/// <summary>
/// Processes the image.
/// </summary>
/// <param name="context">
/// the <see cref="T:System.Web.HttpContext">HttpContext</see> object that provides
/// references to the intrinsic server objects
/// </param>
/// <returns>
/// The <see cref="T:System.Threading.Tasks.Task"/>.
/// </returns>
private async Task ProcessImageAsync(HttpContext context)
{
HttpRequest request = context.Request;
// Should we ignore this request?
if (request.Unvalidated.RawUrl.ToUpperInvariant().Contains("IPIGNORE=TRUE"))
{
return;
}
IImageService currentService = this.GetImageServiceForRequest(request);
if (currentService != null)
{
bool isFileLocal = currentService.IsFileLocalService;
string url = request.Url.ToString();
bool isLegacy = ProtocolRegex.Matches(url).Count > 1;
bool hasMultiParams = url.Count(f => f == '?') > 1;
string requestPath;
string queryString = string.Empty;
string urlParameters = string.Empty;
// Legacy support. I'd like to remove this asap.
if (isLegacy && hasMultiParams)
{
// We need to split the querystring to get the actual values we want.
string[] paths = url.Split('?');
requestPath = paths[1];
// Handle extension-less urls.
if (paths.Length > 3)
{
queryString = paths[3];
urlParameters = paths[2];
}
else if (paths.Length > 1)
{
queryString = paths[2];
}
}
else
{
if (string.IsNullOrWhiteSpace(currentService.Prefix))
{
requestPath = currentService.IsFileLocalService
? HostingEnvironment.MapPath(request.Path)
: request.Path;
queryString = request.QueryString.ToString();
}
else
{
// Parse any protocol values from settings.
string protocol = currentService.Settings.ContainsKey("Protocol")
? currentService.Settings["Protocol"] + "://"
: currentService.GetType() == typeof(RemoteImageService) ? request.Url.Scheme + "://" : string.Empty;
// Handle requests that require parameters.
if (hasMultiParams)
{
string[] paths = url.Split('?');
requestPath = protocol
+ request.Path.TrimStart('/').Remove(0, currentService.Prefix.Length).TrimStart('/')
+ "?" + paths[1];
queryString = paths[2];
}
else
{
requestPath = protocol + request.Path.TrimStart('/').Remove(0, currentService.Prefix.Length).TrimStart('/');
queryString = request.QueryString.ToString();
}
}
}
// Replace any presets in the querystring with the actual value.
queryString = this.ReplacePresetsInQueryString(queryString);
HttpContextWrapper httpContextBase = new HttpContextWrapper(context);
// Execute the handler which can change the querystring
// LEGACY:
#pragma warning disable 618
queryString = this.CheckQuerystringHandler(context, queryString, request.Unvalidated.RawUrl);
#pragma warning restore 618
// NEW WAY:
ValidatingRequestEventArgs validatingArgs = new ValidatingRequestEventArgs(httpContextBase, queryString);
this.OnValidatingRequest(validatingArgs);
// If the validation has failed based on events, return
if (validatingArgs.Cancel)
{
ImageProcessorBootstrapper.Instance.Logger.Log<ImageProcessingModule>("Image processing has been cancelled by an event");
return;
}
// Re-assign based on event handlers
queryString = validatingArgs.QueryString;
// Break out if we don't meet critera.
bool interceptAll = interceptAllRequests != null && interceptAllRequests.Value;
if (string.IsNullOrWhiteSpace(requestPath) || (!interceptAll && string.IsNullOrWhiteSpace(queryString)))
{
return;
}
string parts = !string.IsNullOrWhiteSpace(urlParameters) ? "?" + urlParameters : string.Empty;
string fullPath = string.Format("{0}{1}?{2}", requestPath, parts, queryString);
object resourcePath;
// More legacy support code.
if (hasMultiParams)
{
resourcePath = string.IsNullOrWhiteSpace(urlParameters)
? new Uri(requestPath, UriKind.RelativeOrAbsolute)
: new Uri(requestPath + "?" + urlParameters, UriKind.RelativeOrAbsolute);
}
else
{
resourcePath = requestPath;
}
// Check whether the path is valid for other requests.
