70 lines
2.4 KiB
C++
70 lines
2.4 KiB
C++
/* Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License, version 2.0,
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as published by the Free Software Foundation.
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This program is also distributed with certain software (including
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but not limited to OpenSSL) that is licensed under separate terms,
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as designated in a particular file or component or in included license
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documentation. The authors of MySQL hereby grant you an additional
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permission to link the program and your derivative works with the
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separately licensed software that they have included with MySQL.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License, version 2.0, for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
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/* Calculate a checksum for a row */
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#include <sys/types.h>
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#include "my_byteorder.h"
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#include "my_inttypes.h"
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#include "sql/field.h"
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#include "storage/myisam/myisamdef.h"
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ha_checksum mi_checksum(MI_INFO *info, const uchar *buf) {
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uint i;
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ha_checksum crc = 0;
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MI_COLUMNDEF *rec = info->s->rec;
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for (i = info->s->base.fields; i--; buf += (rec++)->length) {
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const uchar *pos;
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ulong length;
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switch (rec->type) {
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case FIELD_BLOB: {
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length =
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_mi_calc_blob_length(rec->length - portable_sizeof_char_ptr, buf);
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memcpy(&pos, buf + rec->length - portable_sizeof_char_ptr,
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sizeof(char *));
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break;
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}
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case FIELD_VARCHAR: {
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uint pack_length = HA_VARCHAR_PACKLENGTH(rec->length - 1);
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if (pack_length == 1)
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length = (ulong)*buf;
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else
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length = uint2korr(buf);
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pos = buf + pack_length;
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break;
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}
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default:
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length = rec->length;
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pos = buf;
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break;
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}
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crc = my_checksum(crc, pos ? pos : pointer_cast<const uchar *>(""), length);
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}
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return crc;
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}
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ha_checksum mi_static_checksum(MI_INFO *info, const uchar *pos) {
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return my_checksum(0, pos, info->s->base.reclength);
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}
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