package org.apache.lucene.search;
/**
* Copyright 2004 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 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.search.FieldCache.StringIndex; // required by GCJ
import java.io.IOException;
import java.util.Map;
import java.util.WeakHashMap;
import java.util.HashMap;
/**
* Expert: The default cache implementation, storing all values in memory.
* A WeakHashMap is used for storage.
*
* <p>Created: May 19, 2004 4:40:36 PM
*
* @author Tim Jones (Nacimiento Software)
* @since lucene 1.4
* @version $Id: FieldCacheImpl.java 377502 2006-02-13 21:46:13Z yonik $
*/
class FieldCacheImpl
implements FieldCache {
/** Expert: Every key in the internal cache is of this type. */
static class Entry {
final String field; // which Field
final int type; // which SortField type
final Object custom; // which custom comparator
/** Creates one of these objects. */
Entry (String field, int type) {
this.field = field.intern();
this.type = type;
this.custom = null;
}
/** Creates one of these objects for a custom comparator. */
Entry (String field, Object custom) {
this.field = field.intern();
this.type = SortField.CUSTOM;
this.custom = custom;
}
/** Two of these are equal iff they reference the same field and type. */
public boolean equals (Object o) {
if (o instanceof Entry) {
Entry other = (Entry) o;
if (other.field == field && other.type == type) {
if (other.custom == null) {
if (custom == null) return true;
} else if (other.custom.equals (custom)) {
return true;
}
}
}
return false;
}
/** Composes a hashcode based on the field and type. */
public int hashCode() {
return field.hashCode() ^ type ^ (custom==null ? 0 : custom.hashCode());
}
}
private static final IntParser INT_PARSER = new IntParser() {
public int parseInt(String value) {
return Integer.parseInt(value);
}
};
private static final FloatParser FLOAT_PARSER = new FloatParser() {
public float parseFloat(String value) {
return Float.parseFloat(value);
}
};
/** The internal cache. Maps Entry to array of interpreted term values. **/
final Map cache = new WeakHashMap();
/** See if an object is in the cache. */
Object lookup (IndexReader reader, String field, int type) {
Entry entry = new Entry (field, type);
synchronized (this) {
HashMap readerCache = (HashMap)cache.get(reader);
if (readerCache == null) return null;
return readerCache.get (entry);
}
}
/** See if a custom object is in the cache. */
Object lookup (IndexReader reader, String field, Object comparer) {
Entry entry = new Entry (field, comparer);
synchronized (this) {
HashMap readerCache = (HashMap)cache.get(reader);
if (readerCache == null) return null;
return readerCache.get (entry);
}
}
/** Put an object into the cache. */
Object store (IndexReader reader, String field, int type, Object value) {
Entry entry = new Entry (field, type);
synchronized (this) {
HashMap readerCache = (HashMap)cache.get(reader);
if (readerCache == null) {
readerCache = new HashMap();
cache.put(reader,readerCache);
}
return readerCache.put (entry, value);
}
}
/** Put a custom object into the cache. */
Object store (IndexReader reader, String field, Object comparer, Object value) {
Entry entry = new Entry (field, comparer);
synchronized (this) {
HashMap readerCache = (HashMap)cache.get(reader);
if (readerCache == null) {
readerCache = new HashMap();
cache.put(reader, readerCache);
}
return readerCache.put (entry, value);
}
}
// inherit javadocs
public int[] getInts (IndexReader reader, String field) throws IOException {
return getInts(reader, field, INT_PARSER);
}
// inherit javadocs
public int[] getInts (IndexReader reader, String field, IntParser parser)
throws IOException {
field = field.intern();
Object ret = lookup (reader, field, parser);
if (ret == null) {
final int[] retArray = new int[reader.maxDoc()];
TermDocs termDocs = reader.termDocs();
TermEnum termEnum = reader.terms (new Term (field, ""));
try {
do {
Term term = termEnum.term();
if (term==null || term.field() != field) break;
int termval = parser.parseInt(term.text());
termDocs.seek (termEnum);
while (termDocs.next()) {
retArray[termDocs.doc()] = termval;
}
} while (termEnum.next());
} finally {
termDocs.close();
termEnum.close();
}
store (reader, field, parser, retArray);
return retArray;
}
return (int[]) ret;
}
// inherit javadocs
public float[] getFloats (IndexReader reader, String field)
throws IOException {
return getFloats(reader, field, FLOAT_PARSER);
}
// inherit javadocs
public float[] getFloats (IndexReader reader, String field,
FloatParser parser) throws IOException {
field = field.intern();
Object ret = lookup (reader, field, parser);
if (ret == null) {
final float[] retArray = new float[reader.maxDoc()];
TermDocs termDocs = reader.termDocs();
TermEnum termEnum = reader.terms (new Term (field, ""));
try {
do {
Term term = termEnum.term();
if (term==null || term.field() != field) break;
float termval = parser.parseFloat(term.text());
termDocs.seek (termEnum);
while (termDocs.next()) {
retArray[termDocs.doc()] = termval;
}
} while (termEnum.next());
} finally {
termDocs.close();
termEnum.close();
}
store (reader, field, parser, retArray);
return retArray;
}
return (float[]) ret;
}
// inherit javadocs
public String[] getStrings (IndexReader reader, String field)
throws IOException {
field = field.intern();
Object ret = lookup (reader, field, SortField.STRING);
if (ret == null) {
final String[] retArray = new String[reader.maxDoc()];
TermDocs termDocs = reader.termDocs();
TermEnum termEnum = reader.terms (new Term (field, ""));
try {
do {
Term term = termEnum.term();
if (term==null || term.field() != field) break;
String termval = term.text();
termDocs.seek (termEnum);
while (termDocs.next()) {
retArray[termDocs.doc()] = termval;
}
} while (termEnum.next());
} finally {
termDocs.close();
termEnum.close();
}
store (reader, field, SortField.STRING, retArray);
return retArray;
}
return (String[]) ret;
}
// inherit javadocs
public StringIndex getStringIndex (IndexReader reader, String field)
throws IOException {
field = field.intern();
Object ret = lookup (reader, field, STRING_INDEX);
if (ret == null) {
final int[] retArray = new int[reader.maxDoc()];
String[] mterms = new String[reader.maxDoc()+1];
TermDocs termDocs = reader.termDocs();
TermEnum termEnum = reader.terms (new Term (field, ""));
int t = 0; // current term number
// an entry for documents that have no terms in this field
// should a document with no terms be at top or bottom?
