StoredContainer.java

/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 2000-2005
 *      Sleepycat Software.  All rights reserved.
 *
 * $Id: StoredContainer.java,v 12.3 2005/08/01 20:25:19 mark Exp $
 */

package com.sleepycat.collections;

import com.sleepycat.compat.DbCompat;
import com.sleepycat.db.CursorConfig;
import com.sleepycat.db.DatabaseException;
import com.sleepycat.db.OperationStatus;
import com.sleepycat.util.RuntimeExceptionWrapper;

public abstract class StoredContainer implements Cloneable {

    DataView view;

    StoredContainer(DataView view) {

        this.view = view;
    }

    public final boolean isWriteAllowed() {

        return view.writeAllowed;
    }

    public final CursorConfig getCursorConfig() {

        return DbCompat.cloneCursorConfig(view.cursorConfig);
    }

    public final boolean isDirtyReadAllowed() {

        return view.readUncommittedAllowed;
    }

    public final boolean isDirtyRead() {

        return view.cursorConfig.getReadUncommitted();
    }

    public final boolean isTransactional() {

        return view.transactional;
    }

    final StoredContainer configuredClone(CursorConfig config) {

        try {
            StoredContainer cont = (StoredContainer) clone();
            cont.view = cont.view.configuredView(config);
            cont.initAfterClone();
            return cont;
        } catch (CloneNotSupportedException willNeverOccur) { return null; }
    }

    void initAfterClone() {
    }

    public final boolean areDuplicatesAllowed() {

        return view.dupsAllowed;
    }

    public final boolean areDuplicatesOrdered() {

        return view.dupsOrdered;
    }

    public final boolean areKeysRenumbered() {

        return view.keysRenumbered;
    }

    public final boolean isOrdered() {

        return view.ordered;
    }

    public final boolean isSecondary() {

        return view.isSecondary();
    }

    public int size() {

        throw new UnsupportedOperationException(
            "collection size not available");
    }

    public boolean isEmpty() {

        try {
            return view.isEmpty();
        } catch (Exception e) {
            throw convertException(e);
        }
    }

    public void clear() {

        boolean doAutoCommit = beginAutoCommit();
        try {
            view.clear();
            commitAutoCommit(doAutoCommit);
        } catch (Exception e) {
            throw handleException(e, doAutoCommit);
        }
    }

    Object get(Object key) {

        DataCursor cursor = null;
        try {
            cursor = new DataCursor(view, false);
            if (OperationStatus.SUCCESS ==
                cursor.getSearchKey(key, null, false)) {
                return cursor.getCurrentValue();
            } else {
                return null;
            }
        } catch (Exception e) {
            throw StoredContainer.convertException(e);
        } finally {
            closeCursor(cursor);
        }
    }

    Object put(final Object key, final Object value) {

        DataCursor cursor = null;
        boolean doAutoCommit = beginAutoCommit();
        try {
            cursor = new DataCursor(view, true);
            Object[] oldValue = new Object[1];
            cursor.put(key, value, oldValue, false);
            closeCursor(cursor);
            commitAutoCommit(doAutoCommit);
            return oldValue[0];
        } catch (Exception e) {
            closeCursor(cursor);
            throw handleException(e, doAutoCommit);
        }
    }

    final boolean removeKey(final Object key, final Object[] oldVal) {

        DataCursor cursor = null;
        boolean doAutoCommit = beginAutoCommit();
        try {
            cursor = new DataCursor(view, true);
            boolean found = false;
            OperationStatus status = cursor.getSearchKey(key, null, true);
            while (status == OperationStatus.SUCCESS) {
                cursor.delete();
                found = true;
                if (oldVal != null && oldVal[0] == null) {
                    oldVal[0] = cursor.getCurrentValue();
                }
                status = areDuplicatesAllowed() ?
                    cursor.getNextDup(true): OperationStatus.NOTFOUND;
            }
            closeCursor(cursor);
            commitAutoCommit(doAutoCommit);
            return found;
        } catch (Exception e) {
            closeCursor(cursor);
            throw handleException(e, doAutoCommit);
        }
    }

    boolean containsKey(Object key) {

        DataCursor cursor = null;
        try {
            cursor = new DataCursor(view, false);
            return OperationStatus.SUCCESS ==
                   cursor.getSearchKey(key, null, false);
        } catch (Exception e) {
            throw StoredContainer.convertException(e);
        } finally {
            closeCursor(cursor);
        }
    }

    final boolean removeValue(Object value) {

        DataCursor cursor = null;
        boolean doAutoCommit = beginAutoCommit();
        try {
            cursor = new DataCursor(view, true);
            OperationStatus status = cursor.find(value, true);
            if (status == OperationStatus.SUCCESS) {
                cursor.delete();
            }
            closeCursor(cursor);
            commitAutoCommit(doAutoCommit);
            return (status == OperationStatus.SUCCESS);
        } catch (Exception e) {
            closeCursor(cursor);
            throw handleException(e, doAutoCommit);
        }
    }

    boolean containsValue(Object value) {

        DataCursor cursor = null;
        try {
            cursor = new DataCursor(view, false);
            OperationStatus status = cursor.find(value, true);
            return (status == OperationStatus.SUCCESS);
        } catch (Exception e) {
            throw StoredContainer.convertException(e);
        } finally {
            closeCursor(cursor);
        }
    }

    final void closeCursor(DataCursor cursor) {

        if (cursor != null) {
            try {
                cursor.close();
            } catch (Exception e) {
                throw StoredContainer.convertException(e);
            }
        }
    }

    final boolean beginAutoCommit() {

        if (view.transactional) {
            CurrentTransaction currentTxn = view.getCurrentTxn();
            try {
                if (currentTxn.isAutoCommitAllowed()) {
                    currentTxn.beginTransaction(null);
                    return true;
                }
            } catch (DatabaseException e) {
                throw new RuntimeExceptionWrapper(e);
            }
        }
        return false;
    }

    final void commitAutoCommit(boolean doAutoCommit)
        throws DatabaseException {

        if (doAutoCommit) view.getCurrentTxn().commitTransaction();
    }

    final RuntimeException handleException(Exception e, boolean doAutoCommit) {

        if (doAutoCommit) {
            try {
                view.getCurrentTxn().abortTransaction();
            } catch (DatabaseException ignored) {
                /* Klockwork - ok */
            }
        }
        return StoredContainer.convertException(e);
    }

    static RuntimeException convertException(Exception e) {

        if (e instanceof RuntimeException) {
            return (RuntimeException) e;
        } else {
            return new RuntimeExceptionWrapper(e);
        }
    }
}

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