/// <summary> Returns <code>true</code> iff the index in the named directory is
/// currently locked.
/// </summary>
/// <param name="directory">the directory to check for a lock
/// </param>
/// <throws> IOException if there is a low-level IO error </throws>
public static bool IsLocked(Directory directory)
{
return directory.MakeLock(WRITE_LOCK_NAME).IsLocked();
}
/// <summary> Forcibly unlocks the index in the named directory.
/// <p/>
/// Caution: this should only be used by failure recovery code,
/// when it is known that no other process nor thread is in fact
/// currently accessing this index.
/// </summary>
public static void Unlock(Directory directory)
{
directory.MakeLock(IndexWriter.WRITE_LOCK_NAME).Release();
}
private void Init(Directory d, Analyzer a, bool create, bool closeDir, IndexDeletionPolicy deletionPolicy, bool autoCommit, int maxFieldLength, IndexingChain indexingChain, IndexCommit commit)
{
this.closeDir = closeDir;
directory = d;
analyzer = a;
SetMessageID(defaultInfoStream);
this.maxFieldLength = maxFieldLength;
if (indexingChain == null)
indexingChain = DocumentsWriter.DefaultIndexingChain;
if (create)
{
// Clear the write lock in case it's leftover:
directory.ClearLock(WRITE_LOCK_NAME);
}
Lock writeLock = directory.MakeLock(WRITE_LOCK_NAME);
if (!writeLock.Obtain(writeLockTimeout))
// obtain write lock
{
throw new LockObtainFailedException("Index locked for write: " + writeLock);
}
this.writeLock = writeLock; // save it
bool success = false;
try
{
if (create)
{
// Try to read first. This is to allow create
// against an index that's currently open for
// searching. In this case we write the next
// segments_N file with no segments:
bool doCommit;
try
{
segmentInfos.Read(directory);
segmentInfos.Clear();
doCommit = false;
}
catch (System.IO.IOException e)
{
// Likely this means it's a fresh directory
doCommit = true;
}
if (autoCommit || doCommit)
{
// Always commit if autoCommit=true, else only
// commit if there is no segments file in this dir
// already.
segmentInfos.Commit(directory);
SupportClass.CollectionsHelper.AddAllIfNotContains(synced, segmentInfos.Files(directory, true));
}
else
{
// Record that we have a change (zero out all
// segments) pending:
changeCount++;
}
}
else
{
segmentInfos.Read(directory);
if (commit != null)
{
// Swap out all segments, but, keep metadata in
// SegmentInfos, like version & generation, to
// preserve write-once. This is important if
// readers are open against the future commit
// points.
if (commit.GetDirectory() != directory)
throw new System.ArgumentException("IndexCommit's directory doesn't match my directory");
SegmentInfos oldInfos = new SegmentInfos();
oldInfos.Read(directory, commit.GetSegmentsFileName());
segmentInfos.Replace(oldInfos);
changeCount++;
if (infoStream != null)
Message("init: loaded commit \"" + commit.GetSegmentsFileName() + "\"");
}
// We assume that this segments_N was previously
// properly sync'd:
SupportClass.CollectionsHelper.AddAllIfNotContains(synced, segmentInfos.Files(directory, true));
}
this.autoCommit = autoCommit;
SetRollbackSegmentInfos(segmentInfos);
docWriter = new DocumentsWriter(directory, this, indexingChain);
docWriter.SetInfoStream(infoStream);
docWriter.SetMaxFieldLength(maxFieldLength);
// Default deleter (for backwards compatibility) is
// KeepOnlyLastCommitDeleter:
deleter = new IndexFileDeleter(directory, deletionPolicy == null?new KeepOnlyLastCommitDeletionPolicy():deletionPolicy, segmentInfos, infoStream, docWriter,synced);
if (deleter.startingCommitDeleted)
// Deletion policy deleted the "head" commit point.
// We have to mark ourself as changed so that if we
// are closed w/o any further changes we write a new
// segments_N file.
changeCount++;
PushMaxBufferedDocs();
if (infoStream != null)
{
Message("init: create=" + create);
MessageState();
}
success = true;
}
finally
{
if (!success)
{
if (infoStream != null)
{
Message("init: hit exception on init; releasing write lock");
}
try
{
writeLock.Release();
}
catch (Exception t)
{
// don't mask the original exception
}
writeLock = null;
}
}
}