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Apache Lucene (module: codecs)
package org.apache.lucene.codecs.memory;
/*
* 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.util.ArrayList;
import java.util.Arrays;
import java.util.BitSet;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.TreeMap;
import org.apache.lucene.codecs.BlockTermState;
import org.apache.lucene.codecs.CodecUtil;
import org.apache.lucene.codecs.FieldsProducer;
import org.apache.lucene.codecs.PostingsReaderBase;
import org.apache.lucene.codecs.memory.FSTTermsReader.TermsReader;
import org.apache.lucene.index.CorruptIndexException;
import org.apache.lucene.index.DocsAndPositionsEnum;
import org.apache.lucene.index.DocsEnum;
import org.apache.lucene.index.FieldInfo.IndexOptions;
import org.apache.lucene.index.FieldInfo;
import org.apache.lucene.index.FieldInfos;
import org.apache.lucene.index.IndexFileNames;
import org.apache.lucene.index.SegmentInfo;
import org.apache.lucene.index.SegmentReadState;
import org.apache.lucene.index.TermState;
import org.apache.lucene.index.Terms;
import org.apache.lucene.index.TermsEnum;
import org.apache.lucene.store.ByteArrayDataInput;
import org.apache.lucene.store.ChecksumIndexInput;
import org.apache.lucene.store.IndexInput;
import org.apache.lucene.util.ArrayUtil;
import org.apache.lucene.util.Bits;
import org.apache.lucene.util.BytesRef;
import org.apache.lucene.util.IOUtils;
import org.apache.lucene.util.RamUsageEstimator;
import org.apache.lucene.util.automaton.ByteRunAutomaton;
import org.apache.lucene.util.automaton.CompiledAutomaton;
import org.apache.lucene.util.fst.BytesRefFSTEnum.InputOutput;
import org.apache.lucene.util.fst.BytesRefFSTEnum;
import org.apache.lucene.util.fst.FST;
import org.apache.lucene.util.fst.Outputs;
import org.apache.lucene.util.fst.PositiveIntOutputs;
import org.apache.lucene.util.fst.Util;
/**
* FST-based terms dictionary reader.
*
* The FST index maps each term and its ord, and during seek
* the ord is used fetch metadata from a single block.
* The term dictionary is fully memory resident.
*
* @lucene.experimental
*/
public class FSTOrdTermsReader extends FieldsProducer {
static final int INTERVAL = FSTOrdTermsWriter.SKIP_INTERVAL;
final TreeMap fields = new TreeMap<>();
final PostingsReaderBase postingsReader;
int version;
//static final boolean TEST = false;
public FSTOrdTermsReader(SegmentReadState state, PostingsReaderBase postingsReader) throws IOException {
final String termsIndexFileName = IndexFileNames.segmentFileName(state.segmentInfo.name, state.segmentSuffix, FSTOrdTermsWriter.TERMS_INDEX_EXTENSION);
final String termsBlockFileName = IndexFileNames.segmentFileName(state.segmentInfo.name, state.segmentSuffix, FSTOrdTermsWriter.TERMS_BLOCK_EXTENSION);
this.postingsReader = postingsReader;
ChecksumIndexInput indexIn = null;
IndexInput blockIn = null;
boolean success = false;
try {
indexIn = state.directory.openChecksumInput(termsIndexFileName, state.context);
blockIn = state.directory.openInput(termsBlockFileName, state.context);
version = readHeader(indexIn);
readHeader(blockIn);
if (version >= FSTOrdTermsWriter.TERMS_VERSION_CHECKSUM) {
CodecUtil.checksumEntireFile(blockIn);
}
this.postingsReader.init(blockIn);
seekDir(blockIn);
final FieldInfos fieldInfos = state.fieldInfos;
final int numFields = blockIn.readVInt();
for (int i = 0; i < numFields; i++) {
FieldInfo fieldInfo = fieldInfos.fieldInfo(blockIn.readVInt());
boolean hasFreq = fieldInfo.getIndexOptions() != IndexOptions.DOCS_ONLY;
long numTerms = blockIn.readVLong();
long sumTotalTermFreq = hasFreq ? blockIn.readVLong() : -1;
long sumDocFreq = blockIn.readVLong();
int docCount = blockIn.readVInt();
int longsSize = blockIn.readVInt();
