public async Task <IActionResult> Edit(int id, [Bind("CritterImageVariantId,CritterImageModifiedId,CritterImageOriginalId,Height,Timestamp,Width")] CritterImageVariant val)
{
if (val.CritterImageVariantId != id)
{
return(NotFound());
}
this.FixNullFields(val);
if (ModelState.IsValid)
{
try
{
_context.Update(val);
await _context.SaveChangesAsync();
}
catch (DbUpdateConcurrencyException)
{
if (!Exists(val.CritterImageVariantId))
{
return(NotFound());
}
else
{
throw;
}
}
return(RedirectToAction(nameof(Index)));
}
ViewData["CritterImageModifiedId"] = new SelectList(_context.CritterImage, "CritterImageId", "CritterImageId", val.CritterImageModifiedId);
ViewData["CritterImageOriginalId"] = new SelectList(_context.CritterImage, "CritterImageId", "CritterImageId", val.CritterImageOriginalId);
return(View(val));
}
public async Task <IActionResult> Create([Bind("CritterImageVariantId,CritterImageModifiedId,CritterImageOriginalId,Height,Timestamp,Width")] CritterImageVariant val)
{
this.FixNullFields(val);
if (ModelState.IsValid)
{
_context.Add(val);
await _context.SaveChangesAsync();
return(RedirectToAction(nameof(Index)));
}
ViewData["CritterImageModifiedId"] = new SelectList(_context.CritterImage, "CritterImageId", "CritterImageId", val.CritterImageModifiedId);
ViewData["CritterImageOriginalId"] = new SelectList(_context.CritterImage, "CritterImageId", "CritterImageId", val.CritterImageOriginalId);
return(View(val));
}
public async Task <IActionResult> Image(int critterId, int cacheVersion, int?width, int?height, CancellationToken cancelToken)
{
// Limit to only processing a certain amount of image requests, to prevent the rest of the
// website from dying when someone needs to get a lot of images.
while (Interlocked.Read(ref _imageRequestCounter) >= MAX_IMAGE_SIMUL_REQUESTS)
{
await Task.Delay(IMAGE_DELAY_MS);
cancelToken.ThrowIfCancellationRequested();
}
try
{
Interlocked.Increment(ref _imageRequestCounter);
var critter = await this._livestock.Critter.FirstAsync(c => c.CritterId == critterId);
// If the critter has an image, retrieve it.
if (critter.CritterImageId != null)
{
CritterImage image = null;
// If we need a specific size, either retrieve or create it.
if (width != null && height != null)
{
// Prevent exploits
if (width > MAX_IMAGE_RESIZE_WIDTH || height > MAX_IMAGE_RESIZE_HEIGHT)
{
return(BadRequest("Width or height was too high."));
}
if (width < 0 || height < 0)
{
return(BadRequest("Width or height cannot be negative."));
}
var variant = await this._livestock.CritterImageVariant
.FirstOrDefaultAsync(v => v.CritterImageOriginalId == critter.CritterImageId &&
v.Width == width &&
v.Height == height);
if (variant != null)
{
return(await this.GetAndCacheImage(critter, variant.CritterImageModifiedId, cacheVersion, width, height));
}
else
{
variant = new CritterImageVariant
{
CritterImageOriginalId = critter.CritterImageId.Value,
Width = width.Value,
Height = height.Value
};
await this._livestock.Entry(critter).Reference(c => c.CritterImage).LoadAsync();
image = critter.CritterImage;
// Resize it, then upload it so it's cached.
var resized = await this.ResizeImageAsyncPOOLED(image.Data, width.Value, height.Value);
image = new CritterImage
{
Data = resized
};
variant.CritterImageModified = image;
try
{
await this._livestock.CritterImage.AddAsync(image);
await this._livestock.CritterImageVariant.AddAsync(variant);
await this._livestock.SaveChangesAsync();
}
finally // I can count on one hand the amount of times I've used 'finally'.
{
// We detach the entity, since the image data shouldn't be reference anymore once it's returned.
// And if we set it to 'null', then we can accidentally remove the image data if we save at some point.
// So it's safer to just detach it, and take the performance hit of downloading a new version of it when needed.
this._livestock.Entry(image).State = EntityState.Detached;
_imageBufferPool.Return(resized);
}
return(File(image.Data, "image/png"));
}
}
else // Otherwise, return the original.
{
return(await this.GetAndCacheImage(critter, critter.CritterImageId.Value, cacheVersion, width, height));
}
}
else
{
return(Redirect("/images/icons/default.png"));
}
}
finally
{
Interlocked.Decrement(ref _imageRequestCounter);
}
}
private void FixNullFields(CritterImageVariant val)
{
}
