private async Task <bool> FetchIsOn(IFeatureEvaluationRequest request, CancellationToken token = default)
{
var httpRequest = request.ToHttpRequestMessage();
if (!token.IsCancellationRequested)
{
try
{
var response = await this._client.SendAsync(httpRequest, token);
if (response.IsSuccessStatusCode)
{
return(await response.Content.ReadFromJsonAsync <bool>(this._jsonOptions, token));
}
var content = await response.Content.ReadAsStringAsync(token);
var e = new FailedToCommunicateWithEvaluationsException(response, content);
throw e;
}
catch (Exception e)
{
this._logger.LogError(e, $"An error occurred while requesting if feature was On ${e.Message}.");
throw;
}
}
throw new OperationCanceledException("Cancellation was requested while attempting to request feature IsOn.");
}
public async Task <bool> isOn(IFeatureEvaluationRequest request, Func <Task <bool> > isOnTask)
{
return(await this._cache.GetOrCreateAsync(request.GetCacheKey(), entry =>
{
entry.SlidingExpiration = this._configuration.CacheTimeout;
return isOnTask();
}));
}
public async Task <bool> IsOn(IFeatureEvaluationRequest request, CancellationToken token = default)
{
if (!token.IsCancellationRequested)
{
return(await this._cache.isOn(request, () => this.FetchIsOn(request, token)));
}
throw new OperationCanceledException("Cancellation was requested while attempting to evaluate the cache for feature IsOn.");
}
internal static IFeatureEvaluationRequest WithStrategies(
this IFeatureEvaluationRequest request,
params string[] strategies)
{
return(new FeatureEvaluationRequest
{
Name = request.Name,
Path = request.Path,
Strategies = strategies.Select(_ => new KeyValuePair <string, string>(_, _))
});
}
internal static HttpRequestMessage ToHttpRequestMessage(
this IFeatureEvaluationRequest request)
{
var encoder = UrlEncoder.Default;
var builder = new UriBuilder();
builder.Path = "features";
var query = HttpUtility.ParseQueryString(builder.Query);
query["name"] = encoder.Encode(request.Name);
query["path"] = encoder.Encode(request.Path);
builder.Query = query.ToString();
var httpRequestMessage = new HttpRequestMessage(
HttpMethod.Get,
new Uri($"{builder.Path}?{builder.Query}", UriKind.Relative));
foreach (var(key, value) in request.Strategies)
{
httpRequestMessage.Headers.TryAddWithoutValidation(key, value);
}
return(httpRequestMessage);
}
public Task <bool> isOn(IFeatureEvaluationRequest request, Func <Task <bool> > isOnTask)
{
return(Task.FromResult(this._expected));
}
public Task <bool> isOn(IFeatureEvaluationRequest request, Func <Task <bool> > isOnTask)
{
return(isOnTask());
}
private FeatureEvaluationRequestBuilder(IFeatureEvaluationRequest request)
{
this._request = request;
}
internal FeatureEvaluationRequestBuilder()
{
this._request = new FeatureEvaluationRequest();
}
internal static string GetCacheKey(this IFeatureEvaluationRequest request)
{
var strategies = request.Strategies.OrderBy(_ => _.Key).Select(_ => _.Key + _.Value);
return($"${request.Name}${request.Path}${string.Join("_", strategies)}");
}
