rocksdb/table/sst_file_reader.cc
sdong e1c468d16f Do readahead in VerifyChecksum() (#5713)
Summary:
Right now VerifyChecksum() doesn't do read-ahead. In some use cases, users won't be able to achieve good performance. With this change, by default, RocksDB will do a default readahead, and users will be able to overwrite the readahead size by passing in a ReadOptions.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5713

Test Plan: Add a new unit test.

Differential Revision: D16860874

fbshipit-source-id: 0cff0fe79ac855d3d068e6ccd770770854a68413
2019-08-16 16:42:56 -07:00

90 lines
3 KiB
C++

// 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).
#ifndef ROCKSDB_LITE
#include "rocksdb/sst_file_reader.h"
#include "db/db_iter.h"
#include "db/dbformat.h"
#include "options/cf_options.h"
#include "table/get_context.h"
#include "table/table_builder.h"
#include "table/table_reader.h"
#include "util/file_reader_writer.h"
namespace rocksdb {
struct SstFileReader::Rep {
Options options;
EnvOptions soptions;
ImmutableCFOptions ioptions;
MutableCFOptions moptions;
std::unique_ptr<TableReader> table_reader;
Rep(const Options& opts)
: options(opts),
soptions(options),
ioptions(options),
moptions(ColumnFamilyOptions(options)) {}
};
SstFileReader::SstFileReader(const Options& options) : rep_(new Rep(options)) {}
SstFileReader::~SstFileReader() {}
Status SstFileReader::Open(const std::string& file_path) {
auto r = rep_.get();
Status s;
uint64_t file_size = 0;
std::unique_ptr<RandomAccessFile> file;
std::unique_ptr<RandomAccessFileReader> file_reader;
s = r->options.env->GetFileSize(file_path, &file_size);
if (s.ok()) {
s = r->options.env->NewRandomAccessFile(file_path, &file, r->soptions);
}
if (s.ok()) {
file_reader.reset(new RandomAccessFileReader(std::move(file), file_path));
}
if (s.ok()) {
TableReaderOptions t_opt(r->ioptions, r->moptions.prefix_extractor.get(),
r->soptions, r->ioptions.internal_comparator);
// Allow open file with global sequence number for backward compatibility.
t_opt.largest_seqno = kMaxSequenceNumber;
s = r->options.table_factory->NewTableReader(t_opt, std::move(file_reader),
file_size, &r->table_reader);
}
return s;
}
Iterator* SstFileReader::NewIterator(const ReadOptions& options) {
auto r = rep_.get();
auto sequence = options.snapshot != nullptr
? options.snapshot->GetSequenceNumber()
: kMaxSequenceNumber;
auto internal_iter = r->table_reader->NewIterator(
options, r->moptions.prefix_extractor.get(), /*arena=*/nullptr,
/*skip_filters=*/false, TableReaderCaller::kSSTFileReader);
return NewDBIterator(r->options.env, options, r->ioptions, r->moptions,
r->ioptions.user_comparator, internal_iter, sequence,
r->moptions.max_sequential_skip_in_iterations,
nullptr /* read_callback */);
}
std::shared_ptr<const TableProperties> SstFileReader::GetTableProperties()
const {
return rep_->table_reader->GetTableProperties();
}
Status SstFileReader::VerifyChecksum(const ReadOptions& read_options) {
return rep_->table_reader->VerifyChecksum(read_options,
TableReaderCaller::kSSTFileReader);
}
} // namespace rocksdb
#endif // !ROCKSDB_LITE