package org.apache.lucene.index.memory;
/**
* Copyright 2005 The Apache Software Foundation
*
* Licensed 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.Serializable;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.Token;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.document.Document;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.Term;
import org.apache.lucene.index.TermDocs;
import org.apache.lucene.index.TermEnum;
import org.apache.lucene.index.TermFreqVector;
import org.apache.lucene.index.TermPositionVector;
import org.apache.lucene.index.TermPositions;
import org.apache.lucene.search.HitCollector;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.Searcher;
import org.apache.lucene.search.Similarity;
/**
* High-performance single-document main memory Apache Lucene fulltext search index.
*
* <h4>Overview</h4>
*
* This class is a replacement/substitute for a large subset of
* {@link org.apache.lucene.store.RAMDirectory} functionality. It is designed to
* enable maximum efficiency for on-the-fly matchmaking combining structured and
* fuzzy fulltext search in realtime streaming applications such as Nux XQuery based XML
* message queues, publish-subscribe systems for Blogs/newsfeeds, text chat, data acquisition and
* distribution systems, application level routers, firewalls, classifiers, etc.
* Rather than targetting fulltext search of infrequent queries over huge persistent
* data archives (historic search), this class targets fulltext search of huge
* numbers of queries over comparatively small transient realtime data (prospective
* search).
* For example as in <code>float score = search(String text, Query query)</code>.
* <p>
* Each instance can hold at most one Lucene "document", with a document containing
* zero or more "fields", each field having a name and a fulltext value. The
* fulltext value is tokenized (split and transformed) into zero or more index terms
* (aka words) on <code>addField()</code>, according to the policy implemented by an
* Analyzer. For example, Lucene analyzers can split on whitespace, normalize to lower case
* for case insensitivity, ignore common terms with little discriminatory value such as "he", "in", "and" (stop
* words), reduce the terms to their natural linguistic root form such as "fishing"
* being reduced to "fish" (stemming), resolve synonyms/inflexions/thesauri
* (upon indexing and/or querying), etc. For details, see
* <a target="_blank" href="http://today.java.net/pub/a/today/2003/07/30/LuceneIntro.html">Lucene Analyzer Intro</a>.
* <p>
* Arbitrary Lucene queries can be run against this class - see <a target="_blank"
* href="http://lucene.apache.org/java/docs/queryparsersyntax.html">Lucene Query Syntax</a>
* as well as <a target="_blank"
* href="http://today.java.net/pub/a/today/2003/11/07/QueryParserRules.html">Query Parser Rules</a>.
* Note that a Lucene query selects on the field names and associated (indexed)
* tokenized terms, not on the original fulltext(s) - the latter are not stored
* but rather thrown away immediately after tokenization.
* <p>
* For some interesting background information on search technology, see Bob Wyman's
* <a target="_blank"
* href="http://bobwyman.pubsub.com/main/2005/05/mary_hodder_poi.html">Prospective Search</a>,
* Jim Gray's
* <a target="_blank" href="http://www.acmqueue.org/modules.php?name=Content&pa=showpage&pid=293&page=4">
* A Call to Arms - Custom subscriptions</a>, and Tim Bray's
* <a target="_blank"
* href="http://www.tbray.org/ongoing/When/200x/2003/07/30/OnSearchTOC">On Search, the Series</a>.
*
*
* <h4>Example Usage</h4>
*
* <pre>
* Analyzer analyzer = PatternAnalyzer.DEFAULT_ANALYZER;
* //Analyzer analyzer = new SimpleAnalyzer();
* MemoryIndex index = new MemoryIndex();
* index.addField("content", "Readings about Salmons and other select Alaska fishing Manuals", analyzer);
* index.addField("author", "Tales of James", analyzer);
* float score = index.search(QueryParser.parse("+author:james +salmon~ +fish* manual~", "content", analyzer));
* if (score > 0.0f) {
* System.out.println("it's a match");
* } else {
* System.out.println("no match found");
* }
* System.out.println("indexData=" + index.toString());
* </pre>
*
*
* <h4>Example XQuery Usage</h4>
*
* <pre>
* (: An XQuery that finds all books authored by James that have something to do with "salmon fishing manuals", sorted by relevance :)
* declare namespace lucene = "java:nux.xom.pool.FullTextUtil";
* declare variable $query := "+salmon~ +fish* manual~"; (: any arbitrary Lucene query can go here :)
*
* for $book in /books/book[author="James" and lucene:match(abstract, $query) > 0.0]
* let $score := lucene:match($book/abstract, $query)
* order by $score descending
* return $book
* </pre>
*
*
* <h4>No thread safety guarantees</h4>
*
* An instance can be queried multiple times with the same or different queries,
* but an instance is not thread-safe. If desired use idioms such as:
* <pre>
* MemoryIndex index = ...