FST index = new FST<>(indexIn, PositiveIntOutputs.getSingleton());
TermsReader current = new TermsReader(fieldInfo, blockIn, numTerms, sumTotalTermFreq, sumDocFreq, docCount, longsSize, index);
TermsReader previous = fields.put(fieldInfo.name, current);
checkFieldSummary(state.segmentInfo, indexIn, blockIn, current, previous);
}
if (version >= FSTOrdTermsWriter.TERMS_VERSION_CHECKSUM) {
CodecUtil.checkFooter(indexIn);
} else {
CodecUtil.checkEOF(indexIn);
}
success = true;
} finally {
if (success) {
IOUtils.close(indexIn, blockIn);
} else {
IOUtils.closeWhileHandlingException(indexIn, blockIn);
}
}
}
private int readHeader(IndexInput in) throws IOException {
return CodecUtil.checkHeader(in, FSTOrdTermsWriter.TERMS_CODEC_NAME,
FSTOrdTermsWriter.TERMS_VERSION_START,
FSTOrdTermsWriter.TERMS_VERSION_CURRENT);
}
private void seekDir(IndexInput in) throws IOException {
if (version >= FSTOrdTermsWriter.TERMS_VERSION_CHECKSUM) {
in.seek(in.length() - CodecUtil.footerLength() - 8);
} else {
in.seek(in.length() - 8);
}
in.seek(in.readLong());
}
private void checkFieldSummary(SegmentInfo info, IndexInput indexIn, IndexInput blockIn, TermsReader field, TermsReader previous) throws IOException {
// #docs with field must be <= #docs
if (field.docCount < 0 || field.docCount > info.getDocCount()) {
throw new CorruptIndexException("invalid docCount: " + field.docCount + " maxDoc: " + info.getDocCount() + " (resource=" + indexIn + ", " + blockIn + ")");
}
// #postings must be >= #docs with field
if (field.sumDocFreq < field.docCount) {
throw new CorruptIndexException("invalid sumDocFreq: " + field.sumDocFreq + " docCount: " + field.docCount + " (resource=" + indexIn + ", " + blockIn + ")");
}
// #positions must be >= #postings
if (field.sumTotalTermFreq != -1 && field.sumTotalTermFreq < field.sumDocFreq) {
throw new CorruptIndexException("invalid sumTotalTermFreq: " + field.sumTotalTermFreq + " sumDocFreq: " + field.sumDocFreq + " (resource=" + indexIn + ", " + blockIn + ")");
}
if (previous != null) {
throw new CorruptIndexException("duplicate fields: " + field.fieldInfo.name + " (resource=" + indexIn + ", " + blockIn + ")");
}
}
@Override
public Iterator iterator() {
return Collections.unmodifiableSet(fields.keySet()).iterator();
}
@Override
public Terms terms(String field) throws IOException {
assert field != null;
return fields.get(field);
}
@Override
public int size() {
return fields.size();
}
@Override
public void close() throws IOException {
try {
IOUtils.close(postingsReader);
} finally {
fields.clear();
}
}
final class TermsReader extends Terms {
final FieldInfo fieldInfo;
final long numTerms;
final long sumTotalTermFreq;
final long sumDocFreq;
final int docCount;
final int longsSize;
final FST index;
final int numSkipInfo;
final long[] skipInfo;
final byte[] statsBlock;
final byte[] metaLongsBlock;
final byte[] metaBytesBlock;
TermsReader(FieldInfo fieldInfo, IndexInput blockIn, long numTerms, long sumTotalTermFreq, long sumDocFreq, int docCount, int longsSize, FST index) throws IOException {
this.fieldInfo = fieldInfo;
this.numTerms = numTerms;
this.sumTotalTermFreq = sumTotalTermFreq;
this.sumDocFreq = sumDocFreq;
this.docCount = docCount;
this.longsSize = longsSize;
this.index = index;
assert (numTerms & (~0xffffffffL)) == 0;
final int numBlocks = (int)(numTerms + INTERVAL - 1) / INTERVAL;
this.numSkipInfo = longsSize + 3;
this.skipInfo = new long[numBlocks * numSkipInfo];
this.statsBlock = new byte[(int)blockIn.readVLong()];
this.metaLongsBlock = new byte[(int)blockIn.readVLong()];
this.metaBytesBlock = new byte[(int)blockIn.readVLong()];
int last = 0, next = 0;
for (int i = 1; i < numBlocks; i++) {
next = numSkipInfo * i;
for (int j = 0; j < numSkipInfo; j++) {
