hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/impls/BTreeOpContext.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.impls;

import edu.uci.ics.hyracks.storage.am.btree.api.IBTreeInteriorFrame;
import edu.uci.ics.hyracks.storage.am.btree.api.IBTreeLeafFrame;
import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexCursor;
import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexMetaDataFrame;
import edu.uci.ics.hyracks.storage.am.common.ophelpers.IndexOp;
import edu.uci.ics.hyracks.storage.am.common.ophelpers.IndexOpContext;
import edu.uci.ics.hyracks.storage.am.common.ophelpers.IntArrayList;

public final class BTreeOpContext implements IndexOpContext {
    public final IndexOp op;
    public final IBTreeLeafFrame leafFrame;
    public final IBTreeInteriorFrame interiorFrame;
    public final ITreeIndexMetaDataFrame metaFrame;
    public ITreeIndexCursor cursor;
    public BTreeCursorInitialState cursorInitialState;
    public RangePredicate pred;
    public final BTreeSplitKey splitKey;
    public int opRestarts = 0;
    public final IntArrayList pageLsns; // used like a stack
    public final IntArrayList smPages;
    public final IntArrayList freePages;

    public BTreeOpContext(IndexOp op, IBTreeLeafFrame leafFrame, IBTreeInteriorFrame interiorFrame,
            ITreeIndexMetaDataFrame metaFrame, int treeHeightHint) {
        this.op = op;
        this.leafFrame = leafFrame;
        this.interiorFrame = interiorFrame;
        this.metaFrame = metaFrame;

        pageLsns = new IntArrayList(treeHeightHint, treeHeightHint);
        if (op != IndexOp.SEARCH && op != IndexOp.DISKORDERSCAN) {
            smPages = new IntArrayList(treeHeightHint, treeHeightHint);
            freePages = new IntArrayList(treeHeightHint, treeHeightHint);
            pred = new RangePredicate(true, null, null, true, true, null, null);
            splitKey = new BTreeSplitKey(leafFrame.getTupleWriter().createTupleReference());
        } else {
            smPages = null;
            freePages = null;
            splitKey = null;
            cursorInitialState = new BTreeCursorInitialState(null);
        }
    }

    public void reset() {
        if (pageLsns != null)
            pageLsns.clear();
        if (freePages != null)
            freePages.clear();
        if (smPages != null)
            smPages.clear();
        opRestarts = 0;
    }
}