Update of query cache code

Docs/manual.texi:
  Added information about RESET
sql/mysql_priv.h:
  Fixed wrong type
sql/sql_base.cc:
  Removed wrong info in DBUG output
sql/sql_class.cc:
  cleanup
sql/sql_parse.cc:
  Fixed wrong type

Docs/manual.texi

@@ -17477,6 +17477,7 @@ information and a description of what it means.
 * OPTIMIZE TABLE::              @code{OPTIMIZE TABLE} Syntax
 * ANALYZE TABLE::               @code{ANALYZE TABLE} Syntax
 * FLUSH::                       @code{FLUSH} Syntax
+* RESET::                       @code{RESET} Syntax
 * KILL::                        @code{KILL} Syntax
 * SHOW::                        @code{SHOW} Syntax
 @end menu
@@ -17564,7 +17565,7 @@ If the table hasn't changed since the last @code{ANALYZE TABLE} command,
 the table will not be analysed again.
 
 
-@node FLUSH, KILL, ANALYZE TABLE, Database Administration
+@node FLUSH, RESET, ANALYZE TABLE, Database Administration
 @subsection @code{FLUSH} Syntax
 
 @findex FLUSH
@@ -17605,7 +17606,9 @@ signal to the @code{mysqld} server.
 @item @code{PRIVILEGES} @tab Reloads the privileges from the grant tables in
 the @code{mysql} database.
 
-@item @code{TABLES} @tab Closes all open tables and force all tables in use to be closed.
+@item @code{QUERY CACHE} @tab Defragment the query cache to better utilize the memory.  This command will not remove any queries from the cache.
+
+@item @code{TABLES} @tab Closes all open tables and force all tables in use to be closed. This also flushes the query cache.
 
 @item @code{[TABLE | TABLES] table_name [,table_name...]} @tab Flushes only the given tables.
 
@@ -17618,12 +17621,34 @@ You can also access each of the commands shown above with the @code{mysqladmin}
 utility, using the @code{flush-hosts}, @code{flush-logs}, @code{reload},
 or @code{flush-tables} commands.
 
-Take also a look at the @code{RESET} command used with
-replication. @xref{Replication SQL}.
+Take also a look at the @code{RESET} command used with replication.
+@xref{RESET}.
 
+@node RESET, KILL, FLUSH, Database Administration
+@subsection @code{RESET} Syntax
 
+@example
+FLUSH flush_option [,flush_option]
+@end example
+
+The @code{RESET} command is used to clear things. It also acts as an stronger
+version of the @code{FLUSH} command.  @xref{FLUSH}.
+
+@multitable @columnfractions .15 .85
+@item @code{MASTER}
+@tab Deletes all binary logs listed in the index file, resetting the binlog
+index file to be empty. In pre-3.23.26 versions, @code{FLUSH MASTER} (Master)
+
+@item @code{SLAVE}
+@tab Makes the slave forget its replication position in the master
+logs. In pre 3.23.26 versions the command was called
+@code{FLUSH SLAVE}(Slave)
+
+@item @code{QUERY CACHE}
+@tab Removes all query results from the query cache.
+@end multitable
 
-@node KILL, SHOW, FLUSH, Database Administration
+@node KILL, SHOW, RESET, Database Administration
 @subsection @code{KILL} Syntax
 
 @findex KILL

include/mysql_com.h

@@ -78,8 +78,9 @@ enum enum_server_command {COM_SLEEP,COM_QUIT,COM_INIT_DB,COM_QUERY,
 #define REFRESH_READ_LOCK	16384	/* Lock tables for read */
 #define REFRESH_FAST		32768	/* Intern flag */
 
-#define REFRESH_QUERY_CACHE	65536	/* flush query cache */
-#define REFRESH_QUERY_CACHE_FREE 0x10000L /* pack query cache */
+/* RESET (remove all queries) from query cache */
+#define REFRESH_QUERY_CACHE	65536
+#define REFRESH_QUERY_CACHE_FREE 0x20000L /* pack query cache */
 