* synchronized (index) {
* // read and/or write index (i.e. add fields and/or query)
* }
* </pre>
*
*
* <h4>Performance Notes</h4>
*
* Internally there's a new data structure geared towards efficient indexing
* and searching, plus the necessary support code to seamlessly plug into the Lucene
* framework.
* <p>
* This class performs very well for very small texts (e.g. 10 chars)
* as well as for large texts (e.g. 10 MB) and everything in between.
* Typically, it is about 10-100 times faster than <code>RAMDirectory</code>.
* Note that <code>RAMDirectory</code> has particularly
* large efficiency overheads for small to medium sized texts, both in time and space.
* Indexing a field with N tokens takes O(N) in the best case, and O(N logN) in the worst
* case. Memory consumption is probably larger than for <code>RAMDirectory</code>.
* <p>
* If you're curious about
* the whereabouts of bottlenecks, run java 1.5 with the non-perturbing '-server
* -agentlib:hprof=cpu=samples,depth=10' flags, then study the trace log and
* correlate its hotspot trailer with its call stack headers (see <a
* target="_blank"
* href="http://java.sun.com/developer/technicalArticles/Programming/HPROF.html">
* hprof tracing </a>).
*
* @author whoschek.AT.lbl.DOT.gov
*/
public class MemoryIndex {
/** info for each field: Map<String fieldName, Info field> */
private final HashMap fields = new HashMap();
/** fields sorted ascending by fieldName; lazily computed on demand */
private transient Map.Entry[] sortedFields;
/** pos: positions[3*i], startOffset: positions[3*i +1], endOffset: positions[3*i +2] */
private final int stride;
private static final long serialVersionUID = 2782195016849084649L;
private static final boolean DEBUG = false;
/**
* Sorts term entries into ascending order; also works for
* Arrays.binarySearch() and Arrays.sort()
*/
private static final Comparator termComparator = new Comparator() {
public int compare(Object o1, Object o2) {
if (o1 instanceof Map.Entry) o1 = ((Map.Entry) o1).getKey();
if (o2 instanceof Map.Entry) o2 = ((Map.Entry) o2).getKey();
if (o1 == o2) return 0;
return ((String) o1).compareTo((String) o2);
}
};
/**
* Constructs an empty instance.
*/
public MemoryIndex() {
this(false);
}
/**
* Constructs an empty instance that can optionally store the start and end
* character offset of each token term in the text. This can be useful for
* highlighting of hit locations with the Lucene highlighter package.
* Private until the highlighter package matures, so that this can actually
* be meaningfully integrated.
*
* @param storeOffsets
* whether or not to store the start and end character offset of
* each token term in the text
*/
private MemoryIndex(boolean storeOffsets) {
this.stride = storeOffsets ? 3 : 1;
}
/**
* Convenience method; Tokenizes the given field text and adds the resulting
* terms to the index; Equivalent to adding a tokenized, indexed,
* termVectorStored, unstored, non-keyword Lucene
* {@link org.apache.lucene.document.Field}.
*
* @param fieldName
* a name to be associated with the text
* @param text
* the text to tokenize and index.
