root/net/quic/quic_bandwidth.cc

DEFINITIONS

1. Zero
2. FromBitsPerSecond
3. FromKBitsPerSecond
4. FromBytesPerSecond
5. FromKBytesPerSecond
6. FromBytesAndTimeDelta
7. ToBitsPerSecond
8. ToKBitsPerSecond
9. ToBytesPerSecond
10. ToKBytesPerSecond
11. ToBytesPerPeriod
12. ToKBytesPerPeriod
13. IsZero
14. Add
15. Subtract
16. Scale
17. TransferTime

// 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 "net/quic/quic_bandwidth.h"

#include "base/logging.h"
#include "base/time/time.h"

namespace net {

// Highest number that QuicBandwidth can hold.
const int64 kQuicInfiniteBandwidth = GG_INT64_C(0x7fffffffffffffff);

// static
QuicBandwidth QuicBandwidth::Zero() {
  return QuicBandwidth(0);
}

// static
QuicBandwidth QuicBandwidth::FromBitsPerSecond(int64 bits_per_second) {
  return QuicBandwidth(bits_per_second);
}

// static
QuicBandwidth QuicBandwidth::FromKBitsPerSecond(int64 k_bits_per_second) {
  DCHECK(k_bits_per_second < kQuicInfiniteBandwidth / 1000);
  return QuicBandwidth(k_bits_per_second * 1000);
}

// static
QuicBandwidth QuicBandwidth::FromBytesPerSecond(int64 bytes_per_second) {
  DCHECK(bytes_per_second < kQuicInfiniteBandwidth / 8);
  return QuicBandwidth(bytes_per_second * 8);
}

// static
QuicBandwidth QuicBandwidth::FromKBytesPerSecond(int64 k_bytes_per_second) {
  DCHECK(k_bytes_per_second < kQuicInfiniteBandwidth / 8000);
  return QuicBandwidth(k_bytes_per_second * 8000);
}

// static
QuicBandwidth QuicBandwidth::FromBytesAndTimeDelta(QuicByteCount bytes,
                                                   QuicTime::Delta delta) {
  DCHECK_LT(bytes,
            static_cast<uint64>(kQuicInfiniteBandwidth /
                                (8 * base::Time::kMicrosecondsPerSecond)));
  int64 bytes_per_second = (bytes * base::Time::kMicrosecondsPerSecond) /
      delta.ToMicroseconds();
  return QuicBandwidth(bytes_per_second * 8);
}

QuicBandwidth::QuicBandwidth(int64 bits_per_second)
    : bits_per_second_(bits_per_second) {
  DCHECK_GE(bits_per_second, 0);
}

int64 QuicBandwidth::ToBitsPerSecond() const {
  return bits_per_second_;
}

int64 QuicBandwidth::ToKBitsPerSecond() const {
  return bits_per_second_ / 1000;
}

int64 QuicBandwidth::ToBytesPerSecond() const {
  return bits_per_second_ / 8;
}

int64 QuicBandwidth::ToKBytesPerSecond() const {
  return bits_per_second_ / 8000;
}

QuicByteCount QuicBandwidth::ToBytesPerPeriod(
    QuicTime::Delta time_period) const {
  return ToBytesPerSecond() * time_period.ToMicroseconds() /
      base::Time::kMicrosecondsPerSecond;
}

int64 QuicBandwidth::ToKBytesPerPeriod(QuicTime::Delta time_period) const {
  return ToKBytesPerSecond() * time_period.ToMicroseconds() /
      base::Time::kMicrosecondsPerSecond;
}

bool QuicBandwidth::IsZero() const {
  return (bits_per_second_ == 0);
}

QuicBandwidth QuicBandwidth::Add(const QuicBandwidth& delta) const {
  return QuicBandwidth(bits_per_second_ + delta.bits_per_second_);
}

QuicBandwidth QuicBandwidth::Subtract(const QuicBandwidth& delta) const {
  return QuicBandwidth(bits_per_second_ - delta.bits_per_second_);
}

QuicBandwidth QuicBandwidth::Scale(float scale_factor) const {
  return QuicBandwidth(bits_per_second_ * scale_factor);
}

QuicTime::Delta QuicBandwidth::TransferTime(QuicByteCount bytes) const {
  return QuicTime::Delta::FromMicroseconds(
      bytes * 8 * base::Time::kMicrosecondsPerSecond / bits_per_second_);
}

}  // namespace net