Merge pull request #86 from graphql-java/clock-updates

Clock improvements and test re-org

Author: bbakerman

src/main/java/org/dataloader/DataLoader.java

@@ -23,6 +23,7 @@
 import org.dataloader.stats.StatisticsCollector;
 
 import java.time.Clock;
+import java.time.Duration;
 import java.time.Instant;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -404,19 +405,21 @@ public DataLoader(BatchLoader<K, V> batchLoadFunction, DataLoaderOptions options
         this((Object) batchLoadFunction, options);
     }
 
+    @VisibleForTesting
     DataLoader(Object batchLoadFunction, DataLoaderOptions options) {
+        this(batchLoadFunction, options, Clock.systemUTC());
+    }
+
+    @VisibleForTesting
+    DataLoader(Object batchLoadFunction, DataLoaderOptions options, Clock clock) {
         DataLoaderOptions loaderOptions = options == null ? new DataLoaderOptions() : options;
         this.futureCache = determineCacheMap(loaderOptions);
         // order of keys matter in data loader
         this.stats = nonNull(loaderOptions.getStatisticsCollector());
 
-        this.helper = new DataLoaderHelper<>(this, batchLoadFunction, loaderOptions, this.futureCache, this.stats, clock());
+        this.helper = new DataLoaderHelper<>(this, batchLoadFunction, loaderOptions, this.futureCache, this.stats, clock);
     }
 
-    @VisibleForTesting
-    Clock clock() {
-        return Clock.systemUTC();
-    }
 
     @SuppressWarnings("unchecked")
     private CacheMap<Object, CompletableFuture<V>> determineCacheMap(DataLoaderOptions loaderOptions) {
@@ -433,6 +436,15 @@ public Instant getLastDispatchTime() {
         return helper.getLastDispatchTime();
     }
 
+    /**
+     * This returns the {@link Duration} since the data loader was dispatched.  When the data loader is created this is zero.
+     *
+     * @return the time duration since the last dispatch
+     */
+    public Duration getTimeSinceDispatch() {
+        return Duration.between(helper.getLastDispatchTime(), helper.now());
+    }
+
 
     /**
      * Requests to load the data with the specified key asynchronously, and returns a future of the resulting value.

src/main/java/org/dataloader/DataLoaderHelper.java

@@ -79,8 +79,8 @@ Object getCallContext() {
         this.lastDispatchTime.set(now());
     }
 
-    private Instant now() {
-        return Instant.now(clock);
+    Instant now() {
+        return clock.instant();
     }
 
     public Instant getLastDispatchTime() {

src/test/java/org/dataloader/ClockDataLoader.java

@@ -0,0 +1,15 @@
+package org.dataloader;
+
+import java.time.Clock;
+
+public class ClockDataLoader<K, V> extends DataLoader<K, V> {
+
+    ClockDataLoader(Object batchLoadFunction, Clock clock) {
+        this(batchLoadFunction, null, clock);
+    }
+
+    ClockDataLoader(Object batchLoadFunction, DataLoaderOptions options, Clock clock) {
+        super(batchLoadFunction, options, clock);
+    }
+
+}

src/test/java/org/dataloader/DataLoaderMapBatchLoaderTest.java

@@ -16,8 +16,8 @@
 import static org.awaitility.Awaitility.await;
 import static org.dataloader.DataLoaderFactory.newDataLoader;
 import static org.dataloader.DataLoaderOptions.newOptions;
-import static org.dataloader.TestKit.futureError;
-import static org.dataloader.TestKit.listFrom;
+import static org.dataloader.fixtures.TestKit.futureError;
+import static org.dataloader.fixtures.TestKit.listFrom;
 import static org.dataloader.impl.CompletableFutureKit.cause;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.instanceOf;

src/test/java/org/dataloader/DataLoaderTest.java

@@ -16,6 +16,8 @@
 
 package org.dataloader;
 
