Query refactoring: refactored IdsQueryBuilder and Parser and added test

Split the parse(QueryParseContext ctx) method into a parsing and a query building part,
adding Streamable for serialization and hashCode(), equals() for better testing.
Add basic unit test for Builder and Parser.

Closes #10670

Author: cbuescher

src/main/java/org/elasticsearch/index/query/IdsQueryBuilder.java

@@ -19,45 +19,73 @@
 
 package org.elasticsearch.index.query;
 
+import com.google.common.collect.Iterables;
+
+import org.apache.lucene.queries.TermsQuery;
+import org.apache.lucene.search.Query;
+import org.apache.lucene.util.BytesRef;
+import org.elasticsearch.common.io.stream.StreamInput;
+import org.elasticsearch.common.io.stream.StreamOutput;
+import org.elasticsearch.common.io.stream.Streamable;
+import org.elasticsearch.common.lucene.search.Queries;
 import org.elasticsearch.common.xcontent.XContentBuilder;
+import org.elasticsearch.index.mapper.Uid;
+import org.elasticsearch.index.mapper.internal.UidFieldMapper;
 
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
+import java.util.Objects;
 
 /**
  * A query that will return only documents matching specific ids (and a type).
  */
-public class IdsQueryBuilder extends BaseQueryBuilder implements BoostableQueryBuilder<IdsQueryBuilder> {
+public class IdsQueryBuilder extends BaseQueryBuilder implements Streamable, BoostableQueryBuilder<IdsQueryBuilder> {
 
-    private final List<String> types;
+    private List<String> types = new ArrayList<>();
 
-    private List<String> values = new ArrayList<>();
+    private List<String> ids = new ArrayList<>();
 
-    private float boost = -1;
+    private float boost = 1.0f;
 
     private String queryName;
 
     public IdsQueryBuilder(String... types) {
-        this.types = types == null ? null : Arrays.asList(types);
+        this.types = (types == null || types.length == 0) ? new ArrayList<String>() : Arrays.asList(types);
+    }
+
+    /**
+     * Get the types used in this query
+     * @return the types
+     */
+    public Collection<String> types() {
+        return this.types;
     }
 
     /**
-     * Adds ids to the filter.
+     * Adds ids to the query.
      */
     public IdsQueryBuilder addIds(String... ids) {
-        values.addAll(Arrays.asList(ids));
+        this.ids.addAll(Arrays.asList(ids));
         return this;
     }
 
     /**
-     * Adds ids to the filter.
+     * Adds ids to the query.
      */
     public IdsQueryBuilder ids(String... ids) {
         return addIds(ids);
     }
 
+    /**
+     * Gets the ids for the query.
+     */
+    public Collection<String> ids() {
+        return this.ids;
+    }
+
     /**
      * Sets the boost for this query.  Documents matching this query will (in addition to the normal
      * weightings) have their score multiplied by the boost provided.
@@ -69,13 +97,27 @@ public IdsQueryBuilder boost(float boost) {
     }
 
     /**
-     * Sets the query name for the filter that can be used when searching for matched_filters per hit.
+     * Gets the boost for this query.
+     */
+    public float boost() {
+        return this.boost;
+    }
+
+    /**
+     * Sets the query name for the query that can be used when searching for matched_filters per hit.
      */
     public IdsQueryBuilder queryName(String queryName) {
         this.queryName = queryName;
         return this;
     }
 
+    /**
+     * Gets the query name for the query.
+     */
+    public String queryName() {
+        return this.queryName;
+    }
+
     @Override
     protected void doXContent(XContentBuilder builder, Params params) throws IOException {
         builder.startObject(IdsQueryParser.NAME);
@@ -84,14 +126,14 @@ protected void doXContent(XContentBuilder builder, Params params) throws IOExcep
                 builder.field("type", types.get(0));
             } else {
                 builder.startArray("types");
-                for (Object type : types) {
+                for (String type : types) {
                     builder.value(type);
                 }
                 builder.endArray();
             }
         }
         builder.startArray("values");
-        for (Object value : values) {
+        for (String value : ids) {
             builder.value(value);
         }
         builder.endArray();
@@ -108,4 +150,66 @@ protected void doXContent(XContentBuilder builder, Params params) throws IOExcep
     protected String parserName() {
         return IdsQueryParser.NAME;
     }
+
+    public Query toQuery(QueryParseContext parseContext) throws IOException, QueryParsingException {
+        if (this.ids.isEmpty()) {
+            return Queries.newMatchNoDocsQuery();
+        }
+
+        Collection<String> typesForQuery = this.types;
+        if (typesForQuery == null || typesForQuery.isEmpty()) {
+            typesForQuery = parseContext.queryTypes();
+        } else if (typesForQuery.size() == 1 && Iterables.getFirst(typesForQuery, null).equals("_all")) {
+            typesForQuery = parseContext.mapperService().types();
+        }
+
+        TermsQuery query = new TermsQuery(UidFieldMapper.NAME, Uid.createTypeUids(typesForQuery, ids));
+        query.setBoost(boost);
+        if (queryName != null) {
+            parseContext.addNamedQuery(queryName, query);
+        }
+        return query;
+    }
+
+    @Override
+    public QueryValidationException validate() {
+        // all fields can be empty or null
+        return null;
+    }
+
+    @Override
+    public void readFrom(StreamInput in) throws IOException {
+        this.types = in.readStringList();
+        this.ids = in.readStringList();
+        queryName = in.readOptionalString();
+        boost = in.readFloat();
+    }
+
+    @Override
+    public void writeTo(StreamOutput out) throws IOException {
+        out.writeStringList(this.types);
+        out.writeStringList(this.ids);
+        out.writeOptionalString(queryName);
+        out.writeFloat(boost);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(ids, types, boost, queryName);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj == null || getClass() != obj.getClass()) {
+            return false;
+        }
+        IdsQueryBuilder other = (IdsQueryBuilder) obj;
+        return Objects.equals(ids, other.ids) &&
+               Objects.equals(types, other.types) &&
+               Objects.equals(boost, other.boost) &&
+               Objects.equals(queryName, other.queryName);
+    }
 }