skipInfo[next + j] = skipInfo[last + j] + blockIn.readVLong();
}
last = next;
}
blockIn.readBytes(statsBlock, 0, statsBlock.length);
blockIn.readBytes(metaLongsBlock, 0, metaLongsBlock.length);
blockIn.readBytes(metaBytesBlock, 0, metaBytesBlock.length);
}
@Override
public Comparator getComparator() {
return BytesRef.getUTF8SortedAsUnicodeComparator();
}
@Override
public boolean hasFreqs() {
return fieldInfo.getIndexOptions().compareTo(IndexOptions.DOCS_AND_FREQS) >= 0;
}
@Override
public boolean hasOffsets() {
return fieldInfo.getIndexOptions().compareTo(IndexOptions.DOCS_AND_FREQS_AND_POSITIONS_AND_OFFSETS) >= 0;
}
@Override
public boolean hasPositions() {
return fieldInfo.getIndexOptions().compareTo(IndexOptions.DOCS_AND_FREQS_AND_POSITIONS) >= 0;
}
@Override
public boolean hasPayloads() {
return fieldInfo.hasPayloads();
}
@Override
public long size() {
return numTerms;
}
@Override
public long getSumTotalTermFreq() {
return sumTotalTermFreq;
}
@Override
public long getSumDocFreq() throws IOException {
return sumDocFreq;
}
@Override
public int getDocCount() throws IOException {
return docCount;
}
@Override
public TermsEnum iterator(TermsEnum reuse) throws IOException {
return new SegmentTermsEnum();
}
@Override
public TermsEnum intersect(CompiledAutomaton compiled, BytesRef startTerm) throws IOException {
return new IntersectTermsEnum(compiled, startTerm);
}
// Only wraps common operations for PBF interact
abstract class BaseTermsEnum extends TermsEnum {
/* Current term, null when enum ends or unpositioned */
BytesRef term;
/* Current term's ord, starts from 0 */
long ord;
/* Current term stats + decoded metadata (customized by PBF) */
final BlockTermState state;
/* Datainput to load stats & metadata */
final ByteArrayDataInput statsReader = new ByteArrayDataInput();
final ByteArrayDataInput metaLongsReader = new ByteArrayDataInput();
final ByteArrayDataInput metaBytesReader = new ByteArrayDataInput();
/* To which block is buffered */
int statsBlockOrd;
int metaBlockOrd;
/* Current buffered metadata (long[] & byte[]) */
long[][] longs;
int[] bytesStart;
int[] bytesLength;
/* Current buffered stats (df & ttf) */
int[] docFreq;
long[] totalTermFreq;
BaseTermsEnum() throws IOException {
this.state = postingsReader.newTermState();
this.term = null;
this.statsReader.reset(statsBlock);
this.metaLongsReader.reset(metaLongsBlock);
this.metaBytesReader.reset(metaBytesBlock);
this.longs = new long[INTERVAL][longsSize];
this.bytesStart = new int[INTERVAL];
this.bytesLength = new int[INTERVAL];
this.docFreq = new int[INTERVAL];
this.totalTermFreq = new long[INTERVAL];
this.statsBlockOrd = -1;
this.metaBlockOrd = -1;
if (!hasFreqs()) {
Arrays.fill(totalTermFreq, -1);
}
}
@Override
public Comparator getComparator() {
return BytesRef.getUTF8SortedAsUnicodeComparator();
}
/** Decodes stats data into term state */
void decodeStats() throws IOException {
final int upto = (int)ord % INTERVAL;
final int oldBlockOrd = statsBlockOrd;
statsBlockOrd = (int)ord / INTERVAL;
if (oldBlockOrd != statsBlockOrd) {
refillStats();
}
state.docFreq = docFreq[upto];
state.totalTermFreq = totalTermFreq[upto];
}
/** Let PBF decode metadata */
void decodeMetaData() throws IOException {
final int upto = (int)ord % INTERVAL;
final int oldBlockOrd = metaBlockOrd;
metaBlockOrd = (int)ord / INTERVAL;
if (metaBlockOrd != oldBlockOrd) {
refillMetadata();
}
metaBytesReader.setPosition(bytesStart[upto]);
postingsReader.decodeTerm(longs[upto], metaBytesReader, fieldInfo, state, true);
}
/** Load current stats shard */
final void refillStats() throws IOException {
final int offset = statsBlockOrd * numSkipInfo;
final int statsFP = (int)skipInfo[offset];
statsReader.setPosition(statsFP);
for (int i = 0; i < INTERVAL && !statsReader.eof(); i++) {
