org.eclipse.jdt.internal.core.index.DiskIndex Maven / Gradle / Ivy
/*******************************************************************************
* Copyright (c) 2000, 2017 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.jdt.internal.core.index;
import java.io.*;
import org.eclipse.jdt.core.compiler.CharOperation;
import org.eclipse.jdt.core.search.*;
import org.eclipse.jdt.internal.core.util.*;
import org.eclipse.jdt.internal.compiler.util.HashtableOfIntValues;
import org.eclipse.jdt.internal.compiler.util.HashtableOfObject;
import org.eclipse.jdt.internal.compiler.util.SimpleLookupTable;
import org.eclipse.jdt.internal.compiler.util.SimpleSet;
import org.eclipse.jdt.internal.compiler.util.SimpleSetOfCharArray;
public class DiskIndex {
IndexLocation indexLocation;
private int headerInfoOffset;
private int numberOfChunks;
private int sizeOfLastChunk;
private int[] chunkOffsets;
private int documentReferenceSize; // 1, 2 or more bytes... depends on # of document names
private int startOfCategoryTables;
private HashtableOfIntValues categoryOffsets, categoryEnds;
private int cacheUserCount;
private String[][] cachedChunks; // decompressed chunks of document names
private HashtableOfObject categoryTables; // category name -> HashtableOfObject(words -> int[] of document #'s) or offset if not read yet
private char[] cachedCategoryName;
private static final int DEFAULT_BUFFER_SIZE = 2048;
private static int BUFFER_READ_SIZE = DEFAULT_BUFFER_SIZE;
private static final int BUFFER_WRITE_SIZE = DEFAULT_BUFFER_SIZE;
private byte[] streamBuffer;
private int bufferIndex, bufferEnd; // used when reading from the file into the streamBuffer
private int streamEnd; // used when writing data from the streamBuffer to the file
char separator = Index.DEFAULT_SEPARATOR;
public static final String SIGNATURE= "INDEX VERSION 1.130"; //$NON-NLS-1$
private static final char[] SIGNATURE_CHARS = SIGNATURE.toCharArray();
public static boolean DEBUG = false;
private static final int RE_INDEXED = -1;
private static final int DELETED = -2;
private static final int CHUNK_SIZE = 100;
private static final SimpleSetOfCharArray INTERNED_CATEGORY_NAMES = new SimpleSetOfCharArray(20);
private static final String TMP_EXT = ".tmp"; //$NON-NLS-1$
static class IntList {
int size;
int[] elements;
IntList(int[] elements) {
this.elements = elements;
this.size = elements.length;
}
void add(int newElement) {
if (this.size == this.elements.length) {
int newSize = this.size * 3;
if (newSize < 7) newSize = 7;
System.arraycopy(this.elements, 0, this.elements = new int[newSize], 0, this.size);
}
this.elements[this.size++] = newElement;
}
int[] asArray() {
int[] result = new int[this.size];
System.arraycopy(this.elements, 0, result, 0, this.size);
return result;
}
}
DiskIndex() {
this.headerInfoOffset = -1;
this.numberOfChunks = -1;
this.sizeOfLastChunk = -1;
this.chunkOffsets = null;
this.documentReferenceSize = -1;
this.cacheUserCount = -1;
this.cachedChunks = null;
this.categoryTables = null;
this.cachedCategoryName = null;
this.categoryOffsets = null;
this.categoryEnds = null;
}
DiskIndex(IndexLocation location) throws IOException {
this();
if (location == null) {
throw new IllegalArgumentException();
}
this.indexLocation = location;
}
SimpleSet addDocumentNames(String substring, MemoryIndex memoryIndex) throws IOException {
// must skip over documents which have been added/changed/deleted in the memory index
String[] docNames = readAllDocumentNames();
SimpleSet results = new SimpleSet(docNames.length);
if (substring == null) {
if (memoryIndex == null) {
for (int i = 0, l = docNames.length; i < l; i++)
results.add(docNames[i]);
} else {
SimpleLookupTable docsToRefs = memoryIndex.docsToReferences;
for (int i = 0, l = docNames.length; i < l; i++) {
String docName = docNames[i];
if (!docsToRefs.containsKey(docName))
results.add(docName);
}
}
} else {
if (memoryIndex == null) {
for (int i = 0, l = docNames.length; i < l; i++)
if (docNames[i].startsWith(substring, 0))
results.add(docNames[i]);
} else {
SimpleLookupTable docsToRefs = memoryIndex.docsToReferences;
for (int i = 0, l = docNames.length; i < l; i++) {
String docName = docNames[i];
if (docName.startsWith(substring, 0) && !docsToRefs.containsKey(docName))
results.add(docName);
}
}
}
return results;
}
private HashtableOfObject addQueryResult(HashtableOfObject results, char[] word, Object docs, MemoryIndex memoryIndex, boolean prevResults) throws IOException {
// must skip over documents which have been added/changed/deleted in the memory index
if (results == null)
results = new HashtableOfObject(13);
EntryResult result = prevResults ? (EntryResult) results.get(word) : null;
if (memoryIndex == null) {
if (result == null)
results.putUnsafely(word, new EntryResult(word, docs));
else
result.addDocumentTable(docs);
} else {
SimpleLookupTable docsToRefs = memoryIndex.docsToReferences;
if (result == null) result = new EntryResult(word, null);
int[] docNumbers = readDocumentNumbers(docs);
for (int i = 0, l = docNumbers.length; i < l; i++) {
String docName = readDocumentName(docNumbers[i]);
if (!docsToRefs.containsKey(docName))
result.addDocumentName(docName);
}
if (!result.isEmpty())
results.put(word, result);
}
return results;
}
HashtableOfObject addQueryResults(char[][] categories, char[] key, int matchRule, MemoryIndex memoryIndex) throws IOException {
// assumes sender has called startQuery() & will call stopQuery() when finished
if (this.categoryOffsets == null) return null; // file is empty
HashtableOfObject results = null; // initialized if needed
// No need to check the results table for duplicates while processing the
// first category table or if the first category tables doesn't have any results.
