/// <summary>
/// Queries ESI to send a request.
/// </summary>
/// <typeparam name="T">The type of the response.</typeparam>
/// <param name="method">The HTTP method to use when making the request.</param>
/// <param name="request">The ESI request to make.</param>
/// <param name="content">The content to send with the request.</param>
/// <returns>The data from the ESI request.</returns>
private async Task <EsiResult <T> > QueryEsiAsync <T>(HttpMethod method,
EsiRequestHeaders request, HttpContent content = null)
{
string url = await request.GetESIUrlAsync(Language).ConfigureAwait(false);
var message = new HttpRequestMessage(method, url);
if (content != null)
{
// Update content type if requested
string contentType = request.ContentType.GetAttributeOfType <
DescriptionAttribute>()?.Description;
if (contentType != null && content.Headers != null)
{
content.Headers.ContentType.MediaType = contentType;
}
message.Content = content;
}
EsiResult <T> esiResult;
// If previous request expiration is available, add ETag/If-Modified-Since
request.CacheInfo?.AddRequestHeaders(message.Headers);
try {
using (var response = await client.SendAsync(message).ConfigureAwait(false)) {
esiResult = await HandleResponseAsync <T>(response);
}
} catch (IOException e) {
// I/O errors become EsiResultStatus.NetworkError
esiResult = new EsiResult <T>(EsiResultStatus.NetworkError, default(T), e);
} catch (TimeoutException e) {
// Time outs become EsiResultStatus.NetworkError
esiResult = new EsiResult <T>(EsiResultStatus.NetworkError, default(T), e);
} catch (OperationCanceledException e) {
// Cancellations become EsiResultStatus.NetworkError
esiResult = new EsiResult <T>(EsiResultStatus.NetworkError, default(T), e);
}
return(esiResult);
}
/// <summary>
/// Handles a response from ESI.
/// </summary>
/// <typeparam name="T">The type of the response.</typeparam>
/// <param name="response">The response message from the server.</param>
/// <returns>The data from the ESI request.</returns>
private async Task <EsiResult <T> > HandleResponseAsync <T>(HttpResponseMessage response)
{
var headers = response.Headers;
var received = DateTime.UtcNow;
EsiResult <T> result;
headers.ThrowIfNull(nameof(headers));
// Update error count
int?ec = GetIntParam(headers, "X-Esi-Error-Limit-Remain");
if (ec != null)
{
errorCount = (int)ec;
}
// Update error count refresh time, no more than 2 minutes in the future
int?ecReset = GetIntParam(headers, "X-Esi-Error-Limit-Reset");
if (ecReset != null)
{
errorCountRefresh = received.AddSeconds(Math.Min((int)ecReset, 120));
}
var status = ToEsiStatusCode(response.StatusCode);
int pages = GetIntParam(headers, "X-Pages") ?? 0;
if (pages < 1)
{
pages = 1;
}
if (status == EsiResultStatus.OK)
{
try {
// Parse the ESI payload, content should not be null if response was OK
var serializer = new JsonSerializer {
DateTimeZoneHandling = DateTimeZoneHandling.Utc
};
var content = response.Content;
content.ThrowIfNull(nameof(content));
using (var jr = new JsonTextReader(new StreamReader(await content.
ReadAsStreamAsync(), Encoding.UTF8))) {
jr.CloseInput = true;
// JSON parsing
result = new EsiResult <T>(status, serializer.Deserialize <T>(jr))
{
CacheInfo = new EsiCacheInfo(headers.ETag?.Tag, content.Headers.
Expires?.UtcDateTime ?? received),
Pages = pages
};
// Determine date and time on the server, no more laggy NIST time sync
var serverDate = headers.Date;
if (serverDate != null)
{
result.ServerTime = ((DateTimeOffset)serverDate).UtcDateTime;
}
jr.Close();
}
} catch (JsonException e) {
// JSON parse failures become EsiResultStatus.Error
result = new EsiResult <T>(EsiResultStatus.Error, default(T), e);
}
}
else
{
result = new EsiResult <T>(status);
}
return(result);
}