DocumentMemoryCache Class (original) (raw)
Summary
Document memory cache support.
Syntax
public class DocumentMemoryCache public:
ref class DocumentMemoryCache
class DocumentMemoryCache: Example
This example will simulate a client loading a small and then a large document from URI and then shows the times used. This sample will produce results similar to the following:
Using memory cache is False
Initial load from leadtools.pdf took 0 seconds
Is using memory cache is False
Multi-threaded load of all pages took ~0 seconds
Initial load from complex.xlsx took ~10 seconds
Is using memory cache is False 1
Multi-threaded load of all pages took **13** 1 seconds
Using memory cache is True
Initial load from leadtools.pdf took 0 seconds
Is using memory cache is False
Multi-threaded load of all pages took ~0 seconds
Initial load from complex.xlsx took ~10 seconds
Is using memory cache is True 2
Multi-threaded load of all pages took **0** 2 seconds
Notice how the time it took to load all the pages of complex.xlsx in a multi-threaded code decreased from 13 to almost 0 seconds when memory cache is used.
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,
});
}
}