/// <summary>Get a listing of all the snapshots of a snapshottable directory</summary>
/// <exception cref="System.IO.IOException"/>
private static DirectoryListing GetSnapshotsListing(FSDirectory fsd, string src,
byte[] startAfter)
{
Preconditions.CheckState(fsd.HasReadLock());
Preconditions.CheckArgument(src.EndsWith(HdfsConstants.SeparatorDotSnapshotDir),
"%s does not end with %s", src, HdfsConstants.SeparatorDotSnapshotDir);
string dirPath = FSDirectory.NormalizePath(Sharpen.Runtime.Substring(src, 0, src.
Length - HdfsConstants.DotSnapshotDir.Length));
INode node = fsd.GetINode(dirPath);
INodeDirectory dirNode = INodeDirectory.ValueOf(node, dirPath);
DirectorySnapshottableFeature sf = dirNode.GetDirectorySnapshottableFeature();
if (sf == null)
{
throw new SnapshotException("Directory is not a snapshottable directory: " + dirPath
);
}
ReadOnlyList <Org.Apache.Hadoop.Hdfs.Server.Namenode.Snapshot.Snapshot> snapshots =
sf.GetSnapshotList();
int skipSize = ReadOnlyList.Util.BinarySearch(snapshots, startAfter);
skipSize = skipSize < 0 ? -skipSize - 1 : skipSize + 1;
int numOfListing = Math.Min(snapshots.Size() - skipSize, fsd.GetLsLimit());
HdfsFileStatus[] listing = new HdfsFileStatus[numOfListing];
for (int i = 0; i < numOfListing; i++)
{
Snapshot.Root sRoot = snapshots.Get(i + skipSize).GetRoot();
listing[i] = CreateFileStatus(fsd, src, sRoot.GetLocalNameBytes(), sRoot, BlockStoragePolicySuite
.IdUnspecified, Org.Apache.Hadoop.Hdfs.Server.Namenode.Snapshot.Snapshot.CurrentStateId
, false, INodesInPath.FromINode(sRoot));
}
return(new DirectoryListing(listing, snapshots.Size() - skipSize - numOfListing));
}
/// <param name="name">the name of the child</param>
/// <param name="snapshotId">
/// if it is not
/// <see cref="Org.Apache.Hadoop.Hdfs.Server.Namenode.Snapshot.Snapshot.CurrentStateId
/// "/>
/// , get the result
/// from the corresponding snapshot; otherwise, get the result from
/// the current directory.
/// </param>
/// <returns>the child inode.</returns>
public virtual INode GetChild(byte[] name, int snapshotId)
{
DirectoryWithSnapshotFeature sf;
if (snapshotId == Org.Apache.Hadoop.Hdfs.Server.Namenode.Snapshot.Snapshot.CurrentStateId ||
(sf = GetDirectoryWithSnapshotFeature()) == null)
{
ReadOnlyList <INode> c = GetCurrentChildrenList();
int i = ReadOnlyList.Util.BinarySearch(c, name);
return(i < 0 ? null : c.Get(i));
}
return(sf.GetChild(this, name, snapshotId));
}
protected internal virtual ContentSummaryComputationContext ComputeDirectoryContentSummary
(ContentSummaryComputationContext summary, int snapshotId)
{
ReadOnlyList <INode> childrenList = GetChildrenList(snapshotId);
// Explicit traversing is done to enable repositioning after relinquishing
// and reacquiring locks.
for (int i = 0; i < childrenList.Size(); i++)
{
INode child = childrenList.Get(i);
byte[] childName = child.GetLocalNameBytes();
long lastYieldCount = summary.GetYieldCount();
child.ComputeContentSummary(summary);
// Check whether the computation was paused in the subtree.
// The counts may be off, but traversing the rest of children
// should be made safe.
if (lastYieldCount == summary.GetYieldCount())
{
continue;
}
// The locks were released and reacquired. Check parent first.
if (GetParent() == null)
{
// Stop further counting and return whatever we have so far.
break;
}
// Obtain the children list again since it may have been modified.
childrenList = GetChildrenList(snapshotId);
// Reposition in case the children list is changed. Decrement by 1
// since it will be incremented when loops.
i = NextChild(childrenList, childName) - 1;
}
// Increment the directory count for this directory.
summary.GetCounts().AddContent(Content.Directory, 1);
// Relinquish and reacquire locks if necessary.