// We've already checked the unprefixed requests in GetImageServiceForRequest().
if (!string.IsNullOrWhiteSpace(currentService.Prefix) && !currentService.IsValidRequest(resourcePath.ToString()))
{
return;
}
string combined = requestPath + fullPath;
using (await Locker.LockAsync(combined))
{
// Create a new cache to help process and cache the request.
this.imageCache = (IImageCache)ImageProcessorConfiguration.Instance
.ImageCache.GetInstance(requestPath, fullPath, queryString);
// Is the file new or updated?
bool isNewOrUpdated = await this.imageCache.IsNewOrUpdatedAsync();
string cachedPath = this.imageCache.CachedPath;
// Only process if the file has been updated.
if (isNewOrUpdated)
{
byte[] imageBuffer = null;
string mimeType;
try
{
imageBuffer = await currentService.GetImage(resourcePath);
}
catch (HttpException ex)
{
// We want 404's to be handled by IIS so that other handlers/modules can still run.
if (ex.GetHttpCode() == (int)HttpStatusCode.NotFound)
{
ImageProcessorBootstrapper.Instance.Logger.Log<ImageProcessingModule>(ex.Message);
return;
}
}
if (imageBuffer == null)
{
return;
}
using (MemoryStream inStream = new MemoryStream(imageBuffer))
{
// Process the Image
MemoryStream outStream = new MemoryStream();
if (!string.IsNullOrWhiteSpace(queryString))
{
// Animation is not a processor but can be a specific request so we should allow it.
bool processAnimation;
AnimationProcessMode mode = this.ParseAnimationMode(queryString, out processAnimation);
// Attempt to match querystring and processors.
IWebGraphicsProcessor[] processors = ImageFactoryExtensions.GetMatchingProcessors(queryString);
if (processors.Any() || processAnimation)
{
// Process the image.
bool exif = preserveExifMetaData != null && preserveExifMetaData.Value;
bool gamma = fixGamma != null && fixGamma.Value;
using (ImageFactory imageFactory = new ImageFactory(exif, gamma) { AnimationProcessMode = mode })
{
imageFactory.Load(inStream).AutoProcess(processors).Save(outStream);
mimeType = imageFactory.CurrentImageFormat.MimeType;
}
}
else if (this.ParseCacheBuster(queryString))
{
// We're cachebustng. Allow the value to be cached
await inStream.CopyToAsync(outStream);
mimeType = FormatUtilities.GetFormat(outStream).MimeType;
}
else
{
// No match? Someone is either attacking the server or hasn't read the instructions.
// Either way throw an exception to prevent caching.
string message = string.Format(
"The request {0} could not be understood by the server due to malformed syntax.",
request.Unvalidated.RawUrl);
ImageProcessorBootstrapper.Instance.Logger.Log<ImageProcessingModule>(message);
throw new HttpException((int)HttpStatusCode.BadRequest, message);
}
}
else
{
// We're capturing all requests.
await inStream.CopyToAsync(outStream);
mimeType = FormatUtilities.GetFormat(outStream).MimeType;
}
// Fire the post processing event.
EventHandler<PostProcessingEventArgs> handler = OnPostProcessing;
if (handler != null)
{
string extension = Path.GetExtension(cachedPath);
PostProcessingEventArgs args = new PostProcessingEventArgs
{
Context = context,
ImageStream = outStream,
ImageExtension = extension
};
handler(this, args);
outStream = args.ImageStream;
}
// Add to the cache.
await this.imageCache.AddImageToCacheAsync(outStream, mimeType);
// Cleanup
outStream.Dispose();
}
// Store the response type and cache dependency in the context for later retrieval.
context.Items[CachedResponseTypeKey] = mimeType;
bool isFileCached = new Uri(cachedPath).IsFile;
if (isFileLocal)
{
if (isFileCached)
{
// Some services might only provide filename so we can't monitor for the browser.
context.Items[CachedResponseFileDependency] = Path.GetFileName(requestPath) == requestPath
? new[] { cachedPath }
: new[] { requestPath, cachedPath };
}
else
{
context.Items[CachedResponseFileDependency] = Path.GetFileName(requestPath) == requestPath
? null
: new[] { requestPath };
}
}
else if (isFileCached)
{
context.Items[CachedResponseFileDependency] = new[] { cachedPath };
}
}
// The cached file is valid so just rewrite the path.
this.imageCache.RewritePath(context);
// Redirect if not a locally store file.
if (!new Uri(cachedPath).IsFile)
{
context.ApplicationInstance.CompleteRequest();
}
}
}
}
/// <summary>
/// Raises the ValidatingRequest event
/// </summary>
/// <param name="args">The <see cref="ValidatingRequestEventArgs"/></param>
private void OnValidatingRequest(ValidatingRequestEventArgs args)
{
ValidatingRequest?.Invoke(this, args);
}
/// <summary>
/// Processes the image.
