First push for WL#3146 "less locking in auto_increment". It is a 0-real-change patch.

New prototype for get_auto_increment() (but new arguments not yet used), to be able
to reserve a finite interval of auto_increment values from cooperating engines.
A hint on how many values to reserve is found in handler::estimation_rows_to_insert,
filled by ha_start_bulk_insert(), new wrapper around start_bulk_insert().
NOTE: this patch changes nothing, for all engines. But it makes the API ready for those
engines which will want to do reservation.
More csets will come to complete WL#3146.


sql/ha_berkeley.cc:
  update to new prototype of get_auto_increment
sql/ha_berkeley.h:
  update to new prototype of get_auto_increment
sql/ha_heap.cc:
  update to new prototype of get_auto_increment
sql/ha_heap.h:
  update to new prototype of get_auto_increment
sql/ha_innodb.cc:
  update to new prototype of get_auto_increment
sql/ha_innodb.h:
  update to new prototype of get_auto_increment
sql/ha_myisam.cc:
  update to new prototype of get_auto_increment
sql/ha_myisam.h:
  update to new prototype of get_auto_increment
sql/ha_ndbcluster.cc:
  update to new prototype of get_auto_increment
sql/ha_ndbcluster.h:
  update to new prototype of get_auto_increment
sql/ha_partition.cc:
  update to new prototype of get_auto_increment
sql/ha_partition.h:
  update to new prototype of get_auto_increment
sql/handler.cc:
  new prototype of get_auto_increment, comments, preparation for when the MySQL layer is capable
  of getting finite auto_increment intervals from cooperating engines.
sql/handler.h:
  a wrapper around start_bulk_insert(): ha_bulk_insert(), which stores the argument (number
  of rows expected for insertion) into a member of handler: estimation_rows_to_insert.
  This member will soon be used to decide how much auto_increment values we want to reserve
  from cooperating engines.
  New prototype for get_auto_increment, preparing for cooperating engines to reserve finite auto_increment
  intervals.
  release_auto_increment() will be used by the MySQL layer to inform the engine that it has
  not used all of the interval (engine can reclaim it).
sql/log.cc:
  note for the future
sql/log_event.cc:
  name of wrapper
sql/sql_insert.cc:
  name of wrapper. When done with inserting, return unused auto_inc values to engine.
sql/sql_load.cc:
  name of wrapper. When done with inserting, return unused auto_inc values to engine.
sql/sql_select.cc:
  name of wrapper
sql/sql_table.cc:
  name of wrapper
storage/archive/ha_archive.cc:
  update to new prototype of get_auto_increment.
  Archive reserves only one value (Archive's god - Brian - told me that's the truth).
storage/archive/ha_archive.h:
  update to new prototype of get_auto_increment()

1 files changed, 15 insertions, 2 deletions

diff --git a/sql/ha_berkeley.cc b/sql/ha_berkeley.cc
index 473fb149871..dfdffcb70b5 100644
--- a/sql/ha_berkeley.cc
+++ b/sql/ha_berkeley.cc
@@ -2255,8 +2255,12 @@ ha_rows ha_berkeley::records_in_range(uint keynr, key_range *start_key,
 }
 
 
-ulonglong ha_berkeley::get_auto_increment()
+void ha_berkeley::get_auto_increment(ulonglong offset, ulonglong increment,
+                                     ulonglong nb_desired_values,
+                                     ulonglong *first_value,
+                                     ulonglong *nb_reserved_values)
 {
+  /* Ideally in case of real error (not "empty table") nr should be ~ULL(0) */
   ulonglong nr=1;				// Default if error or new key
   int error;
   (void) ha_berkeley::extra(HA_EXTRA_KEYREAD);
@@ -2267,9 +2271,18 @@ ulonglong ha_berkeley::get_auto_increment()
   if (!table_share->next_number_key_offset)
   {						// Autoincrement at key-start
     error=ha_berkeley::index_last(table->record[1]);
+    /* has taken read lock on page of max key so reserves to infinite  */
+    *nb_reserved_values= ULONGLONG_MAX;
   }
   else
   {
+    /*
+      MySQL needs to call us for next row: assume we are inserting ("a",null)
+      here, we return 3, and next this statement will want to insert ("b",null):
+      there is no reason why ("b",3+1) would be the good row to insert: maybe it
+      already exists, maybe 3+1 is too large...
+    */
+    *nb_reserved_values= 1;
     DBT row,old_key;
     bzero((char*) &row,sizeof(row));
     KEY *key_info= &table->key_info[active_index];
@@ -2310,7 +2323,7 @@ ulonglong ha_berkeley::get_auto_increment()
       table->next_number_field->val_int_offset(table_share->rec_buff_length)+1;
   ha_berkeley::index_end();
   (void) ha_berkeley::extra(HA_EXTRA_NO_KEYREAD);
-  return nr;
+  *first_value= nr;
 }
 
 void ha_berkeley::print_error(int error, myf errflag)