/*
 * Licensed to Crate under one or more contributor license agreements.
 * See the NOTICE file distributed with this work for additional
 * information regarding copyright ownership.  Crate licenses this file
 * to you 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.
 *
 * However, if you have executed another commercial license agreement
 * with Crate these terms will supersede the license and you may use the
 * software solely pursuant to the terms of the relevant commercial
 * agreement.
 */

package io.crate.data;

import io.crate.concurrent.CompletableFutures;

import java.util.concurrent.CompletionStage;

public class LimitingBatchIterator<T> extends CloseAssertingBatchIterator<T> {

    private final int endPos;
    private int pos = -1;

    public static <T> BatchIterator<T> newInstance(BatchIterator<T> delegate, int limit) {
        return new LimitingBatchIterator<>(delegate, limit);
    }

    private LimitingBatchIterator(BatchIterator<T> delegate, int limit) {
        super(delegate);
        this.endPos = limit - 1;
    }

    @Override
    public void moveToStart() {
        pos = -1;
        super.moveToStart();
    }

    @Override
    public boolean moveNext() {
        if (pos >= endPos) {
            return false;
        }
        if (super.moveNext()) {
            pos++;
            return true;
        }
        return false;
    }

    @Override
    public CompletionStage<?> loadNextBatch() {
        if (allLoaded()) {
            return CompletableFutures.failedFuture(new IllegalStateException("Iterator already fully loaded"));
        }
        return super.loadNextBatch();
    }

    @Override
    public boolean allLoaded() {
        return pos >= endPos || super.allLoaded();
    }
}

/*
 * Licensed to Crate under one or more contributor license agreements.
 * See the NOTICE file distributed with this work for additional
 * information regarding copyright ownership.  Crate licenses this file
 * to you 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.
 *
 * However, if you have executed another commercial license agreement
 * with Crate these terms will supersede the license and you may use the
 * software solely pursuant to the terms of the relevant commercial
 * agreement.
 */

package io.crate.data;

import io.crate.concurrent.CompletableFutures;

import java.util.concurrent.CompletionStage;

public final class LimitingBatchIterator<T> extends ForwardingBatchIterator<T> {

    private final int endPos;
    private final BatchIterator<T> delegate;
    private int pos = -1;

    public static <T> BatchIterator<T> newInstance(BatchIterator<T> delegate, int limit) {
        return new LimitingBatchIterator<>(delegate, limit);
    }

    private LimitingBatchIterator(BatchIterator<T> delegate, int limit) {
        this.delegate = delegate;
        this.endPos = limit - 1;
    }

    @Override
    protected BatchIterator<T> delegate() {
        return delegate;
    }

    @Override
    public void moveToStart() {
        pos = -1;
        super.moveToStart();
    }

    @Override
    public boolean moveNext() {
        if (pos >= endPos) {
            return false;
        }
        if (super.moveNext()) {
            pos++;
            return true;
        }
        return false;
    }

    @Override
    public CompletionStage<?> loadNextBatch() {
        if (allLoaded()) {
            return CompletableFutures.failedFuture(new IllegalStateException("Iterator already fully loaded"));
        }
        return super.loadNextBatch();
    }

    @Override
    public boolean allLoaded() {
        return pos >= endPos || super.allLoaded();
    }
}

Remove close and kill handling from LimitingBatchIterator