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
|
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
#include "rocksdb/flush_block_policy.h"
#include <cassert>
#include <mutex>
#include "rocksdb/options.h"
#include "rocksdb/slice.h"
#include "rocksdb/utilities/customizable_util.h"
#include "table/block_based/block_based_table_reader.h"
#include "table/block_based/block_builder.h"
#include "table/block_based/flush_block_policy.h"
#include "table/format.h"
namespace ROCKSDB_NAMESPACE {
// Flush block by size
class FlushBlockBySizePolicy : public FlushBlockPolicy {
public:
// @params block_size: Approximate size of user data packed per
// block.
// @params block_size_deviation: This is used to close a block before it
// reaches the configured
FlushBlockBySizePolicy(const uint64_t block_size,
const uint64_t block_size_deviation, const bool align,
const BlockBuilder& data_block_builder)
: block_size_(block_size),
block_size_deviation_limit_(
((block_size * (100 - block_size_deviation)) + 99) / 100),
align_(align),
data_block_builder_(data_block_builder) {}
bool Update(const Slice& key, const Slice& value) override {
// it makes no sense to flush when the data block is empty
if (data_block_builder_.empty()) {
return false;
}
auto curr_size = data_block_builder_.CurrentSizeEstimate();
// Do flush if one of the below two conditions is true:
// 1) if the current estimated size already exceeds the block size,
// 2) block_size_deviation is set and the estimated size after appending
// the kv will exceed the block size and the current size is under the
// the deviation.
return curr_size >= block_size_ || BlockAlmostFull(key, value);
}
private:
bool BlockAlmostFull(const Slice& key, const Slice& value) const {
if (block_size_deviation_limit_ == 0) {
return false;
}
const auto curr_size = data_block_builder_.CurrentSizeEstimate();
auto estimated_size_after =
data_block_builder_.EstimateSizeAfterKV(key, value);
if (align_) {
estimated_size_after += BlockBasedTable::kBlockTrailerSize;
return estimated_size_after > block_size_;
}
return estimated_size_after > block_size_ &&
curr_size > block_size_deviation_limit_;
}
const uint64_t block_size_;
const uint64_t block_size_deviation_limit_;
const bool align_;
const BlockBuilder& data_block_builder_;
};
FlushBlockPolicy* FlushBlockBySizePolicyFactory::NewFlushBlockPolicy(
const BlockBasedTableOptions& table_options,
const BlockBuilder& data_block_builder) const {
return new FlushBlockBySizePolicy(
table_options.block_size, table_options.block_size_deviation,
table_options.block_align, data_block_builder);
}
FlushBlockPolicy* FlushBlockBySizePolicyFactory::NewFlushBlockPolicy(
const uint64_t size, const int deviation,
const BlockBuilder& data_block_builder) {
return new FlushBlockBySizePolicy(size, deviation, false, data_block_builder);
}
#ifndef ROCKSDB_LITE
static int RegisterFlushBlockPolicyFactories(ObjectLibrary& library,
const std::string& /*arg*/) {
library.AddFactory<FlushBlockPolicyFactory>(
FlushBlockBySizePolicyFactory::kClassName(),
[](const std::string& /*uri*/,
std::unique_ptr<FlushBlockPolicyFactory>* guard,
std::string* /* errmsg */) {
guard->reset(new FlushBlockBySizePolicyFactory());
return guard->get();
});
library.AddFactory<FlushBlockPolicyFactory>(
FlushBlockEveryKeyPolicyFactory::kClassName(),
[](const std::string& /*uri*/,
std::unique_ptr<FlushBlockPolicyFactory>* guard,
std::string* /* errmsg */) {
guard->reset(new FlushBlockEveryKeyPolicyFactory());
return guard->get();
});
return 2;
}
#endif // ROCKSDB_LITE
static bool LoadFlushPolicyFactory(
const std::string& id, std::shared_ptr<FlushBlockPolicyFactory>* result) {
if (id.empty()) {
result->reset(new FlushBlockBySizePolicyFactory());
#ifdef ROCKSDB_LITE
} else if (id == FlushBlockBySizePolicyFactory::kClassName()) {
result->reset(new FlushBlockBySizePolicyFactory());
} else if (id == FlushBlockEveryKeyPolicyFactory::kClassName()) {
result->reset(new FlushBlockEveryKeyPolicyFactory());
#endif // ROCKSDB_LITE
} else {
return false;
}
return true;
}
FlushBlockBySizePolicyFactory::FlushBlockBySizePolicyFactory()
: FlushBlockPolicyFactory() {}
Status FlushBlockPolicyFactory::CreateFromString(
const ConfigOptions& config_options, const std::string& value,
std::shared_ptr<FlushBlockPolicyFactory>* factory) {
#ifndef ROCKSDB_LITE
static std::once_flag once;
std::call_once(once, [&]() {
RegisterFlushBlockPolicyFactories(*(ObjectLibrary::Default().get()), "");
});
#endif // ROCKSDB_LITE
return LoadSharedObject<FlushBlockPolicyFactory>(
config_options, value, LoadFlushPolicyFactory, factory);
}
} // namespace ROCKSDB_NAMESPACE
|
