feat: add S3 SAIL with Parquet columnar storage engine

core/repository/api/src/main/resources/org/eclipse/rdf4j/repository/config/s3.ttl

@@ -0,0 +1,26 @@
+#
+# Configuration template for an S3Store
+#
+# S3 connection settings (bucket, endpoint, region, credentials) are configured
+# at the RDF4J instance level via environment variables or system properties:
+#
+#   RDF4J_S3_BUCKET, RDF4J_S3_ENDPOINT, RDF4J_S3_REGION,
+#   RDF4J_S3_ACCESS_KEY, RDF4J_S3_SECRET_KEY, RDF4J_S3_FORCE_PATH_STYLE
+#
+# Each repository uses s3Prefix to partition its data within the shared bucket.
+#
+@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#>.
+@prefix config: <tag:rdf4j.org,2023:config/>.
+@prefix s3: <http://rdf4j.org/config/sail/s3#>.
+
+[] a config:Repository ;
+   config:rep.id "{%Repository ID|s3%}" ;
+   rdfs:label "{%Repository title|S3 Store%}" ;
+   config:rep.impl [
+      config:rep.type "openrdf:SailRepository" ;
+      config:sail.impl [
+         config:sail.type "rdf4j:S3Store" ;
+         s3:s3Prefix "{%S3 Prefix|%}" ;
+         s3:dataDir "{%Data Directory|%}"
+      ]
+   ].

core/sail/pom.xml

@@ -19,6 +19,7 @@
 		<module>model</module>
 		<module>shacl</module>
 		<module>lmdb</module>
+		<module>s3</module>
 		<module>lucene-api</module>
 		<module>lucene</module>
 		<module>elasticsearch</module>

core/sail/s3/docker-compose.yml

@@ -0,0 +1,32 @@
+services:
+  minio:
+    image: minio/minio:latest
+    ports:
+      - "9000:9000"
+      - "9001:9001"
+    environment:
+      MINIO_ROOT_USER: minioadmin
+      MINIO_ROOT_PASSWORD: minioadmin
+    command: server /data --console-address ":9001"
+    volumes:
+      - minio-data:/data
+    healthcheck:
+      test: ["CMD", "mc", "ready", "local"]
+      interval: 5s
+      timeout: 5s
+      retries: 5
+
+  createbucket:
+    image: minio/mc:latest
+    depends_on:
+      minio:
+        condition: service_healthy
+    entrypoint: >
+      /bin/sh -c "
+      mc alias set local http://minio:9000 minioadmin minioadmin;
+      mc mb --ignore-existing local/rdf4j-data;
+      echo 'Bucket ready';
+      "
+
+volumes:
+  minio-data:

