public Task <string> GetTokenAsync(HttpContext context, bool createIfNotExists)
{
string current = context.Request.Cookies[_cookieName];
if (current == null && createIfNotExists)
{
return(GenerateAndSetCookie());
}
return(Task.FromResult(current));
async Task <string> GenerateAndSetCookie()
{
long next;
using (CancellationTokenSource source = new CancellationTokenSource(TimeSpan.FromSeconds(1.5)))
{
Sequence actual = await _authorizedUsersSequence.GetNextSequenceValue(source.Token).ConfigureAwait(false);
next = actual.Value;
}
string value = _converter.GenerateKey(next);
context.Response.Cookies.Append(_cookieName, value);
return(value);
}
}
public Task <string> Compress(string url)
{
if (!Uri.IsWellFormedUriString(url, UriKind.Absolute))
{
Response.StatusCode = 400; // bad request
return(Task.FromResult("Error: url should be absolute")); // don't allocate an async state machine if user provided invalid input
}
return(CompressInternal());
async Task <string> CompressInternal()
{
string userKey = await _authTokenProvider.GetTokenAsync(HttpContext, createIfNotExists : true).ConfigureAwait(false);
long newlyGeneratedLinkId;
Sequence seq = await _sequenceProvider.GetSequenceAsync("linksSequence_" + userKey).ConfigureAwait(false);
using (CancellationTokenSource source = new CancellationTokenSource(_defaultTimeout))
{
seq = await seq.GetNextSequenceValue(source.Token).ConfigureAwait(false);
newlyGeneratedLinkId = seq.Value;
}
string key = String.Concat(userKey, "~", _converter.GenerateKey(newlyGeneratedLinkId));
long userId = _converter.RegenerateId(userKey);
ShortenedLinkModel model = new ShortenedLinkModel {
Id = new ShortenedLinkModelId {
LinkId = newlyGeneratedLinkId, UserId = userId
}, Key = key, Value = url
};
using (CancellationTokenSource source = new CancellationTokenSource(_defaultTimeout))
await _links.InsertOneAsync(model, _insertOptions, source.Token).ConfigureAwait(false);
return(model.Key);
}
}
