package org.apache.lucene.index;
import java.util.regex.Pattern;
/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* 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 ({@link #matchesExtension(String, String)
* matchesExtension}), as well as generating file names from a segment name,
* generation and extension (
* {@link #fileNameFromGeneration(String, String, long) fileNameFromGeneration},
* {@link #segmentFileName(String, String) segmentFileName}).
*
* @lucene.internal
*/
public final class IndexFileNames {
/** Name of the index segment file */
public static final String SEGMENTS = "segments";
public static final String SEGMENTS_CHECKSUM = "yn_segments_crc";
/** Name of the generation reference file name */
public static final String SEGMENTS_GEN = "segments.gen";
/** Name of the index deletable file (only used in
* pre-lockless indices) */
public static final String DELETABLE = "deletable";
/** Extension of norms file */
public static final String NORMS_EXTENSION = "nrm";
/** Extension of freq postings file */
public static final String FREQ_EXTENSION = "frq";
/** Extension of prox postings file */
public static final String PROX_EXTENSION = "prx";
/** Extension of terms file */
public static final String TERMS_EXTENSION = "tis";
/** Extension of terms index file */
public static final String TERMS_INDEX_EXTENSION = "tii";
/** Extension of terms file */
public static final String TERMS_EXTENSION_SIZE = "yntis";
/** Extension of terms index file */
public static final String TERMS_INDEX_EXTENSION_SIZE = "yntii";
public static final String TERMS_INDEX_EXTENSION_QUICK = "quicktii";
public static final String TERMS_EXTENSION_QUICK_OLD = "quicktis";
public static final String TERMS_EXTENSION_QUICK = "doctotm";
public static final String TERMS_EXTENSION_QUICK_TXT = "tmtorealval";
public static final String TERMS_EXTENSION_QUICK_VAL = "tmtonumval";
/** Extension of stored fields index file */
public static final String FIELDS_INDEX_EXTENSION = "fdx";
/** Extension of stored fields file */
public static final String FIELDS_EXTENSION = "fdt";
/** Extension of vectors fields file */
public static final String VECTORS_FIELDS_EXTENSION = "tvf";
/** Extension of vectors documents file */
public static final String VECTORS_DOCUMENTS_EXTENSION = "tvd";
/** Extension of vectors index file */
public static final String VECTORS_INDEX_EXTENSION = "tvx";
/** Extension of compound file */
public static final String COMPOUND_FILE_EXTENSION = "cfs";
public static final String COMPOUND_FILE_EXTENSION_POS = "yncfs";
/** Extension of compound file for doc store files*/
public static final String COMPOUND_FILE_STORE_EXTENSION = "cfx";
public static final String COMPOUND_FILE_STORE_EXTENSION_POS = "yncfx";
/** Extension of deletes */
public static final String DELETES_EXTENSION = "del";
/** Extension of field infos */
public static final String FIELD_INFOS_EXTENSION = "fnm";
/** Extension of plain norms */
public static final String PLAIN_NORMS_EXTENSION = "f";
/** Extension of separate norms */
public static final String SEPARATE_NORMS_EXTENSION = "s";
/** Extension of gen file */
public static final String GEN_EXTENSION = "gen";
/**
* This array contains all filename extensions used by
* Lucene's index files, with two exceptions, namely the
* extension made up from <code>.f</code> + a number and
* from <code>.s</code> + a number. Also note that
* Lucene's <code>segments_N</code> files do not have any
* filename extension.
*/
public static final String INDEX_EXTENSIONS[] = new String[] {
COMPOUND_FILE_EXTENSION,
COMPOUND_FILE_EXTENSION_POS,
FIELD_INFOS_EXTENSION,
FIELDS_INDEX_EXTENSION,
FIELDS_EXTENSION,
TERMS_INDEX_EXTENSION,
TERMS_INDEX_EXTENSION_QUICK,
TERMS_INDEX_EXTENSION_SIZE,
TERMS_EXTENSION,
TERMS_EXTENSION_QUICK_OLD,
TERMS_EXTENSION_QUICK,
TERMS_EXTENSION_QUICK_TXT,
TERMS_EXTENSION_QUICK_VAL,
TERMS_EXTENSION_SIZE,
FREQ_EXTENSION,
PROX_EXTENSION,
DELETES_EXTENSION,
VECTORS_INDEX_EXTENSION,
VECTORS_DOCUMENTS_EXTENSION,
VECTORS_FIELDS_EXTENSION,
GEN_EXTENSION,
NORMS_EXTENSION,
COMPOUND_FILE_STORE_EXTENSION,
COMPOUND_FILE_STORE_EXTENSION_POS
};
/** File extensions that are added to a compound file
* (same as above, minus "del", "gen", "cfs"). */
public static final String[] INDEX_EXTENSIONS_IN_COMPOUND_FILE = new String[] {
FIELD_INFOS_EXTENSION,
FIELDS_INDEX_EXTENSION,
FIELDS_EXTENSION,
TERMS_INDEX_EXTENSION,
TERMS_INDEX_EXTENSION_QUICK,
TERMS_INDEX_EXTENSION_SIZE,
TERMS_EXTENSION,
TERMS_INDEX_EXTENSION_QUICK,
TERMS_EXTENSION_QUICK_OLD,
