/// <summary>Take a snapshot of the most recent commit to the
/// index. You must call release() to free this snapshot.
/// Note that while the snapshot is held, the files it
/// references will not be deleted, which will consume
/// additional disk space in your index. If you take a
/// snapshot at a particularly bad time (say just before
/// you call optimize()) then in the worst case this could
/// consume an extra 1X of your total index size, until
/// you release the snapshot.
/// </summary>
// TODO 3.0: change this to return IndexCommit instead
public virtual IndexCommitPoint Snapshot()
{
lock (this)
{
if (lastCommit == null)
{
throw new System.SystemException("no index commits to snapshot !");
}
if (snapshot == null)
{
snapshot = lastCommit.GetSegmentsFileName();
}
else
{
throw new System.SystemException("snapshot is already set; please call release() first");
}
return(lastCommit);
}
}
public System.Object Run(IndexCommit commit)
{
if (commit != null)
{
if (directory != commit.GetDirectory())
throw new System.IO.IOException("the specified commit does not match the specified Directory");
return DoBody(commit.GetSegmentsFileName());
}
System.String segmentFileName = null;
long lastGen = - 1;
long gen = 0;
int genLookaheadCount = 0;
System.IO.IOException exc = null;
bool retry = false;
int method = 0;
// Loop until we succeed in calling doBody() without
// hitting an IOException. An IOException most likely
// means a commit was in process and has finished, in
// the time it took us to load the now-old infos files
// (and segments files). It's also possible it's a
// true error (corrupt index). To distinguish these,
// on each retry we must see "forward progress" on
// which generation we are trying to load. If we
// don't, then the original error is real and we throw
// it.
// We have three methods for determining the current
// generation. We try the first two in parallel, and
// fall back to the third when necessary.
while (true)
{
if (0 == method)
{
// Method 1: list the directory and use the highest
// segments_N file. This method works well as long
// as there is no stale caching on the directory
// contents (NOTE: NFS clients often have such stale
// caching):
System.String[] files = null;
long genA = - 1;
files = directory.ListAll();
if (files != null)
genA = Mono.Lucene.Net.Index.SegmentInfos.GetCurrentSegmentGeneration(files);
Mono.Lucene.Net.Index.SegmentInfos.Message("directory listing genA=" + genA);
// Method 2: open segments.gen and read its
// contents. Then we take the larger of the two
// gens. This way, if either approach is hitting
// a stale cache (NFS) we have a better chance of
// getting the right generation.
long genB = - 1;
for (int i = 0; i < Mono.Lucene.Net.Index.SegmentInfos.defaultGenFileRetryCount; i++)
{
IndexInput genInput = null;
try
{
genInput = directory.OpenInput(IndexFileNames.SEGMENTS_GEN);
}
catch (System.IO.FileNotFoundException e)
{
Mono.Lucene.Net.Index.SegmentInfos.Message("segments.gen open: FileNotFoundException " + e);
break;
}
catch (System.IO.IOException e)
{
Mono.Lucene.Net.Index.SegmentInfos.Message("segments.gen open: IOException " + e);
}
if (genInput != null)
{
try
{
int version = genInput.ReadInt();
if (version == Mono.Lucene.Net.Index.SegmentInfos.FORMAT_LOCKLESS)
{
long gen0 = genInput.ReadLong();
long gen1 = genInput.ReadLong();
Mono.Lucene.Net.Index.SegmentInfos.Message("fallback check: " + gen0 + "; " + gen1);
if (gen0 == gen1)
{
// The file is consistent.
genB = gen0;
break;
}
}
}
catch (System.IO.IOException err2)
{
// will retry
}
finally
{
genInput.Close();
}
}
try
{
System.Threading.Thread.Sleep(new System.TimeSpan((System.Int64) 10000 * Mono.Lucene.Net.Index.SegmentInfos.defaultGenFileRetryPauseMsec));
}
catch (System.Threading.ThreadInterruptedException ie)
{
// In 3.0 we will change this to throw
// InterruptedException instead
SupportClass.ThreadClass.Current().Interrupt();
throw new System.SystemException(ie.Message, ie);
}
}
Mono.Lucene.Net.Index.SegmentInfos.Message(IndexFileNames.SEGMENTS_GEN + " check: genB=" + genB);
// Pick the larger of the two gen's:
if (genA > genB)
gen = genA;
else
gen = genB;
if (gen == - 1)
{
// Neither approach found a generation
System.String s;
if (files != null)
{
s = "";
for (int i = 0; i < files.Length; i++)
s += (" " + files[i]);
}
else
s = " null";
throw new System.IO.FileNotFoundException("no segments* file found in " + directory + ": files:" + s);
}
}
// Third method (fallback if first & second methods
// are not reliable): since both directory cache and
// file contents cache seem to be stale, just
// advance the generation.
if (1 == method || (0 == method && lastGen == gen && retry))
{
method = 1;
if (genLookaheadCount < Mono.Lucene.Net.Index.SegmentInfos.defaultGenLookaheadCount)
{
gen++;
genLookaheadCount++;
Mono.Lucene.Net.Index.SegmentInfos.Message("look ahead increment gen to " + gen);
}
}
if (lastGen == gen)
{
// This means we're about to try the same
// segments_N last tried. This is allowed,
// exactly once, because writer could have been in
// the process of writing segments_N last time.
