AK: Make Time more usable

AK/Tests/TestTime.cpp

@@ -202,4 +202,18 @@ TEST_CASE(subtraction)
     EXPECT_SUBTRACTION(-0x7fff'ffff'ffff'ffff, 999'999'995, 1, 999'999'996, (i64)-0x8000'0000'0000'0000, 0);
 }
 
+TEST_CASE(truncation)
+{
+    EXPECT_EQ(TIME(2, 800'000'000).to_truncated_seconds(), 2);
+    EXPECT_EQ(TIME(-2, -800'000'000).to_truncated_seconds(), -2);
+
+    EXPECT_EQ(TIME(0, 0).to_truncated_seconds(), 0);
+    EXPECT_EQ(TIME(1, 999'999'999).to_truncated_seconds(), 1);
+    EXPECT_EQ(TIME(1, 1'000'000'000).to_truncated_seconds(), 2);
+    EXPECT_EQ(TIME(-2, 0).to_truncated_seconds(), -2);
+
+    EXPECT_EQ(Time::min().to_truncated_seconds(), (i64)-0x8000'0000'0000'0000);
+    EXPECT_EQ(Time::max().to_truncated_seconds(), 0x7fff'ffff'ffff'ffff);
+}
+
 TEST_MAIN(Time)

AK/Time.cpp

@@ -72,6 +72,10 @@ unsigned day_of_week(int year, unsigned month, int day)
     return (year + year / 4 - year / 100 + year / 400 + seek_table[month - 1] + day) % 7;
 }
 
+Time Time::from_nanoseconds(i32 nanoseconds)
+{
+    return Time::from_timespec({ 0, nanoseconds });
+};
 ALWAYS_INLINE static i32 sane_mod(i32& numerator, i32 denominator)
 {
     VERIFY(2 <= denominator && denominator <= 1'000'000'000);
@@ -102,6 +106,14 @@ Time Time::from_timeval(const struct timeval& tv)
     return Time::from_half_sanitized(tv.tv_sec, extra_secs, usecs * 1'000);
 }
 
+i64 Time::to_truncated_seconds() const
+{
+    VERIFY(m_nanoseconds < 1'000'000'000);
+    if (m_seconds < 0 && m_nanoseconds)
+        return m_seconds + 1;
+    else
+        return m_seconds;
+}
 timespec Time::to_timespec() const
 {
     VERIFY(m_nanoseconds < 1'000'000'000);
@@ -172,6 +184,23 @@ Time Time::operator-(const Time& other) const
     return Time { (m_seconds + 0x4000'0000'0000'0000) + 0x4000'0000'0000'0000, m_nanoseconds };
 }
 
+bool Time::operator<(const Time& other) const
+{
+    return m_seconds < other.m_seconds || (m_seconds == other.m_seconds && m_nanoseconds < other.m_nanoseconds);
+}
+bool Time::operator<=(const Time& other) const
+{
+    return m_seconds < other.m_seconds || (m_seconds == other.m_seconds && m_nanoseconds <= other.m_nanoseconds);
+}
+bool Time::operator>(const Time& other) const
+{
+    return m_seconds > other.m_seconds || (m_seconds == other.m_seconds && m_nanoseconds > other.m_nanoseconds);
+}
+bool Time::operator>=(const Time& other) const
+{
+    return m_seconds > other.m_seconds || (m_seconds == other.m_seconds && m_nanoseconds >= other.m_nanoseconds);
+}
+
 Time Time::from_half_sanitized(i64 seconds, i32 extra_seconds, u32 nanoseconds)
 {
     VERIFY(nanoseconds < 1'000'000'000);

AK/Time.h

@@ -82,15 +82,20 @@ inline int years_to_days_since_epoch(int year)
  */
 class Time {
 public:
+    Time() = default;
     Time(const Time&) = default;
 
-    static Time from_seconds(i64 seconds) { return Time(seconds, 0); };
+    static Time from_seconds(i64 seconds) { return Time(seconds, 0); }
+    static Time from_nanoseconds(i32 nanoseconds);
     static Time from_timespec(const struct timespec&);
     static Time from_timeval(const struct timeval&);
     static Time min() { return Time(-0x8000'0000'0000'0000LL, 0); };
     static Time zero() { return Time(0, 0); };
     static Time max() { return Time(0x7fff'ffff'ffff'ffffLL, 999'999'999); };
 
+    // Truncates "2.8 seconds" to 2 seconds.
+    // Truncates "-2.8 seconds" to -2 seconds.
+    i64 to_truncated_seconds() const;
     timespec to_timespec() const;
     timeval to_timeval() const;
 
@@ -98,6 +103,10 @@ public:
     bool operator!=(const Time& other) const { return !(*this == other); }
     Time operator+(const Time& other) const;
     Time operator-(const Time& other) const;
+    bool operator<(const Time& other) const;
+    bool operator<=(const Time& other) const;
+    bool operator>(const Time& other) const;
+    bool operator>=(const Time& other) const;
 
 private:
     explicit Time(i64 seconds, u32 nanoseconds)