int code = statsReader.readVInt();
if (hasFreqs()) {
docFreq[i] = (code >>> 1);
if ((code & 1) == 1) {
totalTermFreq[i] = docFreq[i];
} else {
totalTermFreq[i] = docFreq[i] + statsReader.readVLong();
}
} else {
docFreq[i] = code;
}
}
}
/** Load current metadata shard */
final void refillMetadata() throws IOException {
final int offset = metaBlockOrd * numSkipInfo;
final int metaLongsFP = (int)skipInfo[offset + 1];
final int metaBytesFP = (int)skipInfo[offset + 2];
metaLongsReader.setPosition(metaLongsFP);
for (int j = 0; j < longsSize; j++) {
longs[0][j] = skipInfo[offset + 3 + j] + metaLongsReader.readVLong();
}
bytesStart[0] = metaBytesFP;
bytesLength[0] = (int)metaLongsReader.readVLong();
for (int i = 1; i < INTERVAL && !metaLongsReader.eof(); i++) {
for (int j = 0; j < longsSize; j++) {
longs[i][j] = longs[i-1][j] + metaLongsReader.readVLong();
}
bytesStart[i] = bytesStart[i-1] + bytesLength[i-1];
bytesLength[i] = (int)metaLongsReader.readVLong();
}
}
@Override
public TermState termState() throws IOException {
decodeMetaData();
return state.clone();
}
@Override
public BytesRef term() {
return term;
}
@Override
public int docFreq() throws IOException {
return state.docFreq;
}
@Override
public long totalTermFreq() throws IOException {
return state.totalTermFreq;
}
@Override
public DocsEnum docs(Bits liveDocs, DocsEnum reuse, int flags) throws IOException {
decodeMetaData();
return postingsReader.docs(fieldInfo, state, liveDocs, reuse, flags);
}
@Override
public DocsAndPositionsEnum docsAndPositions(Bits liveDocs, DocsAndPositionsEnum reuse, int flags) throws IOException {
if (!hasPositions()) {
return null;
}
decodeMetaData();
return postingsReader.docsAndPositions(fieldInfo, state, liveDocs, reuse, flags);
}
// TODO: this can be achieved by making use of Util.getByOutput()
// and should have related tests
@Override
public void seekExact(long ord) throws IOException {
throw new UnsupportedOperationException();
}
@Override
public long ord() {
throw new UnsupportedOperationException();
}
}
// Iterates through all terms in this field
private final class SegmentTermsEnum extends BaseTermsEnum {
final BytesRefFSTEnum fstEnum;
/* True when current term's metadata is decoded */
boolean decoded;
/* True when current enum is 'positioned' by seekExact(TermState) */
boolean seekPending;
SegmentTermsEnum() throws IOException {
this.fstEnum = new BytesRefFSTEnum<>(index);
this.decoded = false;
this.seekPending = false;
}
@Override
void decodeMetaData() throws IOException {
if (!decoded && !seekPending) {
super.decodeMetaData();
decoded = true;
}
}
// Update current enum according to FSTEnum
void updateEnum(final InputOutput pair) throws IOException {
if (pair == null) {
term = null;
} else {
term = pair.input;
ord = pair.output;
decodeStats();
}
decoded = false;
seekPending = false;
}
@Override
public BytesRef next() throws IOException {
if (seekPending) { // previously positioned, but termOutputs not fetched
seekPending = false;
SeekStatus status = seekCeil(term);
assert status == SeekStatus.FOUND; // must positioned on valid term
}
updateEnum(fstEnum.next());
return term;
}
@Override
public boolean seekExact(BytesRef target) throws IOException {
updateEnum(fstEnum.seekExact(target));
return term != null;
}
@Override
public SeekStatus seekCeil(BytesRef target) throws IOException {
updateEnum(fstEnum.seekCeil(target));
if (term == null) {
return SeekStatus.END;
} else {
return term.equals(target) ? SeekStatus.FOUND : SeekStatus.NOT_FOUND;
}
}
@Override
public void seekExact(BytesRef target, TermState otherState) {
if (!target.equals(term)) {
state.copyFrom(otherState);
term = BytesRef.deepCopyOf(target);
seekPending = true;
}
}
}
// Iterates intersect result with automaton (cannot seek!)