+import org.dataloader.fixtures.JsonObject;
+import org.dataloader.fixtures.TestKit;
 import org.dataloader.fixtures.User;
 import org.dataloader.fixtures.UserManager;
 import org.dataloader.impl.CompletableFutureKit;
@@ -37,7 +39,7 @@
 import static org.awaitility.Awaitility.await;
 import static org.dataloader.DataLoaderFactory.newDataLoader;
 import static org.dataloader.DataLoaderOptions.newOptions;
-import static org.dataloader.TestKit.listFrom;
+import static org.dataloader.fixtures.TestKit.listFrom;
 import static org.dataloader.impl.CompletableFutureKit.cause;
 import static org.hamcrest.Matchers.empty;
 import static org.hamcrest.Matchers.equalTo;

src/test/java/org/dataloader/DataLoaderTimeTest.java

@@ -1,68 +1,45 @@
 package org.dataloader;
 
+import org.dataloader.fixtures.TestingClock;
 import org.junit.Test;
 
-import java.time.Clock;
-import java.time.Duration;
 import java.time.Instant;
-import java.time.ZoneId;
-import java.util.concurrent.CompletableFuture;
-import java.util.concurrent.atomic.AtomicReference;
 
+import static org.dataloader.fixtures.TestKit.keysAsValues;
 import static org.hamcrest.Matchers.equalTo;
 import static org.junit.Assert.assertThat;
 
 @SuppressWarnings("UnusedReturnValue")
 public class DataLoaderTimeTest {
 
-    private <T> BatchLoader<T, T> keysAsValues() {
-        return CompletableFuture::completedFuture;
-    }
-
-    AtomicReference<Clock> clockRef = new AtomicReference<>();
 
     @Test
     public void should_set_and_instant_if_dispatched() {
-        Clock clock = zeroEpoch();
-        clockRef.set(clock);
-
-        Instant startInstant = now();
 
-        @SuppressWarnings("deprecation")
-        DataLoader<Integer, Integer> dataLoader = new DataLoader<Integer, Integer>(keysAsValues()) {
-            @Override
-            Clock clock() {
-                return clockRef.get();
-            }
-        };
+        TestingClock clock = new TestingClock();
+        DataLoader<Integer, Integer> dataLoader = new ClockDataLoader<>(keysAsValues(), clock);
+        Instant then = clock.instant();
 
-        long sinceMS = msSince(dataLoader.getLastDispatchTime());
+        long sinceMS = dataLoader.getTimeSinceDispatch().toMillis();
         assertThat(sinceMS, equalTo(0L));
-        assertThat(startInstant, equalTo(dataLoader.getLastDispatchTime()));
+        assertThat(then, equalTo(dataLoader.getLastDispatchTime()));
 
-        jump(clock, 1000);
-        dataLoader.dispatch();
+        then = clock.instant();
+        clock.jump(1000);
 
-        sinceMS = msSince(dataLoader.getLastDispatchTime());
+        sinceMS = dataLoader.getTimeSinceDispatch().toMillis();
         assertThat(sinceMS, equalTo(1000L));
-    }
+        assertThat(then, equalTo(dataLoader.getLastDispatchTime()));
 
-    private long msSince(Instant lastDispatchTime) {
-        return Duration.between(lastDispatchTime, now()).toMillis();
-    }
+        // dispatch and hence reset the time of last dispatch
+        then = clock.instant();
+        dataLoader.dispatch();
 
-    private Instant now() {
-        return Instant.now(clockRef.get());
-    }
+        sinceMS = dataLoader.getTimeSinceDispatch().toMillis();
+        assertThat(sinceMS, equalTo(0L));
+        assertThat(then, equalTo(dataLoader.getLastDispatchTime()));
 
-    private Clock jump(Clock clock, int millis) {
-        clock = Clock.offset(clock, Duration.ofMillis(millis));
-        clockRef.set(clock);
-        return clock;
     }
 
