OperatorDistinct

Author: akarnokd

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

@@ -56,7 +56,6 @@
 import rx.operators.OperationDefer;
 import rx.operators.OperationDelay;
 import rx.operators.OperationDematerialize;
-import rx.operators.OperationDistinct;
 import rx.operators.OperationDistinctUntilChanged;
 import rx.operators.OperationFinally;
 import rx.operators.OperationFlatMap;
@@ -95,6 +94,7 @@
 import rx.operators.OperatorAsObservable;
 import rx.operators.OperatorCache;
 import rx.operators.OperatorCast;
+import rx.operators.OperatorDistinct;
 import rx.operators.OperatorDoOnEach;
 import rx.operators.OperatorElementAt;
 import rx.operators.OperatorFilter;
@@ -3606,7 +3606,7 @@ public final <T2> Observable<T2> dematerialize() {
      * @see <a href="http://msdn.microsoft.com/en-us/library/hh229764.aspx">MSDN: Observable.distinct</a>
      */
     public final Observable<T> distinct() {
-        return create(OperationDistinct.distinct(this));
+        return lift(new OperatorDistinct<T, T>(Functions.<T>identity()));
     }
 
     /**
@@ -3623,7 +3623,7 @@ public final Observable<T> distinct() {
      * @see <a href="http://msdn.microsoft.com/en-us/library/hh244310.aspx">MSDN: Observable.distinct</a>
      */
     public final <U> Observable<T> distinct(Func1<? super T, ? extends U> keySelector) {
-        return create(OperationDistinct.distinct(this, keySelector));
+        return lift(new OperatorDistinct<T, U>(keySelector));
     }
 
     /**

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

@@ -0,0 +1,64 @@
+/**
+ * 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 java.util.HashSet;
+import java.util.Set;
+import rx.Observable.Operator;
+import rx.Subscriber;
+import rx.functions.Func1;
+
+/**
+ * Returns an Observable that emits all distinct items emitted by the source.
+ * 
+ * @param <T> the value type
+ * @param <U> the key type
+ */
+public final class OperatorDistinct<T, U> implements Operator<T, T> {
+    final Func1<? super T, ? extends U> keySelector;
+
+    public OperatorDistinct(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) {
+            Set<U> keyMemory = new HashSet<U>();
+
+            @Override
+            public void onNext(T t) {
+                U key = keySelector.call(t);
+                if (keyMemory.add(key)) {
+                    child.onNext(t);
+                }
+            }
+
+            @Override
+            public void onError(Throwable e) {
+                keyMemory = null;
+                child.onError(e);
+            }
+
+            @Override
+            public void onCompleted() {
+                keyMemory = null;
+                child.onCompleted();
+            }
+            
+        };
+    }
+}