private final class IntersectTermsEnum extends BaseTermsEnum {
/* True when current term's metadata is decoded */
boolean decoded;
/* True when there is pending term when calling next() */
boolean pending;
/* stack to record how current term is constructed,
* used to accumulate metadata or rewind term:
* level == term.length + 1,
* == 0 when term is null */
Frame[] stack;
int level;
/* term dict fst */
final FST fst;
final FST.BytesReader fstReader;
final Outputs fstOutputs;
/* query automaton to intersect with */
final ByteRunAutomaton fsa;
private final class Frame {
/* fst stats */
FST.Arc arc;
/* automaton stats */
int state;
Frame() {
this.arc = new FST.Arc<>();
this.state = -1;
}
public String toString() {
return "arc=" + arc + " state=" + state;
}
}
IntersectTermsEnum(CompiledAutomaton compiled, BytesRef startTerm) throws IOException {
//if (TEST) System.out.println("Enum init, startTerm=" + startTerm);
this.fst = index;
this.fstReader = fst.getBytesReader();
this.fstOutputs = index.outputs;
this.fsa = compiled.runAutomaton;
this.level = -1;
this.stack = new Frame[16];
for (int i = 0 ; i < stack.length; i++) {
this.stack[i] = new Frame();
}
Frame frame;
frame = loadVirtualFrame(newFrame());
this.level++;
frame = loadFirstFrame(newFrame());
pushFrame(frame);
this.decoded = false;
this.pending = false;
if (startTerm == null) {
pending = isAccept(topFrame());
} else {
doSeekCeil(startTerm);
pending = !startTerm.equals(term) && isValid(topFrame()) && isAccept(topFrame());
}
}
@Override
void decodeMetaData() throws IOException {
if (!decoded) {
super.decodeMetaData();
decoded = true;
}
}
@Override
void decodeStats() throws IOException {
final FST.Arc arc = topFrame().arc;
assert arc.nextFinalOutput == fstOutputs.getNoOutput();
ord = arc.output;
super.decodeStats();
}
@Override
public SeekStatus seekCeil(BytesRef target) throws IOException {
throw new UnsupportedOperationException();
}
@Override
public BytesRef next() throws IOException {
//if (TEST) System.out.println("Enum next()");
if (pending) {
pending = false;
decodeStats();
return term;
}
decoded = false;
DFS:
while (level > 0) {
Frame frame = newFrame();
if (loadExpandFrame(topFrame(), frame) != null) { // has valid target
pushFrame(frame);
if (isAccept(frame)) { // gotcha
break;
}
continue; // check next target
}
frame = popFrame();
while(level > 0) {
if (loadNextFrame(topFrame(), frame) != null) { // has valid sibling
pushFrame(frame);
if (isAccept(frame)) { // gotcha
break DFS;
}
continue DFS; // check next target
}
frame = popFrame();
}
return null;
}
decodeStats();
return term;
}
BytesRef doSeekCeil(BytesRef target) throws IOException {
//if (TEST) System.out.println("Enum doSeekCeil()");
Frame frame= null;
int label, upto = 0, limit = target.length;
while (upto < limit) { // to target prefix, or ceil label (rewind prefix)
frame = newFrame();
label = target.bytes[upto] & 0xff;
frame = loadCeilFrame(label, topFrame(), frame);
if (frame == null || frame.arc.label != label) {
break;
}
assert isValid(frame); // target must be fetched from automaton
pushFrame(frame);
upto++;
}
if (upto == limit) { // got target
return term;
}
if (frame != null) { // got larger term('s prefix)
pushFrame(frame);
return isAccept(frame) ? term : next();
}
while (level > 0) { // got target's prefix, advance to larger term
frame = popFrame();
while (level > 0 && !canRewind(frame)) {
frame = popFrame();
}
if (loadNextFrame(topFrame(), frame) != null) {
pushFrame(frame);
return isAccept(frame) ? term : next();
}
}
return null;
}
/** Virtual frame, never pop */
Frame loadVirtualFrame(Frame frame) throws IOException {
frame.arc.output = fstOutputs.getNoOutput();
frame.arc.nextFinalOutput = fstOutputs.getNoOutput();
frame.state = -1;
return frame;
}
/** Load frame for start arc(node) on fst */
Frame loadFirstFrame(Frame frame) throws IOException {
frame.arc = fst.getFirstArc(frame.arc);
frame.state = fsa.getInitialState();
