/// <summary>
/// Crops whitespace from an image, caches the result, and returns the cached path
/// </summary>
/// <param name="originalImagePath">The original image path.</param>
/// <param name="dateModified">The date modified.</param>
/// <returns>System.String.</returns>
private async Task <string> GetCroppedImage(string originalImagePath, DateTime dateModified)
{
var name = originalImagePath;
name += "datemodified=" + dateModified.Ticks;
var croppedImagePath = CroppedImageCache.GetResourcePath(name, Path.GetExtension(originalImagePath));
if (!CroppedImageCache.ContainsFilePath(croppedImagePath))
{
using (var fileStream = File.OpenRead(originalImagePath))
{
using (var originalImage = (Bitmap)Bitmap.FromStream(fileStream, true, false))
{
var outputFormat = originalImage.RawFormat;
using (var croppedImage = originalImage.CropWhitespace())
{
await SaveImageToFile(croppedImage, outputFormat, croppedImagePath).ConfigureAwait(false);
}
}
}
}
return(croppedImagePath);
}
/// <summary>
/// Crops whitespace from an image, caches the result, and returns the cached path
/// </summary>
/// <param name="originalImagePath">The original image path.</param>
/// <param name="dateModified">The date modified.</param>
/// <returns>System.String.</returns>
private async Task <string> GetCroppedImage(string originalImagePath, DateTime dateModified)
{
var name = originalImagePath;
name += "datemodified=" + dateModified.Ticks;
var croppedImagePath = CroppedImageCache.GetResourcePath(name, Path.GetExtension(originalImagePath));
var semaphore = GetLock(croppedImagePath);
await semaphore.WaitAsync().ConfigureAwait(false);
// Check again in case of contention
if (File.Exists(croppedImagePath))
{
semaphore.Release();
return(croppedImagePath);
}
try
{
using (var fileStream = new FileStream(originalImagePath, FileMode.Open, FileAccess.Read, FileShare.Read, StreamDefaults.DefaultFileStreamBufferSize, true))
{
// Copy to memory stream to avoid Image locking file
using (var memoryStream = new MemoryStream())
{
await fileStream.CopyToAsync(memoryStream).ConfigureAwait(false);
using (var originalImage = (Bitmap)Image.FromStream(memoryStream, true, false))
{
var outputFormat = originalImage.RawFormat;
using (var croppedImage = originalImage.CropWhitespace())
{
var parentPath = Path.GetDirectoryName(croppedImagePath);
if (!Directory.Exists(parentPath))
{
Directory.CreateDirectory(parentPath);
}
using (var outputStream = new FileStream(croppedImagePath, FileMode.Create, FileAccess.Write, FileShare.Read))
{
croppedImage.Save(outputFormat, outputStream, 100);
}
}
}
}
}
}
catch (Exception ex)
{
// We have to have a catch-all here because some of the .net image methods throw a plain old Exception
_logger.ErrorException("Error cropping image {0}", ex, originalImagePath);
return(originalImagePath);
}
finally
{
semaphore.Release();
}
return(croppedImagePath);
}