54 lines
1.4 KiB
C++
54 lines
1.4 KiB
C++
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// Copyright (c) 2012 The Chromium 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.
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#include "base/metrics/bucket_ranges.h"
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#include <cmath>
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#include "base/logging.h"
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#include "base/metrics/crc32.h"
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namespace base {
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BucketRanges::BucketRanges(size_t num_ranges)
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: ranges_(num_ranges, 0),
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checksum_(0) {}
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BucketRanges::~BucketRanges() = default;
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uint32_t BucketRanges::CalculateChecksum() const {
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// Crc of empty ranges_ happens to be 0. This early exit prevents trying to
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// take the address of ranges_[0] which will fail for an empty vector even
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// if that address is never used.
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const size_t ranges_size = ranges_.size();
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if (ranges_size == 0)
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return 0;
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// Checksum is seeded with the ranges "size".
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return Crc32(static_cast<uint32_t>(ranges_size), &ranges_[0],
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sizeof(ranges_[0]) * ranges_size);
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}
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bool BucketRanges::HasValidChecksum() const {
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return CalculateChecksum() == checksum_;
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}
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void BucketRanges::ResetChecksum() {
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checksum_ = CalculateChecksum();
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}
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bool BucketRanges::Equals(const BucketRanges* other) const {
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if (checksum_ != other->checksum_)
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return false;
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if (ranges_.size() != other->ranges_.size())
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return false;
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for (size_t index = 0; index < ranges_.size(); ++index) {
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if (ranges_[index] != other->ranges_[index])
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return false;
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}
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return true;
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}
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} // namespace base
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