mirror of
https://github.com/openvswitch/ovs
synced 2025-10-17 14:28:02 +00:00
17d18afbfd
Until now, each part of a transaction commit that is interested in whether a column's value has changed has had to do a comparison of the old and new values itself. There can be several interested parties per commit (generally one for file storage and one for each remove OVSDB connection), so this seems like too much redundancy. This commit adds a bitmap to struct ovsdb_txn_row that tracks whether a column's value has actually changed, to reduce this overhead. As a convenient side effect of doing these checks up front, it then becomes easily possible to drop txn_rows (and txn_tables and entire txns) that become no-ops. (This probably fixes bug #2400, which reported that some no-ops actually report updates over monitors.)
100 lines
2.5 KiB
C
100 lines
2.5 KiB
C
/*
|
|
* Copyright (c) 2008, 2009, 2010 Nicira Networks.
|
|
*
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
|
* you may not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at:
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*/
|
|
|
|
#ifndef BITMAP_H
|
|
#define BITMAP_H 1
|
|
|
|
#include <limits.h>
|
|
#include <stdlib.h>
|
|
#include "util.h"
|
|
|
|
#define BITMAP_ULONG_BITS (sizeof(unsigned long) * CHAR_BIT)
|
|
|
|
static inline unsigned long *
|
|
bitmap_unit__(const unsigned long *bitmap, size_t offset)
|
|
{
|
|
return (unsigned long *) &bitmap[offset / BITMAP_ULONG_BITS];
|
|
}
|
|
|
|
static inline unsigned long
|
|
bitmap_bit__(size_t offset)
|
|
{
|
|
return 1UL << (offset % BITMAP_ULONG_BITS);
|
|
}
|
|
|
|
static inline size_t
|
|
bitmap_n_longs(size_t n_bits)
|
|
{
|
|
return DIV_ROUND_UP(n_bits, BITMAP_ULONG_BITS);
|
|
}
|
|
|
|
static inline size_t
|
|
bitmap_n_bytes(size_t n_bits)
|
|
{
|
|
return bitmap_n_longs(n_bits) * sizeof(unsigned long int);
|
|
}
|
|
|
|
static inline unsigned long *
|
|
bitmap_allocate(size_t n_bits)
|
|
{
|
|
return xzalloc(bitmap_n_bytes(n_bits));
|
|
}
|
|
|
|
static inline void
|
|
bitmap_free(unsigned long *bitmap)
|
|
{
|
|
free(bitmap);
|
|
}
|
|
|
|
static inline bool
|
|
bitmap_is_set(const unsigned long *bitmap, size_t offset)
|
|
{
|
|
return (*bitmap_unit__(bitmap, offset) & bitmap_bit__(offset)) != 0;
|
|
}
|
|
|
|
static inline void
|
|
bitmap_set1(unsigned long *bitmap, size_t offset)
|
|
{
|
|
*bitmap_unit__(bitmap, offset) |= bitmap_bit__(offset);
|
|
}
|
|
|
|
static inline void
|
|
bitmap_set0(unsigned long *bitmap, size_t offset)
|
|
{
|
|
*bitmap_unit__(bitmap, offset) &= ~bitmap_bit__(offset);
|
|
}
|
|
|
|
static inline void
|
|
bitmap_set(unsigned long *bitmap, size_t offset, bool value)
|
|
{
|
|
if (value) {
|
|
bitmap_set1(bitmap, offset);
|
|
} else {
|
|
bitmap_set0(bitmap, offset);
|
|
}
|
|
}
|
|
|
|
void bitmap_set_multiple(unsigned long *, size_t start, size_t count,
|
|
bool value);
|
|
bool bitmap_equal(const unsigned long *, const unsigned long *, size_t n);
|
|
size_t bitmap_scan(const unsigned long int *, size_t start, size_t end);
|
|
|
|
#define BITMAP_FOR_EACH_1(IDX, SIZE, BITMAP) \
|
|
for ((IDX) = bitmap_scan(BITMAP, 0, SIZE); (IDX) < (SIZE); \
|
|
(IDX) = bitmap_scan(BITMAP, (IDX) + 1, SIZE))
|
|
|
|
#endif /* bitmap.h */
|