draft for gbh

.gitignore

@@ -1,7 +1,8 @@
 .claude
 CLAUDE.md
 .cursor*
-
+.kiro/
+**/target/**
 # intellij files
 .idea/
 *.iml
@@ -68,3 +69,4 @@ testfixtures_shared/
 
 # build files generated
 doc-tools/missing-doclet/bin/
+/sandbox/plugins/engine-datafusion/target/

gradle/run.gradle

@@ -60,7 +60,9 @@ testClusters {
       for (String p : installedPlugins) {
         // check if its a local plugin first
         if (project.findProject(':plugins:' + p) != null) {
-          plugin('plugins:' + p)
+          plugin(':plugins:' + p)
+        } else if (project.findProject(':sandbox:plugins:' + p) != null) {
+          plugin(':sandbox:plugins:' + p)
         } else {
           // attempt to fetch it from maven
           project.repositories.mavenLocal()

libs/common/src/main/java/org/opensearch/common/CheckedTriFunction.java

@@ -8,11 +8,14 @@
 
 package org.opensearch.common;
 
+import org.opensearch.common.annotation.ExperimentalApi;
+
 /**
  * A {@link TriFunction}-like interface which allows throwing checked exceptions.
  *
  * @opensearch.internal
  */
+@ExperimentalApi
 @FunctionalInterface
 public interface CheckedTriFunction<S, T, U, R, E extends Exception> {
     R apply(S s, T t, U u) throws E;

sandbox/libs/analytics-framework/build.gradle

@@ -14,7 +14,16 @@
 
 def calciteVersion = '1.41.0'
 
+// Guava comes transitively from calcite-core — forbidden on compile classpaths by OpenSearch.
+// Bypass via custom config for classes that extend Calcite types referencing ImmutableList.
+configurations {
+  calciteCompile
+}
+sourceSets.main.compileClasspath += configurations.calciteCompile
+
 dependencies {
+  calciteCompile "com.google.guava:guava:${versions.guava}"
+  compileOnly project(':server')
   api "org.apache.calcite:calcite-core:${calciteVersion}"
   // Calcite's expression tree and Enumerable runtime — required by calcite-core API
   api "org.apache.calcite:calcite-linq4j:${calciteVersion}"
@@ -26,6 +35,30 @@ dependencies {
   // SLF4J — Calcite's logging facade
   runtimeOnly "org.slf4j:slf4j-api:${versions.slf4j}"
 
+  // Calcite optional deps required at runtime — BuiltInMethod.<clinit> reflectively loads ALL
+  // methods which triggers class loading for every type referenced in Calcite's SqlFunctions.
+  // Every single one of these is needed or the class initializer fails with NoClassDefFoundError.
+  runtimeOnly "commons-codec:commons-codec:${versions.commonscodec}"
+  runtimeOnly "org.codehaus.janino:janino:3.1.12"
+  runtimeOnly "org.codehaus.janino:commons-compiler:3.1.12"
+  runtimeOnly 'org.jooq:joou-java-6:0.9.4'
+  runtimeOnly "com.fasterxml.jackson.core:jackson-core:${versions.jackson}"
+  runtimeOnly "com.fasterxml.jackson.core:jackson-databind:${versions.jackson_databind}"
+  runtimeOnly "com.fasterxml.jackson.core:jackson-annotations:${versions.jackson_annotations}"
+  runtimeOnly "org.apache.commons:commons-lang3:${versions.commonslang}"
+  runtimeOnly 'org.apache.commons:commons-text:1.11.0'
+  runtimeOnly 'org.apache.commons:commons-math3:3.6.1'
+  runtimeOnly 'org.immutables:value-annotations:2.8.8'
+  runtimeOnly 'com.jayway.jsonpath:json-path:2.9.0'
+  runtimeOnly "net.minidev:json-smart:${versions.json_smart}"
+  runtimeOnly 'net.minidev:accessors-smart:2.5.2'
+  runtimeOnly 'org.ow2.asm:asm:9.7.1'
+  runtimeOnly 'org.apache.calcite.avatica:avatica-metrics:1.27.0'
+  runtimeOnly "org.locationtech.jts:jts-core:${versions.jts}"
+  runtimeOnly 'org.locationtech.jts.io:jts-io-common:1.19.0'
+  runtimeOnly 'org.locationtech.proj4j:proj4j:1.2.2'
+  runtimeOnly 'com.google.uzaygezen:uzaygezen-core:0.2'
+
   // Calcite bytecode references annotations from apiguardian (@API) and
   // checker-framework (@EnsuresNonNullIf). compileOnlyApi propagates to
   // consumers' compile/javadoc classpath without becoming a runtime dep.
@@ -35,7 +68,7 @@ dependencies {
 
 testingConventions.enabled = false
 
-// analytics-framework does not depend on server
+// analytics-framework depends on server for SearchAnalyticsBackEndPlugin SPI
 tasks.named('forbiddenApisMain').configure {
   replaceSignatureFiles 'jdk-signatures'
   failOnMissingClasses = false

sandbox/libs/analytics-framework/src/main/java/org/opensearch/analytics/backend/EngineResultBatch.java

