Clean up quic_time.h APIs.
* Move QuicTime::Delta out of the subclass into QuicTimeDelta, since it does not access any private members of QuicTime. I currently don't have a plan to rename it everywhere, but it's two less characters to type.
* Clean up some legacy macros.
* Replace QuicTimeDelta::FromAbsl() with a constructor; we don't need an explicitly static method, since the semantics of constructing a TimeDelta from a duration is unambiguous.
* Explain why we don't use absl::Duration. Add a note that we probably should be using absl::Time.
* Other minor cleanups.
PiperOrigin-RevId: 518778525
diff --git a/quiche/quic/core/http/web_transport_http3.cc b/quiche/quic/core/http/web_transport_http3.cc
index dc0e054..7a5fd07 100644
--- a/quiche/quic/core/http/web_transport_http3.cc
+++ b/quiche/quic/core/http/web_transport_http3.cc
@@ -295,8 +295,7 @@
void WebTransportHttp3::SetDatagramMaxTimeInQueue(
absl::Duration max_time_in_queue) {
- connect_stream_->SetMaxDatagramTimeInQueue(
- QuicTime::Delta::FromAbsl(max_time_in_queue));
+ connect_stream_->SetMaxDatagramTimeInQueue(QuicTimeDelta(max_time_in_queue));
}
void WebTransportHttp3::OnHttp3Datagram(QuicStreamId stream_id,
diff --git a/quiche/quic/core/quic_time.h b/quiche/quic/core/quic_time.h
index a148888..ddf0307 100644
--- a/quiche/quic/core/quic_time.h
+++ b/quiche/quic/core/quic_time.h
@@ -2,14 +2,6 @@
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
-// QuicTime represents one point in time, stored in microsecond resolution.
-// QuicTime is monotonically increasing, even across system clock adjustments.
-// The epoch (time 0) of QuicTime is unspecified.
-//
-// This implementation wraps a int64_t of usec since the epoch. While
-// the epoch is the Unix epoch, do not depend on this fact because other
-// implementations, like Chrome's, do NOT have the same epoch.
-
#ifndef QUICHE_QUIC_CORE_QUIC_TIME_H_
#define QUICHE_QUIC_CORE_QUIC_TIME_H_
@@ -22,105 +14,106 @@
#include "absl/time/time.h"
#include "quiche/quic/platform/api/quic_export.h"
-// TODO(vasilvv): replace with ABSL_MUST_USE_RESULT once we're using absl.
-#if defined(__clang__)
-#define QUIC_TIME_WARN_UNUSED_RESULT __attribute__((warn_unused_result))
-#else
-#define QUIC_TIME_WARN_UNUSED_RESULT
-#endif /* defined(__clang__) */
-
namespace quic {
class QuicClock;
+class QuicTime;
-// A QuicTime is a purely relative time. QuicTime values from different clocks
-// cannot be compared to each other. If you need an absolute time, see
-// QuicWallTime, below.
+// A 64-bit signed integer type that stores a time duration as
+// a number of microseconds. QUIC does not use absl::Duration, since the Abseil
+// type is 128-bit, which would adversely affect certain performance-sensitive
+// QUIC data structures.
+class QUIC_EXPORT_PRIVATE QuicTimeDelta {
+ public:
+ // Creates a QuicTimeDelta from an absl::Duration. Note that this inherently
+ // loses precision, since absl::Duration is nanoseconds, and QuicTimeDelta is
+ // microseconds.
+ explicit QuicTimeDelta(absl::Duration duration)
+ : time_offset_((duration == absl::InfiniteDuration())
+ ? kInfiniteTimeUs
+ : absl::ToInt64Microseconds(duration)) {}
+
+ // Create a object with an offset of 0.
+ static constexpr QuicTimeDelta Zero() { return QuicTimeDelta(0); }
+
+ // Create a object with infinite offset time.
+ static constexpr QuicTimeDelta Infinite() {
+ return QuicTimeDelta(kInfiniteTimeUs);
+ }
+
+ // Converts a number of seconds to a time offset.