TERMS_EXTENSION_QUICK,
TERMS_EXTENSION_QUICK_TXT,
TERMS_EXTENSION_QUICK_VAL,
TERMS_EXTENSION_SIZE,
FREQ_EXTENSION,
PROX_EXTENSION,
VECTORS_INDEX_EXTENSION,
VECTORS_DOCUMENTS_EXTENSION,
VECTORS_FIELDS_EXTENSION,
NORMS_EXTENSION
};
public static final String[] STORE_INDEX_EXTENSIONS = new String[] {
VECTORS_INDEX_EXTENSION,
VECTORS_FIELDS_EXTENSION,
VECTORS_DOCUMENTS_EXTENSION,
FIELDS_INDEX_EXTENSION,
FIELDS_EXTENSION
};
public static final String[] NON_STORE_INDEX_EXTENSIONS = new String[] {
FIELD_INFOS_EXTENSION,
FREQ_EXTENSION,
PROX_EXTENSION,
TERMS_EXTENSION,
TERMS_EXTENSION_QUICK_OLD,
TERMS_EXTENSION_QUICK,
TERMS_EXTENSION_QUICK_TXT,
TERMS_EXTENSION_QUICK_VAL,
TERMS_EXTENSION_SIZE,
TERMS_INDEX_EXTENSION,
TERMS_INDEX_EXTENSION_QUICK,
TERMS_INDEX_EXTENSION_SIZE,
NORMS_EXTENSION
};
/** File extensions of old-style index files */
public static final String COMPOUND_EXTENSIONS[] = new String[] {
FIELD_INFOS_EXTENSION,
FREQ_EXTENSION,
PROX_EXTENSION,
FIELDS_INDEX_EXTENSION,
FIELDS_EXTENSION,
TERMS_INDEX_EXTENSION,
TERMS_INDEX_EXTENSION_QUICK,
TERMS_INDEX_EXTENSION_SIZE,
TERMS_EXTENSION,
TERMS_EXTENSION_SIZE
};
/** File extensions for term vector support */
public static final String VECTOR_EXTENSIONS[] = new String[] {
VECTORS_INDEX_EXTENSION,
VECTORS_DOCUMENTS_EXTENSION,
VECTORS_FIELDS_EXTENSION
};
/**
* 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>.<br>
* <b>NOTE:</b> .<ext> is added to the name only if <code>ext</code> is
* not an empty string.
*
* @param base main part of the file name
* @param ext extension of the filename
* @param gen generation
*/
public static final String fileNameFromGeneration(String base, String ext, long gen) {
if (gen == SegmentInfo.NO) {
return null;
} else if (gen == SegmentInfo.WITHOUT_GEN) {
return segmentFileName(base, ext);
} else {
// The '6' part in the length is: 1 for '.', 1 for '_' and 4 as estimate
// to the gen length as string (hopefully an upper limit so SB won't
// expand in the middle.
StringBuilder res = new StringBuilder(base.length() + 6 + ext.length())
.append(base).append('_').append(Long.toString(gen, Character.MAX_RADIX));
if (ext.length() > 0) {
res.append('.').append(ext);
}
return res.toString();
}
}
/**
* Returns true if the provided filename is one of the doc store files (ends
* with an extension in {@link #STORE_INDEX_EXTENSIONS}).
*/
public static final boolean isDocStoreFile(String fileName) {
if (fileName.endsWith(COMPOUND_FILE_STORE_EXTENSION))
return true;
for (String ext : STORE_INDEX_EXTENSIONS) {
if (fileName.endsWith(ext))
return true;
}
return false;
}
/**
* 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 '.'.<br>
* <b>NOTE:</b> .<ext> is added to the result file name only if
* <code>ext</code> is not empty.
*/
public static final String segmentFileName(String segmentName, String ext) {
if (ext.length() > 0) {
return new StringBuilder(segmentName.length() + 1 + ext.length()).append(
segmentName).append('.').append(ext).toString();
} else {
return segmentName;
}
}
/**
* Returns true if the given filename ends with the given extension. One
* should provide a <i>pure</i> extension, without '.'.
*/
public static final boolean matchesExtension(String filename, String ext) {
// It doesn't make a difference whether we allocate a StringBuilder ourself
// or not, since there's only 1 '+' operator.
return filename.endsWith("." + ext);
}
/**
* Strips the segment file name out of the given one. If you used
* {@link #segmentFileName} or {@link #fileNameFromGeneration} to create your
* files, then this method simply removes whatever comes before the first '.',
* or the second '_' (excluding both), in case of deleted docs.
*
* @return the filename with the segment name removed, or the given filename
* if it does not contain a '.' and '_'.
*/
public static final String stripSegmentName(String filename) {
// If it is a .del file, there's an '_' after the first character
int idx = filename.indexOf('_', 1);
if (idx == -1) {
// If it's not, strip everything that's before the '.'
idx = filename.indexOf('.');
}
if (idx != -1) {
filename = filename.substring(idx);
}
return filename;
}
/**
* Returns true if the given filename ends with the separate norms file
* pattern: {@code SEPARATE_NORMS_EXTENSION + "[0-9]+"}.
*/
public static boolean isSeparateNormsFile(String filename) {
int idx = filename.lastIndexOf('.');
if (idx == -1) return false;
String ext = filename.substring(idx + 1);
return Pattern.matches(SEPARATE_NORMS_EXTENSION + "[0-9]+", ext);
}
}