lucene 4: support doc level boost

src/main/java/org/elasticsearch/index/mapper/DocumentMapper.java

@@ -25,6 +25,7 @@ import org.apache.lucene.analysis.Analyzer;
 import org.apache.lucene.document.Document;
 import org.apache.lucene.document.Field;
 import org.apache.lucene.document.FieldType;
+import org.apache.lucene.index.IndexableField;
 import org.apache.lucene.search.Filter;
 import org.elasticsearch.common.Booleans;
 import org.elasticsearch.common.Nullable;
@@ -519,6 +520,17 @@ public class DocumentMapper implements ToXContent {
         if (context.docs().size() > 1) {
             Collections.reverse(context.docs());
         }
+        // apply doc boost
+        if (context.docBoost() != 1.0f) {
+            for (Document doc : context.docs()) {
+                for (IndexableField field : doc) {
+                    if (field.fieldType().indexed() && !field.fieldType().omitNorms()) {
+                        ((Field) field).setBoost(context.docBoost() * field.boost());
+                    }
+                }
+            }
+        }
+
         ParsedDocument doc = new ParsedDocument(context.uid(), context.id(), context.type(), source.routing(), source.timestamp(), source.ttl(), context.docs(), context.analyzer(),
                 context.source(), context.mappingsModified()).parent(source.parent());
         // reset the context to free up memory

src/main/java/org/elasticsearch/index/mapper/ParseContext.java

@@ -21,7 +21,6 @@ package org.elasticsearch.index.mapper;
 
 import org.apache.lucene.analysis.Analyzer;
 import org.apache.lucene.document.Document;
-import org.apache.lucene.document.Field;
 import org.elasticsearch.common.Nullable;
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.lucene.all.AllEntries;
@@ -80,6 +79,8 @@ public class ParseContext {
 
     private AllEntries allEntries = new AllEntries();
 
+    private float docBoost = 1.0f;
+
     public ParseContext(String index, @Nullable Settings indexSettings, DocumentMapperParser docMapperParser, DocumentMapper docMapper, ContentPath path) {
         this.index = index;
         this.indexSettings = indexSettings;
@@ -107,6 +108,7 @@ public class ParseContext {
         this.listener = listener == null ? DocumentMapper.ParseListener.EMPTY : listener;
         this.allEntries = new AllEntries();
         this.ignoredValues.clear();
+        this.docBoost = 1.0f;
     }
 
     public boolean flyweight() {
@@ -273,6 +275,14 @@ public class ParseContext {
         return externalValue;
     }
 
+    public float docBoost() {
+        return this.docBoost;
+    }
+
+    public void docBoost(float docBoost) {
+        this.docBoost = docBoost;
+    }
+
     /**
      * A string builder that can be used to construct complex names for example.
      * Its better to reuse the.

src/main/java/org/elasticsearch/index/mapper/internal/BoostFieldMapper.java

@@ -228,7 +228,7 @@ public class BoostFieldMapper extends NumberFieldMapper<Float> implements Intern
         // we override parse since we want to handle cases where it is not indexed and not stored (the default)
         float value = parseFloatValue(context);
         if (!Float.isNaN(value)) {
-            context.doc().setBoost(value);
+            context.docBoost(value);
         }
         super.parse(context);
     }
@@ -239,7 +239,7 @@ public class BoostFieldMapper extends NumberFieldMapper<Float> implements Intern
         if (Float.isNaN(value)) {
             return null;
         }
-        context.doc().setBoost(value);
+        context.docBoost(value);
         return new FloatFieldMapper.CustomFloatNumericField(this, value, fieldType);
     }