Allow_duplicates option for append processor (#61916)

Author: danhermann

modules/ingest-common/src/main/java/org/elasticsearch/ingest/common/AppendProcessor.java

@@ -40,11 +40,13 @@ public final class AppendProcessor extends AbstractProcessor {
 
     private final TemplateScript.Factory field;
     private final ValueSource value;
+    private final boolean allowDuplicates;
 
-    AppendProcessor(String tag, String description, TemplateScript.Factory field, ValueSource value) {
+    AppendProcessor(String tag, String description, TemplateScript.Factory field, ValueSource value, boolean allowDuplicates) {
         super(tag, description);
         this.field = field;
         this.value = value;
+        this.allowDuplicates = allowDuplicates;
     }
 
     public TemplateScript.Factory getField() {
@@ -57,7 +59,7 @@ public ValueSource getValue() {
 
     @Override
     public IngestDocument execute(IngestDocument ingestDocument) throws Exception {
-        ingestDocument.appendFieldValue(field, value);
+        ingestDocument.appendFieldValue(field, value, allowDuplicates);
         return ingestDocument;
     }
 
@@ -79,9 +81,11 @@ public AppendProcessor create(Map<String, Processor.Factory> registry, String pr
                                       String description, Map<String, Object> config) throws Exception {
             String field = ConfigurationUtils.readStringProperty(TYPE, processorTag, config, "field");
             Object value = ConfigurationUtils.readObject(TYPE, processorTag, config, "value");
+            boolean allowDuplicates = ConfigurationUtils.readBooleanProperty(TYPE, processorTag, config, "allow_duplicates", true);
             TemplateScript.Factory compiledTemplate = ConfigurationUtils.compileTemplate(TYPE, processorTag,
                 "field", field, scriptService);
-            return new AppendProcessor(processorTag, description, compiledTemplate, ValueSource.wrap(value, scriptService));
+            return new AppendProcessor(processorTag, description, compiledTemplate, ValueSource.wrap(value, scriptService),
+                allowDuplicates);
         }
     }
 }

modules/ingest-common/src/test/java/org/elasticsearch/ingest/common/AppendProcessorTests.java

@@ -28,13 +28,16 @@
 import org.elasticsearch.test.ESTestCase;
 
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
 import static org.hamcrest.CoreMatchers.equalTo;
+import static org.hamcrest.CoreMatchers.instanceOf;
 import static org.hamcrest.CoreMatchers.not;
 import static org.hamcrest.CoreMatchers.sameInstance;
+import static org.hamcrest.Matchers.containsInAnyOrder;
 