* @param analyzer
* the analyzer to use for tokenization
*/
public void addField(String fieldName, String text, Analyzer analyzer) {
if (fieldName == null)
throw new IllegalArgumentException("fieldName must not be null");
if (text == null)
throw new IllegalArgumentException("text must not be null");
if (analyzer == null)
throw new IllegalArgumentException("analyzer must not be null");
TokenStream stream;
if (analyzer instanceof PatternAnalyzer) {
stream = ((PatternAnalyzer) analyzer).tokenStream(fieldName, text);
} else {
stream = analyzer.tokenStream(fieldName,
new PatternAnalyzer.FastStringReader(text));
}
addField(fieldName, stream);
}
/**
* Convenience method; Creates and returns a token stream that generates a
* token for each keyword in the given collection, "as is", without any
* transforming text analysis. The resulting token stream can be fed into
* {@link #addField(String, TokenStream)}, perhaps wrapped into another
* {@link org.apache.lucene.analysis.TokenFilter}, as desired.
*
* @param keywords
* the keywords to generate tokens for
* @return the corresponding token stream
*/
public TokenStream keywordTokenStream(final Collection keywords) {
// TODO: deprecate & move this method into AnalyzerUtil?
if (keywords == null)
throw new IllegalArgumentException("keywords must not be null");
return new TokenStream() {
private Iterator iter = keywords.iterator();
private int start = 0;
public Token next() {
if (!iter.hasNext()) return null;
Object obj = iter.next();
if (obj == null)
throw new IllegalArgumentException("keyword must not be null");
String term = obj.toString();
Token token = new Token(term, start, start + term.length());
start += term.length() + 1; // separate words by 1 (blank) character
return token;
}
};
}
/**
* Iterates over the given token stream and adds the resulting terms to the index;
* Equivalent to adding a tokenized, indexed, termVectorStored, unstored,
* Lucene {@link org.apache.lucene.document.Field}.
* Finally closes the token stream. Note that untokenized keywords can be added with this method via
* {@link #keywordTokenStream(Collection)}, the Lucene contrib <code>KeywordTokenizer</code> or similar utilities.
*
* @param fieldName
* a name to be associated with the text
* @param stream
* the token stream to retrieve tokens from.
*/
public void addField(String fieldName, TokenStream stream) {
/*
* Note that this method signature avoids having a user call new
* o.a.l.d.Field(...) which would be much too expensive due to the
* String.intern() usage of that class.
*
* More often than not, String.intern() leads to serious performance
* degradations rather than improvements! If you're curious why, check
* out the JDK's native code, see how it oscillates multiple times back
* and forth between Java code and native code on each intern() call,
* only to end up using a plain vanilla java.util.HashMap on the Java
* heap for it's interned strings! String.equals() has a small cost
* compared to String.intern(), trust me. Application level interning
* (e.g. a HashMap per Directory/Index) typically leads to better
* solutions than frequent hidden low-level calls to String.intern().
*
* Perhaps with some luck, Lucene's Field.java (and Term.java) and
* cousins could be fixed to not use String.intern(). Sigh :-(
*/
try {
if (fieldName == null)
throw new IllegalArgumentException("fieldName must not be null");
if (stream == null)
throw new IllegalArgumentException("token stream must not be null");
if (fields.get(fieldName) != null)
throw new IllegalArgumentException("field must not be added more than once");
HashMap terms = new HashMap();
int numTokens = 0;
int pos = -1;
Token token;
while ((token = stream.next()) != null) {
String term = token.termText();
if (term.length() == 0) continue; // nothing to do
// if (DEBUG) System.err.println("token='" + term + "'");
numTokens++;
pos += token.getPositionIncrement();
ArrayIntList positions = (ArrayIntList) terms.get(term);
if (positions == null) { // term not seen before
positions = new ArrayIntList(stride);
terms.put(term, positions);
}
if (stride == 1) {
positions.add(pos);
} else {
positions.add(pos, token.startOffset(), token.endOffset());
}
}
// ensure infos.numTokens > 0 invariant; needed for correct operation of terms()
if (numTokens > 0) {
fields.put(fieldName, new Info(terms, numTokens));
sortedFields = null; // invalidate sorted view, if any
}
} catch (IOException e) { // can never happen
throw new RuntimeException(e);
} finally {
try {
if (stream != null) stream.close();
} catch (IOException e2) {
throw new RuntimeException(e2);
}
}
}
/**
* Creates and returns a searcher that can be used to execute arbitrary
* Lucene queries and to collect the resulting query results as hits.
