improve logic of when to load fields from source, only if they actually have mappings, otherwise, ignore them (as was the previous behavior)

modules/elasticsearch/src/main/java/org/elasticsearch/index/mapper/AllButSourceFieldSelector.java

@@ -0,0 +1,40 @@
+/*
+ * Licensed to Elastic Search and Shay Banon under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. Elastic Search licenses this
+ * file to you 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.
+ */
+
+package org.elasticsearch.index.mapper;
+
+import org.apache.lucene.document.FieldSelector;
+import org.apache.lucene.document.FieldSelectorResult;
+
+/**
+ * An optimized field selector that loads just the uid and the source.
+ *
+ * @author kimchy (shay.banon)
+ */
+public class AllButSourceFieldSelector implements FieldSelector {
+
+    public static AllButSourceFieldSelector INSTANCE = new AllButSourceFieldSelector();
+
+    @Override public FieldSelectorResult accept(String fieldName) {
+        if (SourceFieldMapper.NAME.equals(fieldName)) {
+            return FieldSelectorResult.NO_LOAD;
+        }
+        return FieldSelectorResult.LOAD;
+    }
+}

modules/elasticsearch/src/main/java/org/elasticsearch/search/fetch/FetchPhase.java

@@ -189,8 +189,9 @@ public class FetchPhase implements SearchPhase {
         }
 
         // asked for all stored fields, just return null so all of them will be loaded
+        // don't load the source field in this case, makes little sense to get it with all stored fields
         if (context.fieldNames().get(0).equals("*")) {
-            return null;
+            return AllButSourceFieldSelector.INSTANCE;
         }
 
         FieldMappersFieldSelector fieldSelector = new FieldMappersFieldSelector();

modules/elasticsearch/src/main/java/org/elasticsearch/search/fetch/FieldsParseElement.java

@@ -36,20 +36,26 @@ public class FieldsParseElement implements SearchParseElement {
         if (token == XContentParser.Token.START_ARRAY) {
             boolean added = false;
             while ((token = parser.nextToken()) != XContentParser.Token.END_ARRAY) {
-                added = true;
                 String name = parser.text();
                 if (name.contains("_source.") || name.contains("doc[")) {
                     // script field to load from source
                     SearchScript searchScript = new SearchScript(context.lookup(), null, name, null, context.scriptService());
-                    context.scriptFields().add(new ScriptFieldsContext.ScriptField(name, searchScript));
+                    context.scriptFields().add(new ScriptFieldsContext.ScriptField(name, searchScript, true));
+                } else {
+                    if ("*".equals(name)) {
+                        added = true;
+                        context.fieldNames().add("*");
                     } else {
                         FieldMapper fieldMapper = context.mapperService().smartNameFieldMapper(name);
-                    if (!"*".equals(name) && (fieldMapper == null || !fieldMapper.stored())) {
+                        if (fieldMapper != null) {
-                        // script field to load from source
+                            if (fieldMapper.stored()) {
-                        SearchScript searchScript = new SearchScript(context.lookup(), null, "_source." + name, null, context.scriptService());
+                                added = true;
-                        context.scriptFields().add(new ScriptFieldsContext.ScriptField(name, searchScript));
-                    } else {
                                 context.fieldNames().add(name);
+                            } else {
+                                SearchScript searchScript = new SearchScript(context.lookup(), "mvel", "_source." + fieldMapper.names().fullName(), null, context.scriptService());
+                                context.scriptFields().add(new ScriptFieldsContext.ScriptField(name, searchScript, true));
+                            }
+                        }
                     }
                 }
             }
@@ -61,15 +67,22 @@ public class FieldsParseElement implements SearchParseElement {
             if (name.contains("_source.") || name.contains("doc[")) {
                 // script field to load from source
                 SearchScript searchScript = new SearchScript(context.lookup(), null, name, null, context.scriptService());
-                context.scriptFields().add(new ScriptFieldsContext.ScriptField(name, searchScript));
+                context.scriptFields().add(new ScriptFieldsContext.ScriptField(name, searchScript, true));
+            } else {
+                if ("*".equals(name)) {
+                    context.fieldNames().add("*");
                 } else {
                     FieldMapper fieldMapper = context.mapperService().smartNameFieldMapper(name);
-                if (!"*".equals(name) && (fieldMapper == null || !fieldMapper.stored())) {
+                    if (fieldMapper != null) {
-                    // script field to load from source
+                        if (fieldMapper.stored()) {
-                    SearchScript searchScript = new SearchScript(context.lookup(), null, "_source." + name, null, context.scriptService());
-                    context.scriptFields().add(new ScriptFieldsContext.ScriptField(name, searchScript));
-                } else {
                             context.fieldNames().add(name);
+                        } else {
+                            SearchScript searchScript = new SearchScript(context.lookup(), "mvel", "_source." + fieldMapper.names().fullName(), null, context.scriptService());
+                            context.scriptFields().add(new ScriptFieldsContext.ScriptField(name, searchScript, true));
+                        }
+                    } else {
+                        context.emptyFieldNames(); // don't load anything if we can't find mapping
+                    }
                 }
             }
         }

