You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
101 lines
3.2 KiB
101 lines
3.2 KiB
5 months ago
|
/* Copyright (c) 2016, 2017, 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, version 2.0,
|
||
|
|
as published by the Free Software Foundation.
|
||
|
|
|
||
|
|
This program is also distributed with certain software (including
|
||
|
|
but not limited to OpenSSL) that is licensed under separate terms,
|
||
|
|
as designated in a particular file or component or in included license
|
||
|
|
documentation. The authors of MySQL hereby grant you an additional
|
||
|
|
permission to link the program and your derivative works with the
|
||
|
|
separately licensed software that they have included with MySQL.
|
||
|
|
|
||
|
|
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, version 2.0, 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 02110-1301 USA */
|
||
|
|
|
||
|
|
#ifndef CMP_VARLEN_KEYS_INCLUDED
|
||
|
|
#define CMP_VARLEN_KEYS_INCLUDED
|
||
|
|
|
||
|
|
#include <stdio.h>
|
||
|
|
#include <functional>
|
||
|
|
|
||
|
|
#include "my_dbug.h"
|
||
|
|
#include "sql/sort_param.h"
|
||
|
|
#include "sql/sql_array.h"
|
||
|
|
|
||
|
|
/**
|
||
|
|
A compare function for variable-length keys used by filesort().
|
||
|
|
For record format documentation, @see Sort_param.
|
||
|
|
|
||
|
|
@param sort_field_array array of field descriptors for sorting
|
||
|
|
@param use_hash compare hash values (for grouping of JSON data)
|
||
|
|
@param s1 pointer to record 1
|
||
|
|
@param s2 pointer to record 2
|
||
|
|
@return true/false according to sorting order
|
||
|
|
*/
|
||
|
|
inline bool cmp_varlen_keys(
|
||
|
|
Bounds_checked_array<st_sort_field> sort_field_array, bool use_hash,
|
||
|
|
const uchar *s1, const uchar *s2) {
|
||
|
|
const uchar *kp1 = s1 + Sort_param::size_of_varlength_field;
|
||
|
|
const uchar *kp2 = s2 + Sort_param::size_of_varlength_field;
|
||
|
|
int res;
|
||
|
|
for (const st_sort_field &sort_field : sort_field_array) {
|
||
|
|
uint kp1_len, kp2_len, kp_len;
|
||
|
|
if (sort_field.maybe_null) {
|
||
|
|
const int k1_nullbyte = *kp1++;
|
||
|
|
const int k2_nullbyte = *kp2++;
|
||
|
|
if (k1_nullbyte != k2_nullbyte) return k1_nullbyte < k2_nullbyte;
|
||
|
|
if (k1_nullbyte == 0 || k1_nullbyte == 0xff) {
|
||
|
|
if (!sort_field.is_varlen) {
|
||
|
|
kp1 += sort_field.length;
|
||
|
|
kp2 += sort_field.length;
|
||
|
|
}
|
||
|
|
continue; // Both key parts are null, nothing to compare
|
||
|
|
}
|
||
|
|
}
|
||
|
|
if (sort_field.is_varlen) {
|
||
|
|
DBUG_ASSERT(uint4korr(kp1) >= 4);
|
||
|
|
DBUG_ASSERT(uint4korr(kp2) >= 4);
|
||
|
|
|
||
|
|
kp1_len = uint4korr(kp1) - 4;
|
||
|
|
kp1 += 4;
|
||
|
|
|
||
|
|
kp2_len = uint4korr(kp2) - 4;
|
||
|
|
kp2 += 4;
|
||
|
|
|
||
|
|
kp_len = std::min(kp1_len, kp2_len);
|
||
|
|
} else {
|
||
|
|
kp_len = kp1_len = kp2_len = sort_field.length;
|
||
|
|
}
|
||
|
|
|
||
|
|
res = memcmp(kp1, kp2, kp_len);
|
||
|
|
|
||
|
|
if (res) return res < 0;
|
||
|
|
if (kp1_len != kp2_len) {
|
||
|
|
if (sort_field.reverse)
|
||
|
|
return kp2_len < kp1_len;
|
||
|
|
else
|
||
|
|
return kp1_len < kp2_len;
|
||
|
|
}
|
||
|
|
|
||
|
|
kp1 += kp1_len;
|
||
|
|
kp2 += kp2_len;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (use_hash) {
|
||
|
|
// Compare hashes at the end of sort keys
|
||
|
|
return memcmp(kp1, kp2, 8) < 0;
|
||
|
|
} else {
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
#endif // CMP_VARLEN_KEYS_INCLUDED
|