Experimental ReplicationFilter and ReplicationFilterCompiler with JavaScript

Author: hideki

src/main/java/com/couchbase/lite/javascript/JavaScriptReplicationFilter.java

@@ -0,0 +1,98 @@
+package com.couchbase.lite.javascript;
+
+import com.couchbase.lite.Emitter;
+import com.couchbase.lite.ReplicationFilter;
+import com.couchbase.lite.SavedRevision;
+import com.couchbase.lite.javascript.scopes.MapGlobalScope;
+import com.couchbase.lite.javascript.wrapper.CustomWrapFactory;
+import com.couchbase.lite.util.Log;
+
+import org.mozilla.javascript.Function;
+import org.mozilla.javascript.Scriptable;
+import org.mozilla.javascript.WrapFactory;
+
+import java.util.Map;
+
+/**
+ * Created by hideki on 10/28/15.
+ */
+public class JavaScriptReplicationFilter implements ReplicationFilter {
+    public static String TAG = "JavaScriptReplicationFilter";
+
+    private static WrapFactory wrapFactory = new CustomWrapFactory();
+    private Scriptable globalScope;
+    private MapGlobalScope mapGlobalScope;
+    private Function mapFunction;
+
+
+    public JavaScriptReplicationFilter(String src){
+        Log.e(TAG, "JavaScriptReplicationFilter(String) src="+src);
+        org.mozilla.javascript.Context ctx = org.mozilla.javascript.Context.enter();
+
+        try {
+            ctx.setOptimizationLevel(-1);
+            ctx.setWrapFactory(wrapFactory);
+            mapGlobalScope = new MapGlobalScope();
+            globalScope = ctx.initStandardObjects(mapGlobalScope, true);
+            mapFunction = ctx.compileFunction(globalScope, src, "filter", 0, null);
+        } finally {
+            org.mozilla.javascript.Context.exit();
+        }
+    }
+
+    public void map(Map<String, Object> document, Emitter emitter) {
+
+        mapGlobalScope.setEmitter(emitter);
+
+        org.mozilla.javascript.Context ctx = org.mozilla.javascript.Context.enter();
+        try {
+            ctx.setOptimizationLevel(-1);
+            ctx.setWrapFactory(wrapFactory);
+
+            Scriptable localScope = ctx.newObject(globalScope);
+            localScope.setPrototype(globalScope);
+            localScope.setParentScope(null);
+
+            Object jsDocument = org.mozilla.javascript.Context.javaToJS(document, localScope);
+
+            try {
+                mapFunction.call(ctx, localScope, null, new Object[]{jsDocument});
+            } catch (org.mozilla.javascript.RhinoException e) {
+                // Error in the JavaScript view - CouchDB swallows  the error and tries the next document
+                return;
+            }
+        } finally {
+            org.mozilla.javascript.Context.exit();
+        }
+    }
+    @Override
+    public boolean filter(SavedRevision revision, Map<String, Object> params) {
+        Log.e(TAG, "filter(SavedRevision, Map<String, Object>)");
+        //mapGlobalScope.setEmitter(emitter);
+
+        org.mozilla.javascript.Context ctx = org.mozilla.javascript.Context.enter();
+        try {
+            ctx.setOptimizationLevel(-1);
+            ctx.setWrapFactory(wrapFactory);
+
+            Scriptable localScope = ctx.newObject(globalScope);
+            localScope.setPrototype(globalScope);
+            localScope.setParentScope(null);
+
+            Object jsDocument = org.mozilla.javascript.Context.javaToJS(revision.getProperties(), localScope);
+            Log.e(TAG, "jsDocument="+jsDocument);
+
+            try {
+                Object result = mapFunction.call(ctx, localScope, null, new Object[]{jsDocument});
+                Log.e(TAG, "result="+result);
+                return ((Boolean)result).booleanValue();
+            } catch (org.mozilla.javascript.RhinoException e) {
+                // Error in the JavaScript view - CouchDB swallows  the error and tries the next document
+                Log.e(TAG, "Error in mapFunction.call()", e);
+                return false;
+            }
+        } finally {
+            org.mozilla.javascript.Context.exit();
+        }
+    }
+}

src/main/java/com/couchbase/lite/javascript/JavaScriptReplicationFilterCompiler.java

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+package com.couchbase.lite.javascript;
+
+import com.couchbase.lite.ReplicationFilter;
+import com.couchbase.lite.ReplicationFilterCompiler;
+import com.couchbase.lite.util.Log;
+
+/**
+ * Created by hideki on 10/28/15.
+ */
+public class JavaScriptReplicationFilterCompiler implements ReplicationFilterCompiler {
+    public static String TAG = "JSReplicationFilterCompiler";
+    @Override
+    public ReplicationFilter compileFilterFunction(String source, String language) {
+        Log.e(TAG, "compileFilterFunction(String, String)");
+        return new JavaScriptReplicationFilter(source);
+    }
+}