@@ -0,0 +1,39 @@
+/*
+ * 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.analytics.backend;
+
+import java.util.List;
+
+/**
+ * Read-only view of a single record batch. Provides field names, row count,
+ * and positional access to field values.
+ *
+ * @opensearch.internal
+ */
+public interface EngineResultBatch {
+
+    /**
+     * Ordered list of field (column) names in this batch.
+     */
+    List<String> getFieldNames();
+
+    /**
+     * Number of rows in this batch.
+     */
+    int getRowCount();
+
+    /**
+     * Returns the value at the given row index for the named field.
+     *
+     * @param fieldName column name
+     * @param rowIndex  zero-based row index
+     * @return the value (may be null)
+     */
+    Object getFieldValue(String fieldName, int rowIndex);
+}

sandbox/libs/analytics-framework/src/main/java/org/opensearch/analytics/backend/EngineResultBatchIterator.java

@@ -0,0 +1,18 @@
+/*
+ * 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.analytics.backend;
+
+import java.util.Iterator;
+
+/**
+ * Single-pass iterator over record batches from an {@link EngineResultStream}.
+ *
+ * @opensearch.internal
+ */
+public interface EngineResultBatchIterator extends Iterator<EngineResultBatch> {}

sandbox/libs/analytics-framework/src/main/java/org/opensearch/analytics/backend/EngineResultStream.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.analytics.backend;
+
+/**
+ * A closeable stream of record batches returned by engine execution.
+ * Callers iterate batches via the returned iterator and MUST close the stream
+ * when done to release native resources.
+ *
+ * @opensearch.internal
+ */
+public interface EngineResultStream extends AutoCloseable {
+
+    /**
+     * Returns an iterator over the record batches in this stream.
+     * Each call returns the same iterator instance — the stream is single-pass.
+     */
+    EngineResultBatchIterator iterator();
+
+    @Override
+    void close();
+}

sandbox/libs/analytics-framework/src/main/java/org/opensearch/analytics/backend/ExecutionContext.java

@@ -0,0 +1,56 @@
+/*
+ * 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.analytics.backend;
+
+import org.opensearch.analytics.delegation.DelegationContext;
+import org.opensearch.analytics.plan.ResolvedPlan;
+import org.opensearch.index.engine.DataFormatAwareEngine;
+import org.opensearch.plugins.ReaderManagerProvider;
+
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+/**
+ * Execution context carrying plan, reader, and delegation state through
+ * the query execution lifecycle.
+ *
+ * @opensearch.internal
+ */
+public class ExecutionContext {
+
+    private final ResolvedPlan plan;
+    private final String tableName;
+    private DelegationContext delegationContext;
+    private ReaderProvider readerProvider;
+
+    public ExecutionContext(ResolvedPlan plan, String tableName) {
+        this.plan = plan;
+        this.tableName = tableName;
+    }
+
+    public ResolvedPlan plan() {
+        return plan;
+    }
+
+    public String getTableName() {
+        return tableName;
+    }
+
+    public void setDelegationContext(DelegationContext delegationContext) {
+        this.delegationContext = delegationContext;
+    }
+
+    public boolean hasDelegation() {
+        return delegationContext != null && delegationContext.hasDelegation();
+    }
+
+    public DelegationContext getDelegationContext() {
+        return delegationContext;
+    }
+}

sandbox/libs/analytics-framework/src/main/java/org/opensearch/analytics/backend/SearchExecEngine.java

@@ -0,0 +1,36 @@
+/*
+ * 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.analytics.backend;
+
+import org.opensearch.analytics.plan.ResolvedPlan;
+import org.opensearch.common.annotation.ExperimentalApi;
+
+import java.io.Closeable;
+import java.io.IOException;
+
+/**
+ * Shard-level search execution engine interface.
+ * @opensearch.experimental
+ */
+@ExperimentalApi
+public interface SearchExecEngine extends Closeable {
+
+    /**
+     * Creates an execution context from a resolved plan.
+     *
+     * @param context               ExecutionContext
+     */
+    void prepare(ExecutionContext context);
+
+    /** Executes the context and returns a result stream. */
+    EngineResultStream execute(ExecutionContext context) throws IOException;
+
+    @Override
+    default void close() throws IOException {}
+}