boolean prevResults = false;
if (key == null) {
for (int i = 0, l = categories.length; i < l; i++) {
HashtableOfObject wordsToDocNumbers = readCategoryTable(categories[i], true); // cache if key is null since its a definite match
if (wordsToDocNumbers != null) {
char[][] words = wordsToDocNumbers.keyTable;
Object[] values = wordsToDocNumbers.valueTable;
if (results == null)
results = new HashtableOfObject(wordsToDocNumbers.elementSize);
for (int j = 0, m = words.length; j < m; j++)
if (words[j] != null)
results = addQueryResult(results, words[j], values[j], memoryIndex, prevResults);
}
prevResults = results != null;
}
if (results != null && this.cachedChunks == null)
cacheDocumentNames();
} else {
switch (matchRule) {
case SearchPattern.R_EXACT_MATCH | SearchPattern.R_CASE_SENSITIVE:
for (int i = 0, l = categories.length; i < l; i++) {
HashtableOfObject wordsToDocNumbers = readCategoryTable(categories[i], false);
Object value;
if (wordsToDocNumbers != null && (value = wordsToDocNumbers.get(key)) != null)
results = addQueryResult(results, key, value, memoryIndex, prevResults);
prevResults = results != null;
}
break;
case SearchPattern.R_PREFIX_MATCH | SearchPattern.R_CASE_SENSITIVE:
for (int i = 0, l = categories.length; i < l; i++) {
HashtableOfObject wordsToDocNumbers = readCategoryTable(categories[i], false);
if (wordsToDocNumbers != null) {
char[][] words = wordsToDocNumbers.keyTable;
Object[] values = wordsToDocNumbers.valueTable;
for (int j = 0, m = words.length; j < m; j++) {
char[] word = words[j];
if (word != null && key[0] == word[0] && CharOperation.prefixEquals(key, word))
results = addQueryResult(results, word, values[j], memoryIndex, prevResults);
}
}
prevResults = results != null;
}
break;
default:
for (int i = 0, l = categories.length; i < l; i++) {
HashtableOfObject wordsToDocNumbers = readCategoryTable(categories[i], false);
if (wordsToDocNumbers != null) {
char[][] words = wordsToDocNumbers.keyTable;
Object[] values = wordsToDocNumbers.valueTable;
for (int j = 0, m = words.length; j < m; j++) {
char[] word = words[j];
if (word != null && Index.isMatch(key, word, matchRule))
results = addQueryResult(results, word, values[j], memoryIndex, prevResults);
}
}
prevResults = results != null;
}
}
}
return results;
}
private void cacheDocumentNames() throws IOException {
// will need all document names so get them now
this.cachedChunks = new String[this.numberOfChunks][];
InputStream stream = this.indexLocation.getInputStream();
try {
if (this.numberOfChunks > 5) BUFFER_READ_SIZE <<= 1;
int offset = this.chunkOffsets[0];
stream.skip(offset);
this.streamBuffer = new byte[BUFFER_READ_SIZE];
this.bufferIndex = 0;
this.bufferEnd = stream.read(this.streamBuffer, 0, this.streamBuffer.length);
for (int i = 0; i < this.numberOfChunks; i++) {
int size = i == this.numberOfChunks - 1 ? this.sizeOfLastChunk : CHUNK_SIZE;
readChunk(this.cachedChunks[i] = new String[size], stream, 0, size);
}
} catch (IOException e) {
this.cachedChunks = null;
throw e;
} finally {
stream.close();
this.indexLocation.close();
this.streamBuffer = null;
BUFFER_READ_SIZE = DEFAULT_BUFFER_SIZE;
}
}
private String[] computeDocumentNames(String[] onDiskNames, int[] positions, SimpleLookupTable indexedDocuments, MemoryIndex memoryIndex) {
int onDiskLength = onDiskNames.length;
Object[] docNames = memoryIndex.docsToReferences.keyTable;
Object[] referenceTables = memoryIndex.docsToReferences.valueTable;
if (onDiskLength == 0) {
// disk index was empty, so add every indexed document
for (int i = 0, l = referenceTables.length; i < l; i++)
if (referenceTables[i] != null)
indexedDocuments.put(docNames[i], null); // remember each new document
String[] newDocNames = new String[indexedDocuments.elementSize];
int count = 0;
Object[] added = indexedDocuments.keyTable;
for (int i = 0, l = added.length; i < l; i++)
if (added[i] != null)
newDocNames[count++] = (String) added[i];
Util.sort(newDocNames);
for (int i = 0, l = newDocNames.length; i < l; i++)
indexedDocuments.put(newDocNames[i], Integer.valueOf(i));
return newDocNames;
}
// initialize positions as if each document will remain in the same position
for (int i = 0; i < onDiskLength; i++)
positions[i] = i;
// find out if the memory index has any new or deleted documents, if not then the names & positions are the same
int numDeletedDocNames = 0;
nextPath : for (int i = 0, l = docNames.length; i < l; i++) {
String docName = (String) docNames[i];
if (docName != null) {
for (int j = 0; j < onDiskLength; j++) {
if (docName.equals(onDiskNames[j])) {
if (referenceTables[i] == null) {
positions[j] = DELETED;
numDeletedDocNames++;
} else {
positions[j] = RE_INDEXED;
}
continue nextPath;
}
}
if (referenceTables[i] != null)
indexedDocuments.put(docName, null); // remember each new document, skip deleted documents which were never saved
}
}
String[] newDocNames = onDiskNames;
if (numDeletedDocNames > 0 || indexedDocuments.elementSize > 0) {
// some new documents have been added or some old ones deleted
newDocNames = new String[onDiskLength + indexedDocuments.elementSize - numDeletedDocNames];
int count = 0;
for (int i = 0; i < onDiskLength; i++)
if (positions[i] >= RE_INDEXED)
newDocNames[count++] = onDiskNames[i]; // keep each unchanged document
Object[] added = indexedDocuments.keyTable;
for (int i = 0, l = added.length; i < l; i++)
if (added[i] != null)
newDocNames[count++] = (String) added[i]; // add each new document
Util.sort(newDocNames);
for (int i = 0, l = newDocNames.length; i < l; i++)
if (indexedDocuments.containsKey(newDocNames[i]))
indexedDocuments.put(newDocNames[i], Integer.valueOf(i)); // remember the position for each new document
}
// need to be able to look up an old position (ref# from a ref[]) and map it to its new position
// if its old position == DELETED then its forgotton
// if its old position == ReINDEXED then its also forgotten but its new position is needed to map references
int count = -1;
for (int i = 0; i < onDiskLength;) {
switch(positions[i]) {
case DELETED :
