1/*
2 Copyright (c) 2012,2015 Monty Program Ab
3
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; version 2 of the License.
7
8 This program is distributed in the hope that it will be useful,
9 but WITHOUT ANY WARRANTY; without even the implied warranty of
10 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 GNU General Public License for more details.
12
13 You should have received a copy of the GNU General Public License
14 along with this program; if not, write to the Free Software
15 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
16#pragma once
17
18/* C++ system header files */
19#include <string>
20
21/* MySQL includes */
22#include "./m_ctype.h"
23
24/* RocksDB header files */
25#include "rocksdb/comparator.h"
26
27/* MyRocks header files */
28#include "./rdb_utils.h"
29
30namespace myrocks {
31
32/*
33 The keys are in form: {index_number} {mem-comparable-key}
34
35 (todo: knowledge about this format is shared between this class and
36 Rdb_key_def)
37*/
38class Rdb_pk_comparator : public rocksdb::Comparator {
39public:
40 Rdb_pk_comparator(const Rdb_pk_comparator &) = delete;
41 Rdb_pk_comparator &operator=(const Rdb_pk_comparator &) = delete;
42 Rdb_pk_comparator() = default;
43
44 static int bytewise_compare(const rocksdb::Slice &a,
45 const rocksdb::Slice &b) {
46 const size_t a_size = a.size();
47 const size_t b_size = b.size();
48 const size_t len = (a_size < b_size) ? a_size : b_size;
49 int res;
50
51 if ((res = memcmp(a.data(), b.data(), len)))
52 return res;
53
54 /* Ok, res== 0 */
55 if (a_size != b_size) {
56 return a_size < b_size ? -1 : 1;
57 }
58 return HA_EXIT_SUCCESS;
59 }
60
61 /* Override virtual methods of interest */
62
63 int Compare(const rocksdb::Slice &a, const rocksdb::Slice &b) const override {
64 return bytewise_compare(a, b);
65 }
66
67 const char *Name() const override { return "RocksDB_SE_v3.10"; }
68
69 // TODO: advanced funcs:
70 // - FindShortestSeparator
71 // - FindShortSuccessor
72
73 // for now, do-nothing implementations:
74 void FindShortestSeparator(std::string *start,
75 const rocksdb::Slice &limit) const override {}
76 void FindShortSuccessor(std::string *key) const override {}
77};
78
79class Rdb_rev_comparator : public rocksdb::Comparator {
80public:
81 Rdb_rev_comparator(const Rdb_rev_comparator &) = delete;
82 Rdb_rev_comparator &operator=(const Rdb_rev_comparator &) = delete;
83 Rdb_rev_comparator() = default;
84
85 static int bytewise_compare(const rocksdb::Slice &a,
86 const rocksdb::Slice &b) {
87 return -Rdb_pk_comparator::bytewise_compare(a, b);
88 }
89
90 int Compare(const rocksdb::Slice &a, const rocksdb::Slice &b) const override {
91 return -Rdb_pk_comparator::bytewise_compare(a, b);
92 }
93 const char *Name() const override { return "rev:RocksDB_SE_v3.10"; }
94 void FindShortestSeparator(std::string *start,
95 const rocksdb::Slice &limit) const override {}
96 void FindShortSuccessor(std::string *key) const override {}
97};
98
99} // namespace myrocks
100