ut0mem.c Merge changes in InnoDB-3.23.43b

ut0ut.c 	Merge changes in InnoDB-3.23.43b
trx0purge.c	Merge changes in InnoDB-3.23.43b
trx0rec.c	Merge changes in InnoDB-3.23.43b
trx0trx.c	Merge changes in InnoDB-3.23.43b
trx0undo.c	Merge changes in InnoDB-3.23.43b
thr0loc.c	Merge changes in InnoDB-3.23.43b
sync0arr.c	Merge changes in InnoDB-3.23.43b
sync0rw.c	Merge changes in InnoDB-3.23.43b
sync0sync.c	Merge changes in InnoDB-3.23.43b
srv0srv.c	Merge changes in InnoDB-3.23.43b
srv0start.c	Merge changes in InnoDB-3.23.43b
row0ins.c	Merge changes in InnoDB-3.23.43b
row0mysql.c	Merge changes in InnoDB-3.23.43b
row0purge.c	Merge changes in InnoDB-3.23.43b
row0sel.c	Merge changes in InnoDB-3.23.43b
row0umod.c	Merge changes in InnoDB-3.23.43b
row0upd.c	Merge changes in InnoDB-3.23.43b
row0vers.c	Merge changes in InnoDB-3.23.43b
rem0cmp.c	Merge changes in InnoDB-3.23.43b
que0que.c	Merge changes in InnoDB-3.23.43b
pars0opt.c	Merge changes in InnoDB-3.23.43b
pars0pars.c	Merge changes in InnoDB-3.23.43b
lexyy.c 	Merge changes in InnoDB-3.23.43b
pars0grm.c	Merge changes in InnoDB-3.23.43b
page0page.c	Merge changes in InnoDB-3.23.43b
os0file.c	Merge changes in InnoDB-3.23.43b
mtr0log.c	Merge changes in InnoDB-3.23.43b
mem0pool.c	Merge changes in InnoDB-3.23.43b
log0log.c	Merge changes in InnoDB-3.23.43b
log0recv.c	Merge changes in InnoDB-3.23.43b
lock0lock.c	Merge changes in InnoDB-3.23.43b
ibuf0ibuf.c	Merge changes in InnoDB-3.23.43b
fil0fil.c	Merge changes in InnoDB-3.23.43b
dict0crea.c	Merge changes in InnoDB-3.23.43b
dict0dict.c	Merge changes in InnoDB-3.23.43b
dict0load.c	Merge changes in InnoDB-3.23.43b
dict0mem.c	Merge changes in InnoDB-3.23.43b
data0data.c	Merge changes in InnoDB-3.23.43b
data0type.c	Merge changes in InnoDB-3.23.43b
buf0buf.c	Merge changes in InnoDB-3.23.43b
buf0lru.c	Merge changes in InnoDB-3.23.43b
btr0btr.c	Merge changes in InnoDB-3.23.43b
btr0cur.c	Merge changes in InnoDB-3.23.43b
btr0pcur.c	Merge changes in InnoDB-3.23.43b
btr0sea.c	Merge changes in InnoDB-3.23.43b
data0type.ic	Merge changes in InnoDB-3.23.43b
dict0dict.ic	Merge changes in InnoDB-3.23.43b
mtr0mtr.ic	Merge changes in InnoDB-3.23.43b
row0upd.ic	Merge changes in InnoDB-3.23.43b
sync0ipm.ic	Merge changes in InnoDB-3.23.43b
sync0rw.ic	Merge changes in InnoDB-3.23.43b
sync0sync.ic	Merge changes in InnoDB-3.23.43b
trx0rseg.ic	Merge changes in InnoDB-3.23.43b
btr0pcur.ic	Merge changes in InnoDB-3.23.43b
buf0buf.ic	Merge changes in InnoDB-3.23.43b
data0data.ic	Merge changes in InnoDB-3.23.43b
row0upd.h	Merge changes in InnoDB-3.23.43b
srv0srv.h	Merge changes in InnoDB-3.23.43b
sync0arr.h	Merge changes in InnoDB-3.23.43b
sync0rw.h	Merge changes in InnoDB-3.23.43b
sync0sync.h	Merge changes in InnoDB-3.23.43b
trx0trx.h	Merge changes in InnoDB-3.23.43b
ut0mem.h	Merge changes in InnoDB-3.23.43b
data0data.h	Merge changes in InnoDB-3.23.43b
data0type.h	Merge changes in InnoDB-3.23.43b
db0err.h	Merge changes in InnoDB-3.23.43b
dict0crea.h	Merge changes in InnoDB-3.23.43b
dict0dict.h	Merge changes in InnoDB-3.23.43b
dict0load.h	Merge changes in InnoDB-3.23.43b
dict0mem.h	Merge changes in InnoDB-3.23.43b
dict0types.h	Merge changes in InnoDB-3.23.43b
fil0fil.h	Merge changes in InnoDB-3.23.43b
ibuf0ibuf.h	Merge changes in InnoDB-3.23.43b
lock0lock.h	Merge changes in InnoDB-3.23.43b
log0log.h	Merge changes in InnoDB-3.23.43b
mtr0mtr.h	Merge changes in InnoDB-3.23.43b
rem0cmp.h	Merge changes in InnoDB-3.23.43b
row0ins.h	Merge changes in InnoDB-3.23.43b
row0mysql.h	Merge changes in InnoDB-3.23.43b
btr0cur.h	Merge changes in InnoDB-3.23.43b
btr0pcur.h	Merge changes in InnoDB-3.23.43b
btr0sea.h	Merge changes in InnoDB-3.23.43b
buf0buf.h	Merge changes in InnoDB-3.23.43b
sql_table.cc	Merge changes in InnoDB-3.23.43b
sql_db.cc	Merge changes in InnoDB-3.23.43b
ha_innobase.cc	Merge changes in InnoDB-3.23.43b
handler.cc	Merge changes in InnoDB-3.23.43b
ha_innobase.h	Merge changes in InnoDB-3.23.43b
handler.h	Merge changes in InnoDB-3.23.43b

