| package org.apache.lucene.index; |
| |
| /* |
| * 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. |
| */ |
| |
| import java.io.IOException; |
| import java.io.PrintStream; |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.Collection; |
| import java.util.Collections; |
| import java.util.HashMap; |
| import java.util.HashSet; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.Map.Entry; |
| import java.util.Map; |
| import java.util.Set; |
| |
| import org.apache.lucene.codecs.Codec; |
| import org.apache.lucene.codecs.CodecUtil; |
| import org.apache.lucene.codecs.DocValuesFormat; |
| import org.apache.lucene.codecs.FieldInfosFormat; |
| import org.apache.lucene.codecs.LiveDocsFormat; |
| import org.apache.lucene.store.ChecksumIndexInput; |
| import org.apache.lucene.store.DataOutput; |
| import org.apache.lucene.store.Directory; |
| import org.apache.lucene.store.IOContext; |
| import org.apache.lucene.store.IndexOutput; |
| import org.apache.lucene.util.IOUtils; |
| import org.apache.lucene.util.StringHelper; |
| |
| /** |
| * A collection of segmentInfo objects with methods for operating on those |
| * segments in relation to the file system. |
| * <p> |
| * The active segments in the index are stored in the segment info file, |
| * <tt>segments_N</tt>. There may be one or more <tt>segments_N</tt> files in |
| * the index; however, the one with the largest generation is the active one |
| * (when older segments_N files are present it's because they temporarily cannot |
| * be deleted, or a custom {@link IndexDeletionPolicy} is in |
| * use). This file lists each segment by name and has details about the codec |
| * and generation of deletes. |
| * </p> |
| * <p> |
| * Files: |
| * <ul> |
| * <li><tt>segments_N</tt>: Header, Version, NameCounter, SegCount, <SegName, |
| * HasSegID, SegID, SegCodec, DelGen, DeletionCount, FieldInfosGen, DocValuesGen, |
| * UpdatesFiles><sup>SegCount</sup>, CommitUserData, Footer |
| * </ul> |
| * </p> |
| * Data types: |
| * <p> |
| * <ul> |
| * <li>Header --> {@link CodecUtil#writeIndexHeader IndexHeader}</li> |
| * <li>NameCounter, SegCount, DeletionCount --> |
| * {@link DataOutput#writeInt Int32}</li> |
| * <li>Generation, Version, DelGen, Checksum, FieldInfosGen, DocValuesGen --> |
| * {@link DataOutput#writeLong Int64}</li> |
| * <li>HasSegID --> {@link DataOutput#writeByte Int8}</li> |
| * <li>SegID --> {@link DataOutput#writeByte Int8<sup>ID_LENGTH</sup>}</li> |
| * <li>SegName, SegCodec --> {@link DataOutput#writeString String}</li> |
| * <li>CommitUserData --> {@link DataOutput#writeStringStringMap |
| * Map<String,String>}</li> |
| * <li>UpdatesFiles --> Map<{@link DataOutput#writeInt Int32}, |
| * {@link DataOutput#writeStringSet(Set) Set<String>}></li> |
| * <li>Footer --> {@link CodecUtil#writeFooter CodecFooter}</li> |
| * </ul> |
| * </p> |
| * Field Descriptions: |
| * <p> |
| * <ul> |
| * <li>Version counts how often the index has been changed by adding or deleting |
| * documents.</li> |
| * <li>NameCounter is used to generate names for new segment files.</li> |
| * <li>SegName is the name of the segment, and is used as the file name prefix |
| * for all of the files that compose the segment's index.</li> |
| * <li>DelGen is the generation count of the deletes file. If this is -1, there |
| * are no deletes. Anything above zero means there are deletes stored by |
| * {@link LiveDocsFormat}.</li> |
| * <li>DeletionCount records the number of deleted documents in this segment.</li> |
| * <li>SegCodec is the {@link Codec#getName() name} of the Codec that encoded |
| * this segment.</li> |
| * <li>HasSegID is nonzero if the segment has an identifier. Otherwise, when it is 0 |
| * the identifier is {@code null} and no SegID is written. Null only happens for Lucene |
| * 4.x segments referenced in commits.</li> |
| * <li>SegID is the identifier of the Codec that encoded this segment. </li> |
