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// 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).
//
// 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 "table/block_based/data_block_footer.h"
#include "rocksdb/table.h"
namespace ROCKSDB_NAMESPACE {
const int kDataBlockIndexTypeBitShift = 31;
// 0x7FFFFFFF
const uint32_t kMaxNumRestarts = (1u << kDataBlockIndexTypeBitShift) - 1u;
// 0x7FFFFFFF
const uint32_t kNumRestartsMask = (1u << kDataBlockIndexTypeBitShift) - 1u;
uint32_t PackIndexTypeAndNumRestarts(
BlockBasedTableOptions::DataBlockIndexType index_type,
uint32_t num_restarts) {
if (num_restarts > kMaxNumRestarts) {
assert(0); // mute travis "unused" warning
}
uint32_t block_footer = num_restarts;
if (index_type == BlockBasedTableOptions::kDataBlockBinaryAndHash) {
block_footer |= 1u << kDataBlockIndexTypeBitShift;
} else if (index_type != BlockBasedTableOptions::kDataBlockBinarySearch) {
assert(0);
}
return block_footer;
}
void UnPackIndexTypeAndNumRestarts(
uint32_t block_footer,
BlockBasedTableOptions::DataBlockIndexType* index_type,
uint32_t* num_restarts) {
if (index_type) {
if (block_footer & 1u << kDataBlockIndexTypeBitShift) {
*index_type = BlockBasedTableOptions::kDataBlockBinaryAndHash;
} else {
*index_type = BlockBasedTableOptions::kDataBlockBinarySearch;
}
}
if (num_restarts) {
*num_restarts = block_footer & kNumRestartsMask;
assert(*num_restarts <= kMaxNumRestarts);
}
}
} // namespace ROCKSDB_NAMESPACE
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