core/sail/s3/pom.xml

@@ -0,0 +1,111 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>org.eclipse.rdf4j</groupId>
+		<artifactId>rdf4j-sail</artifactId>
+		<version>6.0.0-SNAPSHOT</version>
+	</parent>
+	<artifactId>rdf4j-sail-s3</artifactId>
+	<name>RDF4J: S3Store</name>
+	<description>Sail implementation that stores data on S3-compatible object storage using an LSM-tree.</description>
+	<dependencies>
+		<dependency>
+			<groupId>${project.groupId}</groupId>
+			<artifactId>rdf4j-sail-base</artifactId>
+			<version>${project.version}</version>
+		</dependency>
+		<dependency>
+			<groupId>${project.groupId}</groupId>
+			<artifactId>rdf4j-queryalgebra-evaluation</artifactId>
+			<version>${project.version}</version>
+		</dependency>
+		<dependency>
+			<groupId>${project.groupId}</groupId>
+			<artifactId>rdf4j-queryalgebra-model</artifactId>
+			<version>${project.version}</version>
+		</dependency>
+		<dependency>
+			<groupId>${project.groupId}</groupId>
+			<artifactId>rdf4j-query</artifactId>
+			<version>${project.version}</version>
+		</dependency>
+		<dependency>
+			<groupId>${project.groupId}</groupId>
+			<artifactId>rdf4j-model</artifactId>
+			<version>${project.version}</version>
+		</dependency>
+		<dependency>
+			<groupId>io.minio</groupId>
+			<artifactId>minio</artifactId>
+			<version>8.5.7</version>
+		</dependency>
+		<dependency>
+			<groupId>org.slf4j</groupId>
+			<artifactId>slf4j-api</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>com.google.guava</groupId>
+			<artifactId>guava</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>com.fasterxml.jackson.core</groupId>
+			<artifactId>jackson-databind</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.apache.parquet</groupId>
+			<artifactId>parquet-hadoop</artifactId>
+			<version>1.15.2</version>
+			<exclusions>
+				<exclusion>
+					<groupId>javax.annotation</groupId>
+					<artifactId>javax.annotation-api</artifactId>
+				</exclusion>
+			</exclusions>
+		</dependency>
+		<!-- No Hadoop jars needed. Parquet-hadoop references a few Hadoop classes
+		     in method signatures and superclass declarations, but we bypass all
+		     Hadoop runtime paths via PlainParquetConfiguration + SimpleCodecFactory.
+		     Minimal stub classes in org.apache.hadoop.* satisfy JVM class loading. -->
+		<dependency>
+			<groupId>com.github.ben-manes.caffeine</groupId>
+			<artifactId>caffeine</artifactId>
+			<version>3.1.8</version>
+		</dependency>
+		<dependency>
+			<groupId>${project.groupId}</groupId>
+			<artifactId>rdf4j-sail-testsuite</artifactId>
+			<version>${project.version}</version>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>${project.groupId}</groupId>
+			<artifactId>rdf4j-repository-testsuite</artifactId>
+			<version>${project.version}</version>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>${project.groupId}</groupId>
+			<artifactId>rdf4j-repository-sail</artifactId>
+			<version>${project.version}</version>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.junit.jupiter</groupId>
+			<artifactId>junit-jupiter-params</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.testcontainers</groupId>
+			<artifactId>testcontainers</artifactId>
+			<version>${testcontainers.version}</version>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.testcontainers</groupId>
+			<artifactId>testcontainers-junit-jupiter</artifactId>
+			<version>${testcontainers.version}</version>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+</project>

core/sail/s3/src/main/java/org/apache/hadoop/conf/Configuration.java

@@ -0,0 +1,22 @@
+/*******************************************************************************
+ * Copyright (c) 2025 Eclipse RDF4J contributors.
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Distribution License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *******************************************************************************/
+// Minimal stub for org.apache.hadoop.conf.Configuration.
+// Parquet-hadoop references this class in abstract method signatures
+// (WriteSupport.init, ParquetWriter.Builder.getWriteSupport). Our code
+// overrides the ParquetConfiguration variants instead, so this class is
+// never instantiated or used at runtime. It exists only to satisfy the
+// JVM class loader.
+package org.apache.hadoop.conf;
+
+public class Configuration {
+	public Configuration() {
+	}
+}

core/sail/s3/src/main/java/org/apache/hadoop/fs/FileStatus.java

@@ -0,0 +1,16 @@
+/*******************************************************************************
+ * Copyright (c) 2025 Eclipse RDF4J contributors.
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Distribution License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *******************************************************************************/
+// Minimal stub — satisfies JVM class loading for parquet-hadoop.
+// Never instantiated at runtime.
+package org.apache.hadoop.fs;
+
+public class FileStatus {
+}

core/sail/s3/src/main/java/org/apache/hadoop/fs/FileSystem.java

@@ -0,0 +1,16 @@
+/*******************************************************************************
+ * Copyright (c) 2025 Eclipse RDF4J contributors.
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Distribution License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *******************************************************************************/
+// Minimal stub — satisfies JVM class loading for parquet-hadoop.
+// Never instantiated at runtime.
+package org.apache.hadoop.fs;
+
+public abstract class FileSystem {
+}

core/sail/s3/src/main/java/org/apache/hadoop/fs/Path.java

@@ -0,0 +1,16 @@
+/*******************************************************************************
+ * Copyright (c) 2025 Eclipse RDF4J contributors.
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Distribution License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *******************************************************************************/
+// Minimal stub — satisfies JVM class loading for parquet-hadoop.
+// Never instantiated at runtime.
+package org.apache.hadoop.fs;
+
+public class Path {
+}

