/// <exception cref="DiscordHttpApiException"></exception>
async Task <DiscordApiData> ParseResponse(HttpResponseMessage response, RateLimitHeaders rateLimitHeaders)
{
// Read response payload as string
string json;
if (response.StatusCode == HttpStatusCode.NoContent)
{
json = null;
}
else
{
json = await response.Content.ReadAsStringAsync().ConfigureAwait(false);
}
// Attempt to parse the payload as JSON.
DiscordApiData data;
if (DiscordApiData.TryParseJson(json, out data))
{
if (response.IsSuccessStatusCode)
{
// If successful, no more action is required.
return(data);
}
else
{
string message = null;
DiscordHttpErrorCode errorCode = DiscordHttpErrorCode.None;
// Get the Discord-specific error code if it exists.
if ((int)response.StatusCode == 429)
{
errorCode = DiscordHttpErrorCode.TooManyRequests;
}
else if (data.ContainsKey("code"))
{
long?code = data.GetInt64("code");
if (code.HasValue)
{
errorCode = (DiscordHttpErrorCode)code;
}
}
// Get the message.
if (data.ContainsKey("content"))
{
IList <DiscordApiData> content = data.GetArray("content");
StringBuilder sb = new StringBuilder();
for (int i = 0; i < content.Count; i++)
{
sb.Append(content[i]);
if (i < content.Count - 1)
{
sb.Append(", ");
}
}
message = sb.ToString();
}
else if (data.ContainsKey("message"))
{
message = data.GetString("message");
}
else if (response.StatusCode == HttpStatusCode.BadRequest && data.Type == DiscordApiDataType.Container)
{
StringBuilder sb = new StringBuilder();
foreach (KeyValuePair <string, DiscordApiData> pair in data.Entries)
{
sb.Append($"{pair.Key}: ");
if (pair.Value.Type != DiscordApiDataType.Array)
{
// Shouldn't happen, but if it does then this error is not one we can parse.
// Set sb to null so that message ends up null and let the application get
// the raw JSON payload so they at least know what happened until we can
// implement the correct parser.
sb = null;
break;
}
bool addComma = false;
foreach (DiscordApiData errorData in pair.Value.Values)
{
if (addComma)
{
sb.Append(", ");
}
sb.Append(errorData.ToString());
addComma = true;
}
sb.AppendLine();
}
message = sb?.ToString();
}
// Throw the appropriate exception
if (message != null) // If null, let the "unknown error" exception be thrown
{
if ((int)response.StatusCode == 429 && rateLimitHeaders != null)
{
throw new DiscordHttpRateLimitException(rateLimitHeaders, message, errorCode, response.StatusCode);
}
else
{
throw new DiscordHttpApiException(message, errorCode, response.StatusCode);
}
}
}
}
throw new DiscordHttpApiException($"Unknown error. Response: {json}",
DiscordHttpErrorCode.None, response.StatusCode);
}
/// <exception cref="DiscordHttpApiException"></exception>
public async Task <DiscordApiData> Send(Func <HttpRequestMessage> requestCreate, string rateLimitRoute,
CancellationToken?cancