-
Notifications
You must be signed in to change notification settings - Fork 182
/
table_builder.cc
390 lines (332 loc) · 11.8 KB
/
table_builder.cc
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.
#include "leveldb/table_builder.h"
#include <assert.h>
#include "db/dbformat.h"
#include "leveldb/comparator.h"
#include "leveldb/env.h"
#include "leveldb/expiry.h"
#include "leveldb/filter_policy.h"
#include "leveldb/options.h"
#include "leveldb/perf_count.h"
#include "table/block_builder.h"
#include "table/filter_block.h"
#include "table/format.h"
#include "util/coding.h"
#include "util/crc32c.h"
#include "util/lz4.h"
namespace leveldb {
struct TableBuilder::Rep {
Options options;
Options index_block_options;
WritableFile* file;
uint64_t offset;
Status status;
BlockBuilder data_block;
BlockBuilder index_block;
std::string last_key;
int64_t num_entries;
bool closed; // Either Finish() or Abandon() has been called.
FilterBlockBuilder* filter_block;
SstCounters sst_counters;
// We do not emit the index entry for a block until we have seen the
// first key for the next data block. This allows us to use shorter
// keys in the index block. For example, consider a block boundary
// between the keys "the quick brown fox" and "the who". We can use
// "the r" as the key for the index block entry since it is >= all
// entries in the first block and < all entries in subsequent
// blocks.
//
// Invariant: r->pending_index_entry is true only if data_block is empty.
bool pending_index_entry;
BlockHandle pending_handle; // Handle to add to index block
std::string compressed_output;
Rep(const Options& opt, WritableFile* f)
: options(opt),
index_block_options(opt),
file(f),
offset(0),
data_block(&options),
index_block(&index_block_options),
num_entries(0),
closed(false),
filter_block(opt.filter_policy == NULL ? NULL
: new FilterBlockBuilder(opt.filter_policy)),
pending_index_entry(false) {
index_block_options.block_restart_interval = 1;
}
};
TableBuilder::TableBuilder(const Options& options, WritableFile* file)
: rep_(new Rep(options, file)) {
if (rep_->filter_block != NULL) {
rep_->filter_block->StartBlock(0);
}
}
TableBuilder::~TableBuilder() {
assert(rep_->closed); // Catch errors where caller forgot to call Finish()
delete rep_->filter_block;
delete rep_;
}
Status TableBuilder::ChangeOptions(const Options& options) {
// Note: if more fields are added to Options, update
// this function to catch changes that should not be allowed to
// change in the middle of building a Table.
if (options.comparator != rep_->options.comparator) {
return Status::InvalidArgument("changing comparator while building table");
}
// Note that any live BlockBuilders point to rep_->options and therefore
// will automatically pick up the updated options.
rep_->options = options;
rep_->index_block_options = options;
rep_->index_block_options.block_restart_interval = 1;
return Status::OK();
}
void TableBuilder::Add(const Slice& key, const Slice& value) {
Rep* r = rep_;
assert(!r->closed);
if (!ok()) return;
if (r->num_entries > 0) {
assert(r->options.comparator->Compare(key, Slice(r->last_key)) > 0);
}
if (r->pending_index_entry) {
assert(r->data_block.empty());
r->options.comparator->FindShortestSeparator(&r->last_key, key);
std::string handle_encoding;
r->pending_handle.EncodeTo(&handle_encoding);
r->index_block.Add(r->last_key, Slice(handle_encoding));
r->pending_index_entry = false;
r->sst_counters.Inc(eSstCountIndexKeys);
}
if (r->filter_block != NULL) {
r->filter_block->AddKey(key);
}
r->last_key.assign(key.data(), key.size());
r->num_entries++;
r->data_block.Add(key, value);
// statistics
r->sst_counters.Inc(eSstCountKeys);
r->sst_counters.Add(eSstCountKeySize, key.size());
r->sst_counters.Add(eSstCountValueSize, value.size());
if (key.size() < r->sst_counters.Value(eSstCountKeySmallest))
r->sst_counters.Set(eSstCountKeySmallest, key.size());
if (r->sst_counters.Value(eSstCountKeyLargest) < key.size())
r->sst_counters.Set(eSstCountKeyLargest, key.size());
if (value.size() < r->sst_counters.Value(eSstCountValueSmallest))
r->sst_counters.Set(eSstCountValueSmallest, value.size());
if (r->sst_counters.Value(eSstCountValueLargest) < value.size())
r->sst_counters.Set(eSstCountValueLargest, value.size());
// unit tests use non-standard keys ... must ignore the short ones
if (8 < key.size() && kTypeDeletion==ExtractValueType(key))
r->sst_counters.Inc(eSstCountDeleteKey);
// again ignore short keys, save high sequence number for abbreviated repair
if (8 <= key.size()
&& r->sst_counters.Value(eSstCountSequence)<ExtractSequenceNumber(key))
r->sst_counters.Set(eSstCountSequence,ExtractSequenceNumber(key));
// statistics if an expiry key
// Note: not using ExpiryActivated(). Forcing expiry statistics which
// are upgrade / downgrade safe.
