Feat/hunspell cache api

CHANGELOG.md

@@ -21,6 +21,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - WLM group custom search settings - groundwork and timeout ([#20536](https://github.com/opensearch-project/OpenSearch/issues/20536))
 - Expose JVM runtime metrics via telemetry framework ([#20844](https://github.com/opensearch-project/OpenSearch/pull/20844))
 - Add intra segment support for single-value metric aggregations ([#20503](https://github.com/opensearch-project/OpenSearch/pull/20503))
+- Add ref_path support for package-based hunspell dictionary loading ([#20840](https://github.com/opensearch-project/OpenSearch/pull/20840))
 
 ### Changed
 - Make telemetry `Tags` immutable ([#20788](https://github.com/opensearch-project/OpenSearch/pull/20788))

server/src/internalClusterTest/java/org/opensearch/action/admin/indices/cache/hunspell/HunspellCacheIT.java

@@ -0,0 +1,155 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.action.admin.indices.cache.hunspell;
+
+import org.opensearch.common.settings.Settings;
+import org.opensearch.indices.analysis.HunspellService;
+import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.OpenSearchIntegTestCase.ClusterScope;
+
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.greaterThanOrEqualTo;
+
+/**
+ * Integration tests for hunspell cache info and invalidation APIs.
+ *
+ * <p>Tests the full REST→Transport→HunspellService flow on a real cluster:
+ * <ul>
+ *   <li>GET /_hunspell/cache (HunspellCacheInfoAction)</li>
+ *   <li>POST /_hunspell/cache/_invalidate (HunspellCacheInvalidateAction)</li>
+ * </ul>
+ */
+@ClusterScope(scope = OpenSearchIntegTestCase.Scope.TEST)
+public class HunspellCacheIT extends OpenSearchIntegTestCase {
+
+    @Override
+    protected Settings nodeSettings(int nodeOrdinal) {
+        // Enable lazy loading so dictionaries are only loaded on-demand
+        return Settings.builder().put(super.nodeSettings(nodeOrdinal)).put(HunspellService.HUNSPELL_LAZY_LOAD.getKey(), true).build();
+    }
+
+    // ==================== Cache Info Tests ====================
+
+    public void testCacheInfoReturnsEmptyWhenNoDictionariesLoaded() {
+        HunspellCacheInfoResponse response = client().execute(HunspellCacheInfoAction.INSTANCE, new HunspellCacheInfoRequest()).actionGet();
+
+        assertThat(response.getTotalCachedCount(), equalTo(0));
+        assertThat(response.getPackageBasedCount(), equalTo(0));
+        assertThat(response.getTraditionalLocaleCount(), equalTo(0));
+        assertTrue(response.getPackageBasedKeys().isEmpty());
+        assertTrue(response.getTraditionalLocaleKeys().isEmpty());
+    }
+
+    // ==================== Cache Invalidation Tests ====================
+
+    public void testInvalidateAllOnEmptyCache() {
+        HunspellCacheInvalidateRequest request = new HunspellCacheInvalidateRequest();
+        request.setInvalidateAll(true);
+
+        HunspellCacheInvalidateResponse response = client().execute(HunspellCacheInvalidateAction.INSTANCE, request).actionGet();
+
+        assertTrue(response.isAcknowledged());
+        assertThat(response.getInvalidatedCount(), equalTo(0));
+    }
+
+    public void testInvalidateByPackageIdOnEmptyCache() {
+        HunspellCacheInvalidateRequest request = new HunspellCacheInvalidateRequest();
+        request.setPackageId("nonexistent-pkg");
+
+        HunspellCacheInvalidateResponse response = client().execute(HunspellCacheInvalidateAction.INSTANCE, request).actionGet();
+
+        assertTrue(response.isAcknowledged());
+        assertThat(response.getInvalidatedCount(), equalTo(0));
+        assertThat(response.getPackageId(), equalTo("nonexistent-pkg"));
+    }
+
+    public void testInvalidateByCacheKeyOnEmptyCache() {
+        HunspellCacheInvalidateRequest request = new HunspellCacheInvalidateRequest();
+        request.setCacheKey("nonexistent-key");
+
+        HunspellCacheInvalidateResponse response = client().execute(HunspellCacheInvalidateAction.INSTANCE, request).actionGet();
+
+        assertTrue(response.isAcknowledged());
+        assertThat(response.getInvalidatedCount(), equalTo(0));
+    }
+
+    // ==================== Request Validation Tests ====================
+
+    public void testInvalidateRequestValidationFailsWithNoParameters() {
+        HunspellCacheInvalidateRequest request = new HunspellCacheInvalidateRequest();
+        // No parameters set — should fail validation
+
+        assertNotNull(request.validate());
+    }
+
+    public void testInvalidateRequestValidationFailsWithConflictingParameters() {
+        HunspellCacheInvalidateRequest request = new HunspellCacheInvalidateRequest();
+        request.setInvalidateAll(true);
+        request.setPackageId("some-pkg");
+
+        assertNotNull(request.validate());
+    }
+
+    public void testInvalidateRequestValidationFailsWithEmptyPackageId() {
+        HunspellCacheInvalidateRequest request = new HunspellCacheInvalidateRequest();
+        request.setPackageId("   ");
+
+        assertNotNull(request.validate());
+    }
+
+    public void testInvalidateRequestValidationPassesWithPackageIdOnly() {
+        HunspellCacheInvalidateRequest request = new HunspellCacheInvalidateRequest();
+        request.setPackageId("valid-pkg");
+
+        assertNull(request.validate());
+    }
+
+    public void testInvalidateRequestValidationPassesWithPackageIdAndLocale() {
+        HunspellCacheInvalidateRequest request = new HunspellCacheInvalidateRequest();
+        request.setPackageId("valid-pkg");
+        request.setLocale("en_US");
+
+        assertNull(request.validate());
+    }
+
+    public void testInvalidateRequestValidationFailsWithLocaleWithoutPackageId() {
+        HunspellCacheInvalidateRequest request = new HunspellCacheInvalidateRequest();
+        request.setLocale("en_US");
+
+        assertNotNull(request.validate());
+    }
+
+    // ==================== Response Schema Tests ====================
+
+    public void testInvalidateResponseAlwaysIncludesAllFields() {
+        HunspellCacheInvalidateRequest request = new HunspellCacheInvalidateRequest();
+        request.setInvalidateAll(true);
+
+        HunspellCacheInvalidateResponse response = client().execute(HunspellCacheInvalidateAction.INSTANCE, request).actionGet();
+
+        // Response should always include these fields for consistent schema
+        assertTrue(response.isAcknowledged());
+        assertThat(response.getInvalidatedCount(), greaterThanOrEqualTo(0));
+        // Null fields should still be accessible (consistent schema)
+        assertNull(response.getPackageId());
+        assertNull(response.getLocale());
+        assertNull(response.getCacheKey());
+    }
+
+    public void testCacheInfoResponseSchema() {
+        HunspellCacheInfoResponse response = client().execute(HunspellCacheInfoAction.INSTANCE, new HunspellCacheInfoRequest()).actionGet();
+
+        // Verify response schema has all expected fields
+        assertThat(response.getTotalCachedCount(), greaterThanOrEqualTo(0));
+        assertThat(response.getPackageBasedCount(), greaterThanOrEqualTo(0));
+        assertThat(response.getTraditionalLocaleCount(), greaterThanOrEqualTo(0));
+        assertNotNull(response.getPackageBasedKeys());
+        assertNotNull(response.getTraditionalLocaleKeys());
+    }
+}