core/sail/s3/src/main/java/org/apache/hadoop/fs/PathFilter.java

@@ -0,0 +1,16 @@
+/*******************************************************************************
+ * Copyright (c) 2025 Eclipse RDF4J contributors.
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Distribution License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *******************************************************************************/
+// Minimal stub — satisfies JVM class loading for parquet-hadoop.
+// Never instantiated at runtime.
+package org.apache.hadoop.fs;
+
+public interface PathFilter {
+}

core/sail/s3/src/main/java/org/apache/hadoop/mapred/JobConf.java

@@ -0,0 +1,18 @@
+/*******************************************************************************
+ * Copyright (c) 2025 Eclipse RDF4J contributors.
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Distribution License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *******************************************************************************/
+// Minimal stub — satisfies JVM class loading for parquet-hadoop.
+// Never instantiated at runtime.
+package org.apache.hadoop.mapred;
+
+import org.apache.hadoop.conf.Configuration;
+
+public class JobConf extends Configuration {
+}

core/sail/s3/src/main/java/org/apache/hadoop/mapreduce/InputFormat.java

@@ -0,0 +1,16 @@
+/*******************************************************************************
+ * Copyright (c) 2025 Eclipse RDF4J contributors.
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Distribution License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *******************************************************************************/
+// Minimal stub — satisfies JVM class loading for parquet-hadoop.
+// Never instantiated at runtime.
+package org.apache.hadoop.mapreduce;
+
+public abstract class InputFormat<K, V> {
+}

core/sail/s3/src/main/java/org/apache/hadoop/mapreduce/InputSplit.java

@@ -0,0 +1,16 @@
+/*******************************************************************************
+ * Copyright (c) 2025 Eclipse RDF4J contributors.
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Distribution License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *******************************************************************************/
+// Minimal stub — satisfies JVM class loading for parquet-hadoop.
+// Never instantiated at runtime.
+package org.apache.hadoop.mapreduce;
+
+public abstract class InputSplit {
+}

core/sail/s3/src/main/java/org/apache/hadoop/mapreduce/Job.java

@@ -0,0 +1,16 @@
+/*******************************************************************************
+ * Copyright (c) 2025 Eclipse RDF4J contributors.
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Distribution License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *******************************************************************************/
+// Minimal stub — satisfies JVM class loading for parquet-hadoop.
+// Never instantiated at runtime.
+package org.apache.hadoop.mapreduce;
+
+public class Job {
+}

core/sail/s3/src/main/java/org/apache/hadoop/mapreduce/JobContext.java

@@ -0,0 +1,16 @@
+/*******************************************************************************
+ * Copyright (c) 2025 Eclipse RDF4J contributors.
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Distribution License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *******************************************************************************/
+// Minimal stub — satisfies JVM class loading for parquet-hadoop.
+// Never instantiated at runtime.
+package org.apache.hadoop.mapreduce;
+
+public interface JobContext {
+}

core/sail/s3/src/main/java/org/apache/hadoop/mapreduce/RecordReader.java

@@ -0,0 +1,16 @@
+/*******************************************************************************
+ * Copyright (c) 2025 Eclipse RDF4J contributors.
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Distribution License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *******************************************************************************/
+// Minimal stub — satisfies JVM class loading for parquet-hadoop.
+// Never instantiated at runtime.
+package org.apache.hadoop.mapreduce;
+
+public abstract class RecordReader<K, V> {
+}

core/sail/s3/src/main/java/org/apache/hadoop/mapreduce/TaskAttemptContext.java

@@ -0,0 +1,16 @@
+/*******************************************************************************
+ * Copyright (c) 2025 Eclipse RDF4J contributors.
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Distribution License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *******************************************************************************/
+// Minimal stub — satisfies JVM class loading for parquet-hadoop.
+// Never instantiated at runtime.
+package org.apache.hadoop.mapreduce;
+
+public interface TaskAttemptContext extends JobContext {
+}