Revert "Move TimeBudget to vespajlib and use Clock"

2 files changed, 84 insertions, 0 deletions

diff --git a/jdisc_core/src/main/java/com/yahoo/jdisc/TimeBudget.java b/jdisc_core/src/main/java/com/yahoo/jdisc/TimeBudget.java
new file mode 100644
index 00000000000..39322b6e83a
--- /dev/null
+++ b/jdisc_core/src/main/java/com/yahoo/jdisc/TimeBudget.java
@@ -0,0 +1,55 @@
+// Copyright 2018 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.jdisc;
+
+import javax.annotation.concurrent.Immutable;
+import java.time.Duration;
+import java.time.Instant;
+
+/**
+ * A TimeBudget tracks the current time compared to a start time and deadline.
+ *
+ * @author hakon
+ */
+@Immutable
+public class TimeBudget {
+    private final Timer timer;
+    private final Instant start;
+    private final Duration timeout;
+
+    /** Returns a TimeBudget with a start time of now, and with the given timeout. */
+    public static TimeBudget fromNow(Timer timer, Duration timeout) {
+        return new TimeBudget(timer, timer.currentTime(), timeout);
+    }
+
+    private TimeBudget(Timer timer, Instant start, Duration timeout) {
+        this.timer = timer;
+        this.start = start;
+        this.timeout = timeout;
+    }
+
+    /** Time until 'headroom' before deadline. Guaranteed to be non-negative. */
+    public Duration timeBeforeDeadline(Duration headroom) {
+        return nonNegativeBetween(now(), deadline().minus(headroom));
+    }
+
+    /** Returns the original timeout. */
+    public Duration originalTimeout() {
+        return timeout;
+    }
+
+    private static Duration nonNegativeBetween(Instant start, Instant end) {
+        return makeNonNegative(Duration.between(start, end));
+    }
+
+    private static Duration makeNonNegative(Duration duration) {
+        return duration.isNegative() ? Duration.ZERO : duration;
+    }
+
+    private Instant now() {
+        return timer.currentTime();
+    }
+
+    private Instant deadline() {
+        return start.plus(timeout);
+    }
+}
diff --git a/jdisc_core/src/test/java/com/yahoo/jdisc/TimeBudgetTestCase.java b/jdisc_core/src/test/java/com/yahoo/jdisc/TimeBudgetTestCase.java
new file mode 100644
index 00000000000..5afc205beb3
--- /dev/null
+++ b/jdisc_core/src/test/java/com/yahoo/jdisc/TimeBudgetTestCase.java
@@ -0,0 +1,29 @@
+// Copyright 2018 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.jdisc;
+
+import org.junit.Test;
+
+import java.time.Duration;
+import java.time.Instant;
+
+import static org.junit.Assert.assertEquals;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+public class TimeBudgetTestCase {
+    private final Timer timer = mock(Timer.class);
+
+    @Test
+    public void testBasics() {
+        when(timer.currentTime()).thenReturn(Instant.ofEpochSecond(0));
+        TimeBudget timeBudget = TimeBudget.fromNow(timer, Duration.ofSeconds(10));
+
+        when(timer.currentTime()).thenReturn(Instant.ofEpochSecond(7));
+        assertEquals(Duration.ofSeconds(3), timeBudget.timeBeforeDeadline(Duration.ofSeconds(0)));
+        assertEquals(Duration.ofSeconds(1), timeBudget.timeBeforeDeadline(Duration.ofSeconds(2)));
+        assertEquals(Duration.ofSeconds(0), timeBudget.timeBeforeDeadline(Duration.ofSeconds(5)));
+
+        when(timer.currentTime()).thenReturn(Instant.ofEpochSecond(11));
+        assertEquals(Duration.ofSeconds(0), timeBudget.timeBeforeDeadline(Duration.ofSeconds(0)));
+    }
+}
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