if (NULL!=r->options.expiry_module.get())
{
r->options.expiry_module->TableBuilderCallback(key, r->sst_counters);
} // if
const size_t estimated_block_size = r->data_block.CurrentSizeEstimate();
if (estimated_block_size >= r->options.block_size) {
Flush();
}
}
void TableBuilder::Flush() {
Rep* r = rep_;
assert(!r->closed);
if (!ok()) return;
if (r->data_block.empty()) return;
assert(!r->pending_index_entry);
WriteBlock(&r->data_block, &r->pending_handle);
if (ok()) {
r->pending_index_entry = true;
r->status = r->file->Flush();
}
if (r->filter_block != NULL) {
r->filter_block->StartBlock(r->offset);
}
}
void TableBuilder::WriteBlock(BlockBuilder* block, BlockHandle* handle) {
// File format contains a sequence of blocks where each block has:
// block_data: uint8[n]
// type: uint8
// crc: uint32
assert(ok());
Rep* r = rep_;
Slice raw = block->Finish();
r->sst_counters.Inc(eSstCountBlocks);
r->sst_counters.Add(eSstCountBlockSize, raw.size());
Slice block_contents;
CompressionType type = r->options.compression;
// TODO(postrelease): Support more compression options: zlib?
std::string * compressed;
switch (type) {
case kNoCompressionAutomated:
// automation disabled compression
type=kNoCompression;
r->sst_counters.Inc(eSstCountCompressAborted);
block_contents = raw;
break;
case kNoCompression:
block_contents = raw;
break;
case kSnappyCompression:
compressed = &r->compressed_output;
if (port::Snappy_Compress(raw.data(), raw.size(), compressed) &&
compressed->size() < raw.size() - (raw.size() / 8u)) {
block_contents = *compressed;
} else {
// Snappy not supported, or compressed less than 12.5%, so just
// store uncompressed form
block_contents = raw;
type = kNoCompression;
r->sst_counters.Inc(eSstCountCompressAborted);
}
break;
case kLZ4Compression:
compressed = &r->compressed_output;
int limit, result_size;
limit=raw.size() - (raw.size() / 8u);
compressed->resize(limit+4);
result_size=LZ4_compress_default(raw.data(), (char *)(compressed->data())+4, raw.size(), limit);
if (result_size)
{
EncodeFixed32((char *)compressed->data(), raw.size());
compressed->resize(result_size+4);
block_contents = *compressed;
}
else {
// Snappy not supported, or compressed less than 12.5%, so just
// store uncompressed form
block_contents = raw;
type = kNoCompression;
r->sst_counters.Inc(eSstCountCompressAborted);
}
break;
}
WriteRawBlock(block_contents, type, handle);
r->sst_counters.Add(eSstCountBlockWriteSize, block_contents.size());
r->compressed_output.clear();
block->Reset();
}
void TableBuilder::WriteRawBlock(const Slice& block_contents,
CompressionType type,
BlockHandle* handle) {
Rep* r = rep_;
handle->set_offset(r->offset);
handle->set_size(block_contents.size());
r->status = r->file->Append(block_contents);
if (r->status.ok()) {
char trailer[kBlockTrailerSize];
trailer[0] = type;
uint32_t crc = crc32c::Value(block_contents.data(), block_contents.size());
crc = crc32c::Extend(crc, trailer, 1); // Extend crc to cover block type
EncodeFixed32(trailer+1, crc32c::Mask(crc));