i++; // skip over deleted... references are forgotten
break;
case RE_INDEXED :
String newName = newDocNames[++count];
if (newName.equals(onDiskNames[i])) {
indexedDocuments.put(newName, Integer.valueOf(count)); // the reindexed docName that was at position i is now at position count
i++;
}
break;
default :
if (newDocNames[++count].equals(onDiskNames[i]))
positions[i++] = count; // the unchanged docName that was at position i is now at position count
}
}
return newDocNames;
}
private void copyQueryResults(HashtableOfObject categoryToWords, int newPosition) {
char[][] categoryNames = categoryToWords.keyTable;
Object[] wordSets = categoryToWords.valueTable;
for (int i = 0, l = categoryNames.length; i < l; i++) {
char[] categoryName = categoryNames[i];
if (categoryName != null) {
SimpleWordSet wordSet = (SimpleWordSet) wordSets[i];
HashtableOfObject wordsToDocs = (HashtableOfObject) this.categoryTables.get(categoryName);
if (wordsToDocs == null)
this.categoryTables.put(categoryName, wordsToDocs = new HashtableOfObject(wordSet.elementSize));
char[][] words = wordSet.words;
for (int j = 0, m = words.length; j < m; j++) {
char[] word = words[j];
if (word != null) {
Object o = wordsToDocs.get(word);
if (o == null) {
wordsToDocs.putUnsafely(word, new int[] {newPosition});
} else if (o instanceof IntList) {
((IntList) o).add(newPosition);
} else {
IntList list = new IntList((int[]) o);
list.add(newPosition);
wordsToDocs.put(word, list);
}
}
}
}
}
}
void initialize(boolean reuseExistingFile) throws IOException {
if (this.indexLocation.exists()) {
if (reuseExistingFile) {
InputStream stream = this.indexLocation.getInputStream();
if (stream == null) {
throw new IOException("Failed to use the index file"); //$NON-NLS-1$
}
this.streamBuffer = new byte[BUFFER_READ_SIZE];
this.bufferIndex = 0;
this.bufferEnd = stream.read(this.streamBuffer, 0, 128);
try {
char[] signature = readStreamChars(stream);
if (!CharOperation.equals(signature, SIGNATURE_CHARS)) {
throw new IOException(Messages.exception_wrongFormat);
}
this.headerInfoOffset = readStreamInt(stream);
if (this.headerInfoOffset > 0) { // file is empty if its not set
stream.skip(this.headerInfoOffset - this.bufferEnd); // assume that the header info offset is over current buffer end
this.bufferIndex = 0;
this.bufferEnd = stream.read(this.streamBuffer, 0, this.streamBuffer.length);
readHeaderInfo(stream);
}
} finally {
stream.close();
this.indexLocation.close();
}
return;
}
if (!this.indexLocation.delete()) {
if (DEBUG)
System.out.println("initialize - Failed to delete index " + this.indexLocation); //$NON-NLS-1$
throw new IOException("Failed to delete index " + this.indexLocation); //$NON-NLS-1$
}
}
if (this.indexLocation.createNewFile()) {
FileOutputStream stream = new FileOutputStream(this.indexLocation.getIndexFile(), false);
try {
this.streamBuffer = new byte[BUFFER_READ_SIZE];
this.bufferIndex = 0;
writeStreamChars(stream, SIGNATURE_CHARS);
writeStreamInt(stream, -1); // file is empty
// write the buffer to the stream
if (this.bufferIndex > 0) {
stream.write(this.streamBuffer, 0, this.bufferIndex);
this.bufferIndex = 0;
}
} finally {
stream.close();
}
} else {
if (DEBUG)
System.out.println("initialize - Failed to create new index " + this.indexLocation); //$NON-NLS-1$
throw new IOException("Failed to create new index " + this.indexLocation); //$NON-NLS-1$
}
}
private void initializeFrom(DiskIndex diskIndex, File newIndexFile) throws IOException {
if (newIndexFile.exists() && !newIndexFile.delete()) { // delete the temporary index file
if (DEBUG)
System.out.println("initializeFrom - Failed to delete temp index " + this.indexLocation); //$NON-NLS-1$
} else if (!newIndexFile.createNewFile()) {
if (DEBUG)
System.out.println("initializeFrom - Failed to create temp index " + this.indexLocation); //$NON-NLS-1$
throw new IOException("Failed to create temp index " + this.indexLocation); //$NON-NLS-1$
}
int size = diskIndex.categoryOffsets == null ? 8 : diskIndex.categoryOffsets.elementSize;
this.categoryOffsets = new HashtableOfIntValues(size);
this.categoryEnds = new HashtableOfIntValues(size);
this.categoryTables = new HashtableOfObject(size);
this.separator = diskIndex.separator;
}
private void mergeCategories(DiskIndex onDisk, int[] positions, FileOutputStream stream) throws IOException {
// at this point, this.categoryTables contains the names -> wordsToDocs added in copyQueryResults()
char[][] oldNames = onDisk.categoryOffsets.keyTable;
for (int i = 0, l = oldNames.length; i < l; i++) {
char[] oldName = oldNames[i];
if (oldName != null && !this.categoryTables.containsKey(oldName))
this.categoryTables.put(oldName, null);
}
char[][] categoryNames = this.categoryTables.keyTable;
for (int i = 0, l = categoryNames.length; i < l; i++)
if (categoryNames[i] != null)
mergeCategory(categoryNames[i], onDisk, positions, stream);
this.categoryTables = null;
}
private void mergeCategory(char[] categoryName, DiskIndex onDisk, int[] positions, FileOutputStream stream) throws IOException {
HashtableOfObject wordsToDocs = (HashtableOfObject) this.categoryTables.get(categoryName);
if (wordsToDocs == null)
wordsToDocs = new HashtableOfObject(3);
HashtableOfObject oldWordsToDocs = onDisk.readCategoryTable(categoryName, true);
if (oldWordsToDocs != null) {
char[][] oldWords = oldWordsToDocs.keyTable;
Object[] oldArrayOffsets = oldWordsToDocs.valueTable;
nextWord: for (int i = 0, l = oldWords.length; i < l; i++) {
char[] oldWord = oldWords[i];
if (oldWord != null) {
int[] oldDocNumbers = (int[]) oldArrayOffsets[i];
int length = oldDocNumbers.length;
int[] mappedNumbers = new int[length];
int count = 0;
for (int j = 0; j < length; j++) {
int pos = positions[oldDocNumbers[j]];
if (pos > RE_INDEXED) // forget any reference to a document which was deleted or re_indexed
mappedNumbers[count++] = pos;
}
if (count < length) {
if (count == 0) continue nextWord; // skip words which no longer have any references
System.arraycopy(mappedNumbers, 0, mappedNumbers = new int[count], 0, count);
}