server/src/main/java/org/opensearch/action/ActionModule.java

@@ -138,6 +138,10 @@
 import org.opensearch.action.admin.indices.analyze.TransportAnalyzeAction;
 import org.opensearch.action.admin.indices.cache.clear.ClearIndicesCacheAction;
 import org.opensearch.action.admin.indices.cache.clear.TransportClearIndicesCacheAction;
+import org.opensearch.action.admin.indices.cache.hunspell.HunspellCacheInfoAction;
+import org.opensearch.action.admin.indices.cache.hunspell.HunspellCacheInvalidateAction;
+import org.opensearch.action.admin.indices.cache.hunspell.TransportHunspellCacheInfoAction;
+import org.opensearch.action.admin.indices.cache.hunspell.TransportHunspellCacheInvalidateAction;
 import org.opensearch.action.admin.indices.close.CloseIndexAction;
 import org.opensearch.action.admin.indices.close.TransportCloseIndexAction;
 import org.opensearch.action.admin.indices.create.AutoCreateAction;
@@ -333,6 +337,7 @@
 import org.opensearch.identity.IdentityService;
 import org.opensearch.index.seqno.RetentionLeaseActions;
 import org.opensearch.indices.SystemIndices;
+import org.opensearch.indices.analysis.HunspellService;
 import org.opensearch.persistent.CompletionPersistentTaskAction;
 import org.opensearch.persistent.RemovePersistentTaskAction;
 import org.opensearch.persistent.StartPersistentTaskAction;
@@ -419,6 +424,7 @@
 import org.opensearch.rest.action.admin.indices.RestGetIngestionStateAction;
 import org.opensearch.rest.action.admin.indices.RestGetMappingAction;
 import org.opensearch.rest.action.admin.indices.RestGetSettingsAction;
+import org.opensearch.rest.action.admin.indices.RestHunspellCacheInvalidateAction;
 import org.opensearch.rest.action.admin.indices.RestIndexDeleteAliasesAction;
 import org.opensearch.rest.action.admin.indices.RestIndexPutAliasAction;
 import org.opensearch.rest.action.admin.indices.RestIndicesAliasesAction;
@@ -557,6 +563,7 @@ public class ActionModule extends AbstractModule {
     private final ThreadPool threadPool;
     private final ExtensionsManager extensionsManager;
     private final ResponseLimitSettings responseLimitSettings;
+    private final HunspellService hunspellService;
 
