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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 18:00:34 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 18:00:34 +0000
commit3f619478f796eddbba6e39502fe941b285dd97b1 (patch)
treee2c7b5777f728320e5b5542b6213fd3591ba51e2 /storage/heap/hp_block.c
parentInitial commit. (diff)
downloadmariadb-upstream.tar.xz
mariadb-upstream.zip
Adding upstream version 1:10.11.6.upstream/1%10.11.6upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'storage/heap/hp_block.c')
-rw-r--r--storage/heap/hp_block.c155
1 files changed, 155 insertions, 0 deletions
diff --git a/storage/heap/hp_block.c b/storage/heap/hp_block.c
new file mode 100644
index 00000000..324efc8b
--- /dev/null
+++ b/storage/heap/hp_block.c
@@ -0,0 +1,155 @@
+/* Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; version 2 of the License.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */
+
+/* functions on blocks; Keys and records are saved in blocks */
+
+#include "heapdef.h"
+
+/*
+ Find record according to record-position.
+
+ The record is located by factoring position number pos into (p_0, p_1, ...)
+ such that
+ pos = SUM_i(block->level_info[i].records_under_level * p_i)
+ {p_0, p_1, ...} serve as indexes to descend the blocks tree.
+*/
+
+uchar *hp_find_block(HP_BLOCK *block, ulong pos)
+{
+ reg1 int i;
+ reg3 HP_PTRS *ptr; /* block base ptr */
+
+ for (i=block->levels-1, ptr=block->root ; i > 0 ; i--)
+ {
+ ptr=(HP_PTRS*)ptr->blocks[pos/block->level_info[i].records_under_level];
+ pos%=block->level_info[i].records_under_level;
+ }
+ return (uchar*) ptr+ pos*block->recbuffer;
+}
+
+
+/*
+ Get one new block-of-records. Alloc ptr to block if needed
+
+ SYNOPSIS
+ hp_get_new_block()
+ info heap handle
+ block HP_BLOCK tree-like block
+ alloc_length OUT Amount of memory allocated from the heap
+
+ Interrupts are stopped to allow ha_panic in interrupts
+ RETURN
+ 0 OK
+ 1 Out of memory
+*/
+
+int hp_get_new_block(HP_SHARE *info, HP_BLOCK *block, size_t *alloc_length)
+{
+ reg1 uint i,j;
+ HP_PTRS *root;
+
+ for (i=0 ; i < block->levels ; i++)
+ if (block->level_info[i].free_ptrs_in_block)
+ break;
+
+ /*
+ Allocate space for leaf block (data) plus space for upper level blocks
+ up to first level that has a free slot to put the pointer.
+ If this is a new level, we have to allocate pointers to all future
+ lower levels.
+
+ For example, for level 0, we allocate data for X rows.
+ When level 0 is full, we allocate data for HP_PTRS_IN_NOD + X rows.
+ Next time we allocate data for X rows.
+ When level 1 is full, we allocate data for HP_PTRS_IN_NOD at level 2 and 1
+ + X rows at level 0.
+ */
+ *alloc_length= (sizeof(HP_PTRS) * ((i == block->levels) ? i : i - 1) +
+ (ulonglong)block->records_in_block * block->recbuffer);
+ if (!(root=(HP_PTRS*) my_malloc(hp_key_memory_HP_PTRS, *alloc_length,
+ MYF(MY_WME |
+ (info->internal ?
+ MY_THREAD_SPECIFIC : 0)))))
+ return 1;
+
+ if (i == 0)
+ {
+ block->levels=1;
+ block->root=block->level_info[0].last_blocks=root;
+ }
+ else
+ {
+ if ((uint) i == block->levels)
+ {
+ /* Adding a new level on top of the existing ones. */
+ block->levels=i+1;
+ /*
+ Use first allocated HP_PTRS as a top-level block. Put the current
+ block tree into the first slot of a new top-level block.
+ */
+ block->level_info[i].free_ptrs_in_block=HP_PTRS_IN_NOD-1;
+ ((HP_PTRS**) root)[0]= block->root;
+ block->root=block->level_info[i].last_blocks= root++;
+ }
+ /* Occupy the free slot we've found at level i */
+ block->level_info[i].last_blocks->
+ blocks[HP_PTRS_IN_NOD - block->level_info[i].free_ptrs_in_block--]=
+ (uchar*) root;
+
+ /* Add a block subtree with each node having one left-most child */
+ for (j=i-1 ; j >0 ; j--)
+ {
+ block->level_info[j].last_blocks= root++;
+ block->level_info[j].last_blocks->blocks[0]=(uchar*) root;
+ block->level_info[j].free_ptrs_in_block=HP_PTRS_IN_NOD-1;
+ }
+
+ /*
+ root now points to last (block->records_in_block* block->recbuffer)
+ allocated bytes. Use it as a leaf block.
+ */
+ block->level_info[0].last_blocks= root;
+ }
+ return 0;
+}
+
+
+ /* free all blocks under level */
+
+uchar *hp_free_level(HP_BLOCK *block, uint level, HP_PTRS *pos, uchar *last_pos)
+{
+ int i,max_pos;
+ uchar *next_ptr;
+
+ if (level == 1)
+ next_ptr=(uchar*) pos+block->recbuffer;
+ else
+ {
+ max_pos= (block->level_info[level-1].last_blocks == pos) ?
+ HP_PTRS_IN_NOD - block->level_info[level-1].free_ptrs_in_block :
+ HP_PTRS_IN_NOD;
+
+ next_ptr=(uchar*) (pos+1);
+ for (i=0 ; i < max_pos ; i++)
+ next_ptr=hp_free_level(block,level-1,
+ (HP_PTRS*) pos->blocks[i],next_ptr);
+ }
+ if ((uchar*) pos != last_pos)
+ {
+ my_free(pos);
+ return last_pos;
+ }
+ return next_ptr; /* next memory position */
+}