1 | /** |
2 | * Copyright 2021 Alibaba, Inc. and its affiliates. All Rights Reserved. |
3 | * |
4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
5 | * you may not use this file except in compliance with the License. |
6 | * You may obtain a copy of the License at |
7 | * |
8 | * http://www.apache.org/licenses/LICENSE-2.0 |
9 | * |
10 | * Unless required by applicable law or agreed to in writing, software |
11 | * distributed under the License is distributed on an "AS IS" BASIS, |
12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
13 | * See the License for the specific language governing permissions and |
14 | * limitations under the License. |
15 | |
16 | * \author Haichao.chc |
17 | * \date Oct 2020 |
18 | * \brief Provides storage & search ability of lsn context information |
19 | */ |
20 | |
21 | #pragma once |
22 | |
23 | #include <ailego/container/heap.h> |
24 | #include <ailego/parallel/lock.h> |
25 | #include "common/macro_define.h" |
26 | #include "snapshot.h" |
27 | #include "typedef.h" |
28 | |
29 | namespace proxima { |
30 | namespace be { |
31 | namespace index { |
32 | |
33 | class LsnStore; |
34 | using LsnStorePtr = std::shared_ptr<LsnStore>; |
35 | |
36 | /* |
37 | * LsnStore is mainly for storage of mysql log sequence number and context. |
38 | */ |
39 | class LsnStore { |
40 | public: |
41 | /* |
42 | * Header info |
43 | */ |
44 | struct { |
45 | uint64_t {0U}; |
46 | uint64_t {0U}; |
47 | uint64_t [6]; |
48 | }; |
49 | |
50 | static_assert(sizeof(Header) % 64 == 0, |
51 | "Header must be aligned with 64 bytes" ); |
52 | |
53 | /* |
54 | * LSN struct, includes lsn and context |
55 | */ |
56 | struct LSN { |
57 | uint64_t lsn{0U}; |
58 | std::string lsn_context; |
59 | |
60 | LSN() = default; |
61 | |
62 | LSN(uint64_t lsn_val, const std::string &lsn_context_val) { |
63 | lsn = lsn_val; |
64 | lsn_context = lsn_context_val; |
65 | } |
66 | |
67 | bool operator<(const LSN &other) const { |
68 | return lsn < other.lsn; |
69 | } |
70 | |
71 | bool operator>(const LSN &other) const { |
72 | return lsn > other.lsn; |
73 | } |
74 | }; |
75 | |
76 | public: |
77 | PROXIMA_DISALLOW_COPY_AND_ASSIGN(LsnStore); |
78 | |
79 | //! Constructor |
80 | LsnStore(const std::string &coll_name, const std::string &coll_path) |
81 | : collection_name_(coll_name), collection_path_(coll_path) {} |
82 | |
83 | //! Destructor |
84 | ~LsnStore(); |
85 | |
86 | //! Create instance |
87 | static LsnStorePtr Create(const std::string &collection_name, |
88 | const std::string &collection_path); |
89 | |
90 | //! Create instance and open |
91 | static int CreateAndOpen(const std::string &collection_name, |
92 | const std::string &collection_path, |
93 | const ReadOptions &read_options, |
94 | LsnStorePtr *lsn_store); |
95 | |
96 | public: |
97 | //! Open persist storage and initialize |
98 | int open(const ReadOptions &read_options); |
99 | |
100 | //! Flush memory to persist storage |
101 | int flush(); |
102 | |
103 | //! Close persist storage |
104 | int close(); |
105 | |
106 | public: |
107 | //! Append <lsn, lsn_context> pair |
108 | int append(uint64_t lsn, const std::string &lsn_context); |
109 | |
110 | //! Shift inner segment |
111 | int shift(); |
112 | |
113 | //! Get latest lsn and context |
114 | int get_latest_lsn(uint64_t *lsn, std::string *lsn_context); |
115 | |
116 | public: |
117 | //! Return collection name |
118 | const std::string &collection_name() const { |
119 | return collection_name_; |
120 | } |
121 | |
122 | //! Return index file path |
123 | const std::string &file_path() const { |
124 | return file_path_; |
125 | } |
126 | |
127 | //! Return stored lsn count |
128 | size_t count() const { |
129 | return header_.lsn_count; |
130 | } |
131 | |
132 | private: |
133 | int mount(); |
134 | |
135 | void unmount(); |
136 | |
137 | int (); |
138 | |
139 | private: |
140 | static constexpr uint64_t kWindowSize = 2000; |
141 | static constexpr uint64_t kDataBlockCount = 3; |
142 | static constexpr uint64_t kDataBlockSize = 1UL * 1024UL * 1024UL; |
143 | |
144 | private: |
145 | std::string collection_name_{}; |
146 | std::string collection_path_{}; |
147 | std::string file_path_{}; |
148 | |
149 | SnapshotPtr snapshot_{}; |
150 | IndexBlockPtr {}; |
151 | std::vector<IndexBlockPtr> data_blocks_{}; |
152 | Header ; |
153 | ailego::SharedMutex mutex_{}; |
154 | |
155 | bool opened_{false}; |
156 | }; |
157 | |
158 | |
159 | } // end namespace index |
160 | } // namespace be |
161 | } // end namespace proxima |
162 | |