Prepare version storage

server/src/main/java/com/adobe/testing/s3mock/store/ObjectStore.java

@@ -54,6 +54,7 @@ public class ObjectStore extends StoreBase {
   private static final Logger LOG = LoggerFactory.getLogger(ObjectStore.class);
   private static final String META_FILE = "objectMetadata.json";
   private static final String DATA_FILE = "binaryData";
+  private static final String VERSIONS_FILE = "versions.json";
 
   /**
    * This map stores one lock object per S3Object ID.
@@ -471,11 +472,11 @@ private Path getObjectFolderPath(BucketMetadata bucket, UUID id) {
   }
 
   private Path getMetaFilePath(BucketMetadata bucket, UUID id) {
-    return Paths.get(getObjectFolderPath(bucket, id).toString(), META_FILE);
+    return getObjectFolderPath(bucket, id).resolve(META_FILE);
   }
 
   private Path getDataFilePath(BucketMetadata bucket, UUID id) {
-    return Paths.get(getObjectFolderPath(bucket, id).toString(), DATA_FILE);
+    return getObjectFolderPath(bucket, id).resolve(DATA_FILE);
   }
 
   private void writeMetafile(BucketMetadata bucket, S3ObjectMetadata s3ObjectMetadata) {

server/src/main/java/com/adobe/testing/s3mock/store/S3ObjectVersions.java

@@ -0,0 +1,44 @@
+/*************************************************************************
+ * ADOBE CONFIDENTIAL
+ * ___________________
+ *
+ * Copyright 2024 Adobe
+ * All Rights Reserved.
+ *
+ * NOTICE: All information contained herein is, and remains
+ * the property of Adobe and its suppliers, if any. The intellectual
+ * and technical concepts contained herein are proprietary to Adobe
+ * and its suppliers and are protected by all applicable intellectual
+ * property laws, including trade secret and copyright laws.
+ * Dissemination of this information or reproduction of this material
+ * is strictly forbidden unless prior written permission is obtained
+ * from Adobe.
+ **************************************************************************/
+
+package com.adobe.testing.s3mock.store;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.UUID;
+import java.util.concurrent.atomic.AtomicInteger;
+
+public record S3ObjectVersions(
+    UUID id,
+    Map<Integer, String> versions,
+    AtomicInteger latestVersionPointer
+) {
+
+  public S3ObjectVersions(UUID id) {
+    this(id, new HashMap<>(), new AtomicInteger(0));
+  }
+
+  public String createVersion() {
+    String versionId = UUID.randomUUID().toString();
+    versions.put(latestVersionPointer.incrementAndGet(), versionId);
+    return versionId;
+  }
+
+  public String getLatestVersion() {
+    return versions.get(latestVersionPointer.get());
+  }
+}

server/src/test/kotlin/com/adobe/testing/s3mock/store/S3ObjectVersionsTest.java

@@ -0,0 +1,21 @@
+package com.adobe.testing.s3mock.store;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.util.UUID;
+import org.junit.jupiter.api.Test;
+
+class S3ObjectVersionsTest {
+
+  @Test
+  void testVersions() {
+    var iut = new S3ObjectVersions(UUID.randomUUID());
+    assertThat(iut.getLatestVersion()).isNull();
+    assertThat(iut.latestVersionPointer().get()).isZero();
+
+    var version = iut.createVersion();
+    assertThat(version).isNotBlank();
+    assertThat(iut.latestVersionPointer().get()).isOne();
+    assertThat(iut.getLatestVersion()).isEqualTo(version);
+  }
+}