/**
* Recursively compute the difference between snapshots under a given directory/file.
*
* @param node The directory/file under which the diff is computed.
* @param parentPath Relative path (corresponding to the snapshot root) of the node's parent.
* @param diffReport data structure used to store the diff.
*/
private void computeDiffRecursively(
INode node, List<byte[]> parentPath, SnapshotDiffInfo diffReport) {
ChildrenDiff diff = new ChildrenDiff();
byte[][] relativePath = parentPath.toArray(new byte[parentPath.size()][]);
if (node.isDirectory()) {
INodeDirectory dir = node.asDirectory();
if (dir instanceof INodeDirectoryWithSnapshot) {
INodeDirectoryWithSnapshot sdir = (INodeDirectoryWithSnapshot) dir;
boolean change = sdir.computeDiffBetweenSnapshots(diffReport.from, diffReport.to, diff);
if (change) {
diffReport.addDirDiff(sdir, relativePath, diff);
}
}
ReadOnlyList<INode> children =
dir.getChildrenList(diffReport.isFromEarlier() ? diffReport.to : diffReport.from);
for (INode child : children) {
final byte[] name = child.getLocalNameBytes();
if (diff.searchIndex(ListType.CREATED, name) < 0
&& diff.searchIndex(ListType.DELETED, name) < 0) {
parentPath.add(name);
computeDiffRecursively(child, parentPath, diffReport);
parentPath.remove(parentPath.size() - 1);
}
}
} else if (node.isFile() && node.asFile() instanceof FileWithSnapshot) {
FileWithSnapshot file = (FileWithSnapshot) node.asFile();
Snapshot earlierSnapshot = diffReport.isFromEarlier() ? diffReport.from : diffReport.to;
Snapshot laterSnapshot = diffReport.isFromEarlier() ? diffReport.to : diffReport.from;
boolean change = file.getDiffs().changedBetweenSnapshots(earlierSnapshot, laterSnapshot);
if (change) {
diffReport.addFileDiff(file.asINodeFile(), relativePath);
}
}
}
/**
* Find the latest snapshot that 1) covers the given inode (which means the snapshot was either
* taken on the inode or taken on an ancestor of the inode), and 2) was taken before the given
* snapshot (if the given snapshot is not null).
*
* @param inode the given inode that the returned snapshot needs to cover
* @param anchor the returned snapshot should be taken before this given id.
* @return id of the latest snapshot that covers the given inode and was taken before the the
* given snapshot (if it is not null).
*/
public static int findLatestSnapshot(INode inode, final int anchor) {
int latest = NO_SNAPSHOT_ID;
for (; inode != null; inode = inode.getParent()) {
if (inode.isDirectory()) {
final INodeDirectory dir = inode.asDirectory();
if (dir.isWithSnapshot()) {
latest = dir.getDiffs().updatePrior(anchor, latest);
}
}
}
return latest;
}
/** Load the snapshot diff section from fsimage. */
public void loadSnapshotDiffSection(InputStream in) throws IOException {
final List<INodeReference> refList = parent.getLoaderContext().getRefList();
while (true) {
SnapshotDiffSection.DiffEntry entry = SnapshotDiffSection.DiffEntry.parseDelimitedFrom(in);
if (entry == null) {
break;
}
long inodeId = entry.getInodeId();
INode inode = fsDir.getInode(inodeId);
SnapshotDiffSection.DiffEntry.Type type = entry.getType();
switch (type) {
case FILEDIFF:
loadFileDiffList(in, inode.asFile(), entry.getNumOfDiff());
break;
case DIRECTORYDIFF:
loadDirectoryDiffList(in, inode.asDirectory(), entry.getNumOfDiff(), refList);
break;
}
}
}
static Snapshot read(DataInput in, FSImageFormat.Loader loader) throws IOException {
final int snapshotId = in.readInt();
final INode root = loader.loadINodeWithLocalName(false, in, false);
return new Snapshot(snapshotId, root.asDirectory(), null);
}