Make access pattern optional

Author: jbaiera

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

@@ -40,6 +40,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.Set;
 import java.util.function.BiConsumer;
 import java.util.stream.Collectors;
@@ -202,7 +203,7 @@ public <T> T getFieldValue(String path, Class<T> clazz) {
      * or if the field that is found at the provided path is not of the expected type.
      */
     public <T> T getFieldValue(String path, Class<T> clazz, boolean ignoreMissing) {
-        final FieldPath fieldPath = FieldPath.of(path, getCurrentAccessPattern());
+        final FieldPath fieldPath = FieldPath.of(path, getCurrentAccessPatternSafe());
         Object context = fieldPath.initialContext(this);
         ResolveResult result = resolve(fieldPath.pathElements, fieldPath.pathElements.length, path, context, getCurrentAccessPatternSafe());
         if (result.wasSuccessful) {
@@ -271,7 +272,7 @@ public boolean hasField(String path) {
      * @throws IllegalArgumentException if the path is null, empty or invalid.
      */
     public boolean hasField(String path, boolean failOutOfRange) {
-        final FieldPath fieldPath = FieldPath.of(path, getCurrentAccessPattern());
+        final FieldPath fieldPath = FieldPath.of(path, getCurrentAccessPatternSafe());
         Object context = fieldPath.initialContext(this);
         int leafKeyIndex = fieldPath.pathElements.length - 1;
         int lastContainerIndex = fieldPath.pathElements.length - 2;
@@ -425,7 +426,7 @@ public void removeField(String path) {
      * @throws IllegalArgumentException if the path is null, empty, or invalid; or if the field doesn't exist (and ignoreMissing is false).
      */
     public void removeField(String path, boolean ignoreMissing) {
-        final FieldPath fieldPath = FieldPath.of(path, getCurrentAccessPattern());
+        final FieldPath fieldPath = FieldPath.of(path, getCurrentAccessPatternSafe());
         Object context = fieldPath.initialContext(this);
         String leafKey = fieldPath.pathElements[fieldPath.pathElements.length - 1];
         ResolveResult result = resolve(
@@ -735,7 +736,7 @@ public void setFieldValue(String path, Object value, boolean ignoreEmptyValue) {
     }
 
     private void setFieldValue(String path, Object value, boolean append, boolean allowDuplicates) {
-        final FieldPath fieldPath = FieldPath.of(path, getCurrentAccessPattern());
+        final FieldPath fieldPath = FieldPath.of(path, getCurrentAccessPatternSafe());
         Object context = fieldPath.initialContext(this);
         int leafKeyIndex = fieldPath.pathElements.length - 1;
         int lastContainerIndex = fieldPath.pathElements.length - 2;
@@ -1154,18 +1155,18 @@ List<String> getPipelineStack() {
     }
 
     /**
-     * @return The access pattern for any currently executing pipelines, or null if no pipelines are in progress for this doc
+     * @return The access pattern for any currently executing pipelines, or empty if no pipelines are in progress for this doc
      */
-    public IngestPipelineFieldAccessPattern getCurrentAccessPattern() {
-        return accessPatternStack.peek();
+    public Optional<IngestPipelineFieldAccessPattern> getCurrentAccessPattern() {
+        return Optional.ofNullable(accessPatternStack.peek());
     }
 
     /**
      * @return The access pattern for any currently executing pipelines, or {@link IngestPipelineFieldAccessPattern#CLASSIC} if no
      * pipelines are in progress for this doc for the sake of backwards compatibility
      */
     private IngestPipelineFieldAccessPattern getCurrentAccessPatternSafe() {
-        return Objects.requireNonNullElse(getCurrentAccessPattern(), IngestPipelineFieldAccessPattern.CLASSIC);
+        return getCurrentAccessPattern().orElse(IngestPipelineFieldAccessPattern.CLASSIC);
     }
 
     /**

server/src/test/java/org/elasticsearch/ingest/IngestDocumentTests.java

@@ -2034,7 +2034,7 @@ public void testNestedAccessPatternPropagation() {
 
         // At the end of the test, there should be neither pipeline ids nor access patterns left in the stack.
         assertThat(document.getPipelineStack(), is(empty()));
-        assertThat(document.getCurrentAccessPattern(), is(nullValue()));
+        assertThat(document.getCurrentAccessPattern().isEmpty(), is(true));
     }
 
     /**
@@ -2082,7 +2082,8 @@ void doTestNestedAccessPatternPropagation(int level, int maxCallDepth, IngestDoc
 
             // Assert expected state
             assertThat(document.getPipelineStack().getFirst(), is(expectedPipelineId));
-            assertThat(document.getCurrentAccessPattern(), is(expectedAccessPattern));
+            assertThat(document.getCurrentAccessPattern().isPresent(), is(true));
+            assertThat(document.getCurrentAccessPattern().get(), is(expectedAccessPattern));
 
             // Randomly recurse: We recurse only one time per level to avoid hogging test time, but we randomize which
             // pipeline to recurse on, eventually requiring a recursion on the last pipeline run if one hasn't happened yet.
@@ -2099,11 +2100,11 @@ void doTestNestedAccessPatternPropagation(int level, int maxCallDepth, IngestDoc
             assertThat(document.getPipelineStack().size(), is(equalTo(level)));
             if (level == 0) {
                 // Top level means access pattern should be empty
-                assertThat(document.getCurrentAccessPattern(), is(nullValue()));
+                assertThat(document.getCurrentAccessPattern().isEmpty(), is(true));
             } else {
                 // If we're nested below the top level we should still have an access
                 // pattern on the document for the pipeline above us
-                assertThat(document.getCurrentAccessPattern(), is(not(nullValue())));
+                assertThat(document.getCurrentAccessPattern().isPresent(), is(true));
             }
         }
         logger.debug("LEVEL {}/{}: COMPLETE", level, maxCallDepth);