| * <li>CommitUserData stores an optional user-supplied opaque |
| * Map<String,String> that was passed to |
| * {@link IndexWriter#setCommitData(java.util.Map)}.</li> |
| * <li>FieldInfosGen is the generation count of the fieldInfos file. If this is |
| * -1, there are no updates to the fieldInfos in that segment. Anything above |
| * zero means there are updates to fieldInfos stored by {@link FieldInfosFormat} |
| * .</li> |
| * <li>DocValuesGen is the generation count of the updatable DocValues. If this |
| * is -1, there are no updates to DocValues in that segment. Anything above zero |
| * means there are updates to DocValues stored by {@link DocValuesFormat}.</li> |
| * <li>UpdatesFiles stores the set of files that were updated in that segment |
| * per field.</li> |
| * </ul> |
| * </p> |
| * |
| * @lucene.experimental |
| */ |
| public final class SegmentInfos implements Cloneable, Iterable<SegmentCommitInfo> { |
| |
| /** The file format version for the segments_N codec header, up to 4.5. */ |
| public static final int VERSION_40 = 0; |
| |
| /** The file format version for the segments_N codec header, since 4.6+. */ |
| public static final int VERSION_46 = 1; |
| |
| /** The file format version for the segments_N codec header, since 4.8+ */ |
| public static final int VERSION_48 = 2; |
| |
| /** The file format version for the segments_N codec header, since 4.9+ */ |
| public static final int VERSION_49 = 3; |
| |
| /** The file format version for the segments_N codec header, since 5.0+ */ |
| public static final int VERSION_50 = 4; |
| |
| /** Used to name new segments. */ |
| // TODO: should this be a long ...? |
| public int counter; |
| |
| /** Counts how often the index has been changed. */ |
| public long version; |
| |
| private long generation; // generation of the "segments_N" for the next commit |
| private long lastGeneration; // generation of the "segments_N" file we last successfully read |
| // or wrote; this is normally the same as generation except if |
| // there was an IOException that had interrupted a commit |
| |
| /** Opaque Map<String, String> that user can specify during IndexWriter.commit */ |
| public Map<String,String> userData = Collections.emptyMap(); |
| |
| private List<SegmentCommitInfo> segments = new ArrayList<>(); |
| |
| /** |
| * If non-null, information about loading segments_N files |
| * will be printed here. @see #setInfoStream. |
| */ |
| private static PrintStream infoStream = null; |
| |
| /** Id for this commit; only written starting with Lucene 5.0 */ |
| private byte[] id; |
| |
| /** Sole constructor. Typically you call this and then |
| * use {@link #readLatestCommit(Directory) or |
| * #readCommit(Directory,String)} to populate each {@link |
| * SegmentCommitInfo}. Alternatively, you can add/remove your |
| * own {@link SegmentCommitInfo}s. */ |
| public SegmentInfos() { |
| } |
| |
| /** Returns {@link SegmentCommitInfo} at the provided |
| * index. */ |
| public SegmentCommitInfo info(int i) { |
| return segments.get(i); |
| } |
| |
| /** |
| * Get the generation of the most recent commit to the |
| * list of index files (N in the segments_N file). |
| * |
| * @param files -- array of file names to check |
| */ |
| public static long getLastCommitGeneration(String[] files) { |
| long max = -1; |
| for (String file : files) { |
| if (file.startsWith(IndexFileNames.SEGMENTS) && !file.equals(IndexFileNames.OLD_SEGMENTS_GEN)) { |
| long gen = generationFromSegmentsFileName(file); |
| if (gen > max) { |
| max = gen; |
| } |
| } |
| } |
| return max; |
| } |
| |
| /** |
| * Get the generation of the most recent commit to the |
| * index in this directory (N in the segments_N file). |
| * |
| * @param directory -- directory to search for the latest segments_N file |
| */ |
| public static long getLastCommitGeneration(Directory directory) throws IOException { |