+ static constexpr QuicTimeDelta FromSeconds(int64_t secs) {
+ return QuicTimeDelta(secs * 1000 * 1000);
+ }
+
+ // Converts a number of milliseconds to a time offset.
+ static constexpr QuicTimeDelta FromMilliseconds(int64_t ms) {
+ return QuicTimeDelta(ms * 1000);
+ }
+
+ // Converts a number of microseconds to a time offset.
+ static constexpr QuicTimeDelta FromMicroseconds(int64_t us) {
+ return QuicTimeDelta(us);
+ }
+
+ // Converts the time offset to a rounded number of seconds.
+ constexpr int64_t ToSeconds() const { return time_offset_ / 1000 / 1000; }
+
+ // Converts the time offset to a rounded number of milliseconds.
+ constexpr int64_t ToMilliseconds() const { return time_offset_ / 1000; }
+
+ // Converts the time offset to a rounded number of microseconds.
+ constexpr int64_t ToMicroseconds() const { return time_offset_; }
+
+ // Converts the time offset to an Abseil duration.
+ constexpr absl::Duration ToAbsl() {
+ if (ABSL_PREDICT_FALSE(IsInfinite())) {
+ return absl::InfiniteDuration();
+ }
+ return absl::Microseconds(time_offset_);
+ }
+
+ constexpr bool IsZero() const { return time_offset_ == 0; }
+
+ constexpr bool IsInfinite() const { return time_offset_ == kInfiniteTimeUs; }
+
+ std::string ToDebuggingValue() const;
+
+ private:
+ friend inline bool operator==(QuicTimeDelta lhs, QuicTimeDelta rhs);
+ friend inline bool operator<(QuicTimeDelta lhs, QuicTimeDelta rhs);
+ friend inline QuicTimeDelta operator<<(QuicTimeDelta lhs, size_t rhs);
+ friend inline QuicTimeDelta operator>>(QuicTimeDelta lhs, size_t rhs);
+
+ friend inline constexpr QuicTimeDelta operator+(QuicTimeDelta lhs,
+ QuicTimeDelta rhs);
+ friend inline constexpr QuicTimeDelta operator-(QuicTimeDelta lhs,
+ QuicTimeDelta rhs);
+ friend inline constexpr QuicTimeDelta operator*(QuicTimeDelta lhs, int rhs);
+ // Not constexpr since std::llround() is not constexpr.
+ friend inline QuicTimeDelta operator*(QuicTimeDelta lhs, double rhs);
+
+ friend inline QuicTime operator+(QuicTime lhs, QuicTimeDelta rhs);
+ friend inline QuicTime operator-(QuicTime lhs, QuicTimeDelta rhs);
+ friend inline QuicTimeDelta operator-(QuicTime lhs, QuicTime rhs);
+
+ static constexpr int64_t kInfiniteTimeUs =
+ std::numeric_limits<int64_t>::max();
+
+ explicit constexpr QuicTimeDelta(int64_t time_offset)
+ : time_offset_(time_offset) {}
+
+ int64_t time_offset_;
+ friend class QuicTime;
+};
+
+// A microsecond precision timestamp returned by a QuicClock. It is
+// usually either a Unix timestamp or a timestamp returned by the
+// platform-specific monotonic clock. QuicClock has a method to convert QuicTime
+// to the wall time.
class QUIC_EXPORT_PRIVATE QuicTime {
public:
- // A QuicTime::Delta represents the signed difference between two points in
- // time, stored in microsecond resolution.
- class QUIC_EXPORT_PRIVATE Delta {
- public:
- // Create a object with an offset of 0.
- static constexpr Delta Zero() { return Delta(0); }
-
- // Create a object with infinite offset time.
- static constexpr Delta Infinite() { return Delta(kQuicInfiniteTimeUs); }
-
- // Converts a number of seconds to a time offset.
- static constexpr Delta FromSeconds(int64_t secs) {
- return Delta(secs * 1000 * 1000);
- }
-
- // Converts a number of milliseconds to a time offset.
