Copyright (c) 2000, 2017 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
/*******************************************************************************
 * Copyright (c) 2000, 2017 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.team.core.variants;

import org.eclipse.core.resources.IResource;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.team.core.TeamException;

Provides caching for a AbstractResourceVariantTree using a ResourceVariantByteStore. 
See Also:
IResourceVariantTree
AbstractResourceVariantTree
ResourceVariantByteStore
Since:
3.0/**
 * Provides caching for a {@link AbstractResourceVariantTree} using a
 * {@link ResourceVariantByteStore}.
 *
 * @see IResourceVariantTree
 * @see AbstractResourceVariantTree
 * @see ResourceVariantByteStore
 * @since 3.0
 */
public abstract class ResourceVariantTree extends AbstractResourceVariantTree {

	private ResourceVariantByteStore store;

	
Create a resource variant tree that uses the provided byte store to
cache the resource variant bytes.
Params:
store – the resource variant byte store used to cache resource variants/**
	 * Create a resource variant tree that uses the provided byte store to
	 * cache the resource variant bytes.
	 * @param store the resource variant byte store used to cache resource variants
	 */
	protected ResourceVariantTree(ResourceVariantByteStore store) {
		this.store = store;
	}

	@Override
	public IResource[] members(IResource resource) throws TeamException {
		return getByteStore().members(resource);
	}

	@Override
	public boolean hasResourceVariant(IResource resource) throws TeamException {
		return getByteStore().getBytes(resource) != null;
	}

	@Override
	public void flushVariants(IResource resource, int depth) throws TeamException {
		getByteStore().flushBytes(resource, depth);
	}

	@Override
	protected boolean setVariant(IResource local, IResourceVariant remote) throws TeamException {
		ResourceVariantByteStore cache = getByteStore();
		byte[] newRemoteBytes = getBytes(local, remote);
		boolean changed;
		if (newRemoteBytes == null) {
			changed = cache.deleteBytes(local);
		} else {
			changed = cache.setBytes(local, newRemoteBytes);
		}
		return changed;
	}

	
Get the byte store that is used to cache the serialization bytes
for the resource variants of this tree. A byte store is used
to reduce the memory footprint of the tree.

This method is not intended to be overridden by subclasses.
Returns:
the resource variant tree that is being refreshed./**
	 * Get the byte store that is used to cache the serialization bytes
	 * for the resource variants of this tree. A byte store is used
	 * to reduce the memory footprint of the tree.
	 * <p>
	 * This method is not intended to be overridden by subclasses.
	 *
	 * @return the resource variant tree that is being refreshed.
	 */
	protected ResourceVariantByteStore getByteStore() {
		return store;
	}

	
Get the bytes to be stored in the ResourceVariantByteStore
from the given resource variant. By default, the IResourceVariant#asBytes()
method is used to get the bytes.
Params:
local – the local resource
remote – the corresponding resource variant handle
Returns:
the bytes for the resource variant./**
	 * Get the bytes to be stored in the <code>ResourceVariantByteStore</code>
	 * from the given resource variant. By default, the <code>IResourceVariant#asBytes()</code>
	 * method is used to get the bytes.
	 * @param local the local resource
	 * @param remote the corresponding resource variant handle
	 * @return the bytes for the resource variant.
	 */
	protected byte[] getBytes(IResource local, IResourceVariant remote) throws TeamException {
		if (remote == null) return null;
		return remote.asBytes();
	}

	@Override
	protected IResource[] collectChanges(final IResource local,
			final IResourceVariant remote, final int depth, IProgressMonitor monitor)
			throws TeamException {
		final IResource[][] resources = new IResource[][] { null };
		getByteStore().run(local, monitor1 -> resources[0] = ResourceVariantTree.super.collectChanges(local, remote, depth, monitor1), monitor);
		return resources[0];
	}
}