| return getLastCommitGeneration(directory.listAll()); |
| } |
| |
| /** |
| * Get the filename of the segments_N file for the most |
| * recent commit in the list of index files. |
| * |
| * @param files -- array of file names to check |
| */ |
| |
| public static String getLastCommitSegmentsFileName(String[] files) { |
| return IndexFileNames.fileNameFromGeneration(IndexFileNames.SEGMENTS, |
| "", |
| getLastCommitGeneration(files)); |
| } |
| |
| /** |
| * Get the filename of the segments_N file for the most |
| * recent commit to the index in this Directory. |
| * |
| * @param directory -- directory to search for the latest segments_N file |
| */ |
| public static String getLastCommitSegmentsFileName(Directory directory) throws IOException { |
| return IndexFileNames.fileNameFromGeneration(IndexFileNames.SEGMENTS, |
| "", |
| getLastCommitGeneration(directory)); |
| } |
| |
| /** |
| * Get the segments_N filename in use by this segment infos. |
| */ |
| public String getSegmentsFileName() { |
| return IndexFileNames.fileNameFromGeneration(IndexFileNames.SEGMENTS, |
| "", |
| lastGeneration); |
| } |
| |
| /** |
| * Parse the generation off the segments file name and |
| * return it. |
| */ |
| public static long generationFromSegmentsFileName(String fileName) { |
| if (fileName.equals(IndexFileNames.SEGMENTS)) { |
| return 0; |
| } else if (fileName.startsWith(IndexFileNames.SEGMENTS)) { |
| return Long.parseLong(fileName.substring(1+IndexFileNames.SEGMENTS.length()), |
| Character.MAX_RADIX); |
| } else { |
| throw new IllegalArgumentException("fileName \"" + fileName + "\" is not a segments file"); |
| } |
| } |
| |
| /** return generation of the next pending_segments_N that will be written */ |
| private long getNextPendingGeneration() { |
| if (generation == -1) { |
| return 1; |
| } else { |
| return generation+1; |
| } |
| } |
| |
| /** Since Lucene 5.0, every commit (segments_N) writes a unique id. This will |
| * return that id, or null if this commit was prior to 5.0. */ |
| public byte[] getId() { |
| return id == null ? null : id.clone(); |
| } |
| |
| /** |
| * Read a particular segmentFileName. Note that this may |
| * throw an IOException if a commit is in process. |
| * |
| * @param directory -- directory containing the segments file |
| * @param segmentFileName -- segment file to load |
| * @throws CorruptIndexException if the index is corrupt |
| * @throws IOException if there is a low-level IO error |
| */ |
| public static final SegmentInfos readCommit(Directory directory, String segmentFileName) throws IOException { |
| |
| long generation = generationFromSegmentsFileName(segmentFileName); |
| try (ChecksumIndexInput input = directory.openChecksumInput(segmentFileName, IOContext.READ)) { |
| // NOTE: as long as we want to throw indexformattooold (vs corruptindexexception), we need |
| // to read the magic ourselves. |
| int magic = input.readInt(); |
| if (magic != CodecUtil.CODEC_MAGIC) { |
| throw new IndexFormatTooOldException(input, magic, CodecUtil.CODEC_MAGIC, CodecUtil.CODEC_MAGIC); |
| } |
| // 4.0+ |
| int format = CodecUtil.checkHeaderNoMagic(input, "segments", VERSION_40, VERSION_50); |
| // 5.0+ |
| byte id[] = null; |
| if (format >= VERSION_50) { |
| id = new byte[StringHelper.ID_LENGTH]; |
| input.readBytes(id, 0, id.length); |
| CodecUtil.checkIndexHeaderSuffix(input, Long.toString(generation, Character.MAX_RADIX)); |
| } |
| |
| SegmentInfos infos = new SegmentInfos(); |
| infos.id = id; |
| infos.generation = generation; |
| infos.lastGeneration = generation; |
| infos.version = input.readLong(); |
| infos.counter = input.readInt(); |
| int numSegments = input.readInt(); |
| if (numSegments < 0) { |
| throw new CorruptIndexException("invalid segment count: " + numSegments, input); |
| } |
| for (int seg = 0; seg < numSegments; seg++) { |
| String segName = input.readString(); |
| final byte segmentID[]; |