if (retry)
{
// OK, we've tried the same segments_N file
// twice in a row, so this must be a real
// error. We throw the original exception we
// got.
throw exc;
}
else
{
retry = true;
}
}
else if (0 == method)
{
// Segment file has advanced since our last loop, so
// reset retry:
retry = false;
}
lastGen = gen;
segmentFileName = IndexFileNames.FileNameFromGeneration(IndexFileNames.SEGMENTS, "", gen);
try
{
System.Object v = DoBody(segmentFileName);
Mono.Lucene.Net.Index.SegmentInfos.Message("success on " + segmentFileName);
return v;
}
catch (System.IO.IOException err)
{
// Save the original root cause:
if (exc == null)
{
exc = err;
}
Mono.Lucene.Net.Index.SegmentInfos.Message("primary Exception on '" + segmentFileName + "': " + err + "'; will retry: retry=" + retry + "; gen = " + gen);
if (!retry && gen > 1)
{
// This is our first time trying this segments
// file (because retry is false), and, there is
// possibly a segments_(N-1) (because gen > 1).
// So, check if the segments_(N-1) exists and
// try it if so:
System.String prevSegmentFileName = IndexFileNames.FileNameFromGeneration(IndexFileNames.SEGMENTS, "", gen - 1);
bool prevExists;
prevExists = directory.FileExists(prevSegmentFileName);
if (prevExists)
{
Mono.Lucene.Net.Index.SegmentInfos.Message("fallback to prior segment file '" + prevSegmentFileName + "'");
try
{
System.Object v = DoBody(prevSegmentFileName);
if (exc != null)
{
Mono.Lucene.Net.Index.SegmentInfos.Message("success on fallback " + prevSegmentFileName);
}
return v;
}
catch (System.IO.IOException err2)
{
Mono.Lucene.Net.Index.SegmentInfos.Message("secondary Exception on '" + prevSegmentFileName + "': " + err2 + "'; will retry");
}
}
}
}
}
}
public override System.String GetSegmentsFileName()
{
return(cp.GetSegmentsFileName());
}
private IndexReader DoReopenNoWriter(bool openReadOnly, IndexCommit commit)
{
lock (this)
{
if (commit == null)
{
if (hasChanges)
{
// We have changes, which means we are not readOnly:
System.Diagnostics.Debug.Assert(readOnly == false);
// and we hold the write lock:
System.Diagnostics.Debug.Assert(writeLock != null);
// so no other writer holds the write lock, which
// means no changes could have been done to the index:
System.Diagnostics.Debug.Assert(IsCurrent());
if (openReadOnly)
{
return (IndexReader)Clone(openReadOnly);
}
else
{
return this;
}
}
else if (IsCurrent())
{
if (openReadOnly != readOnly)
{
// Just fallback to clone
return (IndexReader)Clone(openReadOnly);
}
else
{
return this;
}
}
}
else
{
if (directory != commit.GetDirectory())
throw new System.IO.IOException("the specified commit does not match the specified Directory");
if (segmentInfos != null && commit.GetSegmentsFileName().Equals(segmentInfos.GetCurrentSegmentFileName()))
{
if (readOnly != openReadOnly)
{
// Just fallback to clone
return (IndexReader)Clone(openReadOnly);
}
else
{
return this;
}
}
}
return (IndexReader)new AnonymousFindSegmentsFile(directory, openReadOnly, this).Run(commit);
}
}
public System.Object Run(IndexCommit commit)
{
if (commit != null)
{
if (directory != commit.GetDirectory())
{
throw new System.IO.IOException("the specified commit does not match the specified Directory");
}
return(DoBody(commit.GetSegmentsFileName()));
}
System.String segmentFileName = null;
long lastGen = -1;
long gen = 0;
int genLookaheadCount = 0;
System.IO.IOException exc = null;
bool retry = false;
int method = 0;
// Loop until we succeed in calling doBody() without
// hitting an IOException. An IOException most likely
// means a commit was in process and has finished, in
// the time it took us to load the now-old infos files
// (and segments files). It's also possible it's a
// true error (corrupt index). To distinguish these,
// on each retry we must see "forward progress" on
// which generation we are trying to load. If we
// don't, then the original error is real and we throw
// it.