Object o = wordsToDocs.get(oldWord);
if (o == null) {
wordsToDocs.putUnsafely(oldWord, mappedNumbers);
} else {
IntList list = null;
if (o instanceof IntList) {
list = (IntList) o;
} else {
list = new IntList((int[]) o);
wordsToDocs.put(oldWord, list);
}
for (int j = 0; j < count; j++)
list.add(mappedNumbers[j]);
}
}
}
onDisk.categoryTables.put(categoryName, null); // flush cached table
}
writeCategoryTable(categoryName, wordsToDocs, stream);
}
DiskIndex mergeWith(MemoryIndex memoryIndex) throws IOException {
// assume write lock is held
// compute & write out new docNames
if (this.indexLocation == null) {
throw new IOException("Pre-built index file not writeable"); //$NON-NLS-1$
}
String[] docNames = readAllDocumentNames();
int previousLength = docNames.length;
int[] positions = new int[previousLength]; // keeps track of the position of each document in the new sorted docNames
SimpleLookupTable indexedDocuments = new SimpleLookupTable(3); // for each new/changed document in the memoryIndex
docNames = computeDocumentNames(docNames, positions, indexedDocuments, memoryIndex);
if (docNames.length == 0) {
if (previousLength == 0) return this; // nothing to do... memory index contained deleted documents that had never been saved
// index is now empty since all the saved documents were removed
DiskIndex newDiskIndex = new DiskIndex(this.indexLocation);
newDiskIndex.initialize(false);
return newDiskIndex;
}
boolean usingTmp = false;
File oldIndexFile = this.indexLocation.getIndexFile();
String indexFilePath = oldIndexFile.getPath();
if (indexFilePath.endsWith(TMP_EXT)) { // the tmp file could not be renamed last time
indexFilePath = indexFilePath.substring(0, indexFilePath.length()-TMP_EXT.length());
usingTmp = true;
} else {
indexFilePath += TMP_EXT;
}
DiskIndex newDiskIndex = new DiskIndex(new FileIndexLocation(new File(indexFilePath)));
File newIndexFile = newDiskIndex.indexLocation.getIndexFile();
try {
newDiskIndex.initializeFrom(this, newIndexFile);
FileOutputStream stream = new FileOutputStream(newIndexFile, false);
int offsetToHeader = -1;
try {
newDiskIndex.writeAllDocumentNames(docNames, stream);
docNames = null; // free up the space
// add each new/changed doc to empty category tables using its new position #
if (indexedDocuments.elementSize > 0) {
Object[] names = indexedDocuments.keyTable;
Object[] integerPositions = indexedDocuments.valueTable;
for (int i = 0, l = names.length; i < l; i++)
if (names[i] != null)
newDiskIndex.copyQueryResults(
(HashtableOfObject) memoryIndex.docsToReferences.get(names[i]), ((Integer) integerPositions[i]).intValue());
}
indexedDocuments = null; // free up the space
// merge each category table with the new ones & write them out
if (previousLength == 0)
newDiskIndex.writeCategories(stream);
else
newDiskIndex.mergeCategories(this, positions, stream);
offsetToHeader = newDiskIndex.streamEnd;
newDiskIndex.writeHeaderInfo(stream);
positions = null; // free up the space
} finally {
stream.close();
this.streamBuffer = null;
}
newDiskIndex.writeOffsetToHeader(offsetToHeader);
// rename file by deleting previous index file & renaming temp one
if (oldIndexFile.exists() && !oldIndexFile.delete()) {
if (DEBUG)
System.out.println("mergeWith - Failed to delete " + this.indexLocation); //$NON-NLS-1$
throw new IOException("Failed to delete index file " + this.indexLocation); //$NON-NLS-1$
}
if (!usingTmp && !newIndexFile.renameTo(oldIndexFile)) {
// try again after waiting for two milli secs
try {
Thread.sleep(2);
} catch (InterruptedException e) {
//ignore
}
if (!newIndexFile.renameTo(oldIndexFile)) {
if (DEBUG)
System.out.println("mergeWith - Failed to rename " + this.indexLocation); //$NON-NLS-1$
usingTmp = true;
}
}
} catch (IOException e) {
if (newIndexFile.exists() && !newIndexFile.delete())
if (DEBUG)
System.out.println("mergeWith - Failed to delete temp index " + newDiskIndex.indexLocation); //$NON-NLS-1$
throw e;
}
if (!usingTmp) // rename done, use the new file
newDiskIndex.indexLocation = this.indexLocation;
return newDiskIndex;
}
private synchronized String[] readAllDocumentNames() throws IOException {
if (this.numberOfChunks <= 0)
return CharOperation.NO_STRINGS;
InputStream stream = this.indexLocation.getInputStream();
try {
int offset = this.chunkOffsets[0];
stream.skip(offset);
this.streamBuffer = new byte[BUFFER_READ_SIZE];
this.bufferIndex = 0;
this.bufferEnd = stream.read(this.streamBuffer, 0, this.streamBuffer.length);
int lastIndex = this.numberOfChunks - 1;
String[] docNames = new String[lastIndex * CHUNK_SIZE + this.sizeOfLastChunk];
for (int i = 0; i < this.numberOfChunks; i++)
readChunk(docNames, stream, i * CHUNK_SIZE, i < lastIndex ? CHUNK_SIZE : this.sizeOfLastChunk);
return docNames;
} finally {
stream.close();
this.indexLocation.close();
this.streamBuffer = null;
}
}
private synchronized HashtableOfObject readCategoryTable(char[] categoryName, boolean readDocNumbers) throws IOException {
// result will be null if categoryName is unknown
int offset = this.categoryOffsets.get(categoryName);
if (offset == HashtableOfIntValues.NO_VALUE) {
return null;
}
if (this.categoryTables == null) {
this.categoryTables = new HashtableOfObject(3);
} else {
HashtableOfObject cachedTable = (HashtableOfObject) this.categoryTables.get(categoryName);
if (cachedTable != null) {
if (readDocNumbers) { // must cache remaining document number arrays
Object[] arrayOffsets = cachedTable.valueTable;
for (int i = 0, l = arrayOffsets.length; i < l; i++)
if (arrayOffsets[i] instanceof Integer)
arrayOffsets[i] = readDocumentNumbers(arrayOffsets[i]);
}
return cachedTable;
}
}
InputStream stream = this.indexLocation.getInputStream();
HashtableOfObject categoryTable = null;
char[][] matchingWords = null;
int count = 0;
int firstOffset = -1;
this.streamBuffer = new byte[BUFFER_READ_SIZE];
try {
stream.skip(offset);
this.bufferIndex = 0;
this.bufferEnd = stream.read(this.streamBuffer, 0, this.streamBuffer.length);
int size = readStreamInt(stream);
try {
if (size < 0) { // DEBUG