// this puts them at the top - if it is changed, FieldDocSortedHitQueue
// needs to change as well.
mterms[t++] = null;
try {
do {
Term term = termEnum.term();
if (term==null || term.field() != field) break;
// store term text
// we expect that there is at most one term per document
if (t >= mterms.length) throw new RuntimeException ("there are more terms than " +
"documents in field \"" + field + "\", but it's impossible to sort on " +
"tokenized fields");
mterms[t] = term.text();
termDocs.seek (termEnum);
while (termDocs.next()) {
retArray[termDocs.doc()] = t;
}
t++;
} while (termEnum.next());
} finally {
termDocs.close();
termEnum.close();
}
if (t == 0) {
// if there are no terms, make the term array
// have a single null entry
mterms = new String[1];
} else if (t < mterms.length) {
// if there are less terms than documents,
// trim off the dead array space
String[] terms = new String[t];
System.arraycopy (mterms, 0, terms, 0, t);
mterms = terms;
}
StringIndex value = new StringIndex (retArray, mterms);
store (reader, field, STRING_INDEX, value);
return value;
}
return (StringIndex) ret;
}
/** The pattern used to detect integer values in a field */
/** removed for java 1.3 compatibility
protected static final Pattern pIntegers = Pattern.compile ("[0-9\\-]+");
**/
/** The pattern used to detect float values in a field */
/**
* removed for java 1.3 compatibility
* protected static final Object pFloats = Pattern.compile ("[0-9+\\-\\.eEfFdD]+");
*/
// inherit javadocs
public Object getAuto (IndexReader reader, String field)
throws IOException {
field = field.intern();
Object ret = lookup (reader, field, SortField.AUTO);
if (ret == null) {
TermEnum enumerator = reader.terms (new Term (field, ""));
try {
Term term = enumerator.term();
if (term == null) {
throw new RuntimeException ("no terms in field " + field + " - cannot determine sort type");
}
if (term.field() == field) {
String termtext = term.text().trim();
/**
* Java 1.4 level code:
if (pIntegers.matcher(termtext).matches())
return IntegerSortedHitQueue.comparator (reader, enumerator, field);
else if (pFloats.matcher(termtext).matches())
return FloatSortedHitQueue.comparator (reader, enumerator, field);
*/
// Java 1.3 level code:
try {
Integer.parseInt (termtext);
ret = getInts (reader, field);
} catch (NumberFormatException nfe1) {
try {
Float.parseFloat (termtext);
ret = getFloats (reader, field);
} catch (NumberFormatException nfe2) {
ret = getStringIndex (reader, field);
}
}
if (ret != null) {
store (reader, field, SortField.AUTO, ret);
}
} else {
throw new RuntimeException ("field \"" + field + "\" does not appear to be indexed");
}
} finally {
enumerator.close();
}
}
return ret;
}
// inherit javadocs
public Comparable[] getCustom (IndexReader reader, String field, SortComparator comparator)
throws IOException {
field = field.intern();
Object ret = lookup (reader, field, comparator);
if (ret == null) {
final Comparable[] retArray = new Comparable[reader.maxDoc()];
TermDocs termDocs = reader.termDocs();
TermEnum termEnum = reader.terms (new Term (field, ""));
try {
do {
Term term = termEnum.term();
if (term==null || term.field() != field) break;
Comparable termval = comparator.getComparable (term.text());
termDocs.seek (termEnum);
while (termDocs.next()) {
retArray[termDocs.doc()] = termval;
}
} while (termEnum.next());
} finally {
termDocs.close();
termEnum.close();
}
store (reader, field, comparator, retArray);
return retArray;
}
return (Comparable[]) ret;
}
}
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