDER_SHARE *share = spider->share;
+  DBUG_ENTER("spider_check_and_init_casual_read");
+  if (
+    spider_param_sync_autocommit(thd) &&
+    (!thd_test_options(thd, OPTION_NOT_AUTOCOMMIT | OPTION_BEGIN)) &&
+    (
+      result_list->direct_order_limit
+#ifdef HANDLER_HAS_DIRECT_AGGREGATE
+      || result_list->direct_aggregate
+#endif
+    )
+  ) {
+    if (!result_list->casual_read[link_idx])
+    {
+      result_list->casual_read[link_idx] =
+        spider_param_casual_read(thd, share->casual_read);
+    }
+    if ((error_num = spider_check_and_get_casual_read_conn(thd, spider,
+      link_idx)))
+    {
+      DBUG_RETURN(error_num);
+    }
+    SPIDER_CONN *conn = spider->conns[link_idx];
+    if (
+      conn->casual_read_base_conn &&
+      (error_num = spider_create_conn_thread(conn))
+    ) {
+      DBUG_RETURN(error_num);
+    }
+  }
+  DBUG_RETURN(0);
+}
+
 void spider_conn_queue_connect(
   SPIDER_SHARE *share,
   SPIDER_CONN *conn,

storage/spider/spd_conn.h

@@ -70,6 +70,18 @@ int spider_free_conn(
   SPIDER_CONN *conn
 );
 
+int spider_check_and_get_casual_read_conn(
+  THD *thd,
+  ha_spider *spider,
+  int link_idx
+);
+
+int spider_check_and_init_casual_read(
+  THD *thd,
+  ha_spider *spider,
+  int link_idx
+);
+
 void spider_conn_queue_connect(
   SPIDER_SHARE *share,
   SPIDER_CONN *conn,

storage/spider/spd_db_conn.cc

@@ -5177,29 +5177,42 @@ int spider_db_show_records(
   bool pre_call
 ) {
   int error_num;
-  SPIDER_CONN *conn = spider->conns[link_idx];
+  THD *thd = spider->trx->thd;
+  SPIDER_CONN *conn;
   DBUG_ENTER("spider_db_show_records");
   if (pre_call)
   {
-    if (spider_param_bgs_mode(spider->trx->thd, spider->share->bgs_mode))
+    if (spider_param_bgs_mode(thd, spider->share->bgs_mode))
     {
+      if ((error_num = spider_check_and_get_casual_read_conn(thd, spider,
+        link_idx)))
+      {
+        DBUG_RETURN(error_num);
+      }
+      conn = spider->conns[link_idx];
       if (!(error_num = spider_create_conn_thread(conn)))
       {
         spider_bg_conn_simple_action(conn, SPIDER_BG_SIMPLE_RECORDS, FALSE,
           spider, link_idx, (int *) &spider->result_list.bgs_error);
       }
     } else {
+      conn = spider->conns[link_idx];
       error_num = spider->dbton_handler[conn->dbton_id]->show_records(
         link_idx
       );
     }
   } else {
+    conn = spider->conns[link_idx];
     if (spider->use_pre_records)
     {
-      if (spider_param_bgs_mode(spider->trx->thd, spider->share->bgs_mode))
+      if (spider_param_bgs_mode(thd, spider->share->bgs_mode))
       {
         spider_bg_conn_wait(conn);
         error_num = spider->result_list.bgs_error;
+        if (conn->casual_read_base_conn)
+        {
+          spider->conns[link_idx] = conn->casual_read_base_conn;
+        }
       } else {
         error_num = 0;
       }

storage/spider/spd_db_include.h

@@ -1637,6 +1637,7 @@ typedef struct st_spider_result_list
   longlong                first_read;
   longlong                second_read;
   int                     set_split_read_count;
+  int                     *casual_read;
 #ifndef WITHOUT_SPIDER_BG_SEARCH
   /* 0:nomal 1:store 2:store end */
   volatile

storage/spider/spd_include.h

@@ -13,7 +13,7 @@
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
 
-#define SPIDER_DETAIL_VERSION "3.1.11"
+#define SPIDER_DETAIL_VERSION "3.1.12"
 #define SPIDER_HEX_VERSION 0x0301
 
 #if MYSQL_VERSION_ID < 50500
@@ -264,6 +264,9 @@ typedef struct st_spider_conn
   uint               opened_handlers;
   ulonglong          conn_id;
   ulonglong          connection_id;
+  query_id_t         casual_read_query_id;
+  uint               casual_read_current_id;
+  st_spider_conn     *casual_read_base_conn;
   pthread_mutex_t    mta_conn_mutex;
   volatile bool      mta_conn_mutex_lock_already;
   volatile bool      mta_conn_mutex_unlock_later;
@@ -738,6 +741,7 @@ typedef struct st_spider_share
 #ifdef HA_CAN_FORCE_BULK_DELETE
   int                force_bulk_delete;
 #endif
+  int                casual_read;
 
   int                bka_mode;
   char               *bka_engine;

storage/spider/spd_param.cc

@@ -2887,6 +2887,33 @@ uint spider_param_internal_xa_id_type(
   DBUG_RETURN(THDVAR(thd, internal_xa_id_type));
 }
 
