Add more logging to CachingTransport (#619)

Author: bruno-garcia

CHANGELOG.md

@@ -6,6 +6,7 @@
 * Fix Cache deleted on HttpTransport exception. (#610) @lucas-zimerman
 * Add SentryScopeStateProcessor #603
 * Add net5.0 TFM to libraries #606
+* Add more logging to CachingTransport #619
 * Bump Microsoft.Bcl.AsyncInterfaces to 5.0.0 #618
 
 ## 3.0.0-alpha.5

src/Sentry/Internal/Http/CachingTransport.cs

@@ -19,6 +19,7 @@ internal class CachingTransport : ITransport, IAsyncDisposable, IDisposable
         private readonly ITransport _innerTransport;
         private readonly SentryOptions _options;
         private readonly string _isolatedCacheDirectoryPath;
+        private readonly int _keepCount;
 
         // When a file is getting processed, it's moved to a child directory
         // to avoid getting picked up by other threads.
@@ -43,6 +44,10 @@ public CachingTransport(ITransport innerTransport, SentryOptions options)
             _innerTransport = innerTransport;
             _options = options;
 
+            _keepCount = _options.MaxQueueItems >= 1
+                ? _options.MaxQueueItems - 1
+                : 0; // just in case MaxQueueItems is set to an invalid value somehow (shouldn't happen)
+
             _isolatedCacheDirectoryPath = !string.IsNullOrWhiteSpace(options.CacheDirectoryPath)
                 ? _isolatedCacheDirectoryPath = Path.Combine(
                     options.CacheDirectoryPath,
@@ -113,17 +118,14 @@ private void EnsureFreeSpaceInCache()
             // [f1] [f2] [f3] [f4] [f5]
             //                |-------| <- keep these ones
             // |------------|           <- delete these ones
-            var keepCount = _options.MaxQueueItems >= 1
-                ? _options.MaxQueueItems - 1
-                : 0; // just in case MaxQueueItems is set to an invalid value somehow (shouldn't happen)
-
-            var excessCacheFilePaths = GetCacheFilePaths().SkipLast(keepCount).ToArray();
+            var excessCacheFilePaths = GetCacheFilePaths().SkipLast(_keepCount).ToArray();
 
             foreach (var filePath in excessCacheFilePaths)
             {
                 try
                 {
                     File.Delete(filePath);
+                    _options.DiagnosticLogger?.LogDebug("Deleted cached file {0}.", filePath);
                 }
                 catch (FileNotFoundException)
                 {
@@ -221,6 +223,7 @@ exception is OperationCanceledException // Timed-out or Shutdown triggered
             var filePath = GetCacheFilePaths().FirstOrDefault();
             if (string.IsNullOrWhiteSpace(filePath))
             {
+                _options.DiagnosticLogger?.LogDebug("No cached file to process.");
                 return null;
             }
 
@@ -236,10 +239,6 @@ private async Task StoreToCacheAsync(
             Envelope envelope,
             CancellationToken cancellationToken = default)
         {
-            using var lockClaim = await _cacheDirectoryLock.AcquireAsync(cancellationToken).ConfigureAwait(false);
-
-            EnsureFreeSpaceInCache();
-
             // Envelope file name can be either:
             // 1604679692_b2495755f67e4bb8a75504e5ce91d6c1_17754019.envelope
             // 1604679692__17754019.envelope
@@ -252,6 +251,12 @@ private async Task StoreToCacheAsync(
                 $".{EnvelopeFileExt}"
             );
 
+            _options.DiagnosticLogger?.LogDebug("Storing file {0}.", envelopeFilePath);
+
+            using var lockClaim = await _cacheDirectoryLock.AcquireAsync(cancellationToken).ConfigureAwait(false);
+
+            EnsureFreeSpaceInCache();
+
             Directory.CreateDirectory(_isolatedCacheDirectoryPath);
 
             using (var stream = File.Create(envelopeFilePath))