/*
* Copyright (c) 2008-2014 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.async.client;
import com.mongodb.Block;
import com.mongodb.Function;
import com.mongodb.ReadPreference;
import com.mongodb.async.AsyncBatchCursor;
import com.mongodb.async.SingleResultCallback;
import com.mongodb.operation.AsyncOperationExecutor;
import com.mongodb.operation.AsyncReadOperation;
import java.util.Collection;
import java.util.List;
import static org.bson.assertions.Assertions.notNull;
class OperationIterable<T> implements MongoIterable<T> {
private final AsyncReadOperation<? extends AsyncBatchCursor<T>> operation;
private final ReadPreference readPreference;
private final AsyncOperationExecutor executor;
OperationIterable(final AsyncReadOperation<? extends AsyncBatchCursor<T>> operation, final ReadPreference readPreference,
final AsyncOperationExecutor executor) {
this.operation = notNull("operation", operation);
this.readPreference = notNull("readPreference", readPreference);
this.executor = notNull("executor", executor);
}
@Override
public void forEach(final Block<? super T> block, final SingleResultCallback<Void> callback) {
notNull("block", block);
notNull("callback", callback);
batchCursor(new SingleResultCallback<AsyncBatchCursor<T>>() {
@Override
public void onResult(final AsyncBatchCursor<T> batchCursor, final Throwable t) {
if (t != null) {
callback.onResult(null, t);
} else {
loopCursor(batchCursor, block, callback);
}
}
});
}
@Override
public <A extends Collection<? super T>> void into(final A target, final SingleResultCallback<A> callback) {
notNull("target", target);
notNull("callback", callback);
batchCursor(new SingleResultCallback<AsyncBatchCursor<T>>() {
@Override
public void onResult(final AsyncBatchCursor<T> batchCursor, final Throwable t) {
if (t != null) {
callback.onResult(null, t);
} else {
loopCursor(batchCursor, new Block<T>() {
@Override
public void apply(final T t) {
target.add(t);
}
}, new SingleResultCallback<Void>() {
@Override
public void onResult(final Void result, final Throwable t) {
if (t != null) {
callback.onResult(null, t);
} else {
callback.onResult(target, null);
}
}
});
}
}
});
}
@Override
public void first(final SingleResultCallback<T> callback) {
notNull("callback", callback);
batchCursor(new SingleResultCallback<AsyncBatchCursor<T>>() {
@Override
public void onResult(final AsyncBatchCursor<T> batchCursor, final Throwable t) {
if (t != null) {
callback.onResult(null, t);
} else {
batchCursor.setBatchSize(1);
batchCursor.next(new SingleResultCallback<List<T>>() {
@Override
public void onResult(final List<T> results, final Throwable t) {
batchCursor.close();
if (t != null) {
callback.onResult(null, t);
} else if (results == null) {
callback.onResult(null, null);
} else {
callback.onResult(results.get(0), null);
}
}
});
}
}
});
}
@Override
public <U> MongoIterable<U> map(final Function<T, U> mapper) {
return new MappingIterable<T, U>(this, mapper);
}
@Override
public OperationIterable<T> batchSize(final int batchSize) {
throw new UnsupportedOperationException();
}
@SuppressWarnings("unchecked")
@Override
public void batchCursor(final SingleResultCallback<AsyncBatchCursor<T>> callback) {
notNull("callback", callback);
executor.execute((AsyncReadOperation<AsyncBatchCursor<T>>) operation, readPreference, callback);
}
private void loopCursor(final AsyncBatchCursor<T> batchCursor, final Block<? super T> block,
final SingleResultCallback<Void> callback) {
batchCursor.next(new SingleResultCallback<List<T>>() {
@Override
public void onResult(final List<T> results, final Throwable t) {
if (t != null || results == null) {
batchCursor.close();
callback.onResult(null, t);
} else {
try {
for (T result : results) {
block.apply(result);
}
loopCursor(batchCursor, block, callback);
} catch (Throwable tr) {
batchCursor.close();
callback.onResult(null, tr);
}
}
}
});
}
}