 public class AppendProcessorTests extends ESTestCase {
 
@@ -53,13 +56,13 @@ public void testAppendValuesToExistingList() throws Exception {
         if (randomBoolean()) {
             Object value = scalar.randomValue();
             values.add(value);
-            appendProcessor = createAppendProcessor(field, value);
+            appendProcessor = createAppendProcessor(field, value, true);
         } else {
             int valuesSize = randomIntBetween(0, 10);
             for (int i = 0; i < valuesSize; i++) {
                 values.add(scalar.randomValue());
             }
-            appendProcessor = createAppendProcessor(field, values);
+            appendProcessor = createAppendProcessor(field, values, true);
         }
         appendProcessor.execute(ingestDocument);
         Object fieldValue = ingestDocument.getFieldValue(field, Object.class);
@@ -82,13 +85,13 @@ public void testAppendValuesToNonExistingList() throws Exception {
         if (randomBoolean()) {
             Object value = scalar.randomValue();
             values.add(value);
-            appendProcessor = createAppendProcessor(field, value);
+            appendProcessor = createAppendProcessor(field, value, true);
         } else {
             int valuesSize = randomIntBetween(0, 10);
             for (int i = 0; i < valuesSize; i++) {
                 values.add(scalar.randomValue());
             }
-            appendProcessor = createAppendProcessor(field, values);
+            appendProcessor = createAppendProcessor(field, values, true);
         }
         appendProcessor.execute(ingestDocument);
         List<?> list = ingestDocument.getFieldValue(field, List.class);
@@ -106,13 +109,13 @@ public void testConvertScalarToList() throws Exception {
         if (randomBoolean()) {
             Object value = scalar.randomValue();
             values.add(value);
-            appendProcessor = createAppendProcessor(field, value);
+            appendProcessor = createAppendProcessor(field, value, true);
         } else {
             int valuesSize = randomIntBetween(0, 10);
             for (int i = 0; i < valuesSize; i++) {
                 values.add(scalar.randomValue());
             }
-            appendProcessor = createAppendProcessor(field, values);
+            appendProcessor = createAppendProcessor(field, values, true);
         }
         appendProcessor.execute(ingestDocument);
         List<?> fieldValue = ingestDocument.getFieldValue(field, List.class);
@@ -132,13 +135,13 @@ public void testAppendMetadataExceptVersion() throws Exception {
         if (randomBoolean()) {
             String value = randomAlphaOfLengthBetween(1, 10);
             values.add(value);
-            appendProcessor = createAppendProcessor(randomMetadata.getFieldName(), value);
+            appendProcessor = createAppendProcessor(randomMetadata.getFieldName(), value, true);
         } else {
             int valuesSize = randomIntBetween(0, 10);
             for (int i = 0; i < valuesSize; i++) {
                 values.add(randomAlphaOfLengthBetween(1, 10));
             }
-            appendProcessor = createAppendProcessor(randomMetadata.getFieldName(), values);
+            appendProcessor = createAppendProcessor(randomMetadata.getFieldName(), values, true);
         }
 
         IngestDocument ingestDocument = RandomDocumentPicks.randomIngestDocument(random());
@@ -156,10 +159,65 @@ public void testAppendMetadataExceptVersion() throws Exception {
         }
     }
 
-    private static Processor createAppendProcessor(String fieldName, Object fieldValue) {
+    public void testAppendingDuplicateValueToScalarDoesNotModifyDocument() throws Exception {
+        IngestDocument ingestDocument = RandomDocumentPicks.randomIngestDocument(random());
+        String originalValue = randomAlphaOfLengthBetween(1, 10);
+        String field = RandomDocumentPicks.addRandomField(random(), ingestDocument, originalValue);
+
+        List<Object> valuesToAppend = new ArrayList<>();
+        valuesToAppend.add(originalValue);
+        Processor appendProcessor = createAppendProcessor(field, valuesToAppend, false);
+        appendProcessor.execute(ingestDocument);
+        Object fieldValue = ingestDocument.getFieldValue(field, Object.class);
+        assertThat(fieldValue, not(instanceOf(List.class)));
+        assertThat(fieldValue, equalTo(originalValue));
+    }
+
+    public void testAppendingUniqueValueToScalar() throws Exception {
+        IngestDocument ingestDocument = RandomDocumentPicks.randomIngestDocument(random());
+        String originalValue = randomAlphaOfLengthBetween(1, 10);
+        String field = RandomDocumentPicks.addRandomField(random(), ingestDocument, originalValue);
+
+        List<Object> valuesToAppend = new ArrayList<>();
+        String newValue = randomAlphaOfLengthBetween(1, 10);
+        valuesToAppend.add(newValue);
+        Processor appendProcessor = createAppendProcessor(field, valuesToAppend, false);
+        appendProcessor.execute(ingestDocument);
+        List<?> list = ingestDocument.getFieldValue(field, List.class);
+        assertThat(list.size(), equalTo(2));
+        assertThat(list, equalTo(List.of(originalValue, newValue)));
+    }
+
+    public void testAppendingToListWithDuplicatesDisallowed() throws Exception {
+        IngestDocument ingestDocument = RandomDocumentPicks.randomIngestDocument(random());
+        List<String> list = new ArrayList<>();
+        int size = randomIntBetween(0, 10);
+        for (int i = 0; i < size; i++) {
+            list.add(randomAlphaOfLengthBetween(1, 10));
+        }
+        String originalField = RandomDocumentPicks.addRandomField(random(), ingestDocument, list);
+        List<String> expectedValues = new ArrayList<>(list);
+        List<String> existingValues = randomSubsetOf(list);
+        int uniqueValuesSize = randomIntBetween(0, 10);
+        List<String> uniqueValues = new ArrayList<>();
+        for (int i = 0; i < uniqueValuesSize; i++) {
+            uniqueValues.add(randomAlphaOfLengthBetween(1, 10));
+        }
+        List<String> valuesToAppend = new ArrayList<>(existingValues);
+        valuesToAppend.addAll(uniqueValues);
+        expectedValues.addAll(uniqueValues);
+        Collections.sort(valuesToAppend);
+        Processor appendProcessor = createAppendProcessor(originalField, valuesToAppend, false);
+        appendProcessor.execute(ingestDocument);
+        List<?> fieldValue = ingestDocument.getFieldValue(originalField, List.class);
+        assertThat(fieldValue, sameInstance(list));
+        assertThat(fieldValue, containsInAnyOrder(expectedValues.toArray()));
+    }
+
+    private static Processor createAppendProcessor(String fieldName, Object fieldValue, boolean allowDuplicates) {
         return new AppendProcessor(randomAlphaOfLength(10),
             null, new TestTemplateService.MockTemplateScript.Factory(fieldName),
-            ValueSource.wrap(fieldValue, TestTemplateService.instance()));
+            ValueSource.wrap(fieldValue, TestTemplateService.instance()), allowDuplicates);
     }
 
