Repo created

TMessagesProj/jni/voip/webrtc/base/metrics/bucket_ranges.cc

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+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/metrics/bucket_ranges.h"
+
+#include <cmath>
+
+#include "base/logging.h"
+#include "base/metrics/crc32.h"
+
+namespace base {
+
+BucketRanges::BucketRanges(size_t num_ranges)
+    : ranges_(num_ranges, 0),
+      checksum_(0) {}
+
+BucketRanges::~BucketRanges() = default;
+
+uint32_t BucketRanges::CalculateChecksum() const {
+  // Crc of empty ranges_ happens to be 0. This early exit prevents trying to
+  // take the address of ranges_[0] which will fail for an empty vector even
+  // if that address is never used.
+  const size_t ranges_size = ranges_.size();
+  if (ranges_size == 0)
+    return 0;
+
+  // Checksum is seeded with the ranges "size".
+  return Crc32(static_cast<uint32_t>(ranges_size), &ranges_[0],
+               sizeof(ranges_[0]) * ranges_size);
+}
+
+bool BucketRanges::HasValidChecksum() const {
+  return CalculateChecksum() == checksum_;
+}
+
+void BucketRanges::ResetChecksum() {
+  checksum_ = CalculateChecksum();
+}
+
+bool BucketRanges::Equals(const BucketRanges* other) const {
+  if (checksum_ != other->checksum_)
+    return false;
+  if (ranges_.size() != other->ranges_.size())
+    return false;
+  for (size_t index = 0; index < ranges_.size(); ++index) {
+    if (ranges_[index] != other->ranges_[index])
+      return false;
+  }
+  return true;
+}
+
+}  // namespace base