Cache work in progress

ChromiumHtmlToPdfLib/Converter.cs

@@ -182,6 +182,16 @@ private enum OutputFormat
     ///     When <c>true</c> then caching will be enabled
     /// </summary>
     private bool _useCache;
+
+    /// <summary>
+    ///     <see cref="SetDiskCache"/>
+    /// </summary>
+    private DirectoryInfo _cacheDirectory;
+
+    /// <summary>
+    ///     <see cref="SetDiskCache"/>
+    /// </summary>
+    private long _cacheSize;
     #endregion
 
     #region Properties
@@ -193,8 +203,10 @@ private string BrowserName
             {
                 case Enums.Browser.Chrome:
                     return "Google Chrome";
+
                 case Enums.Browser.Edge:
                     return "Microsoft Edge";
+
                 default:
                     throw new ArgumentOutOfRangeException();
             }
@@ -430,6 +442,25 @@ public bool DiskCacheDisabled
         set => _useCache = !value;
     }
 
+    /// <summary>
+    ///     Returns a reference to the temp directory
+    /// </summary>
+    private DirectoryInfo GetCacheDirectory
+    {
+        get
+        {
+            // TODO: Make code work
+            CurrentTempDirectory = _tempDirectory == null
+                ? new DirectoryInfo(Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString()))
+                : new DirectoryInfo(Path.Combine(_tempDirectory, Guid.NewGuid().ToString()));
+
+            if (!CurrentTempDirectory.Exists)
+                CurrentTempDirectory.Create();
+
+            return CurrentTempDirectory;
+        }
+    }
+
     /// <summary>
     ///     The timeout in milliseconds when waiting for a websocket to open
     /// </summary>
@@ -776,7 +807,7 @@ public void ResetChromiumArguments()
 
         _defaultChromiumArgument = new List<string>();
 
-        if (UseOldHeaslessMode)
+        if (UseOldHeadlessMode)
             AddChromiumArgument("--headless");
         else
             AddChromiumArgument("--headless", "new");
@@ -999,13 +1030,14 @@ public void SetUserAgent(string value)
     /// <param name="size">The maximum size in megabytes for the cache directory, <c>null</c> to let Chromium decide</param>
     /// <remarks>
     ///     You can not share a cache folder between multiple instances that are running at the same time because a Google
-    ///     Chrome
-    ///     or Microsoft Edge instance locks the cache for it self. If you want to use caching in a multi threaded environment
-    ///     then assign a unique cache folder to each running Google Chrome or Microsoft Edge instance
+    ///     Chrome or Microsoft Edge instance locks the cache for it self. If you want to use caching in a multi threaded
+    ///     environment then assign a unique cache folder to each running Google Chrome or Microsoft Edge instance
     /// </remarks>
     public void SetDiskCache(string directory, long? size)
     {
-        if (!Directory.Exists(directory))
+        _cacheDirectory = new DirectoryInfo(directory);
+
+        if (!_cacheDirectory.Exists)
             throw new DirectoryNotFoundException($"The directory '{directory}' does not exists");
 
         AddChromiumArgument("--disk-cache-dir", directory.TrimEnd('\\', '/'));
@@ -1015,6 +1047,8 @@ public void SetDiskCache(string directory, long? size)
             if (size.Value <= 0)
                 throw new ArgumentException("Has to be a value of 1 or greater", nameof(size));
 
+            _cacheSize = size.Value * 1024 * 1024;
+
             AddChromiumArgument("--disk-cache-size", (size.Value * 1024 * 1024).ToString());
         }
 

ChromiumHtmlToPdfLib/Helpers/DocumentHelper.cs

@@ -91,6 +91,16 @@ internal class DocumentHelper : IDisposable
     private readonly Stopwatch _stopwatch;
 
     private readonly int _imageLoadTimeout;
+
+    /// <summary>
+    ///     The cache folder
+    /// </summary>
+    readonly DirectoryInfo _cacheFolder;
+
+    /// <summary>
+    ///     The cache size
+    /// </summary>
+    private readonly long _cacheSize;
     #endregion
 