*
* @return a searcher
*/
public IndexSearcher createSearcher() {
MemoryIndexReader reader = new MemoryIndexReader();
IndexSearcher searcher = new IndexSearcher(reader); // ensures no auto-close !!
reader.setSearcher(searcher); // to later get hold of searcher.getSimilarity()
return searcher;
}
/**
* Convenience method that efficiently returns the relevance score by
* matching this index against the given Lucene query expression.
*
* @param query
* an arbitrary Lucene query to run against this index
* @return the relevance score of the matchmaking; A number in the range
* [0.0 .. 1.0], with 0.0 indicating no match. The higher the number
* the better the match.
* @see org.apache.lucene.queryParser.QueryParser#parse(String)
*/
public float search(Query query) {
if (query == null)
throw new IllegalArgumentException("query must not be null");
Searcher searcher = createSearcher();
try {
final float[] scores = new float[1]; // inits to 0.0f (no match)
searcher.search(query, new HitCollector() {
public void collect(int doc, float score) {
scores[0] = score;
}
});
float score = scores[0];
return score;
} catch (IOException e) { // can never happen (RAMDirectory)
throw new RuntimeException(e);
} finally {
// searcher.close();
/*
* Note that it is harmless and important for good performance to
* NOT close the index reader!!! This avoids all sorts of
* unnecessary baggage and locking in the Lucene IndexReader
* superclass, all of which is completely unnecessary for this main
* memory index data structure without thread-safety claims.
*
* Wishing IndexReader would be an interface...
*
* Actually with the new tight createSearcher() API auto-closing is now
* made impossible, hence searcher.close() would be harmless...
*/
}
}
/**
* Returns a reasonable approximation of the main memory [bytes] consumed by
* this instance. Useful for smart memory sensititve caches/pools. Assumes
* fieldNames are interned, whereas tokenized terms are memory-overlaid. For
* simplicity, assumes no VM word boundary alignment of instance vars.
*
* @return the main memory consumption
*/
public int getMemorySize() {
// for example usage in a smart cache see nux.xom.pool.Pool
int HEADER = 12; // object header of any java object
int PTR = 4; // pointer on 32 bit VMs
int ARR = HEADER + 4;
int STR = HEADER + 3*4 + PTR + ARR; // string
int INTARRLIST = HEADER + 4 + PTR + ARR;
int HASHMAP = HEADER + 4*PTR + 4*4 + ARR;
int size = 0;
size += HEADER + 2*PTR + 4; // memory index
if (sortedFields != null) size += ARR + PTR * sortedFields.length;
size += HASHMAP + fields.size() * (PTR + HEADER + 3*PTR + 4); // Map.entries
Iterator iter = fields.entrySet().iterator();
while (iter.hasNext()) { // for each Field Info
Map.Entry entry = (Map.Entry) iter.next();
Info info = (Info) entry.getValue();
size += HEADER + 4 + PTR + PTR + PTR; // Info instance vars
if (info.sortedTerms != null) size += ARR + PTR * info.sortedTerms.length;
int len = info.terms.size();
size += HASHMAP + len * (PTR + HEADER + 3*PTR + 4); // Map.entries
Iterator iter2 = info.terms.entrySet().iterator();
while (--len >= 0) { // for each term
Map.Entry e = (Map.Entry) iter2.next();
size += STR - ARR; // assumes substring() memory overlay
// size += STR + 2 * ((String) e.getKey()).length();
ArrayIntList positions = (ArrayIntList) e.getValue();
size += INTARRLIST + 4*positions.size();
}
}
return size;
}
private int numPositions(ArrayIntList positions) {
return positions.size() / stride;
}
/** sorts into ascending order (on demand), reusing memory along the way */
private void sortFields() {
if (sortedFields == null) sortedFields = sort(fields);
}
/** returns a view of the given map's entries, sorted ascending by key */
private static Map.Entry[] sort(HashMap map) {
int size = map.size();
Map.Entry[] entries = new Map.Entry[size];
Iterator iter = map.entrySet().iterator();
for (int i=0; i < size; i++) {
entries[i] = (Map.Entry) iter.next();
}
if (size > 1) Arrays.sort(entries, termComparator);
return entries;
}
/**
* Returns a String representation of the index data for debugging purposes.
