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+/*
+ * Copyright (C) 2003-2014 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef MPD_CHRONO_HXX
+#define MPD_CHRONO_HXX
+
+#include "Compiler.h"
+
+#include <chrono>
+#include <utility>
+#include <cstdint>
+
+#if defined(__GNUC__) && !GCC_CHECK_VERSION(4,7) && !defined(__clang__)
+/* std::chrono::duration operators are "constexpr" since gcc 4.7 */
+#define chrono_constexpr gcc_pure
+#else
+#define chrono_constexpr constexpr
+#endif
+
+/**
+ * A time stamp within a song. Granularity is 1 millisecond and the
+ * maximum value is about 49 days.
+ */
+class SongTime : public std::chrono::duration<std::uint32_t, std::milli> {
+ typedef std::chrono::duration<std::uint32_t, std::milli> Base;
+ typedef Base::rep rep;
+
+public:
+ SongTime() = default;
+
+ template<typename T>
+ explicit constexpr SongTime(T t):Base(t) {}
+
+ static constexpr SongTime zero() {
+ return SongTime(Base::zero());
+ }
+
+ static constexpr SongTime FromS(unsigned s) {
+ return SongTime(rep(s) * 1000);
+ }
+
+ static constexpr SongTime FromS(float s) {
+ return SongTime(rep(s * 1000));
+ }
+
+ static constexpr SongTime FromS(double s) {
+ return SongTime(rep(s * 1000));
+ }
+
+ static constexpr SongTime FromMS(rep ms) {
+ return SongTime(ms);
+ }
+
+ constexpr rep ToS() const {
+ return count() / rep(1000);
+ }
+
+ constexpr rep RoundS() const {
+ return (count() + 500) / rep(1000);
+ }
+
+ constexpr rep ToMS() const {
+ return count();
+ }
+
+ template<typename T=rep>
+ constexpr T ToScale(unsigned scale) const {
+ return count() * T(scale) / 1000;
+ }
+
+ /**
+ * Convert a scalar value with the given scale to a #SongTime
+ * instance.
+ *
+ * @param value the input value
+ * @param scale the value's scale in Hz
+ */
+ template<typename T=rep>
+ static constexpr SongTime FromScale(T value, unsigned scale) {
+ return SongTime(value * T(1000) / T(scale));
+ }
+
+ constexpr double ToDoubleS() const {
+ return double(count()) / 1000.;
+ };
+
+ constexpr bool IsZero() const {
+ return count() == 0;
+ }
+
+ constexpr bool IsPositive() const {
+ return count() > 0;
+ }
+
+ chrono_constexpr SongTime operator+(const SongTime &other) const {
+ return SongTime(*(const Base *)this + (const Base &)other);
+ }
+
+ chrono_constexpr SongTime operator-(const SongTime &other) const {
+ return SongTime(*(const Base *)this - (const Base &)other);
+ }
+};
+
+/**
+ * A variant of #SongTime that is based on a signed integer. It can
+ * be used for relative values.
+ */
+class SignedSongTime : public std::chrono::duration<std::int32_t, std::milli> {
+ typedef std::chrono::duration<std::int32_t, std::milli> Base;
+ typedef Base::rep rep;
+
+public:
+ SignedSongTime() = default;
+
+ template<typename T>
+ explicit constexpr SignedSongTime(T t):Base(t) {}
+
+ /**
+ * Allow implicit conversion from SongTime to SignedSongTime.
+ */
+ constexpr SignedSongTime(SongTime t):Base(t) {}
+
+ static constexpr SignedSongTime zero() {
+ return SignedSongTime(Base::zero());
+ }
+
+ /**
+ * Generate a negative value.
+ */
+ static constexpr SignedSongTime Negative() {
+ return SignedSongTime(-1);
+ }
+
+ static constexpr SignedSongTime FromS(int s) {
+ return SignedSongTime(rep(s) * 1000);
+ }
+
+ static constexpr SignedSongTime FromS(unsigned s) {
+ return SignedSongTime(rep(s) * 1000);
+ }
+
+ static constexpr SignedSongTime FromS(float s) {
+ return SignedSongTime(rep(s * 1000));
+ }
+
+ static constexpr SignedSongTime FromS(double s) {
+ return SignedSongTime(rep(s * 1000));
+ }
+
+ static constexpr SignedSongTime FromMS(rep ms) {
+ return SignedSongTime(ms);
+ }
+
+ constexpr rep ToS() const {
+ return count() / rep(1000);
+ }
+
+ constexpr rep RoundS() const {
+ return (count() + 500) / rep(1000);
+ }
+
+ constexpr rep ToMS() const {
+ return count();
+ }
+
+ template<typename T=rep>
+ constexpr T ToScale(unsigned scale) const {
+ return count() * T(scale) / 1000;
+ }
+
+ /**
+ * Convert a scalar value with the given scale to a
+ * #SignedSongTime instance.
+ *
+ * @param value the input value
+ * @param scale the value's scale in Hz
+ */
+ template<typename T=rep>
+ static constexpr SignedSongTime FromScale(T value, unsigned scale) {
+ return SignedSongTime(value * T(1000) / T(scale));
+ }
+
+ constexpr double ToDoubleS() const {
+ return double(count()) / 1000.;
+ };
+
+ constexpr bool IsZero() const {
+ return count() == 0;
+ }
+
+ constexpr bool IsPositive() const {
+ return count() > 0;
+ }
+
+ constexpr bool IsNegative() const {
+ return count() < 0;
+ }
+
+ chrono_constexpr SignedSongTime operator+(const SignedSongTime &other) const {
+ return SignedSongTime(*(const Base *)this + (const Base &)other);
+ }
+
+ chrono_constexpr SignedSongTime operator-(const SignedSongTime &other) const {
+ return SignedSongTime(*(const Base *)this - (const Base &)other);
+ }
+};
+
+#undef chrono_constexpr
+
+#endif