| if (format >= VERSION_50) { |
| byte hasID = input.readByte(); |
| if (hasID == 1) { |
| segmentID = new byte[StringHelper.ID_LENGTH]; |
| input.readBytes(segmentID, 0, segmentID.length); |
| } else if (hasID == 0) { |
| segmentID = null; // 4.x segment, doesn't have an ID |
| } else { |
| throw new CorruptIndexException("invalid hasID byte, got: " + hasID, input); |
| } |
| } else { |
| segmentID = null; |
| } |
| Codec codec = Codec.forName(input.readString()); |
| SegmentInfo info = codec.segmentInfoFormat().read(directory, segName, segmentID, IOContext.READ); |
| info.setCodec(codec); |
| long delGen = input.readLong(); |
| int delCount = input.readInt(); |
| if (delCount < 0 || delCount > info.getDocCount()) { |
| throw new CorruptIndexException("invalid deletion count: " + delCount + " vs docCount=" + info.getDocCount(), input); |
| } |
| long fieldInfosGen = -1; |
| if (format >= VERSION_46) { |
| fieldInfosGen = input.readLong(); |
| } |
| long dvGen = -1; |
| if (format >= VERSION_49) { |
| dvGen = input.readLong(); |
| } else { |
| dvGen = fieldInfosGen; |
| } |
| SegmentCommitInfo siPerCommit = new SegmentCommitInfo(info, delCount, delGen, fieldInfosGen, dvGen); |
| if (format >= VERSION_46) { |
| if (format < VERSION_49) { |
| // Recorded per-generation files, which were buggy (see |
| // LUCENE-5636). We need to read and keep them so we continue to |
| // reference those files. Unfortunately it means that the files will |
| // be referenced even if the fields are updated again, until the |
| // segment is merged. |
| final int numGensUpdatesFiles = input.readInt(); |
| final Map<Long,Set<String>> genUpdatesFiles; |
| if (numGensUpdatesFiles == 0) { |
| genUpdatesFiles = Collections.emptyMap(); |
| } else { |
| genUpdatesFiles = new HashMap<>(numGensUpdatesFiles); |
| for (int i = 0; i < numGensUpdatesFiles; i++) { |
| genUpdatesFiles.put(input.readLong(), input.readStringSet()); |
| } |
| } |
| siPerCommit.setGenUpdatesFiles(genUpdatesFiles); |
| } else { |
| siPerCommit.setFieldInfosFiles(input.readStringSet()); |
| final Map<Integer,Set<String>> dvUpdateFiles; |
| final int numDVFields = input.readInt(); |
| if (numDVFields == 0) { |
| dvUpdateFiles = Collections.emptyMap(); |
| } else { |
| dvUpdateFiles = new HashMap<>(numDVFields); |
| for (int i = 0; i < numDVFields; i++) { |
| dvUpdateFiles.put(input.readInt(), input.readStringSet()); |
| } |
| } |
| siPerCommit.setDocValuesUpdatesFiles(dvUpdateFiles); |
| } |
| } |
| infos.add(siPerCommit); |
| } |
| infos.userData = input.readStringStringMap(); |
| |
| if (format >= VERSION_48) { |
| CodecUtil.checkFooter(input); |
| } else { |
| final long checksumNow = input.getChecksum(); |
| final long checksumThen = input.readLong(); |
| if (checksumNow != checksumThen) { |
| throw new CorruptIndexException("checksum failed (hardware problem?) : expected=" + Long.toHexString(checksumThen) + |
| " actual=" + Long.toHexString(checksumNow), input); |
| } |
| CodecUtil.checkEOF(input); |
| } |
| |
| return infos; |
| } |
| } |
| |
| /** Find the latest commit ({@code segments_N file}) and |
| * load all {@link SegmentCommitInfo}s. */ |
| public static final SegmentInfos readLatestCommit(Directory directory) throws IOException { |
| return new FindSegmentsFile<SegmentInfos>(directory) { |
| @Override |
| protected SegmentInfos doBody(String segmentFileName) throws IOException { |
| return readCommit(directory, segmentFileName); |
| } |
| }.run(); |
| } |
| |
| // Only true after prepareCommit has been called and |
| // before finishCommit is called |
| boolean pendingCommit; |
| |
| private void write(Directory directory) throws IOException { |
| |
| long nextGeneration = getNextPendingGeneration(); |
| String segmentFileName = IndexFileNames.fileNameFromGeneration(IndexFileNames.PENDING_SEGMENTS, |
| "", |
| nextGeneration); |
| |
| // Always advance the generation on write: |
| generation = nextGeneration; |
