OperatorDistinctUntilChanged

rxjava-core/src/main/java/rx/Observable.java

@@ -57,7 +57,6 @@
 import rx.operators.OperationDelay;
 import rx.operators.OperationDematerialize;
 import rx.operators.OperationDistinct;
-import rx.operators.OperationDistinctUntilChanged;
 import rx.operators.OperationFinally;
 import rx.operators.OperationFlatMap;
 import rx.operators.OperationGroupByUntil;
@@ -95,6 +94,7 @@
 import rx.operators.OperatorAsObservable;
 import rx.operators.OperatorCache;
 import rx.operators.OperatorCast;
+import rx.operators.OperatorDistinctUntilChanged;
 import rx.operators.OperatorDoOnEach;
 import rx.operators.OperatorElementAt;
 import rx.operators.OperatorFilter;
@@ -3638,7 +3638,7 @@ public final <U> Observable<T> distinct(Func1<? super T, ? extends U> keySelecto
      * @see <a href="http://msdn.microsoft.com/en-us/library/hh229494.aspx">MSDN: Observable.distinctUntilChanged</a>
      */
     public final Observable<T> distinctUntilChanged() {
-        return create(OperationDistinctUntilChanged.distinctUntilChanged(this));
+        return lift(new OperatorDistinctUntilChanged<T, T>(Functions.<T>identity()));
     }
 
     /**
@@ -3656,7 +3656,7 @@ public final Observable<T> distinctUntilChanged() {
      * @see <a href="http://msdn.microsoft.com/en-us/library/hh229508.aspx">MSDN: Observable.distinctUntilChanged</a>
      */
     public final <U> Observable<T> distinctUntilChanged(Func1<? super T, ? extends U> keySelector) {
-        return create(OperationDistinctUntilChanged.distinctUntilChanged(this, keySelector));
+        return lift(new OperatorDistinctUntilChanged<T, U>(keySelector));
     }
 
     /**

rxjava-core/src/main/java/rx/operators/OperatorDistinctUntilChanged.java

@@ -0,0 +1,68 @@
+/**
+ * Copyright 2014 Netflix, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package rx.operators;
+
+import rx.Observable.Operator;
+import rx.Subscriber;
+import rx.functions.Func1;
+
+/**
+ * Returns an Observable that emits all sequentially distinct items emitted by the source.
+ * @param <T> the value type
+ * @param <U> the key type
+ */
+public final class OperatorDistinctUntilChanged<T, U> implements Operator<T, T> {
+    final Func1<? super T, ? extends U> keySelector;
+
+    public OperatorDistinctUntilChanged(Func1<? super T, ? extends U> keySelector) {
+        this.keySelector = keySelector;
+    }
+
+    @Override
+    public Subscriber<? super T> call(final Subscriber<? super T> child) {
+        return new Subscriber<T>(child) {
+            U previousKey;
+            boolean hasPrevious;
+            @Override
+            public void onNext(T t) {
+                U currentKey = previousKey;
+                U key = keySelector.call(t);
+                previousKey = key;
+
+                if (hasPrevious) {
+                    if (!(currentKey == key || (key != null && key.equals(currentKey)))) {
+                        child.onNext(t);
+                    }
+                } else {
+                    hasPrevious = true;
+                    child.onNext(t);
+                }
+            }
+
+            @Override
+            public void onError(Throwable e) {
+                child.onError(e);
+            }
+
+            @Override
+            public void onCompleted() {
+                child.onCompleted();
+            }
+
+        };
+    }
+
+}

rxjava-core/src/test/java/rx/operators/OperationDistinctUntilChangedTest.java → rxjava-core/src/test/java/rx/operators/OperatorDistinctUntilChangedTest.java

@@ -22,9 +22,7 @@
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.MockitoAnnotations.initMocks;
-import static rx.operators.OperationDistinctUntilChanged.distinctUntilChanged;
 
-import java.util.Comparator;
 
 import org.junit.Before;
 import org.junit.Test;
@@ -35,7 +33,7 @@
 import rx.Observer;
 import rx.functions.Func1;
 
-public class OperationDistinctUntilChangedTest {
+public class OperatorDistinctUntilChangedTest {
 
     @Mock
     Observer<String> w;
@@ -53,13 +51,6 @@ public String call(String s) {
         }
     };
 
-    final Comparator<String> COMPARE_LENGTH = new Comparator<String>() {
-        @Override
-        public int compare(String s1, String s2) {
-            return s1.length() - s2.length();
-        }
-    };
-
     @Before
     public void before() {
         initMocks(this);
@@ -68,7 +59,7 @@ public void before() {
     @Test
     public void testDistinctUntilChangedOfNone() {
         Observable<String> src = Observable.empty();
-        Observable.create(distinctUntilChanged(src)).subscribe(w);
+        src.distinctUntilChanged().subscribe(w);
 
         verify(w, never()).onNext(anyString());
         verify(w, never()).onError(any(Throwable.class));
@@ -78,7 +69,7 @@ public void testDistinctUntilChangedOfNone() {
     @Test
     public void testDistinctUntilChangedOfNoneWithKeySelector() {
         Observable<String> src = Observable.empty();
-        Observable.create(distinctUntilChanged(src, TO_UPPER_WITH_EXCEPTION)).subscribe(w);
+        src.distinctUntilChanged(TO_UPPER_WITH_EXCEPTION).subscribe(w);
 
         verify(w, never()).onNext(anyString());
         verify(w, never()).onError(any(Throwable.class));
@@ -88,7 +79,7 @@ public void testDistinctUntilChangedOfNoneWithKeySelector() {
     @Test
     public void testDistinctUntilChangedOfNormalSource() {
         Observable<String> src = Observable.from("a", "b", "c", "c", "c", "b", "b", "a", "e");
-        Observable.create(distinctUntilChanged(src)).subscribe(w);
+        src.distinctUntilChanged().subscribe(w);
 
