/*
 * Copyright (c) "Neo4j"
 * Neo4j Sweden AB [http://neo4j.com]
 *
 * This file is part of Neo4j.
 *
 * Neo4j is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.neo4j.io.pagecache.checking;

import java.io.IOException;
import org.neo4j.io.pagecache.PageCursor;
import org.neo4j.io.pagecache.impl.DelegatingPageCursor;

public class AccessCheckingReadPageCursor extends DelegatingPageCursor {
    private boolean hasReadWithoutShouldRetry;

    public AccessCheckingReadPageCursor(PageCursor delegate) {
        super(delegate);
    }

    @Override
    public byte getByte() {
        markAsRead();
        return super.getByte();
    }

    @Override
    public void getBytes(byte[] data) {
        markAsRead();
        super.getBytes(data);
    }

    @Override
    public short getShort() {
        markAsRead();
        return super.getShort();
    }

    @Override
    public short getShort(int offset) {
        markAsRead();
        return super.getShort(offset);
    }

    @Override
    public long getLong() {
        markAsRead();
        return super.getLong();
    }

    @Override
    public long getLong(int offset) {
        markAsRead();
        return super.getLong(offset);
    }

    @Override
    public void getBytes(byte[] data, int arrayOffset, int length) {
        markAsRead();
        super.getBytes(data, arrayOffset, length);
    }

    @Override
    public int getInt(int offset) {
        markAsRead();
        return super.getInt(offset);
    }

    @Override
    public byte getByte(int offset) {
        markAsRead();
        return super.getByte(offset);
    }

    @Override
    public int getInt() {
        markAsRead();
        return super.getInt();
    }

    private void markAsRead() {
        hasReadWithoutShouldRetry = true;
    }

    @Override
    public boolean shouldRetry() throws IOException {
        hasReadWithoutShouldRetry = false;
        return super.shouldRetry();
    }

    @Override
    public boolean next() throws IOException {
        assertNoReadWithoutShouldRetry();
        return super.next();
    }

    @Override
    public void close() {
        assertNoReadWithoutShouldRetry();
        super.close();
    }

    @Override
    public boolean next(long pageId) throws IOException {
        assertNoReadWithoutShouldRetry();
        return super.next(pageId);
    }

    private void assertNoReadWithoutShouldRetry() {
        if (hasReadWithoutShouldRetry) {
            throw new AssertionError("Performed read from a read cursor without shouldRetry");
        }
    }
}