+/*
+ -1 :use table parameter
+  0 :OFF
+  1 :automatic channel
+  2-63 :use custom channel
+ */
+static MYSQL_THDVAR_INT(
+  casual_read, /* name */
+  PLUGIN_VAR_RQCMDARG, /* opt */
+  "Read casually if it is possible", /* comment */
+  NULL, /* check */
+  NULL, /* update */
+  -1, /* def */
+  -1, /* min */
+  63, /* max */
+  0 /* blk */
+);
+
+int spider_param_casual_read(
+  THD *thd,
+  int casual_read
+) {
+  DBUG_ENTER("spider_param_casual_read");
+  DBUG_RETURN(THDVAR(thd, casual_read) == -1 ?
+    casual_read : THDVAR(thd, casual_read));
+}
+
 static struct st_mysql_storage_engine spider_storage_engine =
 { MYSQL_HANDLERTON_INTERFACE_VERSION };
 
@@ -3017,6 +3044,7 @@ static struct st_mysql_sys_var* spider_system_variables[] = {
   MYSQL_SYSVAR(log_result_error_with_sql),
   MYSQL_SYSVAR(version),
   MYSQL_SYSVAR(internal_xa_id_type),
+  MYSQL_SYSVAR(casual_read),
   NULL
 };
 

storage/spider/spd_param.h

@@ -374,3 +374,7 @@ uint spider_param_log_result_error_with_sql();
 uint spider_param_internal_xa_id_type(
   THD *thd
 );
+int spider_param_casual_read(
+  THD *thd,
+  int casual_read
+);

storage/spider/spd_table.cc

@@ -1792,6 +1792,7 @@ int spider_parse_connect_info(
 #ifdef HA_CAN_FORCE_BULK_DELETE
   share->force_bulk_delete = -1;
 #endif
+  share->casual_read = -1;
 
 #ifdef WITH_PARTITION_STORAGE_ENGINE
   for (roop_count = 4; roop_count > 0; roop_count--)
@@ -1921,6 +1922,7 @@ int spider_parse_connect_info(
 #endif
           SPIDER_PARAM_DOUBLE("civ", crd_interval, 0);
           SPIDER_PARAM_INT_WITH_MAX("cmd", crd_mode, 0, 3);
+          SPIDER_PARAM_INT_WITH_MAX("csr", casual_read, 0, 63);
 #ifdef WITH_PARTITION_STORAGE_ENGINE
           SPIDER_PARAM_INT_WITH_MAX("csy", crd_sync, 0, 2);
 #endif
@@ -2111,6 +2113,7 @@ int spider_parse_connect_info(
 #if defined(HS_HAS_SQLCOM) && defined(HAVE_HANDLERSOCKET)
           SPIDER_PARAM_LONG_LIST_WITH_MAX("use_hs_read", use_hs_reads, 0, 1);
 #endif
+          SPIDER_PARAM_INT_WITH_MAX("casual_read", casual_read, 0, 63);
           error_num = ER_SPIDER_INVALID_CONNECT_INFO_NUM;
           my_printf_error(error_num, ER_SPIDER_INVALID_CONNECT_INFO_STR,
             MYF(0), tmp_ptr);
@@ -3436,6 +3439,8 @@ int spider_set_connect_info_default(
   if (share->force_bulk_delete == -1)
     share->force_bulk_delete = 0;
 #endif
+  if (share->casual_read == -1)
+    share->casual_read = 0;
   if (share->bka_mode == -1)
     share->bka_mode = 1;
   if (!share->bka_engine)
@@ -4331,6 +4336,7 @@ SPIDER_SHARE *spider_get_share(
 #endif
 #endif
         &result_list->sql_kind_backup, sizeof(uint) * share->link_count,
+        &result_list->casual_read, sizeof(int) * share->link_count,
         &spider->dbton_handler,
           sizeof(spider_db_handler *) * SPIDER_DBTON_SIZE,
         NullS))
@@ -4772,6 +4778,7 @@ SPIDER_SHARE *spider_get_share(
 #endif
 #endif
         &result_list->sql_kind_backup, sizeof(uint) * share->link_count,
+        &result_list->casual_read, sizeof(int) * share->link_count,
         &spider->dbton_handler,
           sizeof(spider_db_handler *) * SPIDER_DBTON_SIZE,
         NullS))