| |
| IndexOutput segnOutput = null; |
| boolean success = false; |
| |
| try { |
| segnOutput = directory.createOutput(segmentFileName, IOContext.DEFAULT); |
| CodecUtil.writeIndexHeader(segnOutput, "segments", VERSION_50, |
| StringHelper.randomId(), Long.toString(nextGeneration, Character.MAX_RADIX)); |
| segnOutput.writeLong(version); |
| segnOutput.writeInt(counter); // write counter |
| segnOutput.writeInt(size()); // write infos |
| for (SegmentCommitInfo siPerCommit : this) { |
| SegmentInfo si = siPerCommit.info; |
| segnOutput.writeString(si.name); |
| byte segmentID[] = si.getId(); |
| // TODO: remove this in lucene 6, we don't need to include 4.x segments in commits anymore |
| if (segmentID == null) { |
| segnOutput.writeByte((byte)0); |
| } else { |
| if (segmentID.length != StringHelper.ID_LENGTH) { |
| throw new IllegalStateException("cannot write segment: invalid id segment=" + si.name + "id=" + StringHelper.idToString(segmentID)); |
| } |
| segnOutput.writeByte((byte)1); |
| segnOutput.writeBytes(segmentID, segmentID.length); |
| } |
| segnOutput.writeString(si.getCodec().getName()); |
| segnOutput.writeLong(siPerCommit.getDelGen()); |
| int delCount = siPerCommit.getDelCount(); |
| if (delCount < 0 || delCount > si.getDocCount()) { |
| throw new IllegalStateException("cannot write segment: invalid docCount segment=" + si.name + " docCount=" + si.getDocCount() + " delCount=" + delCount); |
| } |
| segnOutput.writeInt(delCount); |
| segnOutput.writeLong(siPerCommit.getFieldInfosGen()); |
| segnOutput.writeLong(siPerCommit.getDocValuesGen()); |
| segnOutput.writeStringSet(siPerCommit.getFieldInfosFiles()); |
| final Map<Integer,Set<String>> dvUpdatesFiles = siPerCommit.getDocValuesUpdatesFiles(); |
| segnOutput.writeInt(dvUpdatesFiles.size()); |
| for (Entry<Integer,Set<String>> e : dvUpdatesFiles.entrySet()) { |
| segnOutput.writeInt(e.getKey()); |
| segnOutput.writeStringSet(e.getValue()); |
| } |
| assert si.dir == directory; |
| } |
| segnOutput.writeStringStringMap(userData); |
| CodecUtil.writeFooter(segnOutput); |
| segnOutput.close(); |
| directory.sync(Collections.singleton(segmentFileName)); |
| success = true; |
| } finally { |
| if (success) { |
| pendingCommit = true; |
| } else { |
| // We hit an exception above; try to close the file |
| // but suppress any exception: |
| IOUtils.closeWhileHandlingException(segnOutput); |
| // Try not to leave a truncated segments_N file in |
| // the index: |
| IOUtils.deleteFilesIgnoringExceptions(directory, segmentFileName); |
| } |
| } |
| } |
| |
| /** |
| * Returns a copy of this instance, also copying each |
| * SegmentInfo. |
| */ |
| |
| @Override |
| public SegmentInfos clone() { |
| try { |
| final SegmentInfos sis = (SegmentInfos) super.clone(); |
| // deep clone, first recreate all collections: |
| sis.segments = new ArrayList<>(size()); |
| for(final SegmentCommitInfo info : this) { |
| assert info.info.getCodec() != null; |
| // dont directly access segments, use add method!!! |
| sis.add(info.clone()); |
| } |
| sis.userData = new HashMap<>(userData); |
| return sis; |
| } catch (CloneNotSupportedException e) { |
| throw new RuntimeException("should not happen", e); |
| } |
| } |
| |
| /** |
| * version number when this SegmentInfos was generated. |
| */ |
| public long getVersion() { |
| return version; |
| } |
| |
| /** Returns current generation. */ |
| public long getGeneration() { |
| return generation; |
| } |
| |
| /** Returns last succesfully read or written generation. */ |
| public long getLastGeneration() { |
| return lastGeneration; |
| } |
| |
| /** If non-null, information about retries when loading |
| * the segments file will be printed to this. |
| */ |
| public static void setInfoStream(PrintStream infoStream) { |
| SegmentInfos.infoStream = infoStream; |
| } |
| |
| /** |
| * Returns {@code infoStream}. |
| * |
| * @see #setInfoStream |
