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Update ImageResizerMiddleware.cs #18

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88 changes: 70 additions & 18 deletions ImageResizer.AspNetCore/ImageResizerMiddleware.cs
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Original file line number Diff line number Diff line change
@@ -1,4 +1,4 @@
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Caching.Memory;
using Microsoft.Extensions.Logging;
Expand All @@ -13,6 +13,8 @@
using Newtonsoft.Json;
using ImageResizer.AspNetCore.Models;
using Microsoft.Extensions.FileProviders;
using System.Security.Cryptography;
using System.Text;

namespace ImageResizer.AspNetCore
{
Expand All @@ -25,6 +27,8 @@ public class ImageResizerMiddleware
private readonly IFileProvider _fileProvider;
private WatermarkTextModel watermarkText;
private WatermarkImageModel watermarkImage;
private const bool CACHE_MEMORY = false;
private const bool CACHE_DISK = true;

private static readonly string[] suffixes = new string[] {
".png",
Expand All @@ -33,9 +37,9 @@ public class ImageResizerMiddleware
};

public ImageResizerMiddleware(
RequestDelegate req,
IWebHostEnvironment env,
ILogger<ImageResizerMiddleware> logger,
RequestDelegate req,
IWebHostEnvironment env,
ILogger<ImageResizerMiddleware> logger,
IMemoryCache memoryCache,
IFileProvider fileProvider)
{
Expand Down Expand Up @@ -95,9 +99,8 @@ public async Task InvokeAsync(HttpContext context)
}
}

// if we got this far, resize it
_logger.LogInformation($"Resizing {path.Value} with params {resizeParams}");
var imagePath = _fileProvider.GetFileInfo(path.Value).PhysicalPath;
// if we got this far, resize it
var imagePath = _fileProvider.GetFileInfo(path.Value).PhysicalPath;
//// get the image location on disk
//var imagePath = Path.Combine(
// rootPath.Replace("\\wwwroot", ""),
Expand All @@ -111,33 +114,57 @@ public async Task InvokeAsync(HttpContext context)
return;
}

var imageData = GetImageData(imagePath, resizeParams, lastWriteTimeUtc);
var imageData = await GetImageData(imagePath, resizeParams, lastWriteTimeUtc);

// write to stream
context.Response.ContentType = resizeParams.format == "png" ? "image/png" : "image/jpeg";
context.Response.ContentLength = imageData.Size;

// Configure caching for static files
//const int durationInSeconds = 60 * 60 * 24 * 30; // 30 days
//context.Response.Headers[Microsoft.Net.Http.Headers.HeaderNames.CacheControl] =
// "public,max-age=" + durationInSeconds;
//context.Response.Headers[Microsoft.Net.Http.Headers.HeaderNames.Expires] =
// new[] { (DateTime.UtcNow.AddSeconds(durationInSeconds)).ToString("R") }; // RFC1123 format

await context.Response.Body.WriteAsync(imageData.ToArray(), 0, (int)imageData.Size);

// cleanup
imageData.Dispose();

}
private SKData GetImageData(string imagePath, ResizeParams resizeParams, DateTime lastWriteTimeUtc)
private async Task<SKData> GetImageData(string imagePath, ResizeParams resizeParams, DateTime lastWriteTimeUtc)
{
// check cache and return if cached
long cacheKey;
string cacheKey;
unchecked
{
cacheKey = imagePath.GetHashCode() + lastWriteTimeUtc.ToBinary() + resizeParams.ToString().GetHashCode();
//+ lastWriteTimeUtc.ToBinary()
cacheKey = CreateMD5(imagePath + resizeParams.ToString());
}

SKData imageData;
bool isCached = _memoryCache.TryGetValue(cacheKey, out byte[] imageBytes);
if (isCached)
var diskCachedPath = "";
if (CACHE_MEMORY)
{
_logger.LogInformation("Serving from cache");
bool isCached = _memoryCache.TryGetValue(cacheKey, out byte[] imageBytes);
_logger.LogInformation("Serving from memory cache");
return SKData.CreateCopy(imageBytes);
}
else if (CACHE_DISK)
{
var ext = Path.GetExtension(imagePath);
var name = Path.GetFileNameWithoutExtension(imagePath);
var nameWithExt = Path.GetFileName(imagePath);
diskCachedPath = imagePath.Replace(nameWithExt, $"{name}_cached_{cacheKey}{ext}");
if (File.Exists(diskCachedPath))
{
_logger.LogInformation("Serving from disk cache");
return SKData.CreateCopy(await File.ReadAllBytesAsync(diskCachedPath));
}
}

_logger.LogInformation($"Resizing {imagePath} with params {resizeParams}");

using (var fs = File.OpenRead(imagePath))
{
Expand Down Expand Up @@ -210,9 +237,16 @@ private SKData GetImageData(string imagePath, ResizeParams resizeParams, DateTim
var encodeFormat = resizeParams.format == "png" ? SKEncodedImageFormat.Png : SKEncodedImageFormat.Jpeg;
imageData = resizedImage.Encode(encodeFormat, resizeParams.quality);

// cache the result
_memoryCache.Set(cacheKey, imageData.ToArray());

if (CACHE_MEMORY)
{
// cache the result
_memoryCache.Set(cacheKey, imageData.ToArray());
}
else if (CACHE_DISK)
{
//disk cache
await File.WriteAllBytesAsync(diskCachedPath, imageData.ToArray());
}
// cleanup
resizedImage.Dispose();
bitmap.Dispose();
Expand All @@ -221,7 +255,25 @@ private SKData GetImageData(string imagePath, ResizeParams resizeParams, DateTim
return imageData;
}
}
private string CreateMD5(string input)
{
// Use input string to calculate MD5 hash
using (System.Security.Cryptography.MD5 md5 = System.Security.Cryptography.MD5.Create())
{
byte[] inputBytes = System.Text.Encoding.ASCII.GetBytes(input);
byte[] hashBytes = md5.ComputeHash(inputBytes);

//return Convert.ToHexString(hashBytes); // .NET 5 +

//Convert the byte array to hexadecimal string prior to.NET 5
StringBuilder sb = new System.Text.StringBuilder();
for (int i = 0; i < hashBytes.Length; i++)
{
sb.Append(hashBytes[i].ToString("X2"));
}
return sb.ToString();
}
}
private SKBitmap LoadBitmap(Stream stream, out SKEncodedOrigin origin)
{
using (var s = new SKManagedStream(stream))
Expand Down Expand Up @@ -277,7 +329,7 @@ private ResizeParams GetResizeParams(PathString path, IQueryCollection query)
if (query.ContainsKey("autorotate"))
bool.TryParse(query["autorotate"], out resizeParams.autorotate);

int quality = 100;
int quality = 80;
if (query.ContainsKey("quality"))
int.TryParse(query["quality"], out quality);
resizeParams.quality = quality;
Expand Down