org.apache.lucene.index
Class IndexFileNames

java.lang.Object
  org.apache.lucene.index.IndexFileNames

public final class IndexFileNames
extends Object

This class contains useful constants representing filenames and extensions used by lucene, as well as convenience methods for querying whether a file name matches an extension (matchesExtension), as well as generating file names from a segment name, generation and extension ( fileNameFromGeneration, segmentFileName).

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

Field Summary

static String[]	COMPOUND_EXTENSIONS File extensions of old-style index files
static String	COMPOUND_FILE_EXTENSION Extension of compound file
static String	COMPOUND_FILE_STORE_EXTENSION Extension of compound file for doc store files
static String	DELETABLE Name of the index deletable file (only used in pre-lockless indices)
static String	DELETES_EXTENSION Extension of deletes
static String	FIELD_INFOS_EXTENSION Extension of field infos
static String	FIELDS_EXTENSION Extension of stored fields file
static String	FIELDS_INDEX_EXTENSION Extension of stored fields index file
static String	FREQ_EXTENSION Extension of freq postings file
static String	GEN_EXTENSION Extension of gen file
static String[]	INDEX_EXTENSIONS This array contains all filename extensions used by Lucene's index files, with two exceptions, namely the extension made up from .f + a number and from .s + a number.
static String[]	INDEX_EXTENSIONS_IN_COMPOUND_FILE File extensions that are added to a compound file (same as above, minus "del", "gen", "cfs").
static String[]	NON_STORE_INDEX_EXTENSIONS
static String	NORMS_EXTENSION Extension of norms file
static String	PLAIN_NORMS_EXTENSION Extension of plain norms
static String	PROX_EXTENSION Extension of prox postings file
static String	SEGMENTS Name of the index segment file
static String	SEGMENTS_GEN Name of the generation reference file name
static String	SEPARATE_NORMS_EXTENSION Extension of separate norms
static String[]	STORE_INDEX_EXTENSIONS
static String	TERMS_EXTENSION Extension of terms file
static String	TERMS_INDEX_EXTENSION Extension of terms index file
static String[]	VECTOR_EXTENSIONS File extensions for term vector support
static String	VECTORS_DOCUMENTS_EXTENSION Extension of vectors documents file
static String	VECTORS_FIELDS_EXTENSION Extension of vectors fields file
static String	VECTORS_INDEX_EXTENSION Extension of vectors index file

Constructor Summary

IndexFileNames()

Method Summary

static String	fileNameFromGeneration(String base, String ext, long gen) Computes the full file name from base, extension and generation.
static boolean	isDocStoreFile(String fileName) Returns true if the provided filename is one of the doc store files (ends with an extension in STORE_INDEX_EXTENSIONS).
static boolean	isSeparateNormsFile(String filename) Returns true if the given filename ends with the separate norms file pattern: SEPARATE_NORMS_EXTENSION + "[0-9]+".
static boolean	matchesExtension(String filename, String ext) Returns true if the given filename ends with the given extension.
static String	segmentFileName(String segmentName, String ext) Returns the file name that matches the given segment name and extension.
static String	stripSegmentName(String filename) Strips the segment file name out of the given one.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

SEGMENTS

public static final String SEGMENTS

Name of the index segment file

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Constant Field Values

SEGMENTS_GEN

public static final String SEGMENTS_GEN

Name of the generation reference file name

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Constant Field Values

DELETABLE

public static final String DELETABLE

Name of the index deletable file (only used in pre-lockless indices)

