Use C#8 language features and extract constant strings

src/Honeycomb.Serilog.Sink/Honeycomb.Serilog.Sink.csproj

@@ -10,6 +10,7 @@
     <Copyright>evilpilaf © $([System.DateTime]::Now.Year)</Copyright>
     <PackageRequireLicenseAcceptance>true</PackageRequireLicenseAcceptance>
     <PackageLicenseFile>LICENSE.TXT</PackageLicenseFile>
+    <LangVersion>latest</LangVersion>
   </PropertyGroup>
 
   <!-- SourceLink -->

src/Honeycomb.Serilog.Sink/HoneycombSerilogSink.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Net.Http;
@@ -13,23 +13,37 @@
 
 namespace Honeycomb.Serilog.Sink
 {
-    internal class HoneycombSerilogSink : IBatchedLogEventSink
+    internal class HoneycombSerilogSink : IBatchedLogEventSink, IDisposable
     {
 #if NETCOREAPP
-        private static readonly SocketsHttpHandler _socketsHttpHandler = new SocketsHttpHandler { PooledConnectionLifetime = TimeSpan.FromMinutes(30) };
+        private static SocketsHttpHandler _socketsHttpHandler;
+
+        private static SocketsHttpHandler SocketsHttpHandler
+        {
+            get
+            {
+                return _socketsHttpHandler ??= new SocketsHttpHandler { PooledConnectionLifetime = TimeSpan.FromMinutes(30) };
+            }
+        }
+
         protected virtual HttpClient Client => BuildHttpClient();
 #else
         private static readonly Lazy<HttpClient> _clientBuilder = new Lazy<HttpClient>(BuildHttpClient);
         protected virtual HttpClient Client => _clientBuilder.Value;
 #endif
         private readonly string _apiKey;
         private readonly string _teamId;
-        private static readonly Uri _honeycombApiUrl = new Uri("https://api.honeycomb.io/");
+        private static readonly Uri _honeycombApiUrl = new Uri(HoneycombBaseUri);
+
+        private const string JsonContentType = "application/json";
+        private const string HoneycombBaseUri = "https://api.honeycomb.io/";
+        private const string HoneycombBatchEndpointTemplate = "/1/batch/{0}";
+        private const string HoneycombTeamIdHeaderName = "X-Honeycomb-Team";
+
+        private const string SelfLogMessageText = "Failure sending event to Honeycomb, received {statusCode} response with content {content}";
 
         /// <param name="teamId">The name of the team to submit the events to</param>
         /// <param name="apiKey">The API key given in the Honeycomb ui</param>
-        /// <param name="batchSizeLimit">The maximum number of events to include in a single batch.</param>
-        /// <param name="period">The time to wait between checking for event batches.</param>
         public HoneycombSerilogSink(string teamId, string apiKey)
         {
             _teamId = string.IsNullOrWhiteSpace(teamId) ? throw new ArgumentNullException(nameof(teamId)) : teamId;
@@ -38,41 +52,35 @@ public HoneycombSerilogSink(string teamId, string apiKey)
 
         public async Task EmitBatchAsync(IEnumerable<LogEvent> events)
         {
-            using (TextWriter writer = new StringWriter())
-            {
-                BuildLogEvent(events, writer);
-                await SendBatchedEvents(writer.ToString());
-            }
+            using TextWriter writer = new StringWriter();
+            BuildLogEvent(events, writer);
+            await SendBatchedEvents(writer.ToString()).ConfigureAwait(false);
         }
 
         private async Task SendBatchedEvents(string events)
         {
-            var requestMessage = new HttpRequestMessage(HttpMethod.Post, $"/1/batch/{_teamId}")
+            using var requestMessage = new HttpRequestMessage(HttpMethod.Post, string.Format(HoneycombBatchEndpointTemplate, _teamId))
             {
-                Content = new StringContent(events, Encoding.UTF8, "application/json"),
+                Content = new StringContent(events, Encoding.UTF8, JsonContentType),
                 Version = new Version(2, 0)
             };
 
-            requestMessage.Headers.Add("X-Honeycomb-Team", _apiKey);
+            requestMessage.Headers.Add(HoneycombTeamIdHeaderName, _apiKey);
             var response = await SendRequest(requestMessage).ConfigureAwait(false);
             if (!response.IsSuccessStatusCode)
             {
-                using (Stream contentStream = await response.Content.ReadAsStreamAsync().ConfigureAwait(false))
-                using (var reader = new StreamReader(contentStream))
-                {
-                    var responseContent = await reader.ReadToEndAsync().ConfigureAwait(false);
-                    SelfLog.WriteLine("Failure sending event to Honeycomb, received {statusCode} response with content {content}", response.StatusCode, responseContent);
-                }
+                using Stream contentStream = await response.Content.ReadAsStreamAsync().ConfigureAwait(false);
+                using var reader = new StreamReader(contentStream);
+                var responseContent = await reader.ReadToEndAsync().ConfigureAwait(false);
+                SelfLog.WriteLine(SelfLogMessageText, response.StatusCode, responseContent);
             }
         }
 
         private async Task<HttpResponseMessage> SendRequest(HttpRequestMessage request)
         {
 #if NETCOREAPP
-            using (var client = Client)
-            {
-                return await client.SendAsync(request, HttpCompletionOption.ResponseHeadersRead);
-            }
+            using var client = Client;
+            return await client.SendAsync(request, HttpCompletionOption.ResponseHeadersRead);
 #else
             return await Client.SendAsync(request, HttpCompletionOption.ResponseHeadersRead);
 #endif
@@ -95,7 +103,7 @@ private static HttpClient BuildHttpClient()
         {
             HttpClient client;
 #if NETCOREAPP
-            client = new HttpClient(_socketsHttpHandler, disposeHandler: false);
+            client = new HttpClient(SocketsHttpHandler, disposeHandler: false);
 #else
             client = new HttpClient();
 #endif
@@ -108,5 +116,24 @@ public Task OnEmptyBatchAsync()
         {
             return Task.CompletedTask;
         }
+
+        private void ReleaseUnmanagedResources()
+        {
+#if NETCORE
+            _socketsHttpHandler?.Dispose();
+            _socketsHttpHandler = null;
+#endif
+        }
+
+        public void Dispose()
+        {
+            ReleaseUnmanagedResources();
+            GC.SuppressFinalize(this);
+        }
+
+        ~HoneycombSerilogSink()
+        {
+            ReleaseUnmanagedResources();
+        }
     }
 }