1 | // Copyright (c) 2011 The LevelDB Authors. All rights reserved. |
2 | // Use of this source code is governed by a BSD-style license that can be |
3 | // found in the LICENSE file. See the AUTHORS file for names of contributors. |
4 | |
5 | #include "db/version_edit.h" |
6 | |
7 | #include "db/version_set.h" |
8 | #include "util/coding.h" |
9 | |
10 | namespace leveldb { |
11 | |
12 | // Tag numbers for serialized VersionEdit. These numbers are written to |
13 | // disk and should not be changed. |
14 | enum Tag { |
15 | kComparator = 1, |
16 | kLogNumber = 2, |
17 | kNextFileNumber = 3, |
18 | kLastSequence = 4, |
19 | kCompactPointer = 5, |
20 | kDeletedFile = 6, |
21 | kNewFile = 7, |
22 | // 8 was used for large value refs |
23 | kPrevLogNumber = 9 |
24 | }; |
25 | |
26 | void VersionEdit::Clear() { |
27 | comparator_.clear(); |
28 | log_number_ = 0; |
29 | prev_log_number_ = 0; |
30 | last_sequence_ = 0; |
31 | next_file_number_ = 0; |
32 | has_comparator_ = false; |
33 | has_log_number_ = false; |
34 | has_prev_log_number_ = false; |
35 | has_next_file_number_ = false; |
36 | has_last_sequence_ = false; |
37 | compact_pointers_.clear(); |
38 | deleted_files_.clear(); |
39 | new_files_.clear(); |
40 | } |
41 | |
42 | void VersionEdit::EncodeTo(std::string* dst) const { |
43 | if (has_comparator_) { |
44 | PutVarint32(dst, kComparator); |
45 | PutLengthPrefixedSlice(dst, comparator_); |
46 | } |
47 | if (has_log_number_) { |
48 | PutVarint32(dst, kLogNumber); |
49 | PutVarint64(dst, log_number_); |
50 | } |
51 | if (has_prev_log_number_) { |
52 | PutVarint32(dst, kPrevLogNumber); |
53 | PutVarint64(dst, prev_log_number_); |
54 | } |
55 | if (has_next_file_number_) { |
56 | PutVarint32(dst, kNextFileNumber); |
57 | PutVarint64(dst, next_file_number_); |
58 | } |
59 | if (has_last_sequence_) { |
60 | PutVarint32(dst, kLastSequence); |
61 | PutVarint64(dst, last_sequence_); |
62 | } |
63 | |
64 | for (size_t i = 0; i < compact_pointers_.size(); i++) { |
65 | PutVarint32(dst, kCompactPointer); |
66 | PutVarint32(dst, compact_pointers_[i].first); // level |
67 | PutLengthPrefixedSlice(dst, compact_pointers_[i].second.Encode()); |
68 | } |
69 | |
70 | for (const auto& deleted_file_kvp : deleted_files_) { |
71 | PutVarint32(dst, kDeletedFile); |
72 | PutVarint32(dst, deleted_file_kvp.first); // level |
73 | PutVarint64(dst, deleted_file_kvp.second); // file number |
74 | } |
75 | |
76 | for (size_t i = 0; i < new_files_.size(); i++) { |
77 | const FileMetaData& f = new_files_[i].second; |
78 | PutVarint32(dst, kNewFile); |
79 | PutVarint32(dst, new_files_[i].first); // level |
80 | PutVarint64(dst, f.number); |
81 | PutVarint64(dst, f.file_size); |
82 | PutLengthPrefixedSlice(dst, f.smallest.Encode()); |
83 | PutLengthPrefixedSlice(dst, f.largest.Encode()); |
84 | } |
85 | } |
86 | |
87 | static bool GetInternalKey(Slice* input, InternalKey* dst) { |
88 | Slice str; |
89 | if (GetLengthPrefixedSlice(input, &str)) { |
90 | return dst->DecodeFrom(str); |
91 | } else { |
92 | return false; |
93 | } |
94 | } |
95 | |
96 | static bool GetLevel(Slice* input, int* level) { |
97 | uint32_t v; |
98 | if (GetVarint32(input, &v) && v < config::kNumLevels) { |
99 | *level = v; |
100 | return true; |
101 | } else { |
102 | return false; |
103 | } |
104 | } |
105 | |
106 | Status VersionEdit::DecodeFrom(const Slice& src) { |
107 | Clear(); |
108 | Slice input = src; |
109 | const char* msg = nullptr; |
110 | uint32_t tag; |
111 | |
112 | // Temporary storage for parsing |
113 | int level; |
114 | uint64_t number; |
115 | FileMetaData f; |
116 | Slice str; |
117 | InternalKey key; |
118 | |
119 | while (msg == nullptr && GetVarint32(&input, &tag)) { |
120 | switch (tag) { |
121 | case kComparator: |
122 | if (GetLengthPrefixedSlice(&input, &str)) { |
123 | comparator_ = str.ToString(); |
124 | has_comparator_ = true; |
125 | } else { |