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Constant Field Values

NORMS_EXTENSION

public static final String NORMS_EXTENSION

Extension of norms file

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Constant Field Values

FREQ_EXTENSION

public static final String FREQ_EXTENSION

Extension of freq postings file

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Constant Field Values

PROX_EXTENSION

public static final String PROX_EXTENSION

Extension of prox postings file

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Constant Field Values

TERMS_EXTENSION

public static final String TERMS_EXTENSION

Extension of terms file

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Constant Field Values

TERMS_INDEX_EXTENSION

public static final String TERMS_INDEX_EXTENSION

Extension of terms index file

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Constant Field Values

FIELDS_INDEX_EXTENSION

public static final String FIELDS_INDEX_EXTENSION

Extension of stored fields index file

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Constant Field Values

FIELDS_EXTENSION

public static final String FIELDS_EXTENSION

Extension of stored fields file

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Constant Field Values

VECTORS_FIELDS_EXTENSION

public static final String VECTORS_FIELDS_EXTENSION

Extension of vectors fields file

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Constant Field Values

VECTORS_DOCUMENTS_EXTENSION

public static final String VECTORS_DOCUMENTS_EXTENSION

Extension of vectors documents file

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Constant Field Values

VECTORS_INDEX_EXTENSION

public static final String VECTORS_INDEX_EXTENSION

Extension of vectors index file

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Constant Field Values

COMPOUND_FILE_EXTENSION

public static final String COMPOUND_FILE_EXTENSION

Extension of compound file

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Constant Field Values

COMPOUND_FILE_STORE_EXTENSION

public static final String COMPOUND_FILE_STORE_EXTENSION

Extension of compound file for doc store files

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Constant Field Values

DELETES_EXTENSION

public static final String DELETES_EXTENSION

Extension of deletes

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Constant Field Values

FIELD_INFOS_EXTENSION

public static final String FIELD_INFOS_EXTENSION

Extension of field infos

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Constant Field Values

PLAIN_NORMS_EXTENSION

public static final String PLAIN_NORMS_EXTENSION

Extension of plain norms

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Constant Field Values

SEPARATE_NORMS_EXTENSION

public static final String SEPARATE_NORMS_EXTENSION

Extension of separate norms

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Constant Field Values

GEN_EXTENSION

public static final String GEN_EXTENSION

Extension of gen file

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Constant Field Values

INDEX_EXTENSIONS

public static final String[] INDEX_EXTENSIONS

This array contains all filename extensions used by Lucene's index files, with two exceptions, namely the extension made up from .f + a number and from .s + a number. Also note that Lucene's segments_N files do not have any filename extension.

INDEX_EXTENSIONS_IN_COMPOUND_FILE

public static final String[] INDEX_EXTENSIONS_IN_COMPOUND_FILE

File extensions that are added to a compound file (same as above, minus "del", "gen", "cfs").

STORE_INDEX_EXTENSIONS

public static final String[] STORE_INDEX_EXTENSIONS

NON_STORE_INDEX_EXTENSIONS

public static final String[] NON_STORE_INDEX_EXTENSIONS

COMPOUND_EXTENSIONS

public static final String[] COMPOUND_EXTENSIONS

File extensions of old-style index files

VECTOR_EXTENSIONS

public static final String[] VECTOR_EXTENSIONS

File extensions for term vector support

Constructor Detail

IndexFileNames

public IndexFileNames()

Method Detail

fileNameFromGeneration

public static final String fileNameFromGeneration(String base,
                                                  String ext,
                                                  long gen)

Computes the full file name from base, extension and generation. If the generation is -1, the file name is null. If it's 0, the file name is <base>.<ext>. If it's > 0, the file name is <base>_<gen>.<ext>.
NOTE: .<ext> is added to the name only if ext is not an empty string.

Parameters:

base - main part of the file name

ext - extension of the filename

gen - generation

isDocStoreFile

public static final boolean isDocStoreFile(String fileName)

Returns true if the provided filename is one of the doc store files (ends with an extension in STORE_INDEX_EXTENSIONS).

segmentFileName

public static final String segmentFileName(String segmentName,
                                           String ext)

Returns the file name that matches the given segment name and extension. This method takes care to return the full file name in the form <segmentName>.<ext>, therefore you don't need to prefix the extension with a '.'.
NOTE: .<ext> is added to the result file name only if ext is not empty.

matchesExtension

public static final boolean matchesExtension(String filename,
                                             String ext)

Returns true if the given filename ends with the given extension. One should provide a pure extension, without '.'.

stripSegmentName

public static final String stripSegmentName(String filename)

Strips the segment file name out of the given one. If you used segmentFileName(java.lang.String, java.lang.String) or fileNameFromGeneration(java.lang.String, java.lang.String, long) to create your files, then this method simply removes whatever comes before the first '.', or the second '_' (excluding both), in case of deleted docs.

Returns:

the filename with the segment name removed, or the given filename if it does not contain a '.' and '_'.

isSeparateNormsFile

public static boolean isSeparateNormsFile(String filename)

Returns true if the given filename ends with the separate norms file pattern: SEPARATE_NORMS_EXTENSION + "[0-9]+".