System.err.println("-------------------- DEBUG --------------------"); //$NON-NLS-1$
System.err.println("file = "+this.indexLocation); //$NON-NLS-1$
System.err.println("offset = "+offset); //$NON-NLS-1$
System.err.println("size = "+size); //$NON-NLS-1$
System.err.println("-------------------- END --------------------"); //$NON-NLS-1$
}
categoryTable = new HashtableOfObject(size);
} catch (OutOfMemoryError oom) {
// DEBUG
oom.printStackTrace();
System.err.println("-------------------- DEBUG --------------------"); //$NON-NLS-1$
System.err.println("file = "+this.indexLocation); //$NON-NLS-1$
System.err.println("offset = "+offset); //$NON-NLS-1$
System.err.println("size = "+size); //$NON-NLS-1$
System.err.println("-------------------- END --------------------"); //$NON-NLS-1$
throw oom;
}
int largeArraySize = 256;
for (int i = 0; i < size; i++) {
char[] word = readStreamChars(stream);
int arrayOffset = readStreamInt(stream);
// if arrayOffset is:
// <= 0 then the array size == 1 with the value -> -arrayOffset
// > 1 & < 256 then the size of the array is > 1 & < 256, the document array follows immediately
// 256 if the array size >= 256 followed by another int which is the offset to the array (written prior to the table)
if (arrayOffset <= 0) {
categoryTable.putUnsafely(word, new int[] {-arrayOffset}); // store 1 element array by negating documentNumber
} else if (arrayOffset < largeArraySize) {
categoryTable.putUnsafely(word, readStreamDocumentArray(stream, arrayOffset)); // read in-lined array providing size
} else {
arrayOffset = readStreamInt(stream); // read actual offset
if (readDocNumbers) {
if (matchingWords == null)
matchingWords = new char[size][];
if (count == 0)
firstOffset = arrayOffset;
matchingWords[count++] = word;
}
categoryTable.putUnsafely(word, Integer.valueOf(arrayOffset)); // offset to array in the file
}
}
this.categoryTables.put(INTERNED_CATEGORY_NAMES.get(categoryName), categoryTable);
// cache the table as long as its not too big
// in practice, some tables can be greater than 500K when they contain more than 10K elements
this.cachedCategoryName = categoryTable.elementSize < 20000 ? categoryName : null;
} catch (IOException ioe) {
this.streamBuffer = null;
throw ioe;
} finally {
stream.close();
this.indexLocation.close();
}
if (matchingWords != null && count > 0) {
stream = this.indexLocation.getInputStream();
try {
stream.skip(firstOffset);
this.bufferIndex = 0;
this.bufferEnd = stream.read(this.streamBuffer, 0, this.streamBuffer.length);
for (int i = 0; i < count; i++) { // each array follows the previous one
categoryTable.put(matchingWords[i], readStreamDocumentArray(stream, readStreamInt(stream)));
}
} catch (IOException ioe) {
this.streamBuffer = null;
throw ioe;
} finally {
stream.close();
this.indexLocation.close();
}
}
this.streamBuffer = null;
return categoryTable;
}
private void readChunk(String[] docNames, InputStream stream, int index, int size) throws IOException {
String current = new String(readStreamChars(stream));
docNames[index++] = current;
for (int i = 1; i < size; i++) {
if (stream != null && this.bufferIndex + 2 >= this.bufferEnd)
readStreamBuffer(stream);
int start = this.streamBuffer[this.bufferIndex++] & 0xFF;
int end = this.streamBuffer[this.bufferIndex++] & 0xFF;
String next = new String(readStreamChars(stream));
if (start > 0) {
if (end > 0) {
int length = current.length();
next = current.substring(0, start) + next + current.substring(length - end, length);
} else {
next = current.substring(0, start) + next;
}
} else if (end > 0) {
int length = current.length();
next = next + current.substring(length - end, length);
}
docNames[index++] = next;
current = next;
}
}
synchronized String readDocumentName(int docNumber) throws IOException {
if (this.cachedChunks == null)
this.cachedChunks = new String[this.numberOfChunks][];
int chunkNumber = docNumber / CHUNK_SIZE;
String[] chunk = this.cachedChunks[chunkNumber];
if (chunk == null) {
boolean isLastChunk = chunkNumber == this.numberOfChunks - 1;
int start = this.chunkOffsets[chunkNumber];
int numberOfBytes = (isLastChunk ? this.startOfCategoryTables : this.chunkOffsets[chunkNumber + 1]) - start;
if (numberOfBytes < 0)
throw new IllegalArgumentException();
this.streamBuffer = new byte[numberOfBytes];
this.bufferIndex = 0;
InputStream file = this.indexLocation.getInputStream();
try {
file.skip(start);
if (file.read(this.streamBuffer, 0, numberOfBytes) != numberOfBytes)
throw new IOException();
} catch (IOException ioe) {
this.streamBuffer = null;
throw ioe;
} finally {
file.close();
this.indexLocation.close();
}
int numberOfNames = isLastChunk ? this.sizeOfLastChunk : CHUNK_SIZE;
chunk = new String[numberOfNames];
try {
readChunk(chunk, null, 0, numberOfNames);
} catch (IOException ioe) {
this.streamBuffer = null;
throw ioe;
}
this.cachedChunks[chunkNumber] = chunk;
}
this.streamBuffer = null;
return chunk[docNumber - (chunkNumber * CHUNK_SIZE)];
}
synchronized int[] readDocumentNumbers(Object arrayOffset) throws IOException {
// arrayOffset is either a cached array of docNumbers or an Integer offset in the file
if (arrayOffset instanceof int[])
return (int[]) arrayOffset;
InputStream stream = this.indexLocation.getInputStream();
try {
int offset = ((Integer) arrayOffset).intValue();
stream.skip(offset);
this.streamBuffer = new byte[BUFFER_READ_SIZE];
this.bufferIndex = 0;
this.bufferEnd = stream.read(this.streamBuffer, 0, this.streamBuffer.length);
return readStreamDocumentArray(stream, readStreamInt(stream));
} finally {
stream.close();
this.indexLocation.close();
this.streamBuffer = null;
}
}
private void readHeaderInfo(InputStream stream) throws IOException {
// must be same order as writeHeaderInfo()
this.numberOfChunks = readStreamInt(stream);
this.sizeOfLastChunk = this.streamBuffer[this.bufferIndex++] & 0xFF;
this.documentReferenceSize = this.streamBuffer[this.bufferIndex++] & 0xFF;
this.separator = (char) (this.streamBuffer[this.bufferIndex++] & 0xFF);
long length = this.indexLocation.length();
if (length != -1 && this.numberOfChunks > length) {