126 | msg = "comparator name" ; |
127 | } |
128 | break; |
129 | |
130 | case kLogNumber: |
131 | if (GetVarint64(&input, &log_number_)) { |
132 | has_log_number_ = true; |
133 | } else { |
134 | msg = "log number" ; |
135 | } |
136 | break; |
137 | |
138 | case kPrevLogNumber: |
139 | if (GetVarint64(&input, &prev_log_number_)) { |
140 | has_prev_log_number_ = true; |
141 | } else { |
142 | msg = "previous log number" ; |
143 | } |
144 | break; |
145 | |
146 | case kNextFileNumber: |
147 | if (GetVarint64(&input, &next_file_number_)) { |
148 | has_next_file_number_ = true; |
149 | } else { |
150 | msg = "next file number" ; |
151 | } |
152 | break; |
153 | |
154 | case kLastSequence: |
155 | if (GetVarint64(&input, &last_sequence_)) { |
156 | has_last_sequence_ = true; |
157 | } else { |
158 | msg = "last sequence number" ; |
159 | } |
160 | break; |
161 | |
162 | case kCompactPointer: |
163 | if (GetLevel(&input, &level) && GetInternalKey(&input, &key)) { |
164 | compact_pointers_.push_back(std::make_pair(level, key)); |
165 | } else { |
166 | msg = "compaction pointer" ; |
167 | } |
168 | break; |
169 | |
170 | case kDeletedFile: |
171 | if (GetLevel(&input, &level) && GetVarint64(&input, &number)) { |
172 | deleted_files_.insert(std::make_pair(level, number)); |
173 | } else { |
174 | msg = "deleted file" ; |
175 | } |
176 | break; |
177 | |
178 | case kNewFile: |
179 | if (GetLevel(&input, &level) && GetVarint64(&input, &f.number) && |
180 | GetVarint64(&input, &f.file_size) && |
181 | GetInternalKey(&input, &f.smallest) && |
182 | GetInternalKey(&input, &f.largest)) { |
183 | new_files_.push_back(std::make_pair(level, f)); |
184 | } else { |
185 | msg = "new-file entry" ; |
186 | } |
187 | break; |
188 | |
189 | default: |
190 | msg = "unknown tag" ; |
191 | break; |
192 | } |
193 | } |
194 | |
195 | if (msg == nullptr && !input.empty()) { |
196 | msg = "invalid tag" ; |
197 | } |
198 | |
199 | Status result; |
200 | if (msg != nullptr) { |
201 | result = Status::Corruption("VersionEdit" , msg); |
202 | } |
203 | return result; |
204 | } |
205 | |
206 | std::string VersionEdit::DebugString() const { |
207 | std::string r; |
208 | r.append("VersionEdit {" ); |
209 | if (has_comparator_) { |
210 | r.append("\n Comparator: " ); |
211 | r.append(comparator_); |
212 | } |
213 | if (has_log_number_) { |
214 | r.append("\n LogNumber: " ); |
215 | AppendNumberTo(&r, log_number_); |
216 | } |
217 | if (has_prev_log_number_) { |
218 | r.append("\n PrevLogNumber: " ); |
219 | AppendNumberTo(&r, prev_log_number_); |
220 | } |
221 | if (has_next_file_number_) { |
222 | r.append("\n NextFile: " ); |
223 | AppendNumberTo(&r, next_file_number_); |
224 | } |
225 | if (has_last_sequence_) { |
226 | r.append("\n LastSeq: " ); |
227 | AppendNumberTo(&r, last_sequence_); |
228 | } |
229 | for (size_t i = 0; i < compact_pointers_.size(); i++) { |
230 | r.append("\n CompactPointer: " ); |
231 | AppendNumberTo(&r, compact_pointers_[i].first); |
232 | r.append(" " ); |
233 | r.append(compact_pointers_[i].second.DebugString()); |
234 | } |
235 | for (const auto& deleted_files_kvp : deleted_files_) { |
236 | r.append("\n RemoveFile: " ); |
237 | AppendNumberTo(&r, deleted_files_kvp.first); |
238 | r.append(" " ); |
239 | AppendNumberTo(&r, deleted_files_kvp.second); |
240 | } |
241 | for (size_t i = 0; i < new_files_.size(); i++) { |
242 | const FileMetaData& f = new_files_[i].second; |
243 | r.append("\n AddFile: " ); |
244 | AppendNumberTo(&r, new_files_[i].first); |
245 | r.append(" " ); |
246 | AppendNumberTo(&r, f.number); |
247 | r.append(" " ); |
248 | AppendNumberTo(&r, f.file_size); |
249 | r.append(" " ); |
250 | r.append(f.smallest.DebugString()); |
251 | r.append(" .. " ); |
252 | r.append(f.largest.DebugString()); |
253 | } |
254 | r.append("\n}\n" ); |
255 | return r; |
256 | } |
257 | |
258 | } // namespace leveldb |
259 | |