| */ |
| public static PrintStream getInfoStream() { |
| return infoStream; |
| } |
| |
| /** |
| * Prints the given message to the infoStream. Note, this method does not |
| * check for null infoStream. It assumes this check has been performed by the |
| * caller, which is recommended to avoid the (usually) expensive message |
| * creation. |
| */ |
| private static void message(String message) { |
| infoStream.println("SIS [" + Thread.currentThread().getName() + "]: " + message); |
| } |
| |
| /** |
| * Utility class for executing code that needs to do |
| * something with the current segments file. This is |
| * necessary with lock-less commits because from the time |
| * you locate the current segments file name, until you |
| * actually open it, read its contents, or check modified |
| * time, etc., it could have been deleted due to a writer |
| * commit finishing. |
| */ |
| public abstract static class FindSegmentsFile<T> { |
| |
| final Directory directory; |
| |
| /** Sole constructor. */ |
| public FindSegmentsFile(Directory directory) { |
| this.directory = directory; |
| } |
| |
| /** Locate the most recent {@code segments} file and |
| * run {@link #doBody} on it. */ |
| public T run() throws IOException { |
| return run(null); |
| } |
| |
| /** Run {@link #doBody} on the provided commit. */ |
| public T run(IndexCommit commit) throws IOException { |
| if (commit != null) { |
| if (directory != commit.getDirectory()) |
| throw new IOException("the specified commit does not match the specified Directory"); |
| return doBody(commit.getSegmentsFileName()); |
| } |
| |
| long lastGen = -1; |
| long gen = -1; |
| IOException exc = null; |
| |
| // Loop until we succeed in calling doBody() without |
| // hitting an IOException. An IOException most likely |
| // means an IW deleted our commit while opening |
| // 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. |
| |
| for (;;) { |
| lastGen = gen; |
| String files[] = directory.listAll(); |
| String files2[] = directory.listAll(); |
| Arrays.sort(files); |
| Arrays.sort(files2); |
| if (!Arrays.equals(files, files2)) { |
| // listAll() is weakly consistent, this means we hit "concurrent modification exception" |
| continue; |
| } |
| gen = getLastCommitGeneration(files); |
| |
| if (infoStream != null) { |
| message("directory listing gen=" + gen); |
| } |
| |
| if (gen == -1) { |
| throw new IndexNotFoundException("no segments* file found in " + directory + ": files: " + Arrays.toString(files)); |
| } else if (gen > lastGen) { |
| String segmentFileName = IndexFileNames.fileNameFromGeneration(IndexFileNames.SEGMENTS, "", gen); |
| |
| try { |
| T t = doBody(segmentFileName); |
| if (infoStream != null) { |
| message("success on " + segmentFileName); |
| } |
| return t; |
| } catch (IOException err) { |
| // Save the original root cause: |
| if (exc == null) { |
| exc = err; |
| } |
| |
| if (infoStream != null) { |
| message("primary Exception on '" + segmentFileName + "': " + err + "'; will retry: gen = " + gen); |
| } |
| } |
| } else { |
| throw exc; |
| } |
| } |
| } |
| |
| /** |
| * Subclass must implement this. The assumption is an |
| * IOException will be thrown if something goes wrong |
| * during the processing that could have been caused by |
| * a writer committing. |
| */ |
| protected abstract T doBody(String segmentFileName) throws IOException; |
| } |
| |
| // Carry over generation numbers from another SegmentInfos |
| void updateGeneration(SegmentInfos other) { |
| lastGeneration = other.lastGeneration; |
| generation = other.generation; |
| } |
| |
| void setGeneration(long generation) { |
| this.generation = generation; |
| this.lastGeneration = generation; |
| } |
| |
| final void rollbackCommit(Directory dir) { |
| if (pendingCommit) { |
| pendingCommit = false; |
| |
| // we try to clean up our pending_segments_N |
| |
| // Must carefully compute fileName from "generation" |
