Copyright (c) 2000, 2005 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, 2005 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.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 ResourceVariantByteStore 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 responsibility of the client of this API to cache enough bytes to meaningfully identify a resource variant (and possibly create an IResourceVariant handle from them).
The bytes for a resource variant are accessed using the local IResource handle
that corresponds to the resource variant (using the getBytes method).
The potential children of a resource variant are also accessed
by using the local handle that corresponds to the resource variant
(using the members method).
Since: 3.0
/**
* 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
* responsibility 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.
/**
* 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 null 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.
Params: - resource – the local resource
Throws: Returns: the bytes that represent the resource's variant
/**
* 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 null. If it is known that the remote
does not exist, deleteBytes(IResource) should be used instead.
If the sync bytes for the remote are stale and should be removed,
flushBytes(IResouce, int) should be called.
Params: - resource – the local resource
- bytes – the bytes that represent the resource's variant
Throws: Returns: true if the bytes changed
/**
* 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, getBytes(resource) will
return null for the affected resources.
Params: - resource – the local resource
- depth – the depth of the operation (one of
IResource.DEPTH_ZERO,
IResource.DEPTH_ONE, or IResource.DEPTH_INFINITE)
Throws: Returns: true if there were bytes present which were removed
/**
* 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 flush(IResource, int) method should be used in the cases
where a client wishes to remove bytes for other reason.
Params: - resource – the local resource
Returns: true if this changes the bytes for the variant
/**
* 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.
Params: - resource – the parent resource
Returns: the members who have resource variants in this tree.
/**
* 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
Params: - syncBytes1 – the first byte array or
null - syncBytes2 – the second byte array or
null
Returns: whether the two arrays are equal (i.e. same content)
/**
* 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 whether 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 modifications
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).
Params: - root – the root resource for all modifications
- runnable – the action to perform
- monitor – a progress monitor.
Throws: - TeamException – if the operation failed.
- OperationCanceledException – if the operation is canceled.
/**
* Run the given action which may contain multiple modifications
* 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 runnable the action to perform
* @param monitor a progress monitor.
* @exception TeamException 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);
}
}
}