refresh the mapping source directly into a compressed buffer

instead of building the mapping source, and then compressing it, we can generate it directly into a compressed buffer

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

@@ -29,12 +29,15 @@ import org.apache.lucene.document.FieldType;
 import org.apache.lucene.index.IndexableField;
 import org.apache.lucene.search.Filter;
 import org.apache.lucene.util.CloseableThreadLocal;
+import org.elasticsearch.ElasticSearchGenerationException;
 import org.elasticsearch.common.Booleans;
 import org.elasticsearch.common.Nullable;
 import org.elasticsearch.common.Preconditions;
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.collect.MapBuilder;
 import org.elasticsearch.common.compress.CompressedString;
+import org.elasticsearch.common.compress.CompressorFactory;
+import org.elasticsearch.common.io.stream.BytesStreamOutput;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.text.StringAndBytesText;
 import org.elasticsearch.common.text.Text;
@@ -655,15 +658,17 @@ public class DocumentMapper implements ToXContent {
         return new MergeResult(mergeContext.buildConflicts());
     }
 
-    public CompressedString refreshSource() throws FailedToGenerateSourceMapperException {
+    public CompressedString refreshSource() throws ElasticSearchGenerationException {
         try {
-            XContentBuilder builder = XContentFactory.contentBuilder(XContentType.JSON);
+            BytesStreamOutput bStream = new BytesStreamOutput();
+            XContentBuilder builder = XContentFactory.contentBuilder(XContentType.JSON, CompressorFactory.defaultCompressor().streamOutput(bStream));
             builder.startObject();
             toXContent(builder, ToXContent.EMPTY_PARAMS);
             builder.endObject();
-            return mappingSource = new CompressedString(builder.bytes());
+            builder.close();
+            return mappingSource = new CompressedString(bStream.bytes());
         } catch (Exception e) {
-            throw new FailedToGenerateSourceMapperException(e.getMessage(), e);
+            throw new ElasticSearchGenerationException("failed to serialize source for type [" + type + "]", e);
         }
     }
 

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

@@ -1,34 +0,0 @@
-/*
- * Licensed to ElasticSearch and Shay Banon under one
- * or more contributor license agreements.  See the NOTICE file
- * distributed with this work for additional information
- * regarding copyright ownership. ElasticSearch 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;
-
-/**
- *
- */
-public class FailedToGenerateSourceMapperException extends MapperException {
-
-    public FailedToGenerateSourceMapperException(String message) {
-        super(message);
-    }
-
-    public FailedToGenerateSourceMapperException(String message, Throwable cause) {
-        super(message, cause);
-    }
-}