*
* @return the string representation
*/
public String toString() {
StringBuffer result = new StringBuffer(256);
sortFields();
int sumChars = 0;
int sumPositions = 0;
int sumTerms = 0;
for (int i=0; i < sortedFields.length; i++) {
Map.Entry entry = sortedFields[i];
String fieldName = (String) entry.getKey();
Info info = (Info) entry.getValue();
info.sortTerms();
result.append(fieldName + ":\n");
int numChars = 0;
int numPositions = 0;
for (int j=0; j < info.sortedTerms.length; j++) {
Map.Entry e = info.sortedTerms[j];
String term = (String) e.getKey();
ArrayIntList positions = (ArrayIntList) e.getValue();
result.append("\t'" + term + "':" + numPositions(positions) + ":");
result.append(positions.toString(stride)); // ignore offsets
result.append("\n");
numPositions += numPositions(positions);
numChars += term.length();
}
result.append("\tterms=" + info.sortedTerms.length);
result.append(", positions=" + numPositions);
result.append(", Kchars=" + (numChars/1000.0f));
result.append("\n");
sumPositions += numPositions;
sumChars += numChars;
sumTerms += info.sortedTerms.length;
}
result.append("\nfields=" + sortedFields.length);
result.append(", terms=" + sumTerms);
result.append(", positions=" + sumPositions);
result.append(", Kchars=" + (sumChars/1000.0f));
return result.toString();
}
///////////////////////////////////////////////////////////////////////////////
// Nested classes:
///////////////////////////////////////////////////////////////////////////////
/**
* Index data structure for a field; Contains the tokenized term texts and
* their positions.
*/
private static final class Info implements Serializable {
/**
* Term strings and their positions for this field: Map <String
* termText, ArrayIntList positions>
*/
private final HashMap terms;
/** Terms sorted ascending by term text; computed on demand */
private transient Map.Entry[] sortedTerms;
/** Number of added tokens for this field */
private final int numTokens;
/** Term for this field's fieldName, lazily computed on demand */
public transient Term template;
private static final long serialVersionUID = 2882195016849084649L;
public Info(HashMap terms, int numTokens) {
this.terms = terms;
this.numTokens = numTokens;
}
/**
* Sorts hashed terms into ascending order, reusing memory along the
* way. Note that sorting is lazily delayed until required (often it's
* not required at all). If a sorted view is required then hashing +
* sort + binary search is still faster and smaller than TreeMap usage
* (which would be an alternative and somewhat more elegant approach,
* apart from more sophisticated Tries / prefix trees).
*/
public void sortTerms() {
if (sortedTerms == null) sortedTerms = sort(terms);
}
/** note that the frequency can be calculated as numPosition(getPositions(x)) */
public ArrayIntList getPositions(String term) {
return (ArrayIntList) terms.get(term);
}
/** note that the frequency can be calculated as numPosition(getPositions(x)) */
public ArrayIntList getPositions(int pos) {
return (ArrayIntList) sortedTerms[pos].getValue();
}
}
///////////////////////////////////////////////////////////////////////////////
// Nested classes:
///////////////////////////////////////////////////////////////////////////////
/**
* Efficient resizable auto-expanding list holding <code>int</code> elements;
* implemented with arrays.