return frame;
}
/** Load frame for target arc(node) on fst */
Frame loadExpandFrame(Frame top, Frame frame) throws IOException {
if (!canGrow(top)) {
return null;
}
frame.arc = fst.readFirstRealTargetArc(top.arc.target, frame.arc, fstReader);
frame.state = fsa.step(top.state, frame.arc.label);
//if (TEST) System.out.println(" loadExpand frame="+frame);
if (frame.state == -1) {
return loadNextFrame(top, frame);
}
return frame;
}
/** Load frame for sibling arc(node) on fst */
Frame loadNextFrame(Frame top, Frame frame) throws IOException {
if (!canRewind(frame)) {
return null;
}
while (!frame.arc.isLast()) {
frame.arc = fst.readNextRealArc(frame.arc, fstReader);
frame.state = fsa.step(top.state, frame.arc.label);
if (frame.state != -1) {
break;
}
}
//if (TEST) System.out.println(" loadNext frame="+frame);
if (frame.state == -1) {
return null;
}
return frame;
}
/** Load frame for target arc(node) on fst, so that
* arc.label >= label and !fsa.reject(arc.label) */
Frame loadCeilFrame(int label, Frame top, Frame frame) throws IOException {
FST.Arc arc = frame.arc;
arc = Util.readCeilArc(label, fst, top.arc, arc, fstReader);
if (arc == null) {
return null;
}
frame.state = fsa.step(top.state, arc.label);
//if (TEST) System.out.println(" loadCeil frame="+frame);
if (frame.state == -1) {
return loadNextFrame(top, frame);
}
return frame;
}
boolean isAccept(Frame frame) { // reach a term both fst&fsa accepts
return fsa.isAccept(frame.state) && frame.arc.isFinal();
}
boolean isValid(Frame frame) { // reach a prefix both fst&fsa won't reject
return /*frame != null &&*/ frame.state != -1;
}
boolean canGrow(Frame frame) { // can walk forward on both fst&fsa
return frame.state != -1 && FST.targetHasArcs(frame.arc);
}
boolean canRewind(Frame frame) { // can jump to sibling
return !frame.arc.isLast();
}
void pushFrame(Frame frame) {
final FST.Arc arc = frame.arc;
arc.output = fstOutputs.add(topFrame().arc.output, arc.output);
term = grow(arc.label);
level++;
assert frame == stack[level];
}
Frame popFrame() {
term = shrink();
return stack[level--];
}
Frame newFrame() {
if (level+1 == stack.length) {
final Frame[] temp = new Frame[ArrayUtil.oversize(level+2, RamUsageEstimator.NUM_BYTES_OBJECT_REF)];
System.arraycopy(stack, 0, temp, 0, stack.length);
for (int i = stack.length; i < temp.length; i++) {
temp[i] = new Frame();
}
stack = temp;
}
return stack[level+1];
}
Frame topFrame() {
return stack[level];
}
BytesRef grow(int label) {
if (term == null) {
term = new BytesRef(new byte[16], 0, 0);
} else {
if (term.length == term.bytes.length) {
term.grow(term.length+1);
}
term.bytes[term.length++] = (byte)label;
}
return term;
}
BytesRef shrink() {
if (term.length == 0) {
term = null;
} else {
term.length--;
}
return term;
}
}
}
static void walk(FST fst) throws IOException {
final ArrayList> queue = new ArrayList<>();
final BitSet seen = new BitSet();
final FST.BytesReader reader = fst.getBytesReader();
final FST.Arc startArc = fst.getFirstArc(new FST.Arc());
queue.add(startArc);
while (!queue.isEmpty()) {
final FST.Arc arc = queue.remove(0);
final long node = arc.target;
//System.out.println(arc);
if (FST.targetHasArcs(arc) && !seen.get((int) node)) {
seen.set((int) node);
fst.readFirstRealTargetArc(node, arc, reader);
while (true) {
queue.add(new FST.Arc().copyFrom(arc));
if (arc.isLast()) {
break;
} else {
fst.readNextRealArc(arc, reader);
}
}
}
}
}
@Override
public long ramBytesUsed() {
long ramBytesUsed = 0;
for (TermsReader r : fields.values()) {
if (r.index != null) {
ramBytesUsed += r.index.sizeInBytes();
ramBytesUsed += RamUsageEstimator.sizeOf(r.metaBytesBlock);
ramBytesUsed += RamUsageEstimator.sizeOf(r.metaLongsBlock);
ramBytesUsed += RamUsageEstimator.sizeOf(r.skipInfo);
ramBytesUsed += RamUsageEstimator.sizeOf(r.statsBlock);
}
}
return ramBytesUsed;
}
@Override
public void checkIntegrity() throws IOException {
postingsReader.checkIntegrity();
}
}