// We have three methods for determining the current
// generation. We try the first two in parallel, and
// fall back to the third when necessary.
while (true)
{
if (0 == method)
{
// Method 1: list the directory and use the highest
// segments_N file. This method works well as long
// as there is no stale caching on the directory
// contents (NOTE: NFS clients often have such stale
// caching):
System.String[] files = null;
long genA = -1;
files = directory.ListAll();
if (files != null)
{
genA = Mono.Lucene.Net.Index.SegmentInfos.GetCurrentSegmentGeneration(files);
}
Mono.Lucene.Net.Index.SegmentInfos.Message("directory listing genA=" + genA);
// Method 2: open segments.gen and read its
// contents. Then we take the larger of the two
// gens. This way, if either approach is hitting
// a stale cache (NFS) we have a better chance of
// getting the right generation.
long genB = -1;
for (int i = 0; i < Mono.Lucene.Net.Index.SegmentInfos.defaultGenFileRetryCount; i++)
{
IndexInput genInput = null;
try
{
genInput = directory.OpenInput(IndexFileNames.SEGMENTS_GEN);
}
catch (System.IO.FileNotFoundException e)
{
Mono.Lucene.Net.Index.SegmentInfos.Message("segments.gen open: FileNotFoundException " + e);
break;
}
catch (System.IO.IOException e)
{
Mono.Lucene.Net.Index.SegmentInfos.Message("segments.gen open: IOException " + e);
}
if (genInput != null)
{
try
{
int version = genInput.ReadInt();
if (version == Mono.Lucene.Net.Index.SegmentInfos.FORMAT_LOCKLESS)
{
long gen0 = genInput.ReadLong();
long gen1 = genInput.ReadLong();
Mono.Lucene.Net.Index.SegmentInfos.Message("fallback check: " + gen0 + "; " + gen1);
if (gen0 == gen1)
{
// The file is consistent.
genB = gen0;
break;
}
}
}
catch (System.IO.IOException err2)
{
// will retry
}
finally
{
genInput.Close();
}
}
try
{
System.Threading.Thread.Sleep(new System.TimeSpan((System.Int64) 10000 * Mono.Lucene.Net.Index.SegmentInfos.defaultGenFileRetryPauseMsec));
}
catch (System.Threading.ThreadInterruptedException ie)
{
// In 3.0 we will change this to throw
// InterruptedException instead
SupportClass.ThreadClass.Current().Interrupt();
throw new System.SystemException(ie.Message, ie);
}
}
Mono.Lucene.Net.Index.SegmentInfos.Message(IndexFileNames.SEGMENTS_GEN + " check: genB=" + genB);
// Pick the larger of the two gen's:
if (genA > genB)
{
gen = genA;
}
else
{
gen = genB;
}
if (gen == -1)
{
// Neither approach found a generation
System.String s;
if (files != null)
{
s = "";
for (int i = 0; i < files.Length; i++)
{
s += (" " + files[i]);
}
}
else
{
s = " null";
}
throw new System.IO.FileNotFoundException("no segments* file found in " + directory + ": files:" + s);
}
}
// Third method (fallback if first & second methods
// are not reliable): since both directory cache and
// file contents cache seem to be stale, just
// advance the generation.
if (1 == method || (0 == method && lastGen == gen && retry))
{
method = 1;
if (genLookaheadCount < Mono.Lucene.Net.Index.SegmentInfos.defaultGenLookaheadCount)
{
gen++;
genLookaheadCount++;
Mono.Lucene.Net.Index.SegmentInfos.Message("look ahead increment gen to " + gen);
}
}
if (lastGen == gen)
{
// This means we're about to try the same
// segments_N last tried. This is allowed,
// exactly once, because writer could have been in
// the process of writing segments_N last time.
if (retry)
{
// OK, we've tried the same segments_N file
// twice in a row, so this must be a real
// error. We throw the original exception we
// got.
throw exc;
}
else
{
retry = true;
}
}
else if (0 == method)
{
// Segment file has advanced since our last loop, so
// reset retry:
retry = false;
}
lastGen = gen;
segmentFileName = IndexFileNames.FileNameFromGeneration(IndexFileNames.SEGMENTS, "", gen);
try
{
System.Object v = DoBody(segmentFileName);
Mono.Lucene.Net.Index.SegmentInfos.Message("success on " + segmentFileName);
return(v);
}
catch (System.IO.IOException err)
{
// Save the original root cause:
if (exc == null)
{
exc = err;
}
Mono.Lucene.Net.Index.SegmentInfos.Message("primary Exception on '" + segmentFileName + "': " + err + "'; will retry: retry=" + retry + "; gen = " + gen);
if (!retry && gen > 1)
{
// This is our first time trying this segments
// file (because retry is false), and, there is
// possibly a segments_(N-1) (because gen > 1).
// So, check if the segments_(N-1) exists and
// try it if so:
System.String prevSegmentFileName = IndexFileNames.FileNameFromGeneration(IndexFileNames.SEGMENTS, "", gen - 1);
bool prevExists;
prevExists = directory.FileExists(prevSegmentFileName);
if (prevExists)
{
Mono.Lucene.Net.Index.SegmentInfos.Message("fallback to prior segment file '" + prevSegmentFileName + "'");
try
{
System.Object v = DoBody(prevSegmentFileName);
if (exc != null)
{
Mono.Lucene.Net.Index.SegmentInfos.Message("success on fallback " + prevSegmentFileName);
}
return(v);
}
catch (System.IO.IOException err2)
{
Mono.Lucene.Net.Index.SegmentInfos.Message("secondary Exception on '" + prevSegmentFileName + "': " + err2 + "'; will retry");
}
}
}
}
}
}
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;
}
}
}