/// </summary>
/// <param name="context">
/// the <see cref="T:System.Web.HttpContext">HttpContext</see> object that provides
/// references to the intrinsic server objects
/// </param>
/// <returns>
/// The <see cref="T:System.Threading.Tasks.Task"/>.
/// </returns>
private async Task ProcessImageAsync(HttpContext context)
{
HttpRequest request = context.Request;
string rawUrl = request.Unvalidated.RawUrl;
// Should we ignore this request?
if (string.IsNullOrWhiteSpace(rawUrl) || rawUrl.ToUpperInvariant().Contains("IPIGNORE=TRUE"))
{
return;
}
// Sometimes the request is url encoded so we have to decode.
// See https://github.com/JimBobSquarePants/ImageProcessor/issues/478
// This causes a bit of a nightmare as the incoming request is corrupted and cannot be used for splitting
// out each url part. This becomes a manual job.
string url = this.DecodeUrlString(rawUrl);
string applicationPath = request.ApplicationPath;
IImageService currentService = this.GetImageServiceForRequest(url, applicationPath);
if (currentService != null)
{
// Remove any service identifier prefixes from the url.
string prefix = currentService.Prefix;
if (!string.IsNullOrWhiteSpace(prefix))
{
url = url.Split(new[] { prefix }, StringSplitOptions.None)[1].TrimStart("?");
}
// Identify each part of the incoming request.
int queryCount = url.Count(f => f == '?');
bool hasParams = queryCount > 0;
bool hasMultiParams = queryCount > 1;
string[] splitPath = url.Split('?');
// Ensure we include any relevent querystring parameters into our request path for third party requests.
string requestPath = hasMultiParams ? string.Join("?", splitPath.Take(splitPath.Length - 1)) : splitPath[0];
string queryString = hasParams ? splitPath[splitPath.Length - 1] : string.Empty;
// Map the request path if file local.
bool isFileLocal = currentService.IsFileLocalService;
if (currentService.IsFileLocalService)
{
requestPath = HostingEnvironment.MapPath(requestPath);
}
// Parse any protocol values from settings if no protocol is present.
if (currentService.Settings.ContainsKey("Protocol") && (ProtocolRegex.Matches(url).Count == 0 || ProtocolRegex.Matches(url)[0].Index > 0))
{
// ReSharper disable once PossibleNullReferenceException
requestPath = currentService.Settings["Protocol"] + "://" + requestPath.TrimStart('/');
}
// Replace any presets in the querystring with the actual value.
queryString = this.ReplacePresetsInQueryString(queryString);
HttpContextWrapper httpContextBase = new HttpContextWrapper(context);
// Execute the handler which can change the querystring
// LEGACY:
#pragma warning disable 618
queryString = this.CheckQuerystringHandler(context, queryString, rawUrl);
#pragma warning restore 618
// NEW WAY:
ValidatingRequestEventArgs validatingArgs = new ValidatingRequestEventArgs(httpContextBase, queryString);
this.OnValidatingRequest(validatingArgs);
// If the validation has failed based on events, return
if (validatingArgs.Cancel)
{
ImageProcessorBootstrapper.Instance.Logger.Log<ImageProcessingModule>("Image processing has been cancelled by an event");
return;
}
// Re-assign based on event handlers
queryString = validatingArgs.QueryString;
// Break out if we don't meet critera.
bool interceptAll = interceptAllRequests != null && interceptAllRequests.Value;
if (string.IsNullOrWhiteSpace(requestPath) || (!interceptAll && string.IsNullOrWhiteSpace(queryString)))
{
return;
}
// Check whether the path is valid for other requests.