*/
private static final class ArrayIntList implements Serializable {
private int[] elements;
private int size = 0;
private static final long serialVersionUID = 2282195016849084649L;
public ArrayIntList() {
this(10);
}
public ArrayIntList(int initialCapacity) {
elements = new int[initialCapacity];
}
public void add(int elem) {
if (size == elements.length) ensureCapacity(size + 1);
elements[size++] = elem;
}
public void add(int pos, int start, int end) {
if (size + 3 > elements.length) ensureCapacity(size + 3);
elements[size] = pos;
elements[size+1] = start;
elements[size+2] = end;
size += 3;
}
public int get(int index) {
if (index >= size) throwIndex(index);
return elements[index];
}
public int size() {
return size;
}
public int[] toArray(int stride) {
int[] arr = new int[size() / stride];
if (stride == 1)
System.arraycopy(elements, 0, arr, 0, size); // fast path
else
for (int i=0, j=0; j < size; i++, j += stride) arr[i] = elements[j];
return arr;
}
private void ensureCapacity(int minCapacity) {
int newCapacity = Math.max(minCapacity, (elements.length * 3) / 2 + 1);
int[] newElements = new int[newCapacity];
System.arraycopy(elements, 0, newElements, 0, size);
elements = newElements;
}
private void throwIndex(int index) {
throw new IndexOutOfBoundsException("index: " + index
+ ", size: " + size);
}
/** returns the first few positions (without offsets); debug only */
public String toString(int stride) {
int s = size() / stride;
int len = Math.min(10, s); // avoid printing huge lists
StringBuffer buf = new StringBuffer(4*len);
buf.append("[");
for (int i = 0; i < len; i++) {
buf.append(get(i*stride));
if (i < len-1) buf.append(", ");
}
if (len != s) buf.append(", ..."); // and some more...
buf.append("]");
return buf.toString();
}
}
///////////////////////////////////////////////////////////////////////////////
// Nested classes:
///////////////////////////////////////////////////////////////////////////////
private static final Term MATCH_ALL_TERM = new Term("", "");
/**
* Search support for Lucene framework integration; implements all methods
* required by the Lucene IndexReader contracts.
*/
private final class MemoryIndexReader extends IndexReader {
private Searcher searcher; // needed to find searcher.getSimilarity()
private MemoryIndexReader() {
super(null); // avoid as much superclass baggage as possible
}
// lucene >= 1.9 or lucene-1.4.3 with patch removing "final" in superclass
protected void finalize() {}
private Info getInfo(String fieldName) {
return (Info) fields.get(fieldName);
}
private Info getInfo(int pos) {
return (Info) sortedFields[pos].getValue();
}
public int docFreq(Term term) {
Info info = getInfo(term.field());
int freq = 0;
if (info != null) freq = info.getPositions(term.text()) != null ? 1 : 0;
if (DEBUG) System.err.println("MemoryIndexReader.docFreq: " + term + ", freq:" + freq);
return freq;
}
public TermEnum terms() {
if (DEBUG) System.err.println("MemoryIndexReader.terms()");
return terms(MATCH_ALL_TERM);
}
public TermEnum terms(Term term) {
if (DEBUG) System.err.println("MemoryIndexReader.terms: " + term);
int i; // index into info.sortedTerms
int j; // index into sortedFields
sortFields();
if (sortedFields.length == 1 && sortedFields[0].getKey() == term.field()) {
j = 0; // fast path
} else {
j = Arrays.binarySearch(sortedFields, term.field(), termComparator);
}
if (j < 0) { // not found; choose successor
j = -j -1;
i = 0;
if (j < sortedFields.length) getInfo(j).sortTerms();
}
else { // found
Info info = getInfo(j);
info.sortTerms();
i = Arrays.binarySearch(info.sortedTerms, term.text(), termComparator);
if (i < 0) { // not found; choose successor
i = -i -1;
if (i >= info.sortedTerms.length) { // move to next successor
j++;
i = 0;
if (j < sortedFields.length) getInfo(j).sortTerms();
}
}
}
final int ix = i;
final int jx = j;
return new TermEnum() {
private int i = ix; // index into info.sortedTerms
private int j = jx; // index into sortedFields
public boolean next() {
if (DEBUG) System.err.println("TermEnum.next");
if (j >= sortedFields.length) return false;
Info info = getInfo(j);
if (++i < info.sortedTerms.length) return true;
// move to successor
j++;
i = 0;
if (j >= sortedFields.length) return false;
getInfo(j).sortTerms();
return true;
}
public Term term() {
if (DEBUG) System.err.println("TermEnum.term: " + i);
if (j >= sortedFields.length) return null;
Info info = getInfo(j);
if (i >= info.sortedTerms.length) return null;
// if (DEBUG) System.err.println("TermEnum.term: " + i + ", " + info.sortedTerms[i].getKey());
return createTerm(info, j, (String) info.sortedTerms[i].getKey());
}
public int docFreq() {
if (DEBUG) System.err.println("TermEnum.docFreq");
if (j >= sortedFields.length) return 0;
Info info = getInfo(j);
if (i >= info.sortedTerms.length) return 0;
return numPositions(info.getPositions(i));
}
public void close() {
if (DEBUG) System.err.println("TermEnum.close");
}
/** Returns a new Term object, minimizing String.intern() overheads. */
private Term createTerm(Info info, int pos, String text) {
// Assertion: sortFields has already been called before
Term template = info.template;
if (template == null) { // not yet cached?
