a30a696034
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
90 lines
3.0 KiB
C++
90 lines
3.0 KiB
C++
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
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// This source code is licensed under the BSD-style license found in the
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// LICENSE file in the root directory of this source tree. An additional grant
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// of patent rights can be found in the PATENTS file in the same directory.
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// This source code is also licensed under the GPLv2 license found in the
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// COPYING file in the root directory of this source tree.
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//
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// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file. See the AUTHORS file for names of contributors.
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#pragma once
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#ifndef ROCKSDB_LITE
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#include <string>
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#include <memory>
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#include <utility>
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#include <vector>
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#include "db/dbformat.h"
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#include "options/cf_options.h"
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#include "rocksdb/env.h"
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#include "rocksdb/options.h"
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#include "table/table_reader.h"
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#include "util/file_reader_writer.h"
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namespace rocksdb {
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class Arena;
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class TableReader;
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class InternalIterator;
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class CuckooTableReader: public TableReader {
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public:
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CuckooTableReader(const ImmutableCFOptions& ioptions,
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std::unique_ptr<RandomAccessFileReader>&& file,
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uint64_t file_size, const Comparator* user_comparator,
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uint64_t (*get_slice_hash)(const Slice&, uint32_t,
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uint64_t));
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~CuckooTableReader() {}
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std::shared_ptr<const TableProperties> GetTableProperties() const override {
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return table_props_;
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}
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Status status() const { return status_; }
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Status Get(const ReadOptions& read_options, const Slice& key,
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GetContext* get_context, bool skip_filters = false) override;
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InternalIterator* NewIterator(
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const ReadOptions&, Arena* arena = nullptr,
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const InternalKeyComparator* icomparator = nullptr,
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bool skip_filters = false) override;
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void Prepare(const Slice& target) override;
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// Report an approximation of how much memory has been used.
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size_t ApproximateMemoryUsage() const override;
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// Following methods are not implemented for Cuckoo Table Reader
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uint64_t ApproximateOffsetOf(const Slice& key) override { return 0; }
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void SetupForCompaction() override {}
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// End of methods not implemented.
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private:
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friend class CuckooTableIterator;
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void LoadAllKeys(std::vector<std::pair<Slice, uint32_t>>* key_to_bucket_id);
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std::unique_ptr<RandomAccessFileReader> file_;
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Slice file_data_;
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bool is_last_level_;
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bool identity_as_first_hash_;
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bool use_module_hash_;
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std::shared_ptr<const TableProperties> table_props_;
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Status status_;
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uint32_t num_hash_func_;
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std::string unused_key_;
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uint32_t key_length_;
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uint32_t user_key_length_;
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uint32_t value_length_;
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uint32_t bucket_length_;
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uint32_t cuckoo_block_size_;
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uint32_t cuckoo_block_bytes_minus_one_;
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uint64_t table_size_;
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const Comparator* ucomp_;
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uint64_t (*get_slice_hash_)(const Slice& s, uint32_t index,
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uint64_t max_num_buckets);
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};
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} // namespace rocksdb
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#endif // ROCKSDB_LITE
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