-    private Clock zeroEpoch() {
-        return Clock.fixed(Instant.ofEpochMilli(0), ZoneId.systemDefault());
-    }
 
 }

src/test/java/org/dataloader/TestKit.java

@@ -1,14 +1,14 @@
-package org.dataloader;
+package org.dataloader.fixtures;
 
 import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.stream.Stream;
 
-class JsonObject {
+public class JsonObject {
 
     private final Map<String, Object> values;
 
-    JsonObject() {
+    public JsonObject() {
         values = new LinkedHashMap<>();
     }
 
@@ -19,8 +19,12 @@ public JsonObject put(String key, Object value) {
 
     @Override
     public boolean equals(Object o) {
-        if (this == o) return true;
-        if (o == null || getClass() != o.getClass()) return false;
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
 
         JsonObject that = (JsonObject) o;
 

src/test/java/org/dataloader/JsonObject.java renamed to src/test/java/org/dataloader/fixtures/JsonObject.java

@@ -0,0 +1,61 @@
+package org.dataloader.fixtures;
+
+import org.dataloader.BatchLoader;
+import org.dataloader.DataLoader;
+import org.dataloader.DataLoaderFactory;
+import org.dataloader.DataLoaderOptions;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+import java.util.concurrent.CompletableFuture;
+import java.util.stream.Collectors;
+
+import static org.dataloader.impl.CompletableFutureKit.failedFuture;
+
+public class TestKit {
+
+    public static <T> BatchLoader<T, T> keysAsValues() {
+        return CompletableFuture::completedFuture;
+    }
+
+    public static <K, V> BatchLoader<K, V> keysAsValues(List<List<K>> loadCalls) {
+        return keys -> {
+            List<K> ks = new ArrayList<>(keys);
+            loadCalls.add(ks);
+            @SuppressWarnings("unchecked")
+            List<V> values = keys.stream()
+                    .map(k -> (V) k)
+                    .collect(Collectors.toList());
+            return CompletableFuture.completedFuture(values);
+        };
+    }
+
+    public static <K, V> DataLoader<K, V> idLoader(List<List<K>> loadCalls) {
+        return idLoader(null, loadCalls);
+    }
+
+    public static <K, V> DataLoader<K, V> idLoader(DataLoaderOptions options, List<List<K>> loadCalls) {
+        return DataLoaderFactory.newDataLoader(keysAsValues(loadCalls), options);
+    }
+
+    public static Collection<Integer> listFrom(int i, int max) {
+        List<Integer> ints = new ArrayList<>();
+        for (int j = i; j < max; j++) {
+            ints.add(j);
+        }
+        return ints;
+    }
+
+    public static <V> CompletableFuture<V> futureError() {
+        return failedFuture(new IllegalStateException("Error"));
+    }
+
+    public static void snooze(int millis) {
+        try {
+            Thread.sleep(millis);
+        } catch (InterruptedException e) {
+            throw new RuntimeException(e);
+        }
+    }
+}

src/test/java/org/dataloader/fixtures/TestKit.java

@@ -0,0 +1,38 @@
+package org.dataloader.fixtures;
+
+import java.time.Clock;
+import java.time.Duration;
+import java.time.Instant;
+import java.time.ZoneId;
+
+/**
+ * A mutable (but time fixed) clock that can jump forward or back in time
+ */
+public class TestingClock extends Clock {
+
+    private Clock clock;
+
+    public TestingClock() {
+        clock = Clock.fixed(Instant.ofEpochMilli(0), ZoneId.systemDefault());
+    }
+
+    public Clock jump(int millisDelta) {
+        clock = Clock.offset(clock, Duration.ofMillis(millisDelta));
+        return clock;
+    }
+
+    @Override
+    public ZoneId getZone() {
+        return clock.getZone();
+    }
+
+    @Override
+    public Clock withZone(ZoneId zone) {
+        return clock.withZone(zone);
+    }
+
+    @Override
+    public Instant instant() {
+        return clock.instant();
+    }
+}