 #define CLIENT_LONG_PASSWORD	1	/* new more secure passwords */
 #define CLIENT_FOUND_ROWS	2	/* Found instead of affected rows */

mysql-test/r/flush.result

@@ -28,3 +28,8 @@ select * from t1;
 n
 345
 drop table t1;
+flush query cache;
+reset query cache;
+show status like "Qcache_queries_in_cache";
+Variable_name	Value
+Qcache_queries_in_cache	0

mysql-test/r/query_cache.result

+reset query cache;
+flush status;
+drop table if exists t1;
+create table t1 (a int not null);
+insert into t1 values (1),(2),(3);
+select * from t1;
+a
+1
+2
+3
+select * from t1;
+a
+1
+2
+3
+select sql_no_cache * from t1;
+a
+1
+2
+3
+select length(now()) from t1;
+length(now())
+19
+19
+19
+show status like "Qcache_queries_in_cache";
+Variable_name	Value
+Qcache_queries_in_cache	1
+show status like "Qcache_inserts";
+Variable_name	Value
+Qcache_inserts	1
+show status like "Qcache_hits";
+Variable_name	Value
+Qcache_hits	1
+drop table t1;
+show status like "Qcache_queries_in_cache";
+Variable_name	Value
+Qcache_queries_in_cache	0

mysql-test/t/flush.test

@@ -66,3 +66,12 @@ connection con2;
 insert into t1 values (345);
 select * from t1;
 drop table t1;
+
+#
+# Test that QUERY CACHE commands doesn't core dump.
+# (Normally we don't have a cache active at this point)
+#
+
+flush query cache;
+reset query cache;
+show status like "Qcache_queries_in_cache";

mysql-test/t/query_cache-master.opt

+--set-variable=query_cache_size=2M

mysql-test/t/query_cache.test

+#
+# Tests with query cache
+#
+
+# Reset query cache variables.
+
+reset query cache;
+flush status;
+drop table if exists t1;
+create table t1 (a int not null);
+insert into t1 values (1),(2),(3);
+select * from t1;
+select * from t1;
+select sql_no_cache * from t1;
+select length(now()) from t1;
+
+# Only check the variables that are independent of the machine and startup
+# options
+
+show status like "Qcache_queries_in_cache";
+show status like "Qcache_inserts";
+show status like "Qcache_hits";
+
+drop table t1;
+
+show status like "Qcache_queries_in_cache";

sql-bench/test-connect.sh

@@ -46,7 +46,7 @@ $opt_loop_count=min(1000, $opt_loop_count) if ($opt_tcpip);
 $small_loop_count=$opt_loop_count/10; # For connect tests
 
 print "Testing the speed of connecting to the server and sending of data\n";
-print "Connect tests are done $opt_small_loop_count and other tests $opt_loop_count times\n\n";
+print "Connect tests are done $small_loop_count times and other tests $opt_loop_count times\n\n";
 
 ################################# PART:1 ###################################
 ####
@@ -139,7 +139,7 @@ if ($limits->{'select_without_from'})
     $sth = $dbh->do("select 10000") or die $DBI::errstr;
   }
   $end_time=new Benchmark;
-  print "Time for select_simple_query_cache ($opt_loop_count): " .
+  print "Time for select_simple_cache ($opt_loop_count): " .
     timestr(timediff($end_time, $loop_time),"all") . "\n\n";
 }
 
@@ -208,8 +208,24 @@ print "Time to select_1_row ($opt_loop_count): " .
   timestr(timediff($end_time, $loop_time),"all") . "\n\n";
 
 #
-# The same test, but with 2 rows.
+# Same test (as with one row) but now with a cacheable query
 #
+
+$loop_time=new Benchmark;
+
+for ($i=0 ; $i < $opt_loop_count ; $i++)
+{
+  $sth = $dbh->do("select a,i,s from bench1") # Select * from table with 1 record
+    or die $DBI::errstr;
+}
+$end_time=new Benchmark;
+print "Time to select_1_row_cache ($opt_loop_count): " .
+  timestr(timediff($end_time, $loop_time),"all") . "\n\n";
+
+#
+# The same test, but with 2 rows (not cacheable).
+#
+
 print "Testing select 2 rows from table\n";
 
 $sth = $dbh->do("insert into bench1 values(2,200,'BBB')")
@@ -227,6 +243,10 @@ $end_time=new Benchmark;
 print "Time to select_2_rows ($opt_loop_count): " .
   timestr(timediff($end_time, $loop_time),"all") . "\n\n";
 
+#
+# Simple test to test speed of functions.
+#
+
 if ($limits->{'functions'})
 {
   print "Test select with aritmetic (+)\n";

sql-bench/test-select.sh

@@ -156,7 +156,7 @@ if ($limits->{'group_functions'})
     fetch_all_rows($dbh,"select sum(idn+100),sum(rev_idn-100) from bench1");
   }
   $end_time=new Benchmark;
-  print "Time for select_query_cache ($opt_loop_count): " .
+  print "Time for select_cache ($opt_loop_count): " .
      timestr(timediff($end_time, $loop_time),"all") . "\n\n";
 