summary.Yield();
return(summary);
}
/// <summary>Check the correctness of snapshot list within snapshottable dir</summary>
private void CheckSnapshotList(INodeDirectory srcRoot, string[] sortedNames, string
[] names)
{
NUnit.Framework.Assert.IsTrue(srcRoot.IsSnapshottable());
ReadOnlyList <Org.Apache.Hadoop.Hdfs.Server.Namenode.Snapshot.Snapshot> listByName
= srcRoot.GetDirectorySnapshottableFeature().GetSnapshotList();
NUnit.Framework.Assert.AreEqual(sortedNames.Length, listByName.Size());
for (int i = 0; i < listByName.Size(); i++)
{
NUnit.Framework.Assert.AreEqual(sortedNames[i], listByName.Get(i).GetRoot().GetLocalName
());
}
IList <DirectoryWithSnapshotFeature.DirectoryDiff> listByTime = srcRoot.GetDiffs()
.AsList();
NUnit.Framework.Assert.AreEqual(names.Length, listByTime.Count);
for (int i_1 = 0; i_1 < listByTime.Count; i_1++)
{
Org.Apache.Hadoop.Hdfs.Server.Namenode.Snapshot.Snapshot s = srcRoot.GetDirectorySnapshottableFeature
().GetSnapshotById(listByTime[i_1].GetSnapshotId());
NUnit.Framework.Assert.AreEqual(names[i_1], s.GetRoot().GetLocalName());
}
}
/// <summary>
/// Get a partial listing of the indicated directory
/// We will stop when any of the following conditions is met:
/// 1) this.lsLimit files have been added
/// 2) needLocation is true AND enough files have been added such
/// that at least this.lsLimit block locations are in the response
/// </summary>
/// <param name="fsd">FSDirectory</param>
/// <param name="iip">
/// the INodesInPath instance containing all the INodes along the
/// path
/// </param>
/// <param name="src">the directory name</param>
/// <param name="startAfter">the name to start listing after</param>
/// <param name="needLocation">if block locations are returned</param>
/// <returns>a partial listing starting after startAfter</returns>
/// <exception cref="System.IO.IOException"/>
private static DirectoryListing GetListing(FSDirectory fsd, INodesInPath iip, string
src, byte[] startAfter, bool needLocation, bool isSuperUser)
{
string srcs = FSDirectory.NormalizePath(src);
bool isRawPath = FSDirectory.IsReservedRawName(src);
fsd.ReadLock();
try
{
if (srcs.EndsWith(HdfsConstants.SeparatorDotSnapshotDir))
{
return(GetSnapshotsListing(fsd, srcs, startAfter));
}
int snapshot = iip.GetPathSnapshotId();
INode targetNode = iip.GetLastINode();
if (targetNode == null)
{
return(null);
}
byte parentStoragePolicy = isSuperUser ? targetNode.GetStoragePolicyID() : BlockStoragePolicySuite
.IdUnspecified;
if (!targetNode.IsDirectory())
{
return(new DirectoryListing(new HdfsFileStatus[] { CreateFileStatus(fsd, src, HdfsFileStatus
.EmptyName, targetNode, needLocation, parentStoragePolicy, snapshot, isRawPath,
iip) }, 0));
}
INodeDirectory dirInode = targetNode.AsDirectory();
ReadOnlyList <INode> contents = dirInode.GetChildrenList(snapshot);
int startChild = INodeDirectory.NextChild(contents, startAfter);
int totalNumChildren = contents.Size();
int numOfListing = Math.Min(totalNumChildren - startChild, fsd.GetLsLimit());
int locationBudget = fsd.GetLsLimit();
int listingCnt = 0;
HdfsFileStatus[] listing = new HdfsFileStatus[numOfListing];
for (int i = 0; i < numOfListing && locationBudget > 0; i++)
{
INode cur = contents.Get(startChild + i);
byte curPolicy = isSuperUser && !cur.IsSymlink() ? cur.GetLocalStoragePolicyID() :
BlockStoragePolicySuite.IdUnspecified;
listing[i] = CreateFileStatus(fsd, src, cur.GetLocalNameBytes(), cur, needLocation
, GetStoragePolicyID(curPolicy, parentStoragePolicy), snapshot, isRawPath, iip);
listingCnt++;
if (needLocation)
{
// Once we hit lsLimit locations, stop.
// This helps to prevent excessively large response payloads.
// Approximate #locations with locatedBlockCount() * repl_factor
LocatedBlocks blks = ((HdfsLocatedFileStatus)listing[i]).GetBlockLocations();
locationBudget -= (blks == null) ? 0 : blks.LocatedBlockCount() * listing[i].GetReplication
();
}
}
// truncate return array if necessary
if (listingCnt < numOfListing)
{
listing = Arrays.CopyOf(listing, listingCnt);
}
return(new DirectoryListing(listing, totalNumChildren - startChild - listingCnt));
}
finally
{
fsd.ReadUnlock();
}
}