     private enum Scalar {

modules/ingest-common/src/test/java/org/elasticsearch/ingest/common/ForEachProcessorTests.java

@@ -203,8 +203,8 @@ public void testModifyFieldsOutsideArray() throws Exception {
 
         ForEachProcessor processor = new ForEachProcessor(
                 "_tag", null, "values", new CompoundProcessor(false,
-                Collections.singletonList(new UppercaseProcessor("_tag_upper", null, "_ingest._value", false, "_ingest._value")),
-                Collections.singletonList(new AppendProcessor("_tag", null, template, (model) -> (Collections.singletonList("added"))))
+                List.of(new UppercaseProcessor("_tag_upper", null, "_ingest._value", false, "_ingest._value")),
+                List.of(new AppendProcessor("_tag", null, template, (model) -> (Collections.singletonList("added")), true))
         ), false);
         processor.execute(ingestDocument, (result, e) -> {});
 

server/src/main/java/org/elasticsearch/ingest/IngestDocument.java

@@ -377,7 +377,24 @@ private static Object resolve(String pathElement, String fullPath, Object contex
      * @throws IllegalArgumentException if the path is null, empty or invalid.
      */
     public void appendFieldValue(String path, Object value) {
-        setFieldValue(path, value, true);
+        appendFieldValue(path, value, true);
+    }
+
+    /**
+     * Appends the provided value to the provided path in the document.
+     * Any non existing path element will be created.
+     * If the path identifies a list, the value will be appended to the existing list.
+     * If the path identifies a scalar, the scalar will be converted to a list and
+     * the provided value will be added to the newly created list.
+     * Supports multiple values too provided in forms of list, in that case all the values will be appended to the
+     * existing (or newly created) list.
+     * @param path The path within the document in dot-notation
+     * @param value The value or values to append to the existing ones
+     * @param allowDuplicates When false, any values that already exist in the field will not be added
+     * @throws IllegalArgumentException if the path is null, empty or invalid.
+     */
+    public void appendFieldValue(String path, Object value, boolean allowDuplicates) {
+        setFieldValue(path, value, true, allowDuplicates);
     }
 
     /**
@@ -397,6 +414,24 @@ public void appendFieldValue(TemplateScript.Factory fieldPathTemplate, ValueSour
         appendFieldValue(fieldPathTemplate.newInstance(model).execute(), valueSource.copyAndResolve(model));
     }
 