- static constexpr Delta FromMilliseconds(int64_t ms) {
- return Delta(ms * 1000);
- }
-
- // Converts a number of microseconds to a time offset.
- static constexpr Delta FromMicroseconds(int64_t us) { return Delta(us); }
-
- // Converts from Abseil duration type.
- static constexpr Delta FromAbsl(absl::Duration duration) {
- if (ABSL_PREDICT_FALSE(duration == absl::InfiniteDuration())) {
- return Infinite();
- }
- return Delta(absl::ToInt64Microseconds(duration));
- }
-
- // Converts the time offset to a rounded number of seconds.
- constexpr int64_t ToSeconds() const { return time_offset_ / 1000 / 1000; }
-
- // Converts the time offset to a rounded number of milliseconds.
- constexpr int64_t ToMilliseconds() const { return time_offset_ / 1000; }
-
- // Converts the time offset to a rounded number of microseconds.
- constexpr int64_t ToMicroseconds() const { return time_offset_; }
-
- // Converts the time offset to an Abseil duration.
- constexpr absl::Duration ToAbsl() {
- if (ABSL_PREDICT_FALSE(IsInfinite())) {
- return absl::InfiniteDuration();
- }
- return absl::Microseconds(time_offset_);
- }
-
- constexpr bool IsZero() const { return time_offset_ == 0; }
-
- constexpr bool IsInfinite() const {
- return time_offset_ == kQuicInfiniteTimeUs;
- }
-
- std::string ToDebuggingValue() const;
-
- private:
- friend inline bool operator==(QuicTime::Delta lhs, QuicTime::Delta rhs);
- friend inline bool operator<(QuicTime::Delta lhs, QuicTime::Delta rhs);
- friend inline QuicTime::Delta operator<<(QuicTime::Delta lhs, size_t rhs);
- friend inline QuicTime::Delta operator>>(QuicTime::Delta lhs, size_t rhs);
-
- friend inline constexpr QuicTime::Delta operator+(QuicTime::Delta lhs,
- QuicTime::Delta rhs);
- friend inline constexpr QuicTime::Delta operator-(QuicTime::Delta lhs,
- QuicTime::Delta rhs);
- friend inline constexpr QuicTime::Delta operator*(QuicTime::Delta lhs,
- int rhs);
- // Not constexpr since std::llround() is not constexpr.
- friend inline QuicTime::Delta operator*(QuicTime::Delta lhs, double rhs);
-
- friend inline QuicTime operator+(QuicTime lhs, QuicTime::Delta rhs);
- friend inline QuicTime operator-(QuicTime lhs, QuicTime::Delta rhs);
- friend inline QuicTime::Delta operator-(QuicTime lhs, QuicTime rhs);
-
- static const int64_t kQuicInfiniteTimeUs =
- std::numeric_limits<int64_t>::max();
-
- explicit constexpr Delta(int64_t time_offset) : time_offset_(time_offset) {}
-
- int64_t time_offset_;
- friend class QuicTime;
- };
+ using Delta = QuicTimeDelta;
// Creates a new QuicTime with an internal value of 0. IsInitialized()
// will return false for these times.
@@ -128,7 +121,7 @@
// Creates a new QuicTime with an infinite time.
static constexpr QuicTime Infinite() {
- return QuicTime(Delta::kQuicInfiniteTimeUs);
+ return QuicTime(Delta::kInfiniteTimeUs);
}
QuicTime(const QuicTime& other) = default;
@@ -151,18 +144,18 @@
friend inline bool operator==(QuicTime lhs, QuicTime rhs);
friend inline bool operator<(QuicTime lhs, QuicTime rhs);
- friend inline QuicTime operator+(QuicTime lhs, QuicTime::Delta rhs);
- friend inline QuicTime operator-(QuicTime lhs, QuicTime::Delta rhs);
- friend inline QuicTime::Delta operator-(QuicTime lhs, QuicTime rhs);
+ friend inline QuicTime operator+(QuicTime lhs, QuicTimeDelta rhs);
+ friend inline QuicTime operator-(QuicTime lhs, QuicTimeDelta rhs);
+ friend inline QuicTimeDelta operator-(QuicTime lhs, QuicTime rhs);
explicit constexpr QuicTime(int64_t time) : time_(time) {}
int64_t time_;
};
-// A QuicWallTime represents an absolute time that is globally consistent. In
-// practice, clock-skew means that comparing values from different machines
-// requires some flexibility.