// We've already checked the unprefixed requests in GetImageServiceForRequest().
if (!string.IsNullOrWhiteSpace(prefix) && !currentService.IsValidRequest(requestPath))
{
return;
}
using (await Locker.LockAsync(rawUrl))
{
// Create a new cache to help process and cache the request.
this.imageCache = (IImageCache)ImageProcessorConfiguration.Instance
.ImageCache.GetInstance(requestPath, url, queryString);
// Is the file new or updated?
bool isNewOrUpdated = await this.imageCache.IsNewOrUpdatedAsync();
string cachedPath = this.imageCache.CachedPath;
// Only process if the file has been updated.
if (isNewOrUpdated)
{
byte[] imageBuffer = null;
string mimeType;
try
{
imageBuffer = await currentService.GetImage(requestPath);
}
catch (HttpException ex)
{
// We want 404's to be handled by IIS so that other handlers/modules can still run.
if (ex.GetHttpCode() == (int)HttpStatusCode.NotFound)
{
ImageProcessorBootstrapper.Instance.Logger.Log<ImageProcessingModule>(ex.Message);
return;
}
}
if (imageBuffer == null)
{
return;
}
using (MemoryStream inStream = new MemoryStream(imageBuffer))
{
// Process the Image
MemoryStream outStream = new MemoryStream();
if (!string.IsNullOrWhiteSpace(queryString))
{
// Animation is not a processor but can be a specific request so we should allow it.
bool processAnimation;
AnimationProcessMode mode = this.ParseAnimationMode(queryString, out processAnimation);
// Attempt to match querystring and processors.
IWebGraphicsProcessor[] processors = ImageFactoryExtensions.GetMatchingProcessors(queryString);
if (processors.Any() || processAnimation)
{
// Process the image.
bool exif = preserveExifMetaData != null && preserveExifMetaData.Value;
bool gamma = fixGamma != null && fixGamma.Value;
using (ImageFactory imageFactory = new ImageFactory(exif, gamma) { AnimationProcessMode = mode })
{
imageFactory.Load(inStream).AutoProcess(processors).Save(outStream);
mimeType = imageFactory.CurrentImageFormat.MimeType;
}
}
else if (this.ParseCacheBuster(queryString))
{
// We're cachebustng. Allow the value to be cached
await inStream.CopyToAsync(outStream);
mimeType = FormatUtilities.GetFormat(outStream).MimeType;
}
else
{
// No match? Someone is either attacking the server or hasn't read the instructions.
// Either way throw an exception to prevent caching.
string message = $"The request {request.Unvalidated.RawUrl} could not be understood by the server due to malformed syntax.";
ImageProcessorBootstrapper.Instance.Logger.Log<ImageProcessingModule>(message);
throw new HttpException((int)HttpStatusCode.BadRequest, message);
}
}
else
{
// We're capturing all requests.
await inStream.CopyToAsync(outStream);
mimeType = FormatUtilities.GetFormat(outStream).MimeType;
}
// Fire the post processing event.
EventHandler<PostProcessingEventArgs> handler = OnPostProcessing;
if (handler != null)
{
string extension = Path.GetExtension(cachedPath);
PostProcessingEventArgs args = new PostProcessingEventArgs
{
Context = context,
ImageStream = outStream,
ImageExtension = extension
};
handler(this, args);
outStream = args.ImageStream;
}
// Add to the cache.
await this.imageCache.AddImageToCacheAsync(outStream, mimeType);
// Cleanup
outStream.Dispose();
}
// Store the response type and cache dependency in the context for later retrieval.
context.Items[CachedResponseTypeKey] = mimeType;
bool isFileCached = new Uri(cachedPath).IsFile;
if (isFileLocal)
{
if (isFileCached)
{
// Some services might only provide filename so we can't monitor for the browser.
context.Items[CachedResponseFileDependency] = Path.GetFileName(requestPath) == requestPath
? new[] { cachedPath }
: new[] { requestPath, cachedPath };
}
else
{
context.Items[CachedResponseFileDependency] = Path.GetFileName(requestPath) == requestPath
? null
: new[] { requestPath };
}
}
else if (isFileCached)
{
context.Items[CachedResponseFileDependency] = new[] { cachedPath };
}
}
// The cached file is valid so just rewrite the path.
this.imageCache.RewritePath(context);
// Redirect if not a locally store file.
if (!new Uri(cachedPath).IsFile)
{
context.ApplicationInstance.CompleteRequest();
}
}
}
}
