rocksdb/table/mock_table.cc
Aaron Gao a30a696034 do not read next datablock if upperbound is reached
Summary:
Now if we have iterate_upper_bound set, we continue read until get a key >= upper_bound. For a lot of cases that neighboring data blocks have a user key gap between them, our index key will be a user key in the middle to get a shorter size. For example, if we have blocks:
[a b c d][f g h]
Then the index key for the first block will be 'e'.
then if upper bound is any key between 'd' and 'e', for example, d1, d2, ..., d99999999999, we don't have to read the second block and also know that we have done our iteration by reaching the last key that smaller the upper bound already.

This diff can reduce RA in most cases.
Closes https://github.com/facebook/rocksdb/pull/2239

Differential Revision: D4990693

Pulled By: lightmark

fbshipit-source-id: ab30ea2e3c6edf3fddd5efed3c34fcf7739827ff
2017-05-05 23:20:01 -07:00

148 lines
4.6 KiB
C++

// 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.
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree. An additional grant
// of patent rights can be found in the PATENTS file in the same directory.
// This source code is also licensed under the GPLv2 license found in the
// COPYING file in the root directory of this source tree.
#include "table/mock_table.h"
#include "db/dbformat.h"
#include "port/port.h"
#include "rocksdb/table_properties.h"
#include "table/get_context.h"
#include "util/coding.h"
#include "util/file_reader_writer.h"
namespace rocksdb {
namespace mock {
namespace {
const InternalKeyComparator icmp_(BytewiseComparator());
} // namespace
stl_wrappers::KVMap MakeMockFile(
std::initializer_list<std::pair<const std::string, std::string>> l) {
return stl_wrappers::KVMap(l, stl_wrappers::LessOfComparator(&icmp_));
}
InternalIterator* MockTableReader::NewIterator(const ReadOptions&,
Arena* arena,
const InternalKeyComparator*,
bool skip_filters) {
return new MockTableIterator(table_);
}
Status MockTableReader::Get(const ReadOptions&, const Slice& key,
GetContext* get_context, bool skip_filters) {
std::unique_ptr<MockTableIterator> iter(new MockTableIterator(table_));
for (iter->Seek(key); iter->Valid(); iter->Next()) {
ParsedInternalKey parsed_key;
if (!ParseInternalKey(iter->key(), &parsed_key)) {
return Status::Corruption(Slice());
}
if (!get_context->SaveValue(parsed_key, iter->value())) {
break;
}
}
return Status::OK();
}
std::shared_ptr<const TableProperties> MockTableReader::GetTableProperties()
const {
return std::shared_ptr<const TableProperties>(new TableProperties());
}
MockTableFactory::MockTableFactory() : next_id_(1) {}
Status MockTableFactory::NewTableReader(
const TableReaderOptions& table_reader_options,
unique_ptr<RandomAccessFileReader>&& file, uint64_t file_size,
unique_ptr<TableReader>* table_reader,
bool prefetch_index_and_filter_in_cache) const {
uint32_t id = GetIDFromFile(file.get());
MutexLock lock_guard(&file_system_.mutex);
auto it = file_system_.files.find(id);
if (it == file_system_.files.end()) {
return Status::IOError("Mock file not found");
}
table_reader->reset(new MockTableReader(it->second));
return Status::OK();
}
TableBuilder* MockTableFactory::NewTableBuilder(
const TableBuilderOptions& table_builder_options, uint32_t column_family_id,
WritableFileWriter* file) const {
uint32_t id = GetAndWriteNextID(file);
return new MockTableBuilder(id, &file_system_);
}
Status MockTableFactory::CreateMockTable(Env* env, const std::string& fname,
stl_wrappers::KVMap file_contents) {
std::unique_ptr<WritableFile> file;
auto s = env->NewWritableFile(fname, &file, EnvOptions());
if (!s.ok()) {
return s;
}
WritableFileWriter file_writer(std::move(file), EnvOptions());
uint32_t id = GetAndWriteNextID(&file_writer);
file_system_.files.insert({id, std::move(file_contents)});
return Status::OK();
}
uint32_t MockTableFactory::GetAndWriteNextID(WritableFileWriter* file) const {
uint32_t next_id = next_id_.fetch_add(1);
char buf[4];
EncodeFixed32(buf, next_id);
file->Append(Slice(buf, 4));
return next_id;
}
uint32_t MockTableFactory::GetIDFromFile(RandomAccessFileReader* file) const {
char buf[4];
Slice result;
file->Read(0, 4, &result, buf);
assert(result.size() == 4);
return DecodeFixed32(buf);
}
void MockTableFactory::AssertSingleFile(
const stl_wrappers::KVMap& file_contents) {
ASSERT_EQ(file_system_.files.size(), 1U);
ASSERT_EQ(file_contents, file_system_.files.begin()->second);
}
void MockTableFactory::AssertLatestFile(
const stl_wrappers::KVMap& file_contents) {
ASSERT_GE(file_system_.files.size(), 1U);
auto latest = file_system_.files.end();
--latest;
if (file_contents != latest->second) {
std::cout << "Wrong content! Content of latest file:" << std::endl;
for (const auto& kv : latest->second) {
ParsedInternalKey ikey;
std::string key, value;
std::tie(key, value) = kv;
ParseInternalKey(Slice(key), &ikey);
std::cout << ikey.DebugString(false) << " -> " << value << std::endl;
}
ASSERT_TRUE(false);
}
}
} // namespace mock
} // namespace rocksdb