+// A UNIX timestamp.
+//
+// TODO(vasilvv): evaluate whether this can be replaced with absl::Time.
class QUIC_EXPORT_PRIVATE QuicWallTime {
public:
// FromUNIXSeconds constructs a QuicWallTime from a count of the seconds
@@ -192,23 +185,22 @@
// AbsoluteDifference returns the absolute value of the time difference
// between |this| and |other|.
- QuicTime::Delta AbsoluteDifference(QuicWallTime other) const;
+ QuicTimeDelta AbsoluteDifference(QuicWallTime other) const;
// Add returns a new QuicWallTime that represents the time of |this| plus
// |delta|.
- QUIC_TIME_WARN_UNUSED_RESULT QuicWallTime Add(QuicTime::Delta delta) const;
+ [[nodiscard]] QuicWallTime Add(QuicTimeDelta delta) const;
// Subtract returns a new QuicWallTime that represents the time of |this|
// minus |delta|.
- QUIC_TIME_WARN_UNUSED_RESULT QuicWallTime
- Subtract(QuicTime::Delta delta) const;
+ [[nodiscard]] QuicWallTime Subtract(QuicTimeDelta delta) const;
bool operator==(const QuicWallTime& other) const {
return microseconds_ == other.microseconds_;
}
- QuicTime::Delta operator-(const QuicWallTime& rhs) const {
- return QuicTime::Delta::FromMicroseconds(microseconds_ - rhs.microseconds_);
+ QuicTimeDelta operator-(const QuicWallTime& rhs) const {
+ return QuicTimeDelta::FromMicroseconds(microseconds_ - rhs.microseconds_);
}
private:
@@ -218,30 +210,30 @@
uint64_t microseconds_;
};
-// Non-member relational operators for QuicTime::Delta.
-inline bool operator==(QuicTime::Delta lhs, QuicTime::Delta rhs) {
+// Non-member relational operators for QuicTimeDelta.
+inline bool operator==(QuicTimeDelta lhs, QuicTimeDelta rhs) {
return lhs.time_offset_ == rhs.time_offset_;
}
-inline bool operator!=(QuicTime::Delta lhs, QuicTime::Delta rhs) {
+inline bool operator!=(QuicTimeDelta lhs, QuicTimeDelta rhs) {
return !(lhs == rhs);
}
-inline bool operator<(QuicTime::Delta lhs, QuicTime::Delta rhs) {
+inline bool operator<(QuicTimeDelta lhs, QuicTimeDelta rhs) {
return lhs.time_offset_ < rhs.time_offset_;
}
-inline bool operator>(QuicTime::Delta lhs, QuicTime::Delta rhs) {
+inline bool operator>(QuicTimeDelta lhs, QuicTimeDelta rhs) {
return rhs < lhs;
}
-inline bool operator<=(QuicTime::Delta lhs, QuicTime::Delta rhs) {
+inline bool operator<=(QuicTimeDelta lhs, QuicTimeDelta rhs) {
return !(rhs < lhs);
}
-inline bool operator>=(QuicTime::Delta lhs, QuicTime::Delta rhs) {
+inline bool operator>=(QuicTimeDelta lhs, QuicTimeDelta rhs) {
return !(lhs < rhs);
}
-inline QuicTime::Delta operator<<(QuicTime::Delta lhs, size_t rhs) {
- return QuicTime::Delta(lhs.time_offset_ << rhs);
+inline QuicTimeDelta operator<<(QuicTimeDelta lhs, size_t rhs) {
+ return QuicTimeDelta(lhs.time_offset_ << rhs);
}
-inline QuicTime::Delta operator>>(QuicTime::Delta lhs, size_t rhs) {
- return QuicTime::Delta(lhs.time_offset_ >> rhs);
+inline QuicTimeDelta operator>>(QuicTimeDelta lhs, size_t rhs) {
+ return QuicTimeDelta(lhs.time_offset_ >> rhs);
}
// Non-member relational operators for QuicTime.
