public async Task <bool> Handle(HttpListenerContext context, CancellationToken cancellationToken)
{
if (context == null)
{
throw new ArgumentNullException(nameof(context));
}
cancellationToken.ThrowIfCancellationRequested();
if (!RouteMatcher.TryMatchImageTransformRequest(context.Request.HttpMethod, context.Request.Url, out var transformType, out var coords))
{
// Not our route - return false, to allow proceed to the next handler (if any)
return(false);
}
// Ensure we have content
if (context.Request.ContentLength64 <= 0)
{
context.SendBadRequest("Image is absent");
return(true);
}
// Ensure it's of valid size
if (context.Request.ContentLength64 > Constants.MAX_IMAGE_SIZE)
{
context.SendBadRequest("Image is to big (over 100Kb)");
return(true);
}
cancellationToken.ThrowIfCancellationRequested(); // Check before starting long-running operation
// Try read image payload
IImage image;
try
{
image = m_ImageFactory.CreateFrom(context.Request.InputStream);
}
catch (Exception)
{
context.SendBadRequest("Bad image format");
return(true);
}
using (image)
{
// Check image size
if (image.Width > Constants.MAX_IMAGE_WIDTH || image.Height > Constants.MAX_IMAGE_HEIGHT)
{
context.SendBadRequest("Image size is to big (over 1000px in width, height or both)");
return(true);
}
cancellationToken.ThrowIfCancellationRequested(); // Check before starting long-running operation
image.Transform(transformType);
cancellationToken.ThrowIfCancellationRequested(); // Check after long running operation and before another one
// Find clipping area
var clipBounds = Rectangle.Intersect(image.Bounds, coords.ToRectangle());
if (clipBounds.IsEmpty)
{
context.SendNoContent();
return(true);
}
// Produce output
context.Response.Headers.Add("Content-Type", "image/png");
if (clipBounds == image.Bounds)
{
// No clipping required - save image as is
await image.SaveAsync(context.Response.OutputStream, cancellationToken);
}
else
{
using (var clippedImage = image.Copy(clipBounds))
{
await clippedImage.SaveAsync(context.Response.OutputStream, cancellationToken);
}
}
context.Response.Close();
return(true);
}
}
public async Task <bool> Handle(HttpListenerContext context, CancellationToken cancellationToken)
{
if (context == null)
{
throw new ArgumentNullException(nameof(context));
}
cancellationToken.ThrowIfCancellationRequested();
if (!RouteMatcher.TryMatchImageFilterRequest(context.Request.HttpMethod, context.Request.Url, out var filterDefinition, out var coords))
{
// Not our route - return false, to allow proceed to the next handler (if any)
return(false);
}
// Ensure we have content
if (context.Request.ContentLength64 <= 0)
{
context.SendBadRequest("Image is absent");
return(true);
}
// Ensure it's of valid size
if (context.Request.ContentLength64 > Constants.MAX_IMAGE_SIZE)
{
context.SendBadRequest("Image is to big (over 100Kb)");
return(true);
}
// Ensure filter is known
var filter = m_Filters.GetFilterByDefinition(filterDefinition);
if (filter == null)
{
context.SendBadRequest($"Unknown filter '{filterDefinition}'");
return(true);
}
cancellationToken.ThrowIfCancellationRequested(); // Check before starting long-running operation
// Try read image payload
IImage image;
try
{
image = m_ImageFactory.CreateFrom(context.Request.InputStream);
}
catch (Exception)
{
context.SendBadRequest("Bad image format");
return(true);
}
using (image)
{
// Check image size
if (image.Width > Constants.MAX_IMAGE_WIDTH || image.Height > Constants.MAX_IMAGE_HEIGHT)
{
context.SendBadRequest("Image size to big");
return(true);
}
cancellationToken.ThrowIfCancellationRequested(); // Check after long running operation
// Find intersection area
var filterBounds = Rectangle.Intersect(image.Bounds, coords.ToRectangle());
if (filterBounds.IsEmpty)
{
context.SendNoContent();
return(true);
}
cancellationToken.ThrowIfCancellationRequested(); // Check before starting long-running operation
await filter.Apply(image, filterBounds, cancellationToken);
cancellationToken.ThrowIfCancellationRequested(); // Check after long running operation and before another one
using (var copy = image.Copy(filterBounds))
{
context.Response.AddHeader("Content-Type", "image/png");
await copy.SaveAsync(context.Response.OutputStream, cancellationToken);
context.Response.Close();
}
return(true);
}
}
