[POC] Optimistic Locking for Delete Operations

Author: anasatirbasa

services-custom/dynamodb-enhanced/src/main/java/software/amazon/awssdk/enhanced/dynamodb/internal/client/DefaultDynamoDbAsyncTable.java

@@ -16,7 +16,7 @@
 package software.amazon.awssdk.enhanced.dynamodb.internal.client;
 
 import static software.amazon.awssdk.enhanced.dynamodb.internal.EnhancedClientUtils.createKeyFromItem;
-import static software.amazon.awssdk.enhanced.dynamodb.model.OptimisticLockingHelper.applyOptimisticLockingIfApplicable;
+import static software.amazon.awssdk.enhanced.dynamodb.model.OptimisticLockingHelper.conditionallyApplyOptimisticLocking;
 
 import java.util.ArrayList;
 import java.util.concurrent.CompletableFuture;
@@ -54,7 +54,6 @@
 import software.amazon.awssdk.enhanced.dynamodb.model.UpdateItemEnhancedRequest;
 import software.amazon.awssdk.enhanced.dynamodb.model.UpdateItemEnhancedResponse;
 import software.amazon.awssdk.services.dynamodb.DynamoDbAsyncClient;
-import software.amazon.awssdk.services.dynamodb.model.AttributeValue;
 import software.amazon.awssdk.services.dynamodb.model.DescribeTableRequest;
 import software.amazon.awssdk.services.dynamodb.model.DescribeTableResponse;
 
@@ -172,7 +171,7 @@ public CompletableFuture<T> deleteItem(T keyItem) {
      */
     public CompletableFuture<T> deleteItem(T keyItem, boolean useOptimisticLocking) {
         DeleteItemEnhancedRequest request = DeleteItemEnhancedRequest.builder().key(keyFrom(keyItem)).build();
-        request = applyOptimisticLockingIfApplicable(request, keyItem, tableSchema, useOptimisticLocking);
+        request = conditionallyApplyOptimisticLocking(request, keyItem, tableSchema, useOptimisticLocking);
         return deleteItem(request);
     }
 

services-custom/dynamodb-enhanced/src/main/java/software/amazon/awssdk/enhanced/dynamodb/internal/client/DefaultDynamoDbTable.java

@@ -16,7 +16,7 @@
 package software.amazon.awssdk.enhanced.dynamodb.internal.client;
 
 import static software.amazon.awssdk.enhanced.dynamodb.internal.EnhancedClientUtils.createKeyFromItem;
-import static software.amazon.awssdk.enhanced.dynamodb.model.OptimisticLockingHelper.applyOptimisticLockingIfApplicable;
+import static software.amazon.awssdk.enhanced.dynamodb.model.OptimisticLockingHelper.conditionallyApplyOptimisticLocking;
 
 import java.util.ArrayList;
 import java.util.function.Consumer;
@@ -172,7 +172,7 @@ public T deleteItem(T keyItem) {
      */
     public T deleteItem(T keyItem, boolean useOptimisticLocking) {
         DeleteItemEnhancedRequest request = DeleteItemEnhancedRequest.builder().key(keyFrom(keyItem)).build();
-        request = applyOptimisticLockingIfApplicable(request, keyItem, tableSchema, useOptimisticLocking);
+        request = conditionallyApplyOptimisticLocking(request, keyItem, tableSchema, useOptimisticLocking);
         return deleteItem(request);
     }
 

services-custom/dynamodb-enhanced/src/main/java/software/amazon/awssdk/enhanced/dynamodb/model/OptimisticLockingHelper.java

@@ -67,28 +67,6 @@ public static TransactDeleteItemEnhancedRequest withOptimisticLocking(
                       .build();
     }
 
-    /**
-     * Applies optimistic locking if the item has version information.
-     *
-     * @param <T>         the type of the item
-     * @param request     the original delete request
-     * @param keyItem     the item containing version information
-     * @param tableSchema the table schema
-     * @return delete request with optimistic locking if version exists, otherwise original request
-     */
-    public static <T> DeleteItemEnhancedRequest applyOptimisticLockingIfApplicable(
-        DeleteItemEnhancedRequest request, T keyItem, TableSchema<T> tableSchema) {
-
-        Optional<String> versionAttributeName = getVersionAttributeName(tableSchema);
-        if (versionAttributeName.isPresent()) {
-            AttributeValue version = tableSchema.attributeValue(keyItem, versionAttributeName.get());
-            if (version != null) {
-                return withOptimisticLocking(request, version, versionAttributeName.get());
-            }
-        }
-        return request;
-    }
-
     /**
      * Conditionally applies optimistic locking if enabled and version information exists.
      *
@@ -99,20 +77,19 @@ public static <T> DeleteItemEnhancedRequest applyOptimisticLockingIfApplicable(
      * @param useOptimisticLocking if true, applies optimistic locking
      * @return delete request with optimistic locking if enabled and version exists, otherwise original request
      */
-    public static <T> DeleteItemEnhancedRequest applyOptimisticLockingIfApplicable(
+    public static <T> DeleteItemEnhancedRequest conditionallyApplyOptimisticLocking(
         DeleteItemEnhancedRequest request, T keyItem, TableSchema<T> tableSchema, boolean useOptimisticLocking) {
-        return useOptimisticLocking ? applyOptimisticLockingIfApplicable(request, keyItem, tableSchema) : request;
-    }
 
-    /**
-     * Gets the version attribute name from table schema.
-     *
-     * @param <T>         the type of the item
-     * @param tableSchema the table schema
-     * @return version attribute name if present, empty otherwise
-     */
-    public static <T> Optional<String> getVersionAttributeName(TableSchema<T> tableSchema) {
-        return tableSchema.tableMetadata().customMetadataObject("VersionedRecordExtension:VersionAttribute", String.class);
+        if (!useOptimisticLocking) {
+            return request;
+        }
+
+        return getVersionAttributeName(tableSchema)
+            .map(versionAttributeName -> {
+                AttributeValue version = tableSchema.attributeValue(keyItem, versionAttributeName);
+                return version != null ? withOptimisticLocking(request, version, versionAttributeName) : request;
+            })
+            .orElse(request);
     }
 
     /**
@@ -128,4 +105,15 @@ public static Expression createVersionCondition(AttributeValue versionValue, Str
                          .putExpressionValue(":version_value", versionValue)
                          .build();
     }
+
+    /**
+     * Gets the version attribute name from table schema.
+     *
+     * @param <T>         the type of the item
+     * @param tableSchema the table schema
+     * @return version attribute name if present, empty otherwise
+     */
+    public static <T> Optional<String> getVersionAttributeName(TableSchema<T> tableSchema) {
+        return tableSchema.tableMetadata().customMetadataObject("VersionedRecordExtension:VersionAttribute", String.class);
+    }
 }