r->status = r->file->Append(Slice(trailer, kBlockTrailerSize));
if (r->status.ok()) {
r->offset += block_contents.size() + kBlockTrailerSize;
}
}
}
Status TableBuilder::status() const {
return rep_->status;
}
Status TableBuilder::Finish() {
Rep* r = rep_;
Flush();
assert(!r->closed);
r->closed = true;
BlockHandle filter_block_handle, metaindex_block_handle, index_block_handle,
sst_stats_block_handle;
// pass hint to Linux fadvise management
r->sst_counters.Set(eSstCountUserDataSize, r->offset);
r->file->SetMetadataOffset(r->offset);
// Write filter block
if (ok() && r->filter_block != NULL) {
WriteRawBlock(r->filter_block->Finish(), kNoCompression,
&filter_block_handle);
}
// Write sst statistic counters
if (ok())
{
std::string encoded_stats;
r->sst_counters.Set(eSstCountBlockSizeUsed, r->options.block_size);
if (r->pending_index_entry)
r->sst_counters.Inc(eSstCountIndexKeys);
r->sst_counters.EncodeTo(encoded_stats);
WriteRawBlock(Slice(encoded_stats), kNoCompression,
&sst_stats_block_handle);
} // if
// Write metaindex block
if (ok()) {
BlockBuilder meta_index_block(&r->options);
std::string key, handle_encoding;
if (r->filter_block != NULL) {
// Add mapping from "filter.Name" to location of filter data
key = "filter.";
key.append(r->options.filter_policy->Name());
handle_encoding.clear();
filter_block_handle.EncodeTo(&handle_encoding);
meta_index_block.Add(key, handle_encoding);
}
// Add mapping for "stats.sst1"
key = "stats.sst1";
handle_encoding.clear();
sst_stats_block_handle.EncodeTo(&handle_encoding);
meta_index_block.Add(key, handle_encoding);
// TODO(postrelease): Add stats and other meta blocks
WriteBlock(&meta_index_block, &metaindex_block_handle);
}
// Write index block
if (ok()) {
if (r->pending_index_entry) {
r->options.comparator->FindShortSuccessor(&r->last_key);
std::string handle_encoding;
r->pending_handle.EncodeTo(&handle_encoding);
r->index_block.Add(r->last_key, Slice(handle_encoding));
r->pending_index_entry = false;
}
WriteBlock(&r->index_block, &index_block_handle);
}
// Write footer
if (ok()) {
Footer footer;
footer.set_metaindex_handle(metaindex_block_handle);
footer.set_index_handle(index_block_handle);
std::string footer_encoding;
footer.EncodeTo(&footer_encoding);
r->status = r->file->Append(footer_encoding);
if (r->status.ok()) {
r->offset += footer_encoding.size();
}
}
return r->status;
}
void TableBuilder::Abandon() {
Rep* r = rep_;
assert(!r->closed);
r->closed = true;
}
uint64_t TableBuilder::NumEntries() const {
return rep_->num_entries;
}
uint64_t TableBuilder::FileSize() const {
return rep_->offset;
}
uint64_t TableBuilder::NumDeletes() const {
return rep_->sst_counters.Value(eSstCountDeleteKey);
}
uint64_t TableBuilder::GetExpiryWriteLow() const {
return rep_->sst_counters.Value(eSstCountExpiry1);
}
uint64_t TableBuilder::GetExpiryWriteHigh() const {
return rep_->sst_counters.Value(eSstCountExpiry2);
}
uint64_t TableBuilder::GetExpiryExplicitHigh() const {
return rep_->sst_counters.Value(eSstCountExpiry3);
}
} // namespace leveldb