     #region Properties
@@ -144,12 +154,16 @@ public DocumentHelper(DirectoryInfo tempDirectory,
         WebProxy webProxy,
         bool useCache,
         int? imageLoadTimeout,
-        ILogger logger)
+        ILogger logger,
+        DirectoryInfo cacheFolder, 
+        long cacheSize)
     {
         _tempDirectory = tempDirectory;
         _webProxy = webProxy;
         _useCache = useCache;
         _logger = logger;
+        _cacheFolder = cacheFolder;
+        _cacheSize = cacheSize;
 
         if (!imageLoadTimeout.HasValue) return;
         _imageLoadTimeout = imageLoadTimeout.Value;

ChromiumHtmlToPdfLib/Helpers/FileCacheHandler.cs

@@ -22,39 +22,38 @@ internal class FileCacheHandler : HttpClientHandler
     /// <summary>
     ///     The cache folder
     /// </summary>
-    DirectoryInfo _cacheFolder;
+    readonly DirectoryInfo _cacheFolder;
+
+    private readonly long _cacheSize;
     #endregion
 
-    internal FileCacheHandler(HttpClientHandler httpClientHandler, DirectoryInfo cacheFolder)
+    internal FileCacheHandler(HttpClientHandler httpClientHandler, FileSystemInfo cacheFolder, long cacheSize)
     {
         _httpClientHandler = httpClientHandler;
-        _cacheFolder = cacheFolder;
+        _cacheFolder = new DirectoryInfo(Path.Combine(cacheFolder.FullName, "HttpClientHandler"));
+        _cacheSize = cacheSize;
+
+        if (!_cacheFolder.Exists)
+            _cacheFolder.Create();
     }
 
     protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
     {
         var hash = GetMd5HashFromString(request.RequestUri.ToString());
+        var cachedFile = new FileInfo(Path.Combine(_cacheFolder.FullName, hash));
 
-        if (File.Exists(hash))
-        {
-            var response = new HttpResponseMessage(HttpStatusCode.OK)
-            {
-                Content = new StreamContent(new FileStream(hash, FileMode.OpenOrCreate)),
-                ReasonPhrase = "Loaded from cache"
-            };
-            return Task.FromResult(response);
-        }
+        if (!cachedFile.Exists) 
+            return base.SendAsync(request, cancellationToken);
+
+        // TODO: Cache file
 
         var response = new HttpResponseMessage(HttpStatusCode.OK)
         {
-            Content = new StreamContent(new FileStream(hash, FileMode.OpenOrCreate)),
+            Content = new StreamContent(cachedFile.OpenRead()),
             ReasonPhrase = "Loaded from cache"
         };
-
-        return Task.FromResult(response);
 
-        //throw new NotImplementedException();
-        return base.SendAsync(request, cancellationToken);
+        return Task.FromResult(response);
     }
 
     #region GetMd5HashFromString
@@ -71,4 +70,34 @@ public string GetMd5HashFromString(string value)
         return bytes.Aggregate(string.Empty, (current, b) => current + b.ToString("X2"));
     }
     #endregion
+
+
+    private static void DeleteOldestFilesIfFolderExceedsSizeLimit(string folderPath, long maxSizeInBytes)
+    {
+        var directoryInfo = new DirectoryInfo(folderPath);
+        var files = directoryInfo.GetFiles();
+
+        var currentFolderSize = files.Sum(file => file.Length);
+
+        if (currentFolderSize <= maxSizeInBytes) return;
+        {
+            var oldestFiles = files.OrderBy(file => file.CreationTime).ToArray();
+
+            foreach (var file in oldestFiles)
+            {
+                try
+                {
+                    file.Delete();
+                    currentFolderSize -= file.Length;
+
+                    if (currentFolderSize <= maxSizeInBytes)
+                        break;
+                }
+                catch (Exception exception)
+                {
+                    throw new Exception($"Failed to delete file: {file.FullName} - {exception.Message}");
+                }
+            }
+        }
+    }
 }