software.amazon.awssdk.enhanced.dynamodb.extensions.annotations.DynamoDbAtomicCounter Maven / Gradle / Ivy

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/*
 * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License").
 * You may not use this file except in compliance with the License.
 * A copy of the License is located at
 *
 *  http://aws.amazon.com/apache2.0
 *
 * or in the "license" file accompanying this file. This file is distributed
 * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
 * express or implied. See the License for the specific language governing
 * permissions and limitations under the License.
 */

package software.amazon.awssdk.enhanced.dynamodb.extensions.annotations;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import software.amazon.awssdk.annotations.SdkPublicApi;
import software.amazon.awssdk.enhanced.dynamodb.internal.mapper.BeanTableSchemaAttributeTags;
import software.amazon.awssdk.enhanced.dynamodb.mapper.annotations.BeanTableSchemaAttributeTag;

/**
 * Used to explicitly designate an attribute to be an auto-generated counter updated unconditionally in DynamoDB.
 * By default, the counter will start on 0 and increment with 1 for each subsequent calls to updateItem.
 * By supplying a negative integer delta value, the attribute works as a decreasing counter.
 */
@SdkPublicApi
@Target({ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@BeanTableSchemaAttributeTag(BeanTableSchemaAttributeTags.class)
public @interface DynamoDbAtomicCounter {
    /**
     * The value to increment (positive) or decrement (negative) the counter with for each update.
     */
    long delta() default 1;

    /**
     * The starting value of the counter.
     */
    long startValue() default 0;
}