Added support for dropping an index by its keys.

 JAVA-1714

Author: jyemin

driver-async/src/main/com/mongodb/async/client/MongoCollection.java

@@ -519,14 +519,23 @@ void bulkWrite(List<? extends WriteModel<? extends TDocument>> requests, BulkWri
     <TResult> ListIndexesIterable<TResult> listIndexes(Class<TResult> resultClass);
 
     /**
-     * Drops the given index.
+     * Drops the index given its name.
      *
      * @param indexName the name of the index to remove
      * @param callback  the callback that is completed once the index has been dropped
      * @mongodb.driver.manual reference/command/dropIndexes/ Drop indexes
      */
     void dropIndex(String indexName, SingleResultCallback<Void> callback);
 
+    /**
+     * Drops the index given the keys used to create it.
+     *
+     * @param keys the keys of the index to remove
+     * @param callback  the callback that is completed once the index has been dropped
+     * @mongodb.driver.manual reference/command/dropIndexes/ Drop indexes
+     */
+    void dropIndex(Bson keys, SingleResultCallback<Void> callback);
+
     /**
      * Drop all the indexes on this collection, except for the default on _id.
      *

driver-async/src/main/com/mongodb/async/client/MongoCollectionImpl.java

@@ -469,6 +469,11 @@ public void dropIndex(final String indexName, final SingleResultCallback<Void> c
         executor.execute(new DropIndexOperation(namespace, indexName), callback);
     }
 
+    @Override
+    public void dropIndex(final Bson keys, final SingleResultCallback<Void> callback) {
+        executor.execute(new DropIndexOperation(namespace, keys.toBsonDocument(BsonDocument.class, codecRegistry)), callback);
+    }
+
     @Override
     public void dropIndexes(final SingleResultCallback<Void> callback) {
         dropIndex("*", callback);

driver-async/src/test/unit/com/mongodb/async/client/MongoCollectionSpecification.groovy

@@ -890,18 +890,29 @@ class MongoCollectionSpecification extends Specification {
 
     def 'should use DropIndexOperation correctly for dropIndex'() {
         given:
-        def executor = new TestOperationExecutor([null])
+        def executor = new TestOperationExecutor([null, null])
         def collection = new MongoCollectionImpl(namespace, Document, codecRegistry, readPreference, writeConcern, executor)
-        def expectedOperation = new DropIndexOperation(namespace, 'indexName')
-        def futureResultCallback = new FutureResultCallback<Void>()
 
         when:
+        def expectedOperation = new DropIndexOperation(namespace, 'indexName')
+        def futureResultCallback = new FutureResultCallback<Void>()
         collection.dropIndex('indexName', futureResultCallback)
         futureResultCallback.get()
         def operation = executor.getWriteOperation() as DropIndexOperation
 
         then:
         expect operation, isTheSameAs(expectedOperation)
+
+        when:
+        def keys = new BsonDocument('x', new BsonInt32(1))
+        expectedOperation = new DropIndexOperation(namespace, keys)
+        futureResultCallback = new FutureResultCallback<Void>()
+        collection.dropIndex(keys, futureResultCallback)
+        futureResultCallback.get()
+        operation = executor.getWriteOperation() as DropIndexOperation
+
+        then:
+        expect operation, isTheSameAs(expectedOperation)
     }
 
     def 'should use DropIndexOperation correctly for dropIndexes'() {

driver-core/src/main/com/mongodb/operation/CreateIndexesOperation.java

@@ -38,7 +38,6 @@
 import org.bson.BsonInt32;
 import org.bson.BsonInt64;
 import org.bson.BsonString;
-import org.bson.BsonValue;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -48,6 +47,7 @@
 import static com.mongodb.internal.async.ErrorHandlingResultCallback.errorHandlingCallback;
 import static com.mongodb.operation.CommandOperationHelper.executeWrappedCommandProtocol;
 import static com.mongodb.operation.CommandOperationHelper.executeWrappedCommandProtocolAsync;
+import static com.mongodb.operation.IndexHelper.generateIndexName;
 import static com.mongodb.operation.OperationHelper.AsyncCallableWithConnection;
 import static com.mongodb.operation.OperationHelper.CallableWithConnection;
 import static com.mongodb.operation.OperationHelper.releasingCallback;
@@ -227,27 +227,4 @@ private MongoException checkForDuplicateKeyError(final MongoCommandException e)
             return e;
         }
     }
-
-    /**
-     * Convenience method to generate an index name from the set of fields it is over.
-     *
-     * @return a string representation of this index's fields
-     */
-    private String generateIndexName(final BsonDocument index) {
-        StringBuilder indexName = new StringBuilder();
-        for (final String keyNames : index.keySet()) {
-            if (indexName.length() != 0) {
-                indexName.append('_');
-            }
-            indexName.append(keyNames).append('_');
-            BsonValue ascOrDescValue = index.get(keyNames);
-            if (ascOrDescValue instanceof BsonInt32) {
-                indexName.append(((BsonInt32) ascOrDescValue).getValue());
-            } else if (ascOrDescValue instanceof BsonString) {
-                indexName.append(((BsonString) ascOrDescValue).getValue().replace(' ', '_'));
-            }
-        }
-        return indexName.toString();
-    }
-
 }

driver-core/src/main/com/mongodb/operation/DropIndexOperation.java

@@ -28,6 +28,7 @@
 import static com.mongodb.operation.CommandOperationHelper.executeWrappedCommandProtocol;
 import static com.mongodb.operation.CommandOperationHelper.executeWrappedCommandProtocolAsync;
 import static com.mongodb.operation.CommandOperationHelper.isNamespaceError;
+import static com.mongodb.operation.IndexHelper.generateIndexName;
 import static com.mongodb.operation.OperationHelper.VoidTransformer;
 