modules/elasticsearch/src/main/java/org/elasticsearch/search/fetch/script/ScriptFieldsContext.java

@@ -32,10 +32,12 @@ public class ScriptFieldsContext {
     public static class ScriptField {
         private final String name;
         private final SearchScript script;
+        private final boolean ignoreException;
 
-        public ScriptField(String name, SearchScript script) {
+        public ScriptField(String name, SearchScript script, boolean ignoreException) {
             this.name = name;
             this.script = script;
+            this.ignoreException = ignoreException;
         }
 
         public String name() {
@@ -45,6 +47,10 @@ public class ScriptFieldsContext {
         public SearchScript script() {
             return this.script;
         }
+
+        public boolean ignoreException() {
+            return ignoreException;
+        }
     }
 
     private List<ScriptField> fields = Lists.newArrayList();

modules/elasticsearch/src/main/java/org/elasticsearch/search/fetch/script/ScriptFieldsParseElement.java

@@ -53,6 +53,7 @@ public class ScriptFieldsParseElement implements SearchParseElement {
                 String script = null;
                 String scriptLang = null;
                 Map<String, Object> params = null;
+                boolean ignoreException = false;
                 while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
                     if (token == XContentParser.Token.FIELD_NAME) {
                         currentFieldName = parser.currentName();
@@ -63,11 +64,13 @@ public class ScriptFieldsParseElement implements SearchParseElement {
                             script = parser.text();
                         } else if ("lang".equals(currentFieldName)) {
                             scriptLang = parser.text();
+                        } else if ("ignore_failure".equals(currentFieldName)) {
+                            ignoreException = parser.booleanValue();
                         }
                     }
                 }
                 SearchScript searchScript = new SearchScript(context.lookup(), scriptLang, script, params, context.scriptService());
-                context.scriptFields().add(new ScriptFieldsContext.ScriptField(fieldName, searchScript));
+                context.scriptFields().add(new ScriptFieldsContext.ScriptField(fieldName, searchScript, ignoreException));
             }
         }
     }

modules/elasticsearch/src/main/java/org/elasticsearch/search/fetch/script/ScriptFieldsSearchHitPhase.java

@@ -58,7 +58,15 @@ public class ScriptFieldsSearchHitPhase implements SearchHitPhase {
         for (ScriptFieldsContext.ScriptField scriptField : context.scriptFields().fields()) {
             scriptField.script().setNextReader(reader);
 
-            Object value = scriptField.script().execute(docId);
+            Object value;
+            try {
+                value = scriptField.script().execute(docId);
+            } catch (RuntimeException e) {
+                if (scriptField.ignoreException()) {
+                    continue;
+                }
+                throw e;
+            }
 
             if (hit.fieldsOrNull() == null) {
                 hit.fields(new HashMap<String, SearchHitField>(2));