﻿// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License.  You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License 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.

using System.Threading;
using Newtonsoft.Json;

namespace Org.Apache.REEF.Common.Telemetry
{
    /// <summary>
    /// Counter metric implementation.
    /// </summary>
    public sealed class CounterMetric : MetricBase<int>, ICounter
    {
        public CounterMetric()
        {
        }

        internal CounterMetric(string name, string description, bool keepHistory = false)
            : base(name, description, keepHistory)
        {
        }

        public void Increment(int number = 1)
        {
            _tracker.Track(Interlocked.Add(ref _typedValue, number));
        }

        public void Decrement(int number = 1)
        {
            _tracker.Track(Interlocked.Add(ref _typedValue, -number));
        }

        public override void AssignNewValue(int value)
        {
            Interlocked.Exchange(ref _typedValue, value);
            _tracker.Track(value);
        }
    }
}
