| /******************************************************************************* |
| * Copyright (c) 2000, 2004 IBM Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Common Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/cpl-v10.html |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.team.core.variants; |
| |
| import org.eclipse.core.resources.IResource; |
| import org.eclipse.core.resources.IWorkspaceRunnable; |
| import org.eclipse.core.runtime.CoreException; |
| import org.eclipse.core.runtime.IProgressMonitor; |
| import org.eclipse.core.runtime.OperationCanceledException; |
| import org.eclipse.team.core.TeamException; |
| |
| /** |
| * The purpose of a <code>ResourceVariantByteStore</code> is to support the caching of |
| * the synchronization bytes for the resource variants that represent |
| * a resource line-up of interest such as a version, baseline or branch. The |
| * cache stores bytes in order to minimize the memory footprint of the tree. It is the |
| * reponsibility of the client of this API to cache enough bytes to meaningfully identify |
| * a resource variant (and possibly create an {@link IResourceVariant} handle from them). |
| * <p> |
| * The bytes for a resource variant are accessed using the local <code>IResource</code> handle |
| * that corresponds to the resource variant (using the <code>getBytes</code> method). |
| * The potential children of a resource variant are also accessed |
| * by using the local handle that corresponds to the resource variant |
| * (using the <code>members</code> method). |
| * |
| * @since 3.0 |
| */ |
| public abstract class ResourceVariantByteStore { |
| |
| /** |
| * Dispose of any cached sync bytes when this cache is no longer needed. |
| */ |
| public abstract void dispose(); |
| |
| /** |
| * Return the bytes for the variant corresponding the given local resource. |
| * A return value of <code>null</code> means that no bytes have been stored |
| * for the resource variant. It is up to the client to determine whether |
| * this means that the resource variant does not exist or that it has not been |
| * fetched or otherwise determined yet. |
| * @param resource the local resource |
| * @return the bytes that represent the resource's variant |
| * @throws TeamException |
| */ |
| public abstract byte[] getBytes(IResource resource) throws TeamException; |
| |
| /** |
| * Set the bytes for the variant corresponding the given local resource. |
| * The bytes should never be <code>null</code>. If it is known that the remote |
| * does not exist, <code>deleteBytes(IResource)</code> should be used instead. |
| * If the sync bytes for the remote are stale and should be removed, |
| * <code>flushBytes(IResouce, int)</code> should be called. |
| * @param resource the local resource |
| * @param bytes the bytes that represent the resource's variant |
| * @return <code>true</code> if the bytes changed |
| * @throws TeamException |
| */ |
| public abstract boolean setBytes(IResource resource, byte[] bytes) throws TeamException; |
| |
| /** |
| * Remove the bytes from the tree for the resource variants corresponding to the |
| * given local resource and its descendants to the given depth. |
| * After the bytes are removed, <code>getBytes(resource)</code> will |
| * return <code>null</code> for the affected resources. |
| * @param resource the local resource |
| * @param depth the depth of the operation (one of <code>IResource.DEPTH_ZERO</code>, |
| * <code>IResource.DEPTH_ONE</code>, or <code>IResource.DEPTH_INFINITE</code>) |
| * @return <code>true</code> if there were bytes present which were removed |
| * @throws TeamException |
| */ |
| public abstract boolean flushBytes(IResource resource, int depth) throws TeamException; |
| |
| /** |
| * Method called to indicate that it is known that there is no variant associated |
| * with the local resource. Subclasses may handle this information in different ways. |
| * The <code>flush(IResource, int)</code> method should be used in the cases |
| * where a client wishes to remove bytes for other reason. |
| * @param resource the local resource |
| * @return <code>true</code> if this changes the bytes for the variant |
| */ |
| public abstract boolean deleteBytes(IResource resource) throws TeamException; |
| |
| /** |
| * Return the children of the given resource that have resource variants in this tree. |
| * @param resource the parent resource |
| * @return the members who have resource variants in this tree. |
| */ |
| public abstract IResource[] members(IResource resource) throws TeamException; |
| |
| /** |
| * Helper method to compare two byte arrays for equality |
| * @param syncBytes1 the first byte array or <code>null</code> |
| * @param syncBytes2 the second byte array or <code>null</code> |
| * @return whetehr the two arrays are equal (i.e. same content) |
| */ |
| protected boolean equals(byte[] syncBytes1, byte[] syncBytes2) { |
| if (syncBytes1 == null) { |
| return syncBytes2 == null; |
| } else if (syncBytes2 == null) { |
| return false; |
| } |
| if (syncBytes1.length != syncBytes2.length) return false; |
| for (int i = 0; i < syncBytes1.length; i++) { |
| if (syncBytes1[i] != syncBytes2[i]) return false; |
| } |
| return true; |
| } |
| |
| /** |
| * Run the given action which may contain multiple modfications |
| * to the byte store. By default, the action is run. Subclasses |
| * may override to obtain scheduling rules or batch deltas (if |
| * the byte store modifies workspace resources). |
| * @param root the root resource for all modifications |
| * @param action the action to perform |
| * @param monitor a progress monitor. |
| * @exception CoreException if the operation failed. |
| * @exception OperationCanceledException if the operation is canceled. |
| */ |
| public void run(IResource root, IWorkspaceRunnable runnable, IProgressMonitor monitor) throws TeamException { |
| try { |
| runnable.run(monitor); |
| } catch (CoreException e) { |
| throw TeamException.asTeamException(e); |
| } |
| } |
| } |