/*
 * 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.multithread;

import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
import edu.uci.ics.hyracks.dataflow.common.comm.io.ArrayTupleBuilder;
import edu.uci.ics.hyracks.dataflow.common.comm.io.ArrayTupleReference;
import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
import edu.uci.ics.hyracks.storage.am.btree.exceptions.BTreeDuplicateKeyException;
import edu.uci.ics.hyracks.storage.am.btree.exceptions.BTreeNonExistentKeyException;
import edu.uci.ics.hyracks.storage.am.btree.exceptions.BTreeNotUpdateableException;
import edu.uci.ics.hyracks.storage.am.btree.impls.BTree;
import edu.uci.ics.hyracks.storage.am.btree.impls.RangePredicate;
import edu.uci.ics.hyracks.storage.am.common.AbstractIndexTestWorker;
import edu.uci.ics.hyracks.storage.am.common.TestOperationSelector;
import edu.uci.ics.hyracks.storage.am.common.TestOperationSelector.TestOperation;
import edu.uci.ics.hyracks.storage.am.common.api.IIndex;
import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexCursor;
import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
import edu.uci.ics.hyracks.storage.am.common.datagen.DataGenThread;
import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;

public class BTreeTestWorker extends AbstractIndexTestWorker {

    private final BTree btree;
    private final int numKeyFields;
    private final ArrayTupleBuilder deleteTb;
    private final ArrayTupleReference deleteTuple = new ArrayTupleReference();

    public BTreeTestWorker(DataGenThread dataGen, TestOperationSelector opSelector, IIndex index, int numBatches) {
        super(dataGen, opSelector, index, numBatches);
        btree = (BTree) index;
        numKeyFields = btree.getComparatorFactories().length;
        deleteTb = new ArrayTupleBuilder(numKeyFields);
    }

    @Override
    public void performOp(ITupleReference tuple, TestOperation op) throws HyracksDataException, IndexException {
        BTree.BTreeAccessor accessor = (BTree.BTreeAccessor) indexAccessor;
        ITreeIndexCursor searchCursor = accessor.createSearchCursor();
        ITreeIndexCursor diskOrderScanCursor = accessor.createDiskOrderScanCursor();
        MultiComparator cmp = accessor.getOpContext().cmp;
        RangePredicate rangePred = new RangePredicate(tuple, tuple, true, true, cmp, cmp);

        switch (op) {
            case INSERT:
                try {
                    accessor.insert(tuple);
                } catch (BTreeDuplicateKeyException e) {
                    // Ignore duplicate keys, since we get random tuples.
                }
                break;

            case DELETE:
                // Create a tuple reference with only key fields.
                deleteTb.reset();
                for (int i = 0; i < numKeyFields; i++) {
                    deleteTb.addField(tuple.getFieldData(i), tuple.getFieldStart(i), tuple.getFieldLength(i));
                }
                deleteTuple.reset(deleteTb.getFieldEndOffsets(), deleteTb.getByteArray());
                try {
                    accessor.delete(deleteTuple);
                } catch (BTreeNonExistentKeyException e) {
                    // Ignore non-existant keys, since we get random tuples.
                }
                break;

            case UPDATE:
                try {
                    accessor.update(tuple);
                } catch (BTreeNonExistentKeyException e) {
                    // Ignore non-existant keys, since we get random tuples.
                } catch (BTreeNotUpdateableException e) {
                    // Ignore not updateable exception due to numKeys == numFields.
                }
                break;

            case UPSERT:
                accessor.upsert(tuple);
                // Upsert should not throw. If it does, there's 
                // a bigger problem and the test should fail.
                break;

            case POINT_SEARCH:
                searchCursor.reset();
                rangePred.setLowKey(tuple, true);
                rangePred.setHighKey(tuple, true);
                accessor.search(searchCursor, rangePred);
                consumeCursorTuples(searchCursor);
                break;

            case SCAN:
                searchCursor.reset();
                rangePred.setLowKey(null, true);
                rangePred.setHighKey(null, true);
                accessor.search(searchCursor, rangePred);
                consumeCursorTuples(searchCursor);
                break;

            case DISKORDER_SCAN:
                diskOrderScanCursor.reset();
                accessor.diskOrderScan(diskOrderScanCursor);
                consumeCursorTuples(diskOrderScanCursor);
                break;

            default:
                throw new HyracksDataException("Op " + op.toString() + " not supported.");
        }
    }

    private void consumeCursorTuples(ITreeIndexCursor cursor) throws HyracksDataException, IndexException {
        try {
            while (cursor.hasNext()) {
                cursor.next();
            }
        } finally {
            cursor.close();
        }
    }
}