migrate MetadataBridge to interface pattern

Author: yaauie

libs/logstash-bridge/src/main/java/org/elasticsearch/logstashbridge/ingest/IngestDocumentBridge.java

@@ -69,6 +69,8 @@ static IngestDocumentBridge create(final Map<String, Object> sourceAndMetadata,
 
     class ProxyInternal extends StableBridgeAPI.ProxyInternal<IngestDocument> implements IngestDocumentBridge {
 
+        private MetadataBridge metadataBridge;
+
         public ProxyInternal(final Map<String, Object> sourceAndMetadata, final Map<String, Object> ingestMetadata) {
             this(new IngestDocument(sourceAndMetadata, ingestMetadata));
         }
@@ -79,7 +81,10 @@ private ProxyInternal(IngestDocument inner) {
 
         @Override
         public MetadataBridge getMetadata() {
-            return new MetadataBridge(internalDelegate.getMetadata());
+            if (metadataBridge == null) {
+                this.metadataBridge = MetadataBridge.fromInternal(internalDelegate.getMetadata());
+            }
+            return this.metadataBridge;
         }
 
         @Override

libs/logstash-bridge/src/main/java/org/elasticsearch/logstashbridge/script/MetadataBridge.java

@@ -16,52 +16,81 @@
 /**
  * An external bridge for {@link Metadata}
  */
-public class MetadataBridge extends StableBridgeAPI.ProxyInternal<Metadata> {
-    public MetadataBridge(final Metadata delegate) {
-        super(delegate);
-    }
+public interface MetadataBridge extends StableBridgeAPI<Metadata> {
 
-    public String getIndex() {
-        return internalDelegate.getIndex();
-    }
+    String getIndex();
 
-    public void setIndex(final String index) {
-        internalDelegate.setIndex(index);
-    }
+    void setIndex(String index);
 
-    public String getId() {
-        return internalDelegate.getId();
-    }
+    String getId();
 
-    public void setId(final String id) {
-        internalDelegate.setId(id);
-    }
+    void setId(String id);
 
-    public long getVersion() {
-        return internalDelegate.getVersion();
-    }
+    long getVersion();
 
-    public void setVersion(final long version) {
-        internalDelegate.setVersion(version);
-    }
+    void setVersion(long version);
 
-    public String getVersionType() {
-        return internalDelegate.getVersionType();
-    }
+    String getVersionType();
 
-    public void setVersionType(final String versionType) {
-        internalDelegate.setVersionType(versionType);
-    }
+    void setVersionType(String versionType);
 
-    public String getRouting() {
-        return internalDelegate.getRouting();
-    }
+    String getRouting();
+
+    void setRouting(String routing);
+
+    ZonedDateTime getNow();
 
-    public void setRouting(final String routing) {
-        internalDelegate.setRouting(routing);
+    static MetadataBridge fromInternal(final Metadata metadata) {
+        return new ProxyInternal(metadata);
     }
 
-    public ZonedDateTime getNow() {
-        return internalDelegate.getNow();
+    class ProxyInternal extends StableBridgeAPI.ProxyInternal<Metadata> implements MetadataBridge {
+        ProxyInternal(final Metadata delegate) {
+            super(delegate);
+        }
+
+        public String getIndex() {
+            return internalDelegate.getIndex();
+        }
+
+        public void setIndex(final String index) {
+            internalDelegate.setIndex(index);
+        }
+
+        public String getId() {
+            return internalDelegate.getId();
+        }
+
+        public void setId(final String id) {
+            internalDelegate.setId(id);
+        }
+
+        public long getVersion() {
+            return internalDelegate.getVersion();
+        }
+
+        public void setVersion(final long version) {
+            internalDelegate.setVersion(version);
+        }
+
+        public String getVersionType() {
+            return internalDelegate.getVersionType();
+        }
+
+        public void setVersionType(final String versionType) {
+            internalDelegate.setVersionType(versionType);
+        }
+
+        public String getRouting() {
+            return internalDelegate.getRouting();
+        }
+
+        public void setRouting(final String routing) {
+            internalDelegate.setRouting(routing);
+        }
+
+        public ZonedDateTime getNow() {
+            return internalDelegate.getNow();
+        }
     }
 }