properly invalidate on core closed reader

src/main/java/org/elasticsearch/index/fielddata/FieldDataStats.java

@@ -0,0 +1,82 @@
+/*
+ * 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.fielddata;
+
+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.unit.ByteSizeValue;
+import org.elasticsearch.common.xcontent.ToXContent;
+import org.elasticsearch.common.xcontent.XContentBuilder;
+import org.elasticsearch.common.xcontent.XContentBuilderString;
+
+import java.io.IOException;
+
+/**
+ */
+public class FieldDataStats implements Streamable, ToXContent {
+
+    long memorySize;
+
+    public FieldDataStats() {
+
+    }
+
+    public FieldDataStats(long memorySize) {
+        this.memorySize = memorySize;
+    }
+
+    public void add(FieldDataStats stats) {
+        this.memorySize += stats.memorySize;
+    }
+
+    public long getMemorySizeInBytes() {
+        return this.memorySize;
+    }
+
+    public ByteSizeValue getMemorySize() {
+        return new ByteSizeValue(memorySize);
+    }
+
+    @Override
+    public void readFrom(StreamInput in) throws IOException {
+        memorySize = in.readVLong();
+    }
+
+    @Override
+    public void writeTo(StreamOutput out) throws IOException {
+        out.writeVLong(memorySize);
+    }
+
+    @Override
+    public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+        builder.startObject(Fields.FIELD_DATA);
+        builder.field(Fields.MEMORY_SIZE, memorySize);
+        builder.field(Fields.MEMORY_SIZE_IN_BYTES, getMemorySize().toString());
+        builder.endObject();
+        return builder;
+    }
+
+    static final class Fields {
+        static final XContentBuilderString FIELD_DATA = new XContentBuilderString("field_data");
+        static final XContentBuilderString MEMORY_SIZE = new XContentBuilderString("memory_size");
+        static final XContentBuilderString MEMORY_SIZE_IN_BYTES = new XContentBuilderString("memory_size_in_bytes");
+    }
+}

src/main/java/org/elasticsearch/index/fielddata/IndexFieldDataCache.java

@@ -59,6 +59,9 @@ public interface IndexFieldDataCache {
             return (FD) cache.get(context.reader().getCoreCacheKey(), new Callable<AtomicFieldData>() {
                 @Override
                 public AtomicFieldData call() throws Exception {
+                    if (context.reader() instanceof SegmentReader) {
+                        ((SegmentReader) context.reader()).addCoreClosedListener(FieldBased.this);
+                    }
                     return indexFieldData.loadDirect(context);
                 }
             });

src/main/java/org/elasticsearch/index/fielddata/IndexFieldDataService.java

@@ -96,6 +96,11 @@ public class IndexFieldDataService extends AbstractIndexComponent {
         }
     }
 
+    public FieldDataStats stats() {
+        // TODO: compute the memory size here...
+        return new FieldDataStats();
+    }
+
     public <IFD extends IndexFieldData> IFD getForField(FieldMapper mapper) {
         return getForField(mapper.names(), mapper.fieldDataType2());
     }