SlidingExpiration Property

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.Document.Writer; 
 
using Leadtools.Document; 
using Leadtools.Caching; 
using Leadtools.Annotations.Engine; 
using Leadtools.Ocr; 
using Leadtools.Barcode; 
using Leadtools.Document.Converter; 
 
public void DocumentMemoryCacheExample() 
{ 
   // The cache we are using 
   FileCache cache = new FileCache(); 
   cache.PolicySerializationMode = CacheSerializationMode.Json; 
   cache.DataSerializationMode = CacheSerializationMode.Json; 
   cache.CacheDirectory = @"c:\cache-dir"; 
 
   // The document files we are using 
   string[] documentFiles = 
   { 
      // PDF files are very fast to load and will not use memory cache 
      @"C:\LEADTOOLS22\Resources\Images\leadtools.pdf", 
      // Large Excel files are complex and loading may take some time, they could use memory cache 
      @"C:\LEADTOOLS22\Resources\Images\complex.xlsx", 
   }; 
 
   // First process without memory cache and obtain some times 
   LoadAndProcessDocument(documentFiles, cache); 
 
   // Then process with memory cache 
 
   // Document memory cache options to use 
   var documentMemoryCacheStartOptions = new DocumentMemoryCacheStartOptions 
   { 
      // Use for documents that take more than 2 seconds to load initially 
      MinimumLoadDuration = TimeSpan.FromSeconds(2), 
      // No maximum limit on the number of cache items to keep in memory 
      MaximumItems = 0, 
      // Purse items from the cache if not touched for 60 seconds 
      SlidingExpiration = TimeSpan.FromSeconds(60), 
      // Check for expired items every 60 seconds 
      TimerInterval = TimeSpan.FromSeconds(60) 
   }; 
 
   // Use it 
   DocumentFactory.DocumentMemoryCache.Start(documentMemoryCacheStartOptions); 
 
   // Run again 
   // For the first document, times should be very close to the since this is a PDF document and is very fast (less than MinimumLoadDuration) 
   // For the second document, initial times should be the same, but loading all pages should be much faster 
   LoadAndProcessDocument(documentFiles, cache); 
 
   // Clean up 
   DocumentFactory.DocumentMemoryCache.Stop(); 
} 
 
private static void LoadAndProcessDocument(string[] documentFiles, ObjectCache cache) 
{ 
   Console.WriteLine($"Using memory cache is {DocumentFactory.DocumentMemoryCache.IsStarted}"); 
   string[] documentIds = new string[documentFiles.Length]; 
 
   var stopwatch = new Stopwatch(); 
   TimeSpan elapsed; 
 
   for (var i = 0; i < documentFiles.Length; i++) 
   { 
      string documentFile = documentFiles[i]; 
      int pageCount; 
 
      // First try without memory cache and obtain some times 
      stopwatch.Restart(); 
      using (LEADDocument document = DocumentFactory.LoadFromFile( 
         documentFile, 
         new LoadDocumentOptions 
         { 
            Cache = cache 
         })) 
      { 
         document.Images.MaximumImagePixelSize = 2048; 
         document.AutoSaveToCache = false; 
         document.AutoDeleteFromCache = false; 
         document.SaveToCache(); 
         documentIds[i] = document.DocumentId; 
         pageCount = document.Pages.Count; 
      } 
      elapsed = stopwatch.Elapsed; 
      Console.WriteLine($"Initial load from {Path.GetFileName(documentFile)} took ~{(int)elapsed.TotalSeconds} seconds"); 
      // Check if it's in the cache 
      Console.WriteLine($"Is using memory cache is {DocumentFactory.DocumentMemoryCache.HasDocument(documentIds[i], false)}"); 
 
      // Next call LoadFromCache and process a page in multiple threads 
      stopwatch.Restart(); 
      LoadAllPagesInThreads(documentIds[i], pageCount, cache); 
      elapsed = stopwatch.Elapsed; 
      Console.WriteLine($"Multi-threaded load of all pages took ~{(int)elapsed.TotalSeconds} seconds"); 
   } 
 
   // Clean up 
   DeleteDocumentsFromCache(documentIds, cache); 
} 
 
private static void LoadAllPagesInThreads(string documentId, int pageCount, ObjectCache cache) 
{ 
   System.Threading.Tasks.Parallel.For( 
      1, 
      pageCount + 1, 
      new System.Threading.Tasks.ParallelOptions { MaxDegreeOfParallelism = 4 }, 
      (int pageNumber) => 
      { 
         // Load the document from the cache 
         using (LEADDocument document = DocumentFactory.LoadFromCache( 
            new LoadFromCacheOptions 
            { 
               Cache = cache, 
               DocumentId = documentId 
            })) 
         { 
            // Simulates processing of the page 
            DocumentPage documentPage = document.Pages[pageNumber - 1]; 
            using (RasterImage image = documentPage.GetImage()) 
            { 
 
            } 
         } 
      }); 
} 
 
private static void DeleteDocumentsFromCache(string[] documentIds, ObjectCache cache) 
{ 
   foreach (string documentId in documentIds) 
   { 
      DocumentFactory.DeleteFromCache(new LoadFromCacheOptions 
      { 
         Cache = cache, 
         DocumentId = documentId, 
      }); 
   } 
}