     public ActionModule(
         Settings settings,
@@ -571,7 +578,8 @@ public ActionModule(
         UsageService usageService,
         SystemIndices systemIndices,
         IdentityService identityService,
-        ExtensionsManager extensionsManager
+        ExtensionsManager extensionsManager,
+        HunspellService hunspellService
     ) {
         this.settings = settings;
         this.indexNameExpressionResolver = indexNameExpressionResolver;
@@ -581,6 +589,7 @@ public ActionModule(
         this.actionPlugins = actionPlugins;
         this.threadPool = threadPool;
         this.extensionsManager = extensionsManager;
+        this.hunspellService = hunspellService;
         actions = setupActions(actionPlugins);
         actionFilters = setupActionFilters(actionPlugins);
         dynamicActionRegistry = new DynamicActionRegistry();
@@ -725,6 +734,8 @@ public <Request extends ActionRequest, Response extends ActionResponse> void reg
         actions.register(UpgradeStatusAction.INSTANCE, TransportUpgradeStatusAction.class);
         actions.register(UpgradeSettingsAction.INSTANCE, TransportUpgradeSettingsAction.class);
         actions.register(ClearIndicesCacheAction.INSTANCE, TransportClearIndicesCacheAction.class);
+        actions.register(HunspellCacheInfoAction.INSTANCE, TransportHunspellCacheInfoAction.class);
+        actions.register(HunspellCacheInvalidateAction.INSTANCE, TransportHunspellCacheInvalidateAction.class);
         actions.register(GetAliasesAction.INSTANCE, TransportGetAliasesAction.class);
         actions.register(GetSettingsAction.INSTANCE, TransportGetSettingsAction.class);
 
@@ -1075,6 +1086,9 @@ public void initRestHandlers(Supplier<DiscoveryNodes> nodesInCluster) {
         registerHandler.accept(new RestPauseIngestionAction());
         registerHandler.accept(new RestResumeIngestionAction());
         registerHandler.accept(new RestGetIngestionStateAction());
+
+        // Hunspell cache management API
+        registerHandler.accept(new RestHunspellCacheInvalidateAction());
     }
 
     @Override
@@ -1110,6 +1124,15 @@ protected void configure() {
         bind(DynamicActionRegistry.class).toInstance(dynamicActionRegistry);
 
         bind(ResponseLimitSettings.class).toInstance(responseLimitSettings);
+
+        // Bind HunspellService for TransportHunspellCacheInfoAction and TransportHunspellCacheInvalidateAction injection.
+        // HunspellService is always available since it's created by AnalysisModule during node bootstrap.
+        // The null check is a defensive guard for edge cases in testing or unusual configurations.
+        if (hunspellService != null) {
+            bind(HunspellService.class).toInstance(hunspellService);
+        } else {
+            logger.warn("HunspellService is null; hunspell cache management APIs will not be functional");
+        }
     }
 
     public ActionFilters getActionFilters() {

server/src/main/java/org/opensearch/action/admin/indices/cache/hunspell/HunspellCacheInfoAction.java

@@ -0,0 +1,28 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.action.admin.indices.cache.hunspell;
+
+import org.opensearch.action.ActionType;
+
+/**
+ * Action for retrieving Hunspell cache information.
+ *
+ * <p>This action requires "cluster:monitor/hunspell/cache" permission when security is enabled.
+ *
+ * @opensearch.internal
+ */
+public class HunspellCacheInfoAction extends ActionType<HunspellCacheInfoResponse> {
+
+    public static final HunspellCacheInfoAction INSTANCE = new HunspellCacheInfoAction();
+    public static final String NAME = "cluster:monitor/hunspell/cache";
+
+    private HunspellCacheInfoAction() {
+        super(NAME, HunspellCacheInfoResponse::new);
+    }
+}

server/src/main/java/org/opensearch/action/admin/indices/cache/hunspell/HunspellCacheInfoRequest.java

@@ -0,0 +1,40 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.action.admin.indices.cache.hunspell;
+
+import org.opensearch.action.ActionRequest;
+import org.opensearch.action.ActionRequestValidationException;
+import org.opensearch.core.common.io.stream.StreamInput;
+import org.opensearch.core.common.io.stream.StreamOutput;
+
+import java.io.IOException;
+
+/**
+ * Request for retrieving Hunspell cache information.
+ *
+ * @opensearch.internal
+ */
+public class HunspellCacheInfoRequest extends ActionRequest {
+
+    public HunspellCacheInfoRequest() {}
+
+    public HunspellCacheInfoRequest(StreamInput in) throws IOException {
+        super(in);
+    }
+
+    @Override
+    public void writeTo(StreamOutput out) throws IOException {
+        super.writeTo(out);
+    }
+
+    @Override
+    public ActionRequestValidationException validate() {
+        return null;
+    }
+}