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Diffstat (limited to 'bundles/org.eclipse.team.core/src/org/eclipse/team/core/subscribers/utils/SynchronizationCache.java')
| -rw-r--r-- | bundles/org.eclipse.team.core/src/org/eclipse/team/core/subscribers/utils/SynchronizationCache.java | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/bundles/org.eclipse.team.core/src/org/eclipse/team/core/subscribers/utils/SynchronizationCache.java b/bundles/org.eclipse.team.core/src/org/eclipse/team/core/subscribers/utils/SynchronizationCache.java new file mode 100644 index 000000000..e45bacd9c --- /dev/null +++ b/bundles/org.eclipse.team.core/src/org/eclipse/team/core/subscribers/utils/SynchronizationCache.java @@ -0,0 +1,107 @@ +/******************************************************************************* + * Copyright (c) 2000, 2003 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.subscribers.utils; + +import org.eclipse.core.resources.IResource; +import org.eclipse.team.core.TeamException; + +/** + * This class defines the API for a synchronization bytes cache. Synchronization + * bytes are associated with a local resource handle. + * It also has API that differentiates the case of no existing remote for + * a local resource from that of the remote state never having been queried + * for that local resource. + */ +public abstract class SynchronizationCache { + + /** + * Dispose of any cached sync bytes when this cache is no longer needed. + */ + public abstract void dispose(); + + /** + * Return the remote sync bytes cached for the given local resource. + * A return value of <code>null</code> can mean either that the + * remote has never been fetched or that it doesn't exist. The method + * <code>isRemoteKnown(IResource)</code> should be used to differentiate + * these two cases. + * @param resource the local resource + * @return the synchronization bytes for a corresponding remote resource + * @throws TeamException + */ + public abstract byte[] getSyncBytes(IResource resource) throws TeamException; + + /** + * Set the remote sync bytes for the given resource. The bytes should never be + * <code>null</code>. If it is known that the remote does not exist, + * <code>setRemoteDoesNotExist(IResource)</code> should be invoked. If the sync + * bytes for the remote are stale and should be removed, <code>removeSyncBytes()</code> + * should be called. + * @param resource the local resource + * @param bytes the synchronization bytes for a corresponding remote resource + * @return <code>true</code> if the sync bytes changed + * @throws TeamException + */ + public abstract boolean setSyncBytes(IResource resource, byte[] bytes) throws TeamException; + + /** + * Remove the remote bytes cached for the given local resource. After this + * operation <code>isRemoteKnown(resource)</code> will return <code>false</code> + * and <code>getSyncBytes(resource)</code> will return <code>null</code> for the + * resource (and potentially it's children depending on the value of the depth parameter. + * @param resource the local resource + * @parem depth the depth of the operation (@see IResource) + * @return <code>true</code> if there were bytes present which were removed + * @throws TeamException + */ + public abstract boolean removeSyncBytes(IResource resource, int depth) throws TeamException; + + /** + * Return true if the remote resources associated with the given local + * resource has been fetched. This method is useful for those cases when + * there are no sync bytes for a remote resource and the client wants to + * know if this means that the remote does exist (i.e. this method returns + * <code>true</code>) or the remote has not been fetched (i.e. this method returns + * <code>false</code>). + * @param resource the local resource + * @throws TeamException + */ + public abstract boolean isRemoteKnown(IResource resource) throws TeamException; + + /** + * This method should be invoked by a client to indicate that it is known that + * there is no remote resource associated with the local resource. After this method + * is invoked, <code>isRemoteKnown(resource)</code> will return <code>true</code> and + * <code>getSyncBytes(resource)</code> will return <code>null</code>. + * @param resource the local resource + * @return <code>true</code> if this changes the remote sync bytes + */ + public abstract boolean setRemoteDoesNotExist(IResource resource) throws TeamException; + + /** + * Helper method to compare two byte arrays for equality + * @param syncBytes1 the first byte array + * @param syncBytes2 the second byte array + * @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; + } +} |