         InOrder inOrder = inOrder(w);
         inOrder.verify(w, times(1)).onNext("a");
@@ -105,7 +96,7 @@ public void testDistinctUntilChangedOfNormalSource() {
     @Test
     public void testDistinctUntilChangedOfNormalSourceWithKeySelector() {
         Observable<String> src = Observable.from("a", "b", "c", "C", "c", "B", "b", "a", "e");
-        Observable.create(distinctUntilChanged(src, TO_UPPER_WITH_EXCEPTION)).subscribe(w);
+        src.distinctUntilChanged(TO_UPPER_WITH_EXCEPTION).subscribe(w);
 
         InOrder inOrder = inOrder(w);
         inOrder.verify(w, times(1)).onNext("a");
@@ -122,7 +113,7 @@ public void testDistinctUntilChangedOfNormalSourceWithKeySelector() {
     @Test
     public void testDistinctUntilChangedOfSourceWithNulls() {
         Observable<String> src = Observable.from(null, "a", "a", null, null, "b", null, null);
-        Observable.create(distinctUntilChanged(src)).subscribe(w);
+        src.distinctUntilChanged().subscribe(w);
 
         InOrder inOrder = inOrder(w);
         inOrder.verify(w, times(1)).onNext(null);
@@ -138,7 +129,7 @@ public void testDistinctUntilChangedOfSourceWithNulls() {
     @Test
     public void testDistinctUntilChangedOfSourceWithExceptionsFromKeySelector() {
         Observable<String> src = Observable.from("a", "b", null, "c");
-        Observable.create(distinctUntilChanged(src, TO_UPPER_WITH_EXCEPTION)).subscribe(w);
+        src.distinctUntilChanged(TO_UPPER_WITH_EXCEPTION).subscribe(w);
 
         InOrder inOrder = inOrder(w);
         inOrder.verify(w, times(1)).onNext("a");
@@ -147,56 +138,4 @@ public void testDistinctUntilChangedOfSourceWithExceptionsFromKeySelector() {
         inOrder.verify(w, never()).onNext(anyString());
         inOrder.verify(w, never()).onCompleted();
     }
-
-    @Test
-    public void testDistinctUntilChangedWithComparator() {
-        Observable<String> src = Observable.from("a", "b", "c", "aa", "bb", "c", "ddd");
-        Observable.create(distinctUntilChanged(src, COMPARE_LENGTH)).subscribe(w);
-        InOrder inOrder = inOrder(w);
-        inOrder.verify(w, times(1)).onNext("a");
-        inOrder.verify(w, times(1)).onNext("aa");
-        inOrder.verify(w, times(1)).onNext("c");
-        inOrder.verify(w, times(1)).onNext("ddd");
-        inOrder.verify(w, times(1)).onCompleted();
-        inOrder.verify(w, never()).onNext(anyString());
-        verify(w, never()).onError(any(Throwable.class));
-    }
-
-    @Test
-    public void testDistinctUntilChangedWithComparatorAndKeySelector() {
-        Observable<String> src = Observable.from("a", "b", "x", "aa", "bb", "c", "ddd");
-        Observable.create(distinctUntilChanged(src, TO_UPPER_WITH_EXCEPTION, COMPARE_LENGTH)).subscribe(w);
-        InOrder inOrder = inOrder(w);
-        inOrder.verify(w, times(1)).onNext("a");
-        inOrder.verify(w, times(1)).onNext("x");
-        inOrder.verify(w, times(1)).onNext("c");
-        inOrder.verify(w, times(1)).onNext("ddd");
-        inOrder.verify(w, times(1)).onCompleted();
-        inOrder.verify(w, never()).onNext(anyString());
-        verify(w, never()).onError(any(Throwable.class));
-    }
-
-    @Test
-    public void testDistinctUntilChangedWithComparatorAndKeySelectorandTwoSubscriptions() {
-        Observable<String> src = Observable.from("a", "b", "x", "aa", "bb", "c", "ddd");
-        Observable.create(distinctUntilChanged(src, TO_UPPER_WITH_EXCEPTION, COMPARE_LENGTH)).subscribe(w);
-        InOrder inOrder = inOrder(w);
-        inOrder.verify(w, times(1)).onNext("a");
-        inOrder.verify(w, times(1)).onNext("x");
-        Observable.create(distinctUntilChanged(src, TO_UPPER_WITH_EXCEPTION, COMPARE_LENGTH)).subscribe(w2);
-        inOrder.verify(w, times(1)).onNext("c");
-        inOrder.verify(w, times(1)).onNext("ddd");
-        inOrder.verify(w, times(1)).onCompleted();
-        inOrder.verify(w, never()).onNext(anyString());
-        verify(w, never()).onError(any(Throwable.class));
-
-        InOrder inOrder2 = inOrder(w2);
-        inOrder2.verify(w2, times(1)).onNext("a");
-        inOrder2.verify(w2, times(1)).onNext("x");
-        inOrder2.verify(w2, times(1)).onNext("c");
-        inOrder2.verify(w2, times(1)).onNext("ddd");
-        inOrder2.verify(w2, times(1)).onCompleted();
-        inOrder2.verify(w2, never()).onNext(anyString());
-        verify(w2, never()).onError(any(Throwable.class));
-    }
 }