String fieldName = (String) sortedFields[pos].getKey();
template = new Term(fieldName, "");
info.template = template;
}
return template.createTerm(text);
}
};
}
public TermPositions termPositions() {
if (DEBUG) System.err.println("MemoryIndexReader.termPositions");
return new TermPositions() {
private boolean hasNext;
private int cursor = 0;
private ArrayIntList current;
public void seek(Term term) {
if (DEBUG) System.err.println(".seek: " + term);
Info info = getInfo(term.field());
current = info == null ? null : info.getPositions(term.text());
hasNext = (current != null);
cursor = 0;
}
public void seek(TermEnum termEnum) {
if (DEBUG) System.err.println(".seekEnum");
seek(termEnum.term());
}
public int doc() {
if (DEBUG) System.err.println(".doc");
return 0;
}
public int freq() {
int freq = current != null ? numPositions(current) : 0;
if (DEBUG) System.err.println(".freq: " + freq);
return freq;
}
public boolean next() {
if (DEBUG) System.err.println(".next: " + current + ", oldHasNext=" + hasNext);
boolean next = hasNext;
hasNext = false;
return next;
}
public int read(int[] docs, int[] freqs) {
if (DEBUG) System.err.println(".read: " + docs.length);
if (!hasNext) return 0;
hasNext = false;
docs[0] = 0;
freqs[0] = freq();
return 1;
}
public boolean skipTo(int target) {
if (DEBUG) System.err.println(".skipTo: " + target);
return next();
}
public void close() {
if (DEBUG) System.err.println(".close");
}
public int nextPosition() { // implements TermPositions
int pos = current.get(cursor);
cursor += stride;
if (DEBUG) System.err.println(".nextPosition: " + pos);
return pos;
}
};
}
public TermDocs termDocs() {
if (DEBUG) System.err.println("MemoryIndexReader.termDocs");
return termPositions();
}
public TermFreqVector[] getTermFreqVectors(int docNumber) {
if (DEBUG) System.err.println("MemoryIndexReader.getTermFreqVectors");
TermFreqVector[] vectors = new TermFreqVector[fields.size()];
// if (vectors.length == 0) return null;
Iterator iter = fields.keySet().iterator();
for (int i=0; i < vectors.length; i++) {
String fieldName = (String) iter.next();
vectors[i] = getTermFreqVector(docNumber, fieldName);
}
return vectors;
}
public TermFreqVector getTermFreqVector(int docNumber, final String fieldName) {
if (DEBUG) System.err.println("MemoryIndexReader.getTermFreqVector");
final Info info = getInfo(fieldName);
if (info == null) return null; // TODO: or return empty vector impl???