 /**
@@ -51,6 +52,17 @@ public DropIndexOperation(final MongoNamespace namespace, final String indexName
         this.indexName = notNull("indexName", indexName);
     }
 
+    /**
+     * Construct a new instance.
+     *
+     * @param namespace the database and collection namespace for the operation.
+     * @param keys the keys of the index to be dropped
+     */
+    public DropIndexOperation(final MongoNamespace namespace, final BsonDocument keys) {
+        this.namespace = notNull("namespace", namespace);
+        this.indexName = generateIndexName(notNull("keys", keys));
+    }
+
     @Override
     public Void execute(final WriteBinding binding) {
         try {

driver-core/src/main/com/mongodb/operation/IndexHelper.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2015 MongoDB, 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 com.mongodb.operation;
+
+import org.bson.BsonDocument;
+import org.bson.BsonInt32;
+import org.bson.BsonString;
+import org.bson.BsonValue;
+
+final class IndexHelper {
+
+    /**
+     * Convenience method to generate an index name from the set of fields it is over.
+     *
+     * @return a string representation of this index's fields
+     */
+    static String generateIndexName(final BsonDocument index) {
+        StringBuilder indexName = new StringBuilder();
+        for (final String keyNames : index.keySet()) {
+            if (indexName.length() != 0) {
+                indexName.append('_');
+            }
+            indexName.append(keyNames).append('_');
+            BsonValue ascOrDescValue = index.get(keyNames);
+            if (ascOrDescValue instanceof BsonInt32) {
+                indexName.append(((BsonInt32) ascOrDescValue).getValue());
+            } else if (ascOrDescValue instanceof BsonString) {
+                indexName.append(((BsonString) ascOrDescValue).getValue().replace(' ', '_'));
+            }
+        }
+        return indexName.toString();
+    }
+
+    private IndexHelper() {
+    }
+}

driver-core/src/test/functional/com/mongodb/operation/DropIndexesOperationSpecification.groovy

@@ -70,7 +70,7 @@ class DropIndexesOperationSpecification extends OperationFunctionalSpecification
         thrown(MongoException)
     }
 
-    def 'should drop existing index'() {
+    def 'should drop existing index by name'() {
         given:
         collectionHelper.createIndex(new BsonDocument('theField', new BsonInt32(1)))
 
@@ -83,6 +83,20 @@ class DropIndexesOperationSpecification extends OperationFunctionalSpecification
         indexes[0].name == '_id_'
     }
 
+    def 'should drop existing index by keys'() {
+        def keys = new BsonDocument('theField', new BsonInt32(1))
+        given:
+        collectionHelper.createIndex(keys)
+
+        when:
+        new DropIndexOperation(getNamespace(), keys).execute(getBinding())
+        List<Document> indexes = getIndexes()
+
+        then:
+        indexes.size() == 1
+        indexes[0].name == '_id_'
+    }
+
     @Category(Async)
     def 'should drop existing index asynchronously'() {
         given:

driver/src/main/com/mongodb/MongoCollectionImpl.java

@@ -437,6 +437,11 @@ public void dropIndex(final String indexName) {
         executor.execute(new DropIndexOperation(namespace, indexName));
     }
 
+    @Override
+    public void dropIndex(final Bson keys) {
+        executor.execute(new DropIndexOperation(namespace, keys.toBsonDocument(BsonDocument.class, codecRegistry)));
+    }
+
     @Override
     public void dropIndexes() {
         dropIndex("*");

driver/src/main/com/mongodb/client/MongoCollection.java

@@ -510,13 +510,21 @@ public interface MongoCollection<TDocument> {
     <TResult> ListIndexesIterable<TResult> listIndexes(Class<TResult> resultClass);
 
     /**
-     * Drops the given index.
+     * Drops the index given its name.
      *
      * @param indexName the name of the index to remove
      * @mongodb.driver.manual reference/command/dropIndexes/ Drop indexes
      */
     void dropIndex(String indexName);
 
+    /**
+     * Drops the index given the keys used to create it.
+     *
+     * @param keys the keys of the index to remove
+     * @mongodb.driver.manual reference/command/dropIndexes/ Drop indexes
+     */
+    void dropIndex(Bson keys);
+
     /**
      * Drop all the indexes on this collection, except for the default on _id.
      *

driver/src/test/acceptance/com/mongodb/acceptancetest/index/DropIndexAcceptanceTest.java

@@ -54,6 +54,23 @@ public void shouldDropSingleNamedIndex() {
         assertThat("Should be one less index", collection.listIndexes().into(new ArrayList<Document>()).size(), is(1));
     }
 
+    @Test
+    public void shouldDropSingleIndexByKeys() {
+        // Given
+        Document keys = new Document("field", 1);
+        collection.createIndex(keys);
+
+        assertThat("Should be default index and new index on the database now",
+                   collection.listIndexes().into(new ArrayList<Document>()).size(),
+                   is(2));
+
+        // When
+        collection.dropIndex(keys);
+
+        // Then
+        assertThat("Should be one less index", collection.listIndexes().into(new ArrayList<Document>()).size(), is(1));
+    }
+
     @Test
     public void shouldDropAllIndexesForCollection() {
         // Given