   # If the database has a query cache, the following loop should be much
@@ -168,7 +168,7 @@ if ($limits->{'group_functions'})
     fetch_all_rows($dbh,"select sum(idn+$tests),sum(rev_idn-$tests) from bench1");
   }
   $end_time=new Benchmark;
-  print "Time for select_query_cache2 ($opt_loop_count): " .
+  print "Time for select_cache2 ($opt_loop_count): " .
      timestr(timediff($end_time, $loop_time),"all") . "\n\n";
 }
 

sql/mysql_priv.h

@@ -277,7 +277,7 @@ bool do_command(THD *thd);
 bool dispatch_command(enum enum_server_command command, THD *thd,
 		      char* packet, uint packet_length);
 bool check_stack_overrun(THD *thd,char *dummy);
-bool reload_acl_and_cache(THD *thd, uint options, TABLE_LIST *tables);
+bool reload_acl_and_cache(THD *thd, ulong options, TABLE_LIST *tables);
 void table_cache_init(void);
 void table_cache_free(void);
 uint cached_tables(void);
@@ -697,7 +697,6 @@ void hostname_cache_refresh(void);
 bool get_interval_info(const char *str,uint length,uint count,
 		       long *values);
 /* sql_cache */
-
 extern bool sql_cache_init();
 extern void sql_cache_free();
 extern int sql_cache_hit(THD *thd, char *inBuf, uint length);

sql/sql_base.cc

@@ -2195,16 +2195,18 @@ int setup_ftfuncs(THD *thd)
 
 int init_ftfuncs(THD *thd, bool no_order)
 {
-  List_iterator<Item_func_match> li(thd->lex.select_lex.ftfunc_list);
-  Item_func_match *ifm;
-  DBUG_PRINT("info",("Performing FULLTEXT search"));
-  thd->proc_info="FULLTEXT initialization";
-
-  while ((ifm=li++))
+  if (thd->lex.select_lex.ftfunc_list.elements)
   {
-    ifm->init_search(no_order);
-  }
+    List_iterator<Item_func_match> li(thd->lex.select_lex.ftfunc_list);
+    Item_func_match *ifm;
+    DBUG_PRINT("info",("Performing FULLTEXT search"));
+    thd->proc_info="FULLTEXT initialization";
 
+    while ((ifm=li++))
+    {
+      ifm->init_search(no_order);
+    }
+  }
   return 0;
 }
 

sql/sql_cache.h

@@ -241,12 +241,12 @@ class Query_cache
   Query_cache_memory_bin *bins;			// free block lists
   Query_cache_memory_bin_step *steps;		// bins spacing info
   HASH queries, tables;
-  uint mem_bin_num, mem_bin_steps;		// See at init_cache & find_bin
-  my_bool initialized;
-
   /* options */
   ulong min_allocation_unit, min_result_data_size;
   uint def_query_hash_size, def_table_hash_size;
+  uint mem_bin_num, mem_bin_steps;		// See at init_cache & find_bin
+
+  my_bool initialized;
 
   /* Exclude/include from cyclic double linked list */
   static void double_linked_list_exclude(Query_cache_block *point,
@@ -368,10 +368,7 @@ class Query_cache
   /* Remove all queries that uses any of the listed following table */
   void invalidate_by_MyISAM_filename(const char *filename);
 
-  /* Remove all queries from cache */
   void flush();
-
-  /* Join result in cache in 1 block (if result length > join_limit) */
   void pack(ulong join_limit = QUERY_CACHE_PACK_LIMIT,
 	    uint iteration_limit = QUERY_CACHE_PACK_ITERATION);
 

sql/sql_class.cc

@@ -122,7 +122,7 @@ THD::THD():user_time(0),fatal_error(0),last_insert_id_used(0),
   server_status=SERVER_STATUS_AUTOCOMMIT;
   update_lock_default= low_priority_updates ? TL_WRITE_LOW_PRIORITY : TL_WRITE;
   options=thd_startup_options;
-  query_cache_type = (byte)query_cache_startup_type;
+  query_cache_type = (byte) query_cache_startup_type;
   sql_mode=(uint) opt_sql_mode;
   inactive_timeout=net_wait_timeout;
   open_options=ha_open_options;

sql/sql_parse.cc

@@ -951,7 +951,7 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
     }
   case COM_REFRESH:
     {
-      uint options=(uchar) packet[0];
+      ulong options= (ulong) (uchar) packet[0];
       if (check_access(thd,RELOAD_ACL,any_db))
 	break;
       mysql_log.write(thd,command,NullS);
@@ -1432,7 +1432,6 @@ mysql_execute_command(void)
                                (ORDER *) select_lex->order_list.first,
 			       lex->drop_primary, lex->duplicates,
 			       lex->alter_keys_onoff, lex->simple_alter);
-	query_cache.invalidate(tables);
       }
       break;
     }
@@ -2984,7 +2983,7 @@ static bool check_dup(const char *db, const char *name, TABLE_LIST *tables)
   return 0;
 }
 