@@ -262,43 +254,39 @@
return output;
}
-// Non-member arithmetic operators for QuicTime::Delta.
-inline constexpr QuicTime::Delta operator+(QuicTime::Delta lhs,
- QuicTime::Delta rhs) {
- return QuicTime::Delta(lhs.time_offset_ + rhs.time_offset_);
+// Non-member arithmetic operators for QuicTimeDelta.
+inline constexpr QuicTimeDelta operator+(QuicTimeDelta lhs, QuicTimeDelta rhs) {
+ return QuicTimeDelta(lhs.time_offset_ + rhs.time_offset_);
}
-inline constexpr QuicTime::Delta operator-(QuicTime::Delta lhs,
- QuicTime::Delta rhs) {
- return QuicTime::Delta(lhs.time_offset_ - rhs.time_offset_);
+inline constexpr QuicTimeDelta operator-(QuicTimeDelta lhs, QuicTimeDelta rhs) {
+ return QuicTimeDelta(lhs.time_offset_ - rhs.time_offset_);
}
-inline constexpr QuicTime::Delta operator*(QuicTime::Delta lhs, int rhs) {
- return QuicTime::Delta(lhs.time_offset_ * rhs);
+inline constexpr QuicTimeDelta operator*(QuicTimeDelta lhs, int rhs) {
+ return QuicTimeDelta(lhs.time_offset_ * rhs);
}
-inline QuicTime::Delta operator*(QuicTime::Delta lhs, double rhs) {
- return QuicTime::Delta(static_cast<int64_t>(
+inline QuicTimeDelta operator*(QuicTimeDelta lhs, double rhs) {
+ return QuicTimeDelta(static_cast<int64_t>(
std::llround(static_cast<double>(lhs.time_offset_) * rhs)));
}
-inline QuicTime::Delta operator*(int lhs, QuicTime::Delta rhs) {
- return rhs * lhs;
-}
-inline QuicTime::Delta operator*(double lhs, QuicTime::Delta rhs) {
+inline QuicTimeDelta operator*(int lhs, QuicTimeDelta rhs) { return rhs * lhs; }
+inline QuicTimeDelta operator*(double lhs, QuicTimeDelta rhs) {
return rhs * lhs;
}
-// Non-member arithmetic operators for QuicTime and QuicTime::Delta.
-inline QuicTime operator+(QuicTime lhs, QuicTime::Delta rhs) {
+// Non-member arithmetic operators for QuicTime and QuicTimeDelta.
+inline QuicTime operator+(QuicTime lhs, QuicTimeDelta rhs) {
return QuicTime(lhs.time_ + rhs.time_offset_);
}
-inline QuicTime operator-(QuicTime lhs, QuicTime::Delta rhs) {
+inline QuicTime operator-(QuicTime lhs, QuicTimeDelta rhs) {
return QuicTime(lhs.time_ - rhs.time_offset_);
}
-inline QuicTime::Delta operator-(QuicTime lhs, QuicTime rhs) {
- return QuicTime::Delta(lhs.time_ - rhs.time_);
+inline QuicTimeDelta operator-(QuicTime lhs, QuicTime rhs) {
+ return QuicTimeDelta(lhs.time_ - rhs.time_);
}
// Override stream output operator for gtest.
inline std::ostream& operator<<(std::ostream& output,
- const QuicTime::Delta delta) {
+ const QuicTimeDelta delta) {
output << delta.ToDebuggingValue();
return output;
}
