org.apache.lucene.index

Class SegmentInfo

java.lang.Object

org.apache.lucene.index.SegmentInfo

public final class SegmentInfo
extends Object

Information about a segment such as it's name, directory, and files related to the segment.

WARNING: This API is experimental and might change in incompatible ways in the next release.

Field Summary

Fields

Modifier and Type	Field and Description
Directory	dir Where this segment resides.
String	name Unique segment name in the directory.
static int	NO Used by some member fields to mean not present (e.g., norms, deletions).
static int	YES Used by some member fields to mean present (e.g., norms, deletions).

Constructor Summary

Constructors

Constructor and Description
SegmentInfo(Directory dir, String version, String name, int docCount, boolean isCompoundFile, Codec codec, Map<String,String> diagnostics) Construct a new complete SegmentInfo instance from input.

Method Summary

Methods

Modifier and Type	Method and Description
void	addFile(String file) Add this file to the set of files written for this segment.
void	addFiles(Collection<String> files) Add these files to the set of files written for this segment.
boolean	equals(Object obj) We consider another SegmentInfo instance equal if it has the same dir and same name.
Set<String>	files() Return all files referenced by this SegmentInfo.
Codec	getCodec() Return Codec that wrote this segment.
Map<String,String>	getDiagnostics() Returns diagnostics saved into the segment when it was written.
int	getDocCount() Returns number of documents in this segment (deletions are not taken into account).
boolean	getUseCompoundFile() Returns true if this segment is stored as a compound file; else, false.
String	getVersion() Returns the version of the code which wrote the segment.
int	hashCode()
void	setCodec(Codec codec) Can only be called once.
void	setFiles(Set<String> files) Sets the files written for this segment.
void	setVersion(String version) Used by DefaultSegmentInfosReader to upgrade a 3.0 segment to record its version is "3.0".
String	toString()
String	toString(Directory dir, int delCount) Used for debugging.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

NO

public static final int NO

Used by some member fields to mean not present (e.g., norms, deletions).

See Also:

Constant Field Values

YES

public static final int YES

Used by some member fields to mean present (e.g., norms, deletions).

See Also:

Constant Field Values

name

public final String name

Unique segment name in the directory.

dir

public final Directory dir

Where this segment resides.

Constructor Detail

SegmentInfo

public SegmentInfo(Directory dir,
           String version,
           String name,
           int docCount,
           boolean isCompoundFile,
           Codec codec,
           Map<String,String> diagnostics)

Construct a new complete SegmentInfo instance from input.

Note: this is public only to allow access from the codecs package.

Method Detail

getDiagnostics

public Map<String,String> getDiagnostics()

Returns diagnostics saved into the segment when it was written.

getUseCompoundFile

public boolean getUseCompoundFile()

Returns true if this segment is stored as a compound file; else, false.

setCodec

public void setCodec(Codec codec)

Can only be called once.

getCodec

public Codec getCodec()

Return Codec that wrote this segment.

getDocCount

public int getDocCount()

Returns number of documents in this segment (deletions are not taken into account).

files

public Set<String> files()

Return all files referenced by this SegmentInfo.

toString

public String toString()

Overrides:

toString in class Object

toString

public String toString(Directory dir,
              int delCount)

Used for debugging. Format may suddenly change.

Current format looks like _a(3.1):c45/4, which means the segment's name is _a; it was created with Lucene 3.1 (or '?' if it's unknown); it's using compound file format (would be C if not compound); it has 45 documents; it has 4 deletions (this part is left off when there are no deletions).

equals

public boolean equals(Object obj)

We consider another SegmentInfo instance equal if it has the same dir and same name.

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

setVersion

public void setVersion(String version)

Used by DefaultSegmentInfosReader to upgrade a 3.0 segment to record its version is "3.0". This method can be removed when we're not required to support 3x indexes anymore, e.g. in 5.0.

NOTE: this method is used for internal purposes only - you should not modify the version of a SegmentInfo, or it may result in unexpected exceptions thrown when you attempt to open the index.

NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.

getVersion

public String getVersion()

Returns the version of the code which wrote the segment.

setFiles

public void setFiles(Set<String> files)

Sets the files written for this segment.

addFiles

public void addFiles(Collection<String> files)

Add these files to the set of files written for this segment.

addFile

public void addFile(String file)

Add this file to the set of files written for this segment.