| // since lastGeneration isn't incremented: |
| final String pending = IndexFileNames.fileNameFromGeneration(IndexFileNames.PENDING_SEGMENTS, "", generation); |
| |
| // Suppress so we keep throwing the original exception |
| // in our caller |
| IOUtils.deleteFilesIgnoringExceptions(dir, pending); |
| } |
| } |
| |
| /** Call this to start a commit. This writes the new |
| * segments file, but writes an invalid checksum at the |
| * end, so that it is not visible to readers. Once this |
| * is called you must call {@link #finishCommit} to complete |
| * the commit or {@link #rollbackCommit} to abort it. |
| * <p> |
| * Note: {@link #changed()} should be called prior to this |
| * method if changes have been made to this {@link SegmentInfos} instance |
| * </p> |
| **/ |
| final void prepareCommit(Directory dir) throws IOException { |
| if (pendingCommit) { |
| throw new IllegalStateException("prepareCommit was already called"); |
| } |
| write(dir); |
| } |
| |
| /** Returns all file names referenced by SegmentInfo |
| * instances matching the provided Directory (ie files |
| * associated with any "external" segments are skipped). |
| * The returned collection is recomputed on each |
| * invocation. */ |
| public Collection<String> files(Directory dir, boolean includeSegmentsFile) throws IOException { |
| HashSet<String> files = new HashSet<>(); |
| if (includeSegmentsFile) { |
| final String segmentFileName = getSegmentsFileName(); |
| if (segmentFileName != null) { |
| files.add(segmentFileName); |
| } |
| } |
| final int size = size(); |
| for(int i=0;i<size;i++) { |
| final SegmentCommitInfo info = info(i); |
| assert info.info.dir == dir; |
| if (info.info.dir == dir) { |
| files.addAll(info.files()); |
| } |
| } |
| |
| return files; |
| } |
| |
| /** Returns the committed segments_N filename. */ |
| final String finishCommit(Directory dir) throws IOException { |
| if (pendingCommit == false) { |
| throw new IllegalStateException("prepareCommit was not called"); |
| } |
| boolean success = false; |
| final String dest; |
| try { |
| final String src = IndexFileNames.fileNameFromGeneration(IndexFileNames.PENDING_SEGMENTS, "", generation); |
| dest = IndexFileNames.fileNameFromGeneration(IndexFileNames.SEGMENTS, "", generation); |
| dir.renameFile(src, dest); |
| success = true; |
| } finally { |
| if (!success) { |
| // deletes pending_segments_N: |
| rollbackCommit(dir); |
| } |
| } |
| |
| pendingCommit = false; |
| lastGeneration = generation; |
| return dest; |
| } |
| |
| /** Writes & syncs to the Directory dir, taking care to |
| * remove the segments file on exception |
| * <p> |
| * Note: {@link #changed()} should be called prior to this |
| * method if changes have been made to this {@link SegmentInfos} instance |
| * </p> |
| **/ |
| final void commit(Directory dir) throws IOException { |
| prepareCommit(dir); |
| finishCommit(dir); |
| } |
| |
| /** Returns readable description of this segment. */ |
| public String toString(Directory directory) { |
| StringBuilder buffer = new StringBuilder(); |
| buffer.append(getSegmentsFileName()).append(": "); |
| final int count = size(); |
| for(int i = 0; i < count; i++) { |
| if (i > 0) { |
| buffer.append(' '); |
| } |
| final SegmentCommitInfo info = info(i); |
| buffer.append(info.toString(directory, 0)); |
| } |
| return buffer.toString(); |
| } |
| |
| /** Return {@code userData} saved with this commit. |
| * |
| * @see IndexWriter#commit() |
| */ |
| public Map<String,String> getUserData() { |
| return userData; |
| } |
| |
| void setUserData(Map<String,String> data) { |
| if (data == null) { |
| userData = Collections.<String,String>emptyMap(); |
| } else { |
| userData = data; |
| } |
| } |
| |
| /** Replaces all segments in this instance, but keeps |
| * generation, version, counter so that future commits |
| * remain write once. |
| */ |
| void replace(SegmentInfos other) { |