// not an accurate check, but good enough https://bugs.eclipse.org/bugs/show_bug.cgi?id=350612
if (DEBUG)
System.out.println("Index file is corrupted " + this.indexLocation); //$NON-NLS-1$
throw new IOException("Index file is corrupted " + this.indexLocation); //$NON-NLS-1$
}
this.chunkOffsets = new int[this.numberOfChunks];
for (int i = 0; i < this.numberOfChunks; i++)
this.chunkOffsets[i] = readStreamInt(stream);
this.startOfCategoryTables = readStreamInt(stream);
int size = readStreamInt(stream);
this.categoryOffsets = new HashtableOfIntValues(size);
this.categoryEnds = new HashtableOfIntValues(size);
if (length != -1 && size > length) {
// not an accurate check, but good enough https://bugs.eclipse.org/bugs/show_bug.cgi?id=350612
if (DEBUG)
System.out.println("Index file is corrupted " + this.indexLocation); //$NON-NLS-1$
throw new IOException("Index file is corrupted " + this.indexLocation); //$NON-NLS-1$
}
char[] previousCategory = null;
int offset = -1;
for (int i = 0; i < size; i++) {
char[] categoryName = INTERNED_CATEGORY_NAMES.get(readStreamChars(stream));
offset = readStreamInt(stream);
this.categoryOffsets.put(categoryName, offset); // cache offset to category table
if (previousCategory != null) {
this.categoryEnds.put(previousCategory, offset); // cache end of the category table
}
previousCategory = categoryName;
}
if (previousCategory != null) {
this.categoryEnds.put(previousCategory, this.headerInfoOffset); // cache end of the category table
}
this.categoryTables = new HashtableOfObject(3);
}
synchronized void startQuery() {
this.cacheUserCount++;
}
synchronized void stopQuery() {
if (--this.cacheUserCount < 0) {
// clear cached items
this.cacheUserCount = -1;
this.cachedChunks = null;
if (this.categoryTables != null) {
if (this.cachedCategoryName == null) {
this.categoryTables = null;
} else if (this.categoryTables.elementSize > 1) {
HashtableOfObject newTables = new HashtableOfObject(3);
newTables.put(this.cachedCategoryName, this.categoryTables.get(this.cachedCategoryName));
this.categoryTables = newTables;
}
}
}
}
private void readStreamBuffer(InputStream stream) throws IOException {
// if we're about to read a known amount at the end of the existing buffer, but it does not completely fit
// so we need to shift the remaining bytes to be read, and fill the buffer from the stream
if (this.bufferEnd < this.streamBuffer.length) {
if (stream.available() == 0)
return; // we're at the end of the stream - nothing left to read
}
int bytesInBuffer = this.bufferEnd - this.bufferIndex;
if (bytesInBuffer > 0)
System.arraycopy(this.streamBuffer, this.bufferIndex, this.streamBuffer, 0, bytesInBuffer);
this.bufferEnd = bytesInBuffer + stream.read(this.streamBuffer, bytesInBuffer, this.bufferIndex);
this.bufferIndex = 0;
}
/**
* Reads in a string from the specified data input stream. The
* string has been encoded using a modified UTF-8 format.
*
* The first two bytes are read as an unsigned short.
* This value gives the number of following bytes that are in the encoded string,
* not the length of the resulting string. The following bytes are then
* interpreted as bytes encoding characters in the UTF-8 format
* and are converted into characters.
*
* This method blocks until all the bytes are read, the end of the
* stream is detected, or an exception is thrown.
*
* @param stream a data input stream.
* @return UTF decoded string as a char array
* @exception EOFException if this end of data input is reached while reading it.
* @exception IOException if an I/O error occurs while reading data input.
* @exception UTFDataFormatException if the bytes do not represent a
* valid UTF-8 encoding of a Unicode string.
*/
private char[] readStreamChars(InputStream stream) throws IOException {
// read chars array length
if (stream != null && this.bufferIndex + 2 >= this.bufferEnd)
readStreamBuffer(stream);
int length = (this.streamBuffer[this.bufferIndex++] & 0xFF) << 8;
length += this.streamBuffer[this.bufferIndex++] & 0xFF;
// fill the chars from bytes buffer
char[] word = new char[length];
int i = 0;
while (i < length) {
// how many characters can be decoded without refilling the buffer?
int charsInBuffer = i + ((this.bufferEnd - this.bufferIndex) / 3);
// all the characters must already be in the buffer if we're at the end of the stream
if (charsInBuffer > length || stream == null || (this.bufferEnd != this.streamBuffer.length && stream.available() == 0))
charsInBuffer = length;
while (i < charsInBuffer) {
byte b = this.streamBuffer[this.bufferIndex++];
switch (b & 0xF0) {
case 0x00 :
case 0x10 :
case 0x20 :
case 0x30 :
case 0x40 :
case 0x50 :
case 0x60 :
case 0x70 :
word[i++]= (char) b;
break;
case 0xC0 :
case 0xD0 :
char next = (char) this.streamBuffer[this.bufferIndex++];
if ((next & 0xC0) != 0x80) {
throw new UTFDataFormatException();
}
char ch = (char) ((b & 0x1F) << 6);
ch |= next & 0x3F;
word[i++] = ch;
break;
case 0xE0 :
char first = (char) this.streamBuffer[this.bufferIndex++];
char second = (char) this.streamBuffer[this.bufferIndex++];
if ((first & second & 0xC0) != 0x80) {
throw new UTFDataFormatException();
}
ch = (char) ((b & 0x0F) << 12);
ch |= ((first& 0x3F) << 6);
ch |= second & 0x3F;
word[i++] = ch;
break;
default:
throw new UTFDataFormatException();
}
}
if (i < length && stream != null)
readStreamBuffer(stream);
}
return word;
}
private int[] readStreamDocumentArray(InputStream stream, int arraySize) throws IOException {
int[] indexes = new int[arraySize];
if (arraySize == 0) return indexes;
int i = 0;
switch (this.documentReferenceSize) {
case 1 :
while (i < arraySize) {
// how many bytes without refilling the buffer?
int bytesInBuffer = i + this.bufferEnd - this.bufferIndex;
if (bytesInBuffer > arraySize)
bytesInBuffer = arraySize;
while (i < bytesInBuffer) {
indexes[i++] = this.streamBuffer[this.bufferIndex++] & 0xFF;
}
if (i < arraySize && stream != null)
readStreamBuffer(stream);
}
break;
case 2 :
while (i < arraySize) {
// how many shorts without refilling the buffer?
