Pass field path updates verbatim through indexing scripts

Avoids having to do a (potentially lossy) round-trip of
update -> document -> update again during processing.

2 files changed, 69 insertions, 6 deletions

diff --git a/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/IdentityFieldPathUpdateAdapter.java b/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/IdentityFieldPathUpdateAdapter.java
new file mode 100644
index 00000000000..42c9bd8c10c
--- /dev/null
+++ b/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/IdentityFieldPathUpdateAdapter.java
@@ -0,0 +1,68 @@
+// Copyright 2018 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.vespa.indexinglanguage;
+
+import com.yahoo.document.DataType;
+import com.yahoo.document.Document;
+import com.yahoo.document.DocumentUpdate;
+import com.yahoo.document.FieldPath;
+import com.yahoo.document.datatypes.FieldValue;
+import com.yahoo.document.fieldpathupdate.FieldPathUpdate;
+import com.yahoo.vespa.indexinglanguage.expressions.Expression;
+import com.yahoo.vespa.indexinglanguage.expressions.FieldValueAdapter;
+
+/**
+ * No-op update adapter which simply passes through the input update unchanged.
+ * I.e. getOutput() will return a DocumentUpdate containing only the FieldPathUpdate
+ * the IdentityFieldPathUpdateAdapter was created with. All other applicable calls are
+ * forwarded to the provided DocumentAdapter instance.
+ *
+ * This removes the need for a potentially lossy round-trip of update -> synthetic document -> update.
+ */
+public class IdentityFieldPathUpdateAdapter implements UpdateAdapter {
+
+    private final FieldPathUpdate update;
+    private final DocumentAdapter fwdAdapter;
+
+    public IdentityFieldPathUpdateAdapter(FieldPathUpdate update, DocumentAdapter fwdAdapter) {
+        this.update = update;
+        this.fwdAdapter = fwdAdapter;
+    }
+
+    @Override
+    public DocumentUpdate getOutput() {
+        Document doc = fwdAdapter.getFullOutput();
+        DocumentUpdate upd = new DocumentUpdate(doc.getDataType(), doc.getId());
+        upd.addFieldPathUpdate(update);
+        return upd;
+    }
+
+    @Override
+    public Expression getExpression(Expression expression) {
+        return expression;
+    }
+
+    @Override
+    public FieldValue getInputValue(String fieldName) {
+        return fwdAdapter.getInputValue(fieldName);
+    }
+
+    @Override
+    public FieldValue getInputValue(FieldPath fieldPath) {
+        return fwdAdapter.getInputValue(fieldPath);
+    }
+
+    @Override
+    public FieldValueAdapter setOutputValue(Expression exp, String fieldName, FieldValue fieldValue) {
+        return fwdAdapter.setOutputValue(exp, fieldName, fieldValue);
+    }
+
+    @Override
+    public DataType getInputType(Expression exp, String fieldName) {
+        return fwdAdapter.getInputType(exp, fieldName);
+    }
+
+    @Override
+    public void tryOutputType(Expression exp, String fieldName, DataType valueType) {
+        fwdAdapter.tryOutputType(exp, fieldName, valueType);
+    }
+}
diff --git a/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/SimpleAdapterFactory.java b/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/SimpleAdapterFactory.java
index 2ad09dfbdc4..038e91b7481 100644
--- a/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/SimpleAdapterFactory.java
+++ b/indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/SimpleAdapterFactory.java
@@ -48,12 +48,7 @@ public class SimpleAdapterFactory implements AdapterFactory {
         DocumentId docId = upd.getId();
         Document complete = new Document(docType, upd.getId());
         for (FieldPathUpdate fieldUpd : upd) {
-            if (FieldPathUpdateHelper.isComplete(fieldUpd)) {
-                FieldPathUpdateHelper.applyUpdate(fieldUpd, complete);
-            } else {
-                Document partial = FieldPathUpdateHelper.newPartialDocument(docId, fieldUpd);
-                ret.add(new FieldPathUpdateAdapter(newDocumentAdapter(partial, true), fieldUpd));
-            }
+            ret.add(new IdentityFieldPathUpdateAdapter(fieldUpd, newDocumentAdapter(complete, true)));
         }
         for (FieldUpdate fieldUpd : upd.getFieldUpdates()) {
             Field field = fieldUpd.getField();