1 files changed, 37 insertions, 27 deletions

diff --git a/innobase/include/btr0pcur.h b/innobase/include/btr0pcur.h
index 6465093e3c1..05b55e4491d 100644
--- a/innobase/include/btr0pcur.h
+++ b/innobase/include/btr0pcur.h
@@ -19,9 +19,15 @@ Created 2/23/1996 Heikki Tuuri
 #include "btr0types.h"
 
 /* Relative positions for a stored cursor position */
-#define BTR_PCUR_ON	1
-#define BTR_PCUR_BEFORE	2
-#define BTR_PCUR_AFTER	3
+#define BTR_PCUR_ON			1
+#define BTR_PCUR_BEFORE			2
+#define BTR_PCUR_AFTER			3
+/* Note that if the tree is not empty, btr_pcur_store_position does not
+use the following, but only uses the above three alternatives, where the
+position is stored relative to a specific record: this makes implementation
+of a scroll cursor easier */
+#define BTR_PCUR_BEFORE_FIRST_IN_TREE	4	/* in an empty tree */
+#define BTR_PCUR_AFTER_LAST_IN_TREE	5	/* in an empty tree */
 
 /******************************************************************
 Allocates memory for a persistent cursor object and initializes the cursor. */
@@ -170,34 +176,16 @@ btr_pcur_close(
 /******************************************************************
 The position of the cursor is stored by taking an initial segment of the
 record the cursor is positioned on, before, or after, and copying it to the
-cursor data structure. NOTE that the page where the cursor is positioned
-must not be empty! */
+cursor data structure, or just setting a flag if the cursor id before the
+first in an EMPTY tree, or after the last in an EMPTY tree. NOTE that the
+page where the cursor is positioned must not be empty if the index tree is
+not totally empty! */
 
 void
 btr_pcur_store_position(
 /*====================*/
-	btr_pcur_t*	cursor, 	/* in: persistent cursor */
-	mtr_t*		mtr);		/* in: mtr */
-/******************************************************************
-If the latch mode of the cursor is BTR_LEAF_SEARCH or BTR_LEAF_MODIFY,
-releases the page latch and bufferfix reserved by the cursor.
-NOTE! In the case of BTR_LEAF_MODIFY, there should not exist changes
-made by the current mini-transaction to the data protected by the
-cursor latch, as then the latch must not be released until mtr_commit. */
-
-void
-btr_pcur_release_leaf(
-/*==================*/
 	btr_pcur_t*	cursor, /* in: persistent cursor */
 	mtr_t*		mtr);	/* in: mtr */
-/*************************************************************
-Gets the rel_pos field for a cursor whose position has been stored. */
-UNIV_INLINE
-ulint
-btr_pcur_get_rel_pos(
-/*=================*/
-				/* out: BTR_PCUR_ON, ... */
-	btr_pcur_t*	cursor);/* in: persistent cursor */
 /******************************************************************
 Restores the stored position of a persistent cursor bufferfixing the page and
 obtaining the specified latches. If the cursor position was saved when the
@@ -207,7 +195,9 @@ to the last record LESS OR EQUAL to the stored record;
 the last record LESS than the user record which was the successor of the page
 infimum;
 (3) cursor was positioned on the page supremum: restores to the first record
-GREATER than the user record which was the predecessor of the supremum. */
+GREATER than the user record which was the predecessor of the supremum.
+(4) cursor was positioned before the first or after the last in an empty tree:
+restores to before first or after the last in the tree. */
 
 ibool
 btr_pcur_restore_position(
@@ -220,6 +210,26 @@ btr_pcur_restore_position(
 	ulint		latch_mode,	/* in: BTR_SEARCH_LEAF, ... */
 	btr_pcur_t*	cursor, 	/* in: detached persistent cursor */
 	mtr_t*		mtr);		/* in: mtr */
+/******************************************************************
+If the latch mode of the cursor is BTR_LEAF_SEARCH or BTR_LEAF_MODIFY,
+releases the page latch and bufferfix reserved by the cursor.
+NOTE! In the case of BTR_LEAF_MODIFY, there should not exist changes
+made by the current mini-transaction to the data protected by the
+cursor latch, as then the latch must not be released until mtr_commit. */
+
+void
+btr_pcur_release_leaf(
+/*==================*/
+	btr_pcur_t*	cursor, /* in: persistent cursor */
+	mtr_t*		mtr);	/* in: mtr */
+/*************************************************************
+Gets the rel_pos field for a cursor whose position has been stored. */
+UNIV_INLINE
+ulint
+btr_pcur_get_rel_pos(
+/*=================*/
+				/* out: BTR_PCUR_ON, ... */
+	btr_pcur_t*	cursor);/* in: persistent cursor */
 /*************************************************************
 Sets the mtr field for a pcur. */
 UNIV_INLINE
@@ -458,7 +468,7 @@ struct btr_pcur_struct{
 	ulint		search_mode;	/* PAGE_CUR_G, ... */
 	/*-----------------------------*/
 	/* NOTE that the following fields may possess dynamically allocated
-	memory, which should be freed if not needed anymore! */
+	memory which should be freed if not needed anymore! */
 
 	mtr_t*		mtr;		/* NULL, or this field may contain
 					a mini-transaction which holds the