hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeDropOperatorNodePushable.java

/*
 * Copyright 2009-2010 by The Regents of the University of California
 * 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 from
 * 
 *     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 edu.uci.ics.hyracks.storage.am.btree.dataflow;

import edu.uci.ics.hyracks.api.comm.IFrameWriter;
import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
import edu.uci.ics.hyracks.api.io.FileReference;
import edu.uci.ics.hyracks.dataflow.std.base.AbstractOperatorNodePushable;
import edu.uci.ics.hyracks.dataflow.std.file.IFileSplitProvider;
import edu.uci.ics.hyracks.storage.common.IStorageManagerInterface;
import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;

public class BTreeDropOperatorNodePushable extends AbstractOperatorNodePushable {
    private final IHyracksStageletContext ctx;
    private IBTreeRegistryProvider btreeRegistryProvider;
    private IStorageManagerInterface storageManager;
    private IFileSplitProvider fileSplitProvider;
    private int partition;

    public BTreeDropOperatorNodePushable(IHyracksStageletContext ctx, IStorageManagerInterface storageManager,
            IBTreeRegistryProvider btreeRegistryProvider, IFileSplitProvider fileSplitProvider, int partition) {
        this.ctx = ctx;
        this.storageManager = storageManager;
        this.btreeRegistryProvider = btreeRegistryProvider;
        this.fileSplitProvider = fileSplitProvider;
        this.partition = partition;
    }

    @Override
    public void deinitialize() throws HyracksDataException {
    }

    @Override
    public int getInputArity() {
        return 0;
    }

    @Override
    public IFrameWriter getInputFrameWriter(int index) {
        return null;
    }

    @Override
    public void initialize() throws HyracksDataException {

        BTreeRegistry btreeRegistry = btreeRegistryProvider.getBTreeRegistry(ctx);
        IBufferCache bufferCache = storageManager.getBufferCache(ctx);
        IFileMapProvider fileMapProvider = storageManager.getFileMapProvider(ctx);

        FileReference f = fileSplitProvider.getFileSplits()[partition].getLocalFile();

        boolean fileIsMapped = fileMapProvider.isMapped(f);
        if (!fileIsMapped) {
            throw new HyracksDataException("Cannot drop B-Tree with name " + f.toString() + ". No file mapping exists.");
        }

        int btreeFileId = fileMapProvider.lookupFileId(f);

        // unregister btree instance
        btreeRegistry.lock();
        try {
            btreeRegistry.unregister(btreeFileId);
        } finally {
            btreeRegistry.unlock();
        }

        // remove name to id mapping
        bufferCache.deleteFile(btreeFileId);
    }

    @Override
    public void setOutputFrameWriter(int index, IFrameWriter writer, RecordDescriptor recordDesc) {
    }
}