Modify PutObject API to add delete functionality

Author: G8XSU

app/src/main/java/org/vss/impl/postgres/PostgresBackendImpl.java

@@ -66,23 +66,31 @@ public PutObjectResponse put(PutObjectRequest request) {
 
     String storeId = request.getStoreId();
 
-    List<VssDbRecord> vssRecords = new ArrayList<>(request.getTransactionItemsList().stream()
+    List<VssDbRecord> vssPutRecords = new ArrayList<>(request.getTransactionItemsList().stream()
+        .map(kv -> buildVssRecord(storeId, kv)).toList());
+
+    List<VssDbRecord> vssDeleteRecords = new ArrayList<>(request.getDeleteItemsList().stream()
         .map(kv -> buildVssRecord(storeId, kv)).toList());
 
     if (request.hasGlobalVersion()) {
       VssDbRecord globalVersionRecord = buildVssRecord(storeId,
           KeyValue.newBuilder()
               .setKey(GLOBAL_VERSION_KEY)
               .setVersion(request.getGlobalVersion())
+              .setValue(ByteString.EMPTY)
               .build());
 
-      vssRecords.add(globalVersionRecord);
+      vssPutRecords.add(globalVersionRecord);
     }
 
     context.transaction((ctx) -> {
       DSLContext dsl = ctx.dsl();
-      List<Query> batchQueries = vssRecords.stream()
-          .map(vssRecord -> buildPutObjectQuery(dsl, vssRecord)).toList();
+      List<Query> batchQueries = new ArrayList<>();
+
+      batchQueries.addAll(vssPutRecords.stream()
+          .map(vssRecord -> buildPutObjectQuery(dsl, vssRecord)).toList());
+      batchQueries.addAll(vssDeleteRecords.stream()
+          .map(vssRecord -> buildDeleteObjectQuery(dsl, vssRecord)).toList());
 
       int[] batchResult = dsl.batch(batchQueries).execute();
 
@@ -97,6 +105,12 @@ public PutObjectResponse put(PutObjectRequest request) {
     return PutObjectResponse.newBuilder().build();
   }
 
+  private Query buildDeleteObjectQuery(DSLContext dsl, VssDbRecord vssRecord) {
+    return dsl.deleteFrom(VSS_DB).where(VSS_DB.STORE_ID.eq(vssRecord.getStoreId())
+        .and(VSS_DB.KEY.eq(vssRecord.getKey()))
+        .and(VSS_DB.VERSION.eq(vssRecord.getVersion())));
+  }
+
   private Query buildPutObjectQuery(DSLContext dsl, VssDbRecord vssRecord) {
     return vssRecord.getVersion() == 0 ? buildInsertRecordQuery(dsl, vssRecord)
         : buildUpdateRecordQuery(dsl, vssRecord);