| rollbackSegmentInfos(other.asList()); |
| lastGeneration = other.lastGeneration; |
| } |
| |
| /** Returns sum of all segment's docCounts. Note that |
| * this does not include deletions */ |
| public int totalDocCount() { |
| int count = 0; |
| for(SegmentCommitInfo info : this) { |
| count += info.info.getDocCount(); |
| } |
| return count; |
| } |
| |
| /** Call this before committing if changes have been made to the |
| * segments. */ |
| public void changed() { |
| version++; |
| } |
| |
| /** applies all changes caused by committing a merge to this SegmentInfos */ |
| void applyMergeChanges(MergePolicy.OneMerge merge, boolean dropSegment) { |
| final Set<SegmentCommitInfo> mergedAway = new HashSet<>(merge.segments); |
| boolean inserted = false; |
| int newSegIdx = 0; |
| for (int segIdx = 0, cnt = segments.size(); segIdx < cnt; segIdx++) { |
| assert segIdx >= newSegIdx; |
| final SegmentCommitInfo info = segments.get(segIdx); |
| if (mergedAway.contains(info)) { |
| if (!inserted && !dropSegment) { |
| segments.set(segIdx, merge.info); |
| inserted = true; |
| newSegIdx++; |
| } |
| } else { |
| segments.set(newSegIdx, info); |
| newSegIdx++; |
| } |
| } |
| |
| // the rest of the segments in list are duplicates, so don't remove from map, only list! |
| segments.subList(newSegIdx, segments.size()).clear(); |
| |
| // Either we found place to insert segment, or, we did |
| // not, but only because all segments we merged becamee |
| // deleted while we are merging, in which case it should |
| // be the case that the new segment is also all deleted, |
| // we insert it at the beginning if it should not be dropped: |
| if (!inserted && !dropSegment) { |
| segments.add(0, merge.info); |
| } |
| } |
| |
| List<SegmentCommitInfo> createBackupSegmentInfos() { |
| final List<SegmentCommitInfo> list = new ArrayList<>(size()); |
| for(final SegmentCommitInfo info : this) { |
| assert info.info.getCodec() != null; |
| list.add(info.clone()); |
| } |
| return list; |
| } |
| |
| void rollbackSegmentInfos(List<SegmentCommitInfo> infos) { |
| this.clear(); |
| this.addAll(infos); |
| } |
| |
| /** Returns an <b>unmodifiable</b> {@link Iterator} of contained segments in order. */ |
| // @Override (comment out until Java 6) |
| @Override |
| public Iterator<SegmentCommitInfo> iterator() { |
| return asList().iterator(); |
| } |
| |
| /** Returns all contained segments as an <b>unmodifiable</b> {@link List} view. */ |
| public List<SegmentCommitInfo> asList() { |
| return Collections.unmodifiableList(segments); |
| } |
| |
| /** Returns number of {@link SegmentCommitInfo}s. */ |
| public int size() { |
| return segments.size(); |
| } |
| |
| /** Appends the provided {@link SegmentCommitInfo}. */ |
| public void add(SegmentCommitInfo si) { |
| segments.add(si); |
| } |
| |
| /** Appends the provided {@link SegmentCommitInfo}s. */ |
| public void addAll(Iterable<SegmentCommitInfo> sis) { |
| for (final SegmentCommitInfo si : sis) { |
| this.add(si); |
| } |
| } |
| |
| /** Clear all {@link SegmentCommitInfo}s. */ |
| public void clear() { |
| segments.clear(); |
| } |
| |
| /** Remove the provided {@link SegmentCommitInfo}. |
| * |
| * <p><b>WARNING</b>: O(N) cost */ |
| public void remove(SegmentCommitInfo si) { |
| segments.remove(si); |
| } |
| |
| /** Remove the {@link SegmentCommitInfo} at the |
| * provided index. |
| * |
| * <p><b>WARNING</b>: O(N) cost */ |
| void remove(int index) { |
| segments.remove(index); |
| } |
| |
| /** Return true if the provided {@link |
| * SegmentCommitInfo} is contained. |
| * |
| * <p><b>WARNING</b>: O(N) cost */ |
| boolean contains(SegmentCommitInfo si) { |
| return segments.contains(si); |
| } |
| |
| /** Returns index of the provided {@link |
| * SegmentCommitInfo}. |
| * |
| * <p><b>WARNING</b>: O(N) cost */ |
| int indexOf(SegmentCommitInfo si) { |
| return segments.indexOf(si); |
| } |
| } |
