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added support for per field boost factor

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git-svn-id: https://svn.apache.org/repos/asf/lucene/java/trunk@450724 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Wolfgang Hoschek 2006-09-28 07:10:30 +00:00
parent c91d5241c5
commit 5c89547898
1 changed files with 37 additions and 5 deletions
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42
contrib/memory/src/java/org/apache/lucene/index/memory/MemoryIndex.java
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@ -20,6 +20,7 @@ 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.document.Field;
import org.apache.lucene.document.FieldSelector;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.Term;
@ -169,6 +170,9 @@ public class MemoryIndex {
/** pos: positions[3*i], startOffset: positions[3*i +1], endOffset: positions[3*i +2] */
private final int stride;
/** Could be made configurable; See {@link Document#setBoost(float)} */
private static final float docBoost = 1.0f;
private static final long serialVersionUID = 2782195016849084649L;
private static final boolean DEBUG = false;
@ -273,6 +277,18 @@ public class MemoryIndex {
};
}
/**
* Equivalent to <code>addField(fieldName, stream, 1.0f)</code>.
*
* @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) {
addField(fieldName, stream, 1.0f);
}
/**
* Iterates over the given token stream and adds the resulting terms to the index;
* Equivalent to adding a tokenized, indexed, termVectorStored, unstored,
@ -284,8 +300,11 @@ public class MemoryIndex {
* a name to be associated with the text
* @param stream
* the token stream to retrieve tokens from.
* @param boost
* the boost factor for hits for this field
* @see Field#setBoost(float)
*/
public void addField(String fieldName, TokenStream stream) {
public void addField(String fieldName, TokenStream stream, float boost) {
/*
* 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
@ -308,7 +327,9 @@ public class MemoryIndex {
if (fieldName == null)
throw new IllegalArgumentException("fieldName must not be null");
if (stream == null)
throw new IllegalArgumentException("token stream must not be null");
throw new IllegalArgumentException("token stream must not be null");
if (boost <= 0.0f)
throw new IllegalArgumentException("boost factor must be greater than 0.0");
if (fields.get(fieldName) != null)
throw new IllegalArgumentException("field must not be added more than once");
@ -338,7 +359,8 @@ public class MemoryIndex {
// ensure infos.numTokens > 0 invariant; needed for correct operation of terms()
if (numTokens > 0) {
fields.put(fieldName, new Info(terms, numTokens));
boost = boost * docBoost; // see DocumentWriter.addDocument(...)
fields.put(fieldName, new Info(terms, numTokens, boost));
sortedFields = null; // invalidate sorted view, if any
}
} catch (IOException e) { // can never happen
@ -435,7 +457,7 @@ public class MemoryIndex {
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
size += HEADER + 4 + 4 + PTR + PTR + PTR; // Info instance vars
if (info.sortedTerms != null) size += ARR + PTR * info.sortedTerms.length;
int len = info.terms.size();
@ -545,14 +567,18 @@ public class MemoryIndex {
/** Number of added tokens for this field */
private final int numTokens;
/** Boost factor for hits for this field */
private final float boost;
/** 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) {
public Info(HashMap terms, int numTokens, float boost) {
this.terms = terms;
this.numTokens = numTokens;
this.boost = boost;
}
/**
@ -577,6 +603,10 @@ public class MemoryIndex {
return (ArrayIntList) sortedTerms[pos].getValue();
}
public float getBoost() {
return boost;
}
}
@ -970,6 +1000,8 @@ public class MemoryIndex {
Info info = getInfo(fieldName);
int numTokens = info != null ? info.numTokens : 0;
float n = sim.lengthNorm(fieldName, numTokens);
float boost = info != null ? info.getBoost() : 1.0f;
n = n * boost; // see DocumentWriter.writeNorms(String segment)
byte norm = Similarity.encodeNorm(n);
norms = new byte[] {norm};