+    /**
+     * Appends the provided value to the provided path in the document.
+     * Any non existing path element will be created.
+     * If the path identifies a list, the value will be appended to the existing list.
+     * If the path identifies a scalar, the scalar will be converted to a list and
+     * the provided value will be added to the newly created list.
+     * Supports multiple values too provided in forms of list, in that case all the values will be appended to the
+     * existing (or newly created) list.
+     * @param fieldPathTemplate Resolves to the path with dot-notation within the document
+     * @param valueSource The value source that will produce the value or values to append to the existing ones
+     * @param allowDuplicates When false, any values that already exist in the field will not be added
+     * @throws IllegalArgumentException if the path is null, empty or invalid.
+     */
+    public void appendFieldValue(TemplateScript.Factory fieldPathTemplate, ValueSource valueSource, boolean allowDuplicates) {
+        Map<String, Object> model = createTemplateModel();
+        appendFieldValue(fieldPathTemplate.newInstance(model).execute(), valueSource.copyAndResolve(model), allowDuplicates);
+    }
+
     /**
      * Sets the provided value to the provided path in the document.
      * Any non existing path element will be created.
@@ -452,6 +487,10 @@ public void setFieldValue(TemplateScript.Factory fieldPathTemplate, ValueSource
     }
 
     private void setFieldValue(String path, Object value, boolean append) {
+        setFieldValue(path, value, append, true);
+    }
+
+    private void setFieldValue(String path, Object value, boolean append, boolean allowDuplicates) {
         FieldPath fieldPath = new FieldPath(path);
         Object context = fieldPath.initialContext;
         for (int i = 0; i < fieldPath.pathElements.length - 1; i++) {
@@ -500,7 +539,7 @@ private void setFieldValue(String path, Object value, boolean append) {
             if (append) {
                 if (map.containsKey(leafKey)) {
                     Object object = map.get(leafKey);
-                    List<Object> list = appendValues(object, value);
+                    Object list = appendValues(object, value, allowDuplicates);
                     if (list != object) {
                         map.put(leafKey, list);
                     }
@@ -528,7 +567,7 @@ private void setFieldValue(String path, Object value, boolean append) {
             }
             if (append) {
                 Object object = list.get(index);
-                List<Object> newList = appendValues(object, value);
+                Object newList = appendValues(object, value, allowDuplicates);
                 if (newList != object) {
                     list.set(index, newList);
                 }
@@ -542,7 +581,7 @@ private void setFieldValue(String path, Object value, boolean append) {
     }
 
     @SuppressWarnings("unchecked")
-    private static List<Object> appendValues(Object maybeList, Object value) {
+    private static Object appendValues(Object maybeList, Object value, boolean allowDuplicates) {
         List<Object> list;
         if (maybeList instanceof List) {
             //maybeList is already a list, we append the provided values to it
@@ -552,8 +591,13 @@ private static List<Object> appendValues(Object maybeList, Object value) {
             list = new ArrayList<>();
             list.add(maybeList);
         }
-        appendValues(list, value);
-        return list;
+        if (allowDuplicates) {
+            appendValues(list, value);
+            return list;
+        } else {
+            // if no values were appended due to duplication, return the original object so the ingest document remains unmodified
+            return appendValuesWithoutDuplicates(list, value) ? list : maybeList;
+        }
     }
 
     private static void appendValues(List<Object> list, Object value) {
@@ -564,6 +608,25 @@ private static void appendValues(List<Object> list, Object value) {
         }
     }
 
+    private static boolean appendValuesWithoutDuplicates(List<Object> list, Object value) {
+        boolean valuesWereAppended = false;
+        if (value instanceof List) {
+            List<?> valueList = (List<?>) value;
+            for (Object val : valueList) {
+                if (list.contains(val) == false) {
+                    list.add(val);
+                    valuesWereAppended = true;
+                }
+            }
+        } else {
+            if (list.contains(value) == false) {
+                list.add(value);
+                valuesWereAppended = true;
+            }
+        }
+        return valuesWereAppended;
+    }
+
     private static <T> T cast(String path, Object object, Class<T> clazz) {
         if (object == null) {
             return null;