-bool reload_acl_and_cache(THD *thd, uint options, TABLE_LIST *tables)
+bool reload_acl_and_cache(THD *thd, ulong options, TABLE_LIST *tables)
 {
   bool result=0;
 
@@ -3006,12 +3005,12 @@ bool reload_acl_and_cache(THD *thd, uint options, TABLE_LIST *tables)
   }
   if (options & REFRESH_QUERY_CACHE_FREE)
   {
-    query_cache.pack();
+    query_cache.pack();				// FLUSH QUERY CACHE
     options &= ~REFRESH_QUERY_CACHE; //don't flush all cache, just free memory
   }
   if (options & (REFRESH_TABLES | REFRESH_QUERY_CACHE))
   {
-    query_cache.flush();
+    query_cache.flush();			// RESET QUERY CACHE
   }
   if (options & (REFRESH_TABLES | REFRESH_READ_LOCK))
   {

sql/sql_table.cc

@@ -951,6 +951,7 @@ static int mysql_admin_table(THD* thd, TABLE_LIST* tables,
       sprintf(buff, ER(ER_OPEN_AS_READONLY), table_name);
       net_store_data(packet, buff);
       close_thread_tables(thd);
+      table->table=0;				// For query cache
       if (my_net_write(&thd->net, (char*) thd->packet.ptr(),
 		       packet->length()))
 	goto err;
@@ -1028,6 +1029,7 @@ static int mysql_admin_table(THD* thd, TABLE_LIST* tables,
       remove_table_from_cache(thd, table->table->table_cache_key,
 			      table->table->real_name);
     close_thread_tables(thd);
+    table->table=0;				// For query cache
     if (my_net_write(&thd->net, (char*) packet->ptr(),
 		     packet->length()))
       goto err;
@@ -1037,9 +1039,12 @@ static int mysql_admin_table(THD* thd, TABLE_LIST* tables,
   DBUG_RETURN(0);
  err:
   close_thread_tables(thd);			// Shouldn't be needed
+  if (table)
+    table->table=0;
   DBUG_RETURN(-1);
 }
 
+
 int mysql_backup_table(THD* thd, TABLE_LIST* table_list)
 {
   DBUG_ENTER("mysql_backup_table");
@@ -1658,24 +1663,30 @@ int mysql_alter_table(THD *thd,char *new_db, char *new_name,
   }
   if (error)
   {
-    // This shouldn't happen.  We solve this the safe way by
-    // closing the locked table.
+    /*
+      This shouldn't happen.  We solve this the safe way by
+      closing the locked table.
+    */
     close_cached_table(thd,table);
     VOID(pthread_mutex_unlock(&LOCK_open));
     goto err;
   }
   if (thd->lock || new_name != table_name)	// True if WIN32
   {
-    // Not table locking or alter table with rename
-    // free locks and remove old table
+    /*
+      Not table locking or alter table with rename
+      free locks and remove old table
+    */
     close_cached_table(thd,table);
     VOID(quick_rm_table(old_db_type,db,old_name));
   }
   else
   {
-    // Using LOCK TABLES without rename.
-    // This code is never executed on WIN32!
-    // Remove old renamed table, reopen table and get new locks
+    /*
+      Using LOCK TABLES without rename.
+      This code is never executed on WIN32!
+      Remove old renamed table, reopen table and get new locks
+    */
     if (table)
     {
       VOID(table->file->extra(HA_EXTRA_FORCE_REOPEN)); // Use new file
@@ -1712,7 +1723,7 @@ int mysql_alter_table(THD *thd,char *new_db, char *new_name,
   }
   VOID(pthread_cond_broadcast(&COND_refresh));
   VOID(pthread_mutex_unlock(&LOCK_open));
-  table_list->table=0;				// Table is closed
+  table_list->table=0;				// For query cache
   query_cache.invalidate(table_list);
 
 end_temporary: