/// <summary>
/// Helper method that returns the redirect url or null
/// </summary>
/// <param name="path">The path to get the redirect url for</param>
/// <returns>The target url, or <c>null</c></returns>
public async Task <string> GetRedirecLinkAsync(string path)
{
if (!FoundCache.TryGetValue(path, out var le))
{
var notFound = await NotFoundCache.TryGetUnlessAsync(path, (a, b) => b < DateTime.Now);
if (notFound.Key)
{
return(null);
}
le = await DB.RunInTransactionAsync(db => db.SelectSingle <LinkEntry>(x => x.Match == path));
if (le == null)
{
await NotFoundCache.AddOrReplaceAsync(path, DateTime.Now.Add(ExpireTimeout));
}
else
{
await FoundCache.AddOrReplaceAsync(path, le);
}
}
if (le != null && le.Enabled && le.IsActive)
{
return(le.TargetUrl);
}
return(null);
}
public async Task <IResult> Get(
[Parameter(ParameterSource.Url)]
string id,
[Parameter(ParameterSource.Query, required: false, name: "w")]
int w = 0,
[Parameter(ParameterSource.Query, required: false, name: "h")]
int h = 0
)
{
if (string.IsNullOrWhiteSpace(id))
{
return(NotFound);
}
// Clamp the values
w = Math.Min(Math.Max(0, w), MAX_DIMENSIONS);
h = Math.Min(Math.Max(0, h), MAX_DIMENSIONS);
var mapentry = await DB.RunInTransactionAsync(db => db.SelectItemById <Database.ImageMap>(id));
if (mapentry == null)
{
return(NotFound);
}
var resp = Context.Response;
if (w == 0 && h == 0)
{
if (!string.IsNullOrWhiteSpace(mapentry.Sha256) && string.Equals(mapentry.Sha256, Context.Request.Headers["If-None-Match"]))
{
return(Status(HttpStatusCode.NotModified));
}
var fi = new FileInfo(mapentry.Path);
if (!fi.Exists)
{
return(NotFound);
}
resp.ContentLength = fi.Length;
if (!string.IsNullOrWhiteSpace(mapentry.ContentType))
{
resp.ContentType = mapentry.ContentType;
}
resp.StatusCode = HttpStatusCode.OK;
resp.SetExpires(TimeSpan.FromHours(6));
if (!string.IsNullOrWhiteSpace(mapentry.Sha256))
{
resp.AddHeader("ETag", mapentry.Sha256);
}
await resp.FlushHeadersAsync();
using (var s = File.OpenRead(mapentry.Path))
using (var rs = resp.GetResponseStream())
await s.CopyToAsync(rs);
return(null);
}
var url = SyntheticUrl(id, w, h);
if (!m_resizecache.TryGetValue(url, out var data))
{
using (var img = Image.Load(mapentry.Path, out var format))
using (var ms = new MemoryStream())
using (var sha256 = System.Security.Cryptography.SHA256.Create())
{
var enc = GetEncoder(format.Name);
img.Mutate(x => x.Resize(w, h));
img.Metadata.ExifProfile = null;
img.Save(ms, enc);
var bytes = ms.ToArray();
data = new KeyValuePair <string, byte[]>(Convert.ToBase64String(sha256.ComputeHash(bytes)), bytes);
}
await m_resizecache.AddOrReplaceAsync(url, data);
}
else
{
if (string.Equals(data.Key, Context.Request.Headers["If-None-Match"]))
{
return(Status(HttpStatusCode.NotModified));
}
}
resp.ContentLength = data.Value.Length;
if (!string.IsNullOrWhiteSpace(mapentry.ContentType))
{
resp.ContentType = mapentry.ContentType;
}
resp.StatusCode = HttpStatusCode.OK;
resp.SetExpires(TimeSpan.FromHours(6));
resp.AddHeader("ETag", data.Key);
await resp.FlushHeadersAsync();
using (var rs = resp.GetResponseStream())
await rs.WriteAsync(data.Value, 0, data.Value.Length);
return(null);
}
