fix batch api errors

dynamodb/batch.odin

@@ -65,6 +65,17 @@ batch_write_item :: proc(
 		unprocessed = make([dynamic]Batch_Write_Table_Request),
 	}
 
+	// Count total operations across all tables
+	total_ops := 0
+	for table_req in table_requests {
+		total_ops += len(table_req.requests)
+	}
+
+	// Enforce DynamoDB limit: 25 operations per batch
+	if total_ops > 25 {
+		return result, .Validation_Error
+	}
+
 	for table_req in table_requests {
 		failed_requests := make([dynamic]Write_Request)
 
@@ -78,13 +89,31 @@ batch_write_item :: proc(
 				var_err = delete_item(engine, table_req.table_name, req.item)
 			}
 
+			// Distinguish validation errors from transient failures
 			if var_err != .None {
-				// Deep copy the failed request for UnprocessedItems
+				#partial switch var_err {
+				case .Missing_Key_Attribute, .Invalid_Key, .Serialization_Error:
+					// Hard validation errors — fail the entire batch
+					batch_write_result_destroy(&result)
+					delete(failed_requests)
+					return result, var_err
+
+				case .RocksDB_Error, .Item_Not_Found, .Table_Not_Found:
+					// Transient/throttling errors — add to unprocessed
 					failed_item := item_deep_copy(req.item)
 					append(&failed_requests, Write_Request{
 						type = req.type,
 						item = failed_item,
 					})
+
+				case .None, .Validation_Error, .Internal_Error:
+					// Should not happen, but handle gracefully
+					failed_item := item_deep_copy(req.item)
+					append(&failed_requests, Write_Request{
+						type = req.type,
+						item = failed_item,
+					})
+				}
 			}
 		}
 
@@ -101,6 +130,7 @@ batch_write_item :: proc(
 	return result, .None
 }
 
+
 // ============================================================================
 // BatchGetItem Types
 // ============================================================================
@@ -157,6 +187,17 @@ batch_get_item :: proc(
 		unprocessed_keys = make([dynamic]Batch_Get_Table_Request),
 	}
 
+	// Count total keys across all tables
+	total_keys := 0
+	for table_req in table_requests {
+		total_keys += len(table_req.keys)
+	}
+
+	// Enforce DynamoDB limit: 100 keys per batch
+	if total_keys > 100 {
+		return result, .Validation_Error
+	}
+
 	for table_req in table_requests {
 		found_items := make([dynamic]Item)
 		failed_keys := make([dynamic]Item)
@@ -164,10 +205,25 @@ batch_get_item :: proc(
 		for key in table_req.keys {
 			item_result, get_err := get_item(engine, table_req.table_name, key)
 
+			// Distinguish validation errors from transient failures
 			if get_err != .None && get_err != .Item_Not_Found {
-				// Storage error — add to unprocessed
+				#partial switch get_err {
+				case .Missing_Key_Attribute, .Invalid_Key, .Serialization_Error:
+					// Hard validation error — fail the entire batch
+					batch_get_result_destroy(&result)
+					delete(found_items)
+					delete(failed_keys)
+					return result, get_err
+
+				case .RocksDB_Error, .Table_Not_Found:
+					// Transient error — add to unprocessed
 					append(&failed_keys, item_deep_copy(key))
 					continue
+
+				case .None, .Validation_Error, .Internal_Error, .Item_Not_Found:
+					// Should not happen here, but handle gracefully
+					continue
+				}
 			}
 
 			if item_val, has_item := item_result.?; has_item {

dynamodb/storage.odin

@@ -22,6 +22,9 @@ Storage_Error :: enum {
 	Serialization_Error,
 	RocksDB_Error,
 	Out_Of_Memory,
+	Validation_Error,
+	Request_Too_Large,
+	Internal_Error,
 }
 
 // Result type for Scan operations with pagination