info.sortTerms();
return new TermPositionVector() {
private final Map.Entry[] sortedTerms = info.sortedTerms;
public String getField() {
return fieldName;
}
public int size() {
return sortedTerms.length;
}
public String[] getTerms() {
String[] terms = new String[sortedTerms.length];
for (int i=sortedTerms.length; --i >= 0; ) {
terms[i] = (String) sortedTerms[i].getKey();
}
return terms;
}
public int[] getTermFrequencies() {
int[] freqs = new int[sortedTerms.length];
for (int i=sortedTerms.length; --i >= 0; ) {
freqs[i] = numPositions((ArrayIntList) sortedTerms[i].getValue());
}
return freqs;
}
public int indexOf(String term) {
int i = Arrays.binarySearch(sortedTerms, term, termComparator);
return i >= 0 ? i : -1;
}
public int[] indexesOf(String[] terms, int start, int len) {
int[] indexes = new int[len];
for (int i=0; i < len; i++) {
indexes[i] = indexOf(terms[start++]);
}
return indexes;
}
// lucene >= 1.4.3
public int[] getTermPositions(int index) {
return ((ArrayIntList) sortedTerms[index].getValue()).toArray(stride);
}
// lucene >= 1.9 (remove this method for lucene-1.4.3)
public org.apache.lucene.index.TermVectorOffsetInfo[] getOffsets(int index) {
if (stride == 1) return null; // no offsets stored
ArrayIntList positions = (ArrayIntList) sortedTerms[index].getValue();
int size = positions.size();
org.apache.lucene.index.TermVectorOffsetInfo[] offsets =
new org.apache.lucene.index.TermVectorOffsetInfo[size / stride];
for (int i=0, j=1; j < size; i++, j += stride) {
int start = positions.get(j);
int end = positions.get(j+1);
offsets[i] = new org.apache.lucene.index.TermVectorOffsetInfo(start, end);
}
return offsets;
}
};
}
private Similarity getSimilarity() {
if (searcher != null) return searcher.getSimilarity();
return Similarity.getDefault();
}
private void setSearcher(Searcher searcher) {
this.searcher = searcher;
}
/** performance hack: cache norms to avoid repeated expensive calculations */
private byte[] cachedNorms;
private String cachedFieldName;
private Similarity cachedSimilarity;
public byte[] norms(String fieldName) {
byte[] norms = cachedNorms;
Similarity sim = getSimilarity();
if (fieldName != cachedFieldName || sim != cachedSimilarity) { // not cached?
Info info = getInfo(fieldName);
int numTokens = info != null ? info.numTokens : 0;
float n = sim.lengthNorm(fieldName, numTokens);
byte norm = Similarity.encodeNorm(n);
norms = new byte[] {norm};
cachedNorms = norms;
cachedFieldName = fieldName;
cachedSimilarity = sim;
if (DEBUG) System.err.println("MemoryIndexReader.norms: " + fieldName + ":" + n + ":" + norm + ":" + numTokens);
}
return norms;
}
public void norms(String fieldName, byte[] bytes, int offset) {
if (DEBUG) System.err.println("MemoryIndexReader.norms*: " + fieldName);
byte[] norms = norms(fieldName);
System.arraycopy(norms, 0, bytes, offset, norms.length);
}
protected void doSetNorm(int doc, String fieldName, byte value) {
throw new UnsupportedOperationException();
}
public int numDocs() {
if (DEBUG) System.err.println("MemoryIndexReader.numDocs");
return fields.size() > 0 ? 1 : 0;
}
public int maxDoc() {
if (DEBUG) System.err.println("MemoryIndexReader.maxDoc");
return 1;
}
public Document document(int n) {
if (DEBUG) System.err.println("MemoryIndexReader.document");
return new Document(); // there are no stored fields
}
public boolean isDeleted(int n) {
if (DEBUG) System.err.println("MemoryIndexReader.isDeleted");
return false;
}
public boolean hasDeletions() {
if (DEBUG) System.err.println("MemoryIndexReader.hasDeletions");
return false;
}
protected void doDelete(int docNum) {
throw new UnsupportedOperationException();
}
protected void doUndeleteAll() {
throw new UnsupportedOperationException();
}
protected void doCommit() {
if (DEBUG) System.err.println("MemoryIndexReader.doCommit");
}
protected void doClose() {
if (DEBUG) System.err.println("MemoryIndexReader.doClose");
}
// lucene >= 1.9 (remove this method for lucene-1.4.3)
public Collection getFieldNames(FieldOption fieldOption) {
if (DEBUG) System.err.println("MemoryIndexReader.getFieldNamesOption");
if (fieldOption == FieldOption.UNINDEXED)
return Collections.EMPTY_SET;
if (fieldOption == FieldOption.INDEXED_NO_TERMVECTOR)
return Collections.EMPTY_SET;
if (fieldOption == FieldOption.TERMVECTOR_WITH_OFFSET && stride == 1)
return Collections.EMPTY_SET;
if (fieldOption == FieldOption.TERMVECTOR_WITH_POSITION_OFFSET && stride == 1)
return Collections.EMPTY_SET;
return Collections.unmodifiableSet(fields.keySet());
}
}
}
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