Added the ability to include the queried document for More Like This API.

docs/reference/search/more-like-this.asciidoc

@@ -25,5 +25,8 @@ Rest parameters relating to search are also allowed, including
 When no `mlt_fields` are specified, all the fields of the document will
 be used in the `more_like_this` query generated.
 
+By default, the queried document is excluded from the response (`include`
+set to false).
+
 Note: In order to use the `mlt` feature a `mlt_field` needs to be either
 be `stored`, store `term_vector` or `source` needs to be enabled.

src/main/java/org/elasticsearch/action/mlt/MoreLikeThisRequest.java

@@ -21,6 +21,7 @@
 
 import org.elasticsearch.ElasticsearchGenerationException;
 import org.elasticsearch.ElasticsearchIllegalArgumentException;
+import org.elasticsearch.Version;
 import org.elasticsearch.action.ActionRequest;
 import org.elasticsearch.action.ActionRequestValidationException;
 import org.elasticsearch.action.ValidateActions;
@@ -72,6 +73,7 @@ public class MoreLikeThisRequest extends ActionRequest<MoreLikeThisRequest> {
     private int minWordLength = -1;
     private int maxWordLength = -1;
     private float boostTerms = -1;
+    private boolean include = false;
 
     private SearchType searchType = SearchType.DEFAULT;
     private int searchSize = 0;
@@ -313,6 +315,21 @@ public float boostTerms() {
         return this.boostTerms;
     }
 
+    /**
+     * Whether to include the queried document. Defaults to <tt>false</tt>.
+     */
+    public MoreLikeThisRequest include(boolean include) {
+        this.include = include;
+        return this;
+    }
+
+    /**
+     * Whether to include the queried document. Defaults to <tt>false</tt>.
+     */
+    public boolean include() {
+        return this.include;
+    }
+
     void beforeLocalFork() {
         if (searchSourceUnsafe) {
             searchSource = searchSource.copyBytesArray();
@@ -553,6 +570,12 @@ public void readFrom(StreamInput in) throws IOException {
         minWordLength = in.readVInt();
         maxWordLength = in.readVInt();
         boostTerms = in.readFloat();
+        if (in.getVersion().onOrAfter(Version.V_1_2_0)) {
+            include = in.readBoolean();
+        } else {
+            include = false; // hard-coded behavior until Elasticsearch 1.2
+        }
+
         searchType = SearchType.fromId(in.readByte());
         if (in.readBoolean()) {
             searchQueryHint = in.readString();
@@ -622,6 +645,9 @@ public void writeTo(StreamOutput out) throws IOException {
         out.writeVInt(minWordLength);
         out.writeVInt(maxWordLength);
         out.writeFloat(boostTerms);
+        if (out.getVersion().onOrAfter(Version.V_1_2_0)) {
+            out.writeBoolean(include);
+        }
 
         out.writeByte(searchType.id());
         if (searchQueryHint == null) {

src/main/java/org/elasticsearch/action/mlt/MoreLikeThisRequestBuilder.java

@@ -140,6 +140,14 @@ public MoreLikeThisRequestBuilder setBoostTerms(float boostTerms) {
         return this;
     }
 
+    /**
+     * Whether to include the queried document. Defaults to <tt>false</tt>.
+     */
+    public MoreLikeThisRequestBuilder setInclude(boolean include) {
+        request.include(include);
+        return this;
+    }
+
     /**
      * An optional search source request allowing to control the search request for the
      * more like this documents.

src/main/java/org/elasticsearch/action/mlt/TransportMoreLikeThisAction.java

@@ -178,9 +178,11 @@ public void onResponse(GetResponse getResponse) {
                     }
 
                     // exclude myself
-                    Term uidTerm = docMapper.uidMapper().term(request.type(), request.id());
-                    boolBuilder.mustNot(termQuery(uidTerm.field(), uidTerm.text()));
-                    boolBuilder.adjustPureNegative(false);
+                    if (!request.include()) {
+                        Term uidTerm = docMapper.uidMapper().term(request.type(), request.id());
+                        boolBuilder.mustNot(termQuery(uidTerm.field(), uidTerm.text()));
+                        boolBuilder.adjustPureNegative(false);
+                    }
                 } catch (Throwable e) {
                     listener.onFailure(e);
                     return;

src/main/java/org/elasticsearch/rest/action/mlt/RestMoreLikeThisAction.java

@@ -70,6 +70,7 @@ public void handleRequest(final RestRequest request, final RestChannel channel)
         mltRequest.minWordLength(request.paramAsInt("min_word_len", request.paramAsInt("min_word_length", -1)));
         mltRequest.maxWordLength(request.paramAsInt("max_word_len", request.paramAsInt("max_word_length", -1)));
         mltRequest.boostTerms(request.paramAsFloat("boost_terms", -1));
+        mltRequest.include(request.paramAsBoolean("include", false));
 
         mltRequest.searchType(SearchType.fromString(request.param("search_type")));
         mltRequest.searchIndices(request.paramAsStringArray("search_indices", null));

src/test/java/org/elasticsearch/mlt/MoreLikeThisActionTests.java

@@ -252,4 +252,40 @@ public void testNumericField() throws Exception {
         assertHitCount(searchResponse, 0l);
     }
 
+    @Test
+    public void testSimpleMoreLikeInclude() throws Exception {
+        logger.info("Creating index test");
+        assertAcked(prepareCreate("test").addMapping("type1",
+                jsonBuilder().startObject().startObject("type1").startObject("properties")
+                        .startObject("text").field("type", "string").endObject()
+                        .endObject().endObject().endObject()));
+
+        logger.info("Running Cluster Health");
+        assertThat(ensureGreen(), equalTo(ClusterHealthStatus.GREEN));
+
+        logger.info("Indexing...");
+        client().index(indexRequest("test").type("type1").id("1").source(
+                jsonBuilder().startObject()
+                        .field("text", "Apache Lucene is a free/open source information retrieval software library").endObject()))
+                .actionGet();
+        client().index(indexRequest("test").type("type1").id("2").source(
+                jsonBuilder().startObject()
+                        .field("text", "Lucene has been ported to other programming languages").endObject()))
+                .actionGet();
+        client().admin().indices().refresh(refreshRequest()).actionGet();
+
+        logger.info("Running More Like This with include true");
+        SearchResponse mltResponse = client().moreLikeThis(
+                moreLikeThisRequest("test").type("type1").id("1").minTermFreq(1).minDocFreq(1).include(true)).actionGet();
+        assertOrderedSearchHits(mltResponse, "1", "2");
+
+        mltResponse = client().moreLikeThis(
+                moreLikeThisRequest("test").type("type1").id("2").minTermFreq(1).minDocFreq(1).include(true)).actionGet();
+        assertOrderedSearchHits(mltResponse, "2", "1");
+
+        logger.info("Running More Like This with include false");
+        mltResponse = client().moreLikeThis(moreLikeThisRequest("test").type("type1").id("1").minTermFreq(1).minDocFreq(1)).actionGet();
+        assertSearchHits(mltResponse, "2");
+    }
+
 }