int shortsInBuffer = i + ((this.bufferEnd - this.bufferIndex) / 2);
if (shortsInBuffer > arraySize)
shortsInBuffer = arraySize;
while (i < shortsInBuffer) {
int val = (this.streamBuffer[this.bufferIndex++] & 0xFF) << 8;
indexes[i++] = val + (this.streamBuffer[this.bufferIndex++] & 0xFF);
}
if (i < arraySize && stream != null)
readStreamBuffer(stream);
}
break;
default :
while (i < arraySize) {
indexes[i++] = readStreamInt(stream);
}
break;
}
return indexes;
}
private int readStreamInt(InputStream stream) throws IOException {
if (this.bufferIndex + 4 >= this.bufferEnd) {
readStreamBuffer(stream);
}
int val = (this.streamBuffer[this.bufferIndex++] & 0xFF) << 24;
val += (this.streamBuffer[this.bufferIndex++] & 0xFF) << 16;
val += (this.streamBuffer[this.bufferIndex++] & 0xFF) << 8;
return val + (this.streamBuffer[this.bufferIndex++] & 0xFF);
}
private void writeAllDocumentNames(String[] sortedDocNames, FileOutputStream stream) throws IOException {
if (sortedDocNames.length == 0)
throw new IllegalArgumentException();
// assume the file was just created by initializeFrom()
this.streamBuffer = new byte[BUFFER_WRITE_SIZE];
this.bufferIndex = 0;
this.streamEnd = 0;
// in order, write: SIGNATURE & headerInfoOffset place holder, then each compressed chunk of document names
writeStreamChars(stream, SIGNATURE_CHARS);
this.headerInfoOffset = this.streamEnd;
writeStreamInt(stream, -1); // will overwrite with correct value later
int size = sortedDocNames.length;
this.numberOfChunks = (size / CHUNK_SIZE) + 1;
this.sizeOfLastChunk = size % CHUNK_SIZE;
if (this.sizeOfLastChunk == 0) {
this.numberOfChunks--;
this.sizeOfLastChunk = CHUNK_SIZE;
}
this.documentReferenceSize = size <= 0x7F ? 1 : (size <= 0x7FFF ? 2 : 4); // number of bytes used to encode a reference
this.chunkOffsets = new int[this.numberOfChunks];
int lastIndex = this.numberOfChunks - 1;
for (int i = 0; i < this.numberOfChunks; i++) {
this.chunkOffsets[i] = this.streamEnd;
int chunkSize = i == lastIndex ? this.sizeOfLastChunk : CHUNK_SIZE;
int chunkIndex = i * CHUNK_SIZE;
String current = sortedDocNames[chunkIndex];
writeStreamChars(stream, current.toCharArray());
for (int j = 1; j < chunkSize; j++) {
String next = sortedDocNames[chunkIndex + j];
int len1 = current.length();
int len2 = next.length();
int max = len1 < len2 ? len1 : len2;
int start = 0; // number of identical characters at the beginning (also the index of first character that is different)
while (current.charAt(start) == next.charAt(start)) {
start++;
if (max == start) break; // current is 'abba', next is 'abbab'
}
if (start > 255) start = 255;
int end = 0; // number of identical characters at the end
while (current.charAt(--len1) == next.charAt(--len2)) {
end++;
if (len2 == start) break; // current is 'abbba', next is 'abba'
if (len1 == 0) break; // current is 'xabc', next is 'xyabc'
}
if (end > 255) end = 255;
if ((this.bufferIndex + 2) >= BUFFER_WRITE_SIZE) {
stream.write(this.streamBuffer, 0, this.bufferIndex);
this.bufferIndex = 0;
}
this.streamBuffer[this.bufferIndex++] = (byte) start;
this.streamBuffer[this.bufferIndex++] = (byte) end;
this.streamEnd += 2;
int last = next.length() - end;
writeStreamChars(stream, (start < last ? CharOperation.subarray(next.toCharArray(), start, last) : CharOperation.NO_CHAR));
current = next;
}
}
this.startOfCategoryTables = this.streamEnd + 1;
}
private void writeCategories(FileOutputStream stream) throws IOException {
char[][] categoryNames = this.categoryTables.keyTable;
Object[] tables = this.categoryTables.valueTable;
for (int i = 0, l = categoryNames.length; i < l; i++)
if (categoryNames[i] != null)
writeCategoryTable(categoryNames[i], (HashtableOfObject) tables[i], stream);
this.categoryTables = null;
}
private void writeCategoryTable(char[] categoryName, HashtableOfObject wordsToDocs, FileOutputStream stream) throws IOException {
// the format of a category table is as follows:
// any document number arrays with >= 256 elements are written before the table (the offset to each array is remembered)
// then the number of word->int[] pairs in the table is written
// for each word -> int[] pair, the word is written followed by:
// an int <= 0 if the array size == 1
// an int > 1 & < 256 for the size of the array if its > 1 & < 256, the document array follows immediately
// 256 if the array size >= 256 followed by another int which is the offset to the array (written prior to the table)
int largeArraySize = 256;
Object[] values = wordsToDocs.valueTable;
for (int i = 0, l = values.length; i < l; i++) {
Object o = values[i];
if (o != null) {
if (o instanceof IntList)
o = values[i] = ((IntList) values[i]).asArray();
int[] documentNumbers = (int[]) o;
if (documentNumbers.length >= largeArraySize) {
values[i] = Integer.valueOf(this.streamEnd);
writeDocumentNumbers(documentNumbers, stream);
}
}
}
this.categoryOffsets.put(categoryName, this.streamEnd); // remember the offset to the start of the table
this.categoryTables.put(categoryName, null); // flush cached table
writeStreamInt(stream, wordsToDocs.elementSize);
char[][] words = wordsToDocs.keyTable;
for (int i = 0, l = words.length; i < l; i++) {
Object o = values[i];
if (o != null) {
writeStreamChars(stream, words[i]);
if (o instanceof int[]) {
int[] documentNumbers = (int[]) o;
if (documentNumbers.length == 1)
writeStreamInt(stream, -documentNumbers[0]); // store an array of 1 element by negating the documentNumber (can be zero)
else
writeDocumentNumbers(documentNumbers, stream);
} else {
writeStreamInt(stream, largeArraySize); // mark to identify that an offset follows
writeStreamInt(stream, ((Integer) o).intValue()); // offset in the file of the array of document numbers
}
}
}
}
private void writeDocumentNumbers(int[] documentNumbers, FileOutputStream stream) throws IOException {
// must store length as a positive int to detect in-lined array of 1 element
int length = documentNumbers.length;
writeStreamInt(stream, length);
Util.sort(documentNumbers);
int start = 0;
switch (this.documentReferenceSize) {
case 1 :
while ((this.bufferIndex + length - start) >= BUFFER_WRITE_SIZE) {
// when documentNumbers is large, write BUFFER_WRITE_SIZE parts & fall thru to write the last part
int bytesLeft = BUFFER_WRITE_SIZE - this.bufferIndex;
for (int i=0; i < bytesLeft; i++) {
this.streamBuffer[this.bufferIndex++] = (byte) documentNumbers[start++];
}
stream.write(this.streamBuffer, 0, this.bufferIndex);
this.bufferIndex = 0;
}
while (start < length) {
this.streamBuffer[this.bufferIndex++] = (byte) documentNumbers[start++];
}
this.streamEnd += length;
break;
case 2 :
while ((this.bufferIndex + ((length - start) * 2)) >= BUFFER_WRITE_SIZE) {
// when documentNumbers is large, write BUFFER_WRITE_SIZE parts & fall thru to write the last part
int shortsLeft = (BUFFER_WRITE_SIZE - this.bufferIndex) / 2;
for (int i=0; i < shortsLeft; i++) {
this.streamBuffer[this.bufferIndex++] = (byte) (documentNumbers[start] >> 8);
this.streamBuffer[this.bufferIndex++] = (byte) documentNumbers[start++];
}
stream.write(this.streamBuffer, 0, this.bufferIndex);
this.bufferIndex = 0;
}
while (start < length) {
this.streamBuffer[this.bufferIndex++] = (byte) (documentNumbers[start] >> 8);
this.streamBuffer[this.bufferIndex++] = (byte) documentNumbers[start++];
}
this.streamEnd += length * 2;
break;
default :
while (start < length) {
writeStreamInt(stream, documentNumbers[start++]);
}
break;
}
}
private void writeHeaderInfo(FileOutputStream stream) throws IOException {
writeStreamInt(stream, this.numberOfChunks);
if ((this.bufferIndex + 3) >= BUFFER_WRITE_SIZE) {
stream.write(this.streamBuffer, 0, this.bufferIndex);
this.bufferIndex = 0;
}
this.streamBuffer[this.bufferIndex++] = (byte) this.sizeOfLastChunk;
this.streamBuffer[this.bufferIndex++] = (byte) this.documentReferenceSize;
this.streamBuffer[this.bufferIndex++] = (byte) this.separator;
this.streamEnd += 3;
// apend the file with chunk offsets
for (int i = 0; i < this.numberOfChunks; i++) {
writeStreamInt(stream, this.chunkOffsets[i]);
}
writeStreamInt(stream, this.startOfCategoryTables);
// append the file with the category offsets... # of name -> offset pairs, followed by each name & an offset to its word->doc# table
writeStreamInt(stream, this.categoryOffsets.elementSize);
char[][] categoryNames = this.categoryOffsets.keyTable;
int[] offsets = this.categoryOffsets.valueTable;
for (int i = 0, l = categoryNames.length; i < l; i++) {
if (categoryNames[i] != null) {
writeStreamChars(stream, categoryNames[i]);
writeStreamInt(stream, offsets[i]);
}
}
// ensure buffer is written to the stream
if (this.bufferIndex > 0) {
stream.write(this.streamBuffer, 0, this.bufferIndex);
this.bufferIndex = 0;
}
}
private void writeOffsetToHeader(int offsetToHeader) throws IOException {
if (offsetToHeader > 0) {
RandomAccessFile file = new RandomAccessFile(this.indexLocation.getIndexFile(), "rw"); //$NON-NLS-1$
try {
file.seek(this.headerInfoOffset); // offset to position in header
file.writeInt(offsetToHeader);
this.headerInfoOffset = offsetToHeader; // update to reflect the correct offset
} finally {
file.close();
}
}
}
/**
* Writes a string to the given output stream using UTF-8
* encoding in a machine-independent manner.
*
* First, two bytes of the array are giving the number of bytes to
* follow. This value is the number of bytes actually written out,
* not the length of the string. Following the length, each character
* of the string is put in the bytes array, in sequence, using the UTF-8
* encoding for the character.
*
*
* Then the entire byte array is written to the output stream
* using {@link OutputStream#write(byte[], int, int)} method.
*
*
* @param array char array to be written.
* @exception IOException if an I/O error occurs while writting
* the bytes array to the stream.
*/
private void writeStreamChars(FileOutputStream stream, char[] array) throws IOException {
if ((this.bufferIndex + 2) >= BUFFER_WRITE_SIZE) {
stream.write(this.streamBuffer, 0, this.bufferIndex);
this.bufferIndex = 0;
}
int length = array.length;
this.streamBuffer[this.bufferIndex++] = (byte) ((length >>> 8) & 0xFF); // store chars array length instead of bytes
this.streamBuffer[this.bufferIndex++] = (byte) (length & 0xFF); // this will allow to read it faster
this.streamEnd += 2;
// we're assuming that very few char[] are so large that we need to flush the buffer more than once, if at all
int totalBytesNeeded = length * 3;
if (totalBytesNeeded <= BUFFER_WRITE_SIZE) {
if (this.bufferIndex + totalBytesNeeded > BUFFER_WRITE_SIZE) {
// flush the buffer now to make sure there is room for the array
stream.write(this.streamBuffer, 0, this.bufferIndex);
this.bufferIndex = 0;
}
writeStreamChars(stream, array, 0, length);
} else {
int charsPerWrite = BUFFER_WRITE_SIZE / 3;
int start = 0;
while (start < length) {
stream.write(this.streamBuffer, 0, this.bufferIndex);
this.bufferIndex = 0;
int charsLeftToWrite = length - start;
int end = start + (charsPerWrite < charsLeftToWrite ? charsPerWrite : charsLeftToWrite);
writeStreamChars(stream, array, start, end);
start = end;
}
}
}
private void writeStreamChars(FileOutputStream stream, char[] array, int start, int end) throws IOException {
// start can NOT be == end
// must have checked that there is enough room for end - start * 3 bytes in the buffer
int oldIndex = this.bufferIndex;
while (start < end) {
int ch = array[start++];
if ((ch & 0x007F) == ch) {
this.streamBuffer[this.bufferIndex++] = (byte) ch;
} else if ((ch & 0x07FF) == ch) {
// first two bits are stored in first byte
byte b = (byte) (ch >> 6);
b &= 0x1F;
b |= 0xC0;
this.streamBuffer[this.bufferIndex++] = b;
// last six bits are stored in second byte
b = (byte) (ch & 0x3F);
b |= 0x80;
this.streamBuffer[this.bufferIndex++] = b;
} else {
// first four bits are stored in first byte
byte b = (byte) (ch >> 12);
b &= 0x0F;
b |= 0xE0;
this.streamBuffer[this.bufferIndex++] = b;
// six following bits are stored in second byte
b = (byte) (ch >> 6);
b &= 0x3F;
b |= 0x80;
this.streamBuffer[this.bufferIndex++] = b;
// last six bits are stored in third byte
b = (byte) (ch & 0x3F);
b |= 0x80;
this.streamBuffer[this.bufferIndex++] = b;
}
}
this.streamEnd += this.bufferIndex - oldIndex;
}
private void writeStreamInt(FileOutputStream stream, int val) throws IOException {
if ((this.bufferIndex + 4) >= BUFFER_WRITE_SIZE) {
stream.write(this.streamBuffer, 0, this.bufferIndex);
this.bufferIndex = 0;
}
this.streamBuffer[this.bufferIndex++] = (byte) (val >> 24);
this.streamBuffer[this.bufferIndex++] = (byte) (val >> 16);
this.streamBuffer[this.bufferIndex++] = (byte) (val >> 8);
this.streamBuffer[this.bufferIndex++] = (byte) val;
this.streamEnd += 4;
}
}