src/main/java/org/elasticsearch/index/query/IdsQueryParser.java

@@ -20,27 +20,18 @@
 package org.elasticsearch.index.query;
 
 import com.google.common.collect.ImmutableList;
-import com.google.common.collect.Iterables;
 
-
-import org.apache.lucene.queries.TermsQuery;
-import org.apache.lucene.search.Query;
-import org.apache.lucene.util.BytesRef;
 import org.elasticsearch.common.inject.Inject;
-import org.elasticsearch.common.lucene.search.Queries;
 import org.elasticsearch.common.xcontent.XContentParser;
-import org.elasticsearch.index.mapper.Uid;
-import org.elasticsearch.index.mapper.internal.UidFieldMapper;
 
 import java.io.IOException;
 import java.util.ArrayList;
-import java.util.Collection;
 import java.util.List;
 
 /**
- *
+ * Parser for the IdsQuery.
  */
-public class IdsQueryParser extends BaseQueryParserTemp {
+public class IdsQueryParser extends BaseQueryParser {
 
     public static final String NAME = "ids";
 
@@ -53,15 +44,18 @@ public String[] names() {
         return new String[]{NAME};
     }
 
+    /**
+     * @return a QueryBuilder representation of the query passed in as XContent in the parse context
+     */
     @Override
-    public Query parse(QueryParseContext parseContext) throws IOException, QueryParsingException {
+    public QueryBuilder fromXContent(QueryParseContext parseContext) throws IOException {
         XContentParser parser = parseContext.parser();
-
-        List<BytesRef> ids = new ArrayList<>();
-        Collection<String> types = null;
-        String currentFieldName = null;
+        List<String> ids = new ArrayList<>();
+        List<String> types = new ArrayList<>();
         float boost = 1.0f;
         String queryName = null;
+
+        String currentFieldName = null;
         XContentParser.Token token;
         boolean idsProvided = false;
         while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
@@ -73,18 +67,17 @@ public Query parse(QueryParseContext parseContext) throws IOException, QueryPars
                     while ((token = parser.nextToken()) != XContentParser.Token.END_ARRAY) {
                         if ((token == XContentParser.Token.VALUE_STRING) ||
                                 (token == XContentParser.Token.VALUE_NUMBER)) {
-                            BytesRef value = parser.utf8BytesOrNull();
-                            if (value == null) {
+                            String id = parser.textOrNull();
+                            if (id == null) {
                                 throw new QueryParsingException(parseContext, "No value specified for term filter");
                             }
-                            ids.add(value);
+                            ids.add(id);
                         } else {
                             throw new QueryParsingException(parseContext, "Illegal value for id, expecting a string or number, got: "
                                     + token);
                         }
                     }
                 } else if ("types".equals(currentFieldName) || "type".equals(currentFieldName)) {
-                    types = new ArrayList<>();
                     while ((token = parser.nextToken()) != XContentParser.Token.END_ARRAY) {
                         String value = parser.textOrNull();
                         if (value == null) {
@@ -107,26 +100,14 @@ public Query parse(QueryParseContext parseContext) throws IOException, QueryPars
                 }
             }
         }
-
         if (!idsProvided) {
             throw new QueryParsingException(parseContext, "[ids] query, no ids values provided");
         }
 
-        if (ids.isEmpty()) {
-            return Queries.newMatchNoDocsQuery();
-        }
-
-        if (types == null || types.isEmpty()) {
-            types = parseContext.queryTypes();
-        } else if (types.size() == 1 && Iterables.getFirst(types, null).equals("_all")) {
-            types = parseContext.mapperService().types();
-        }
-
-        TermsQuery query = new TermsQuery(UidFieldMapper.NAME, Uid.createTypeUids(types, ids));
-        query.setBoost(boost);
-        if (queryName != null) {
-            parseContext.addNamedQuery(queryName, query);
-        }
+        IdsQueryBuilder query = new IdsQueryBuilder(types.toArray(new String[types.size()]));
+        query.addIds(ids.toArray(new String[ids.size()]));
+        query.boost(boost).queryName(queryName);
+        query.validate();
         return query;
     }
 }

src/test/java/org/elasticsearch/index/query/BaseQueryTestCase.java

@@ -193,7 +193,7 @@ protected static QueryParseContext createContext() {
         return new QueryParseContext(index, queryParserService);
     }
 
-    private static void assertQueryHeader(XContentParser parser, String expectedParserName) throws IOException {
+    protected static void assertQueryHeader(XContentParser parser, String expectedParserName) throws IOException {
         assertThat(parser.nextToken(), is(XContentParser.Token.START_OBJECT));
         assertThat(parser.nextToken(), is(XContentParser.Token.FIELD_NAME));
         assertThat(parser.currentName(), is(expectedParserName));