ApmAgentWriter.cs

// <copyright file="ApmAgentWriter.cs" company="Datadog">
// Unless explicitly stated otherwise all files in this repository are licensed under the Apache 2 License.
// This product includes software developed at Datadog (https://www.datadoghq.com/). Copyright 2017 Datadog, Inc.
// </copyright>
#nullable enable

using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using Datadog.Trace.Agent;
using Datadog.Trace.Agent.DiscoveryService;
using Datadog.Trace.Ci.EventModel;
using Datadog.Trace.Configuration;

namespace Datadog.Trace.Ci.Agent;

/// <summary>
/// APM Agent Writer for CI Visibility
/// </summary>
internal class ApmAgentWriter : IEventWriter
{
    private const int DefaultMaxBufferSize = 1024 * 1024 * 10;

    [ThreadStatic]
    private static Span[]? _spanArray;
    private readonly AgentWriter _agentWriter;

    public ApmAgentWriter(ImmutableTracerSettings settings, Action<Dictionary<string, float>> updateSampleRates, IDiscoveryService discoveryService, int maxBufferSize = DefaultMaxBufferSize)
    {
        var partialFlushEnabled = settings.ExporterInternal.PartialFlushEnabledInternal;
        var apiRequestFactory = TracesTransportStrategy.Get(settings.ExporterInternal);
        var api = new Api(apiRequestFactory, null, updateSampleRates, partialFlushEnabled);
        var statsAggregator = StatsAggregator.Create(api, settings, discoveryService);

        _agentWriter = new AgentWriter(api, statsAggregator, null, maxBufferSize: maxBufferSize, appsecStandaloneEnabled: settings.AppsecStandaloneEnabledInternal);
    }

    public ApmAgentWriter(IApi api, int maxBufferSize = DefaultMaxBufferSize)
    {
        _agentWriter = new AgentWriter(api, null, null, maxBufferSize: maxBufferSize);
    }

    public void WriteEvent(IEvent @event)
    {
        // To keep compatibility with the agent version of the payload, any IEvent conversion to span
        // goes here.

        if (_spanArray is not { } spanArray)
        {
            spanArray = new Span[1];
            _spanArray = spanArray;
        }

        if (CIVisibilityEventsFactory.GetSpan(@event) is { } span)
        {
            spanArray[0] = span;
            WriteTrace(new ArraySegment<Span>(spanArray));
        }
    }

    public Task FlushAndCloseAsync()
    {
        return _agentWriter.FlushAndCloseAsync();
    }

    public Task FlushTracesAsync()
    {
        return _agentWriter.FlushTracesAsync();
    }

    public Task<bool> Ping()
    {
        return _agentWriter.Ping();
    }

    public void WriteTrace(ArraySegment<Span> trace)
    {
        _agentWriter.WriteTrace(trace);
    }
}