public async Task <string> GetOrCreate(URLShortenDBContext context)
{
while (await _cache_req.WaitToReadAsync())
{
while (_cache_req.TryRead(out var key))
{
if (!_cache.TryGetValue(key, out string cacheEntry))// Look for cache key.
{
// Key not in cache, so get data.
//TODO: Handle null values way more elegantly
var urlViewModel = context?.UrlViewModels?
.Where(x => x.ShortAddress == key && x.Active == true)?
.FirstOrDefault();
cacheEntry = urlViewModel?.Address ?? "not found";
if (cacheEntry != "not found")
{
_cache.Set(key, cacheEntry);
}
}
return(cacheEntry);
}
}
//TODO: Think of something better than this
return("error");
}
public async Task <string> GetOrCreate(string key, URLShortenDBContext context)
{
var _channel = Channel.CreateUnbounded <string>(new UnboundedChannelOptions()
{
SingleWriter = true,
SingleReader = false
});
var _crequest = new CacheRequest(_channel.Writer, 1);
var _cset = new CacheSet(_channel.Reader, 1);
var _cset2 = new CacheSet(_channel.Reader, 2);
var _cset3 = new CacheSet(_channel.Reader, 3);
await _crequest.GetCache(key)
.ContinueWith(_ => _channel.Writer.Complete());
var address = await Task.WhenAny(_cset.GetOrCreate(context), _cset2.GetOrCreate(context), _cset3.GetOrCreate(context));
return(await address);
}
public static void Init(IServiceProvider svc)
{
using (var context = new URLShortenDBContext(svc.GetRequiredService <DbContextOptions <URLShortenDBContext> >()))
{
//We need to initially set at least one admin here
if (!context.AdminModel.Any())
{
context.AdminModel.AddRange(
new Models.AdminModel
{
User = "******",
Groups = ""
}
);
}
if (context.UrlViewModels.Any())
{
return;
}
context.UrlViewModels.AddRange(
new Models.UrlViewModel
{
Active = true,
Address = "https://mydomain.com",
ShortAddress = "QGe8i",
UrlHash = 12345,
Created = DateTime.Now,
Title = "Alachua County",
User = "******"
}
);
context.SaveChanges();
}
}
public UrlCache(IServiceProvider svc)
{
if (_cache == null)
{
_cache = new MemoryCache(new MemoryCacheOptions());
//constructor should init cache and set it
using (var context = new URLShortenDBContext(svc.GetRequiredService <DbContextOptions <URLShortenDBContext> >()))
{
var cacheEntries = context.UrlViewModels
.Where(c => c.Active == true)
.Select(c => new { c.ShortAddress, c.Address })
.ToList();
foreach (var entry in cacheEntries)
{
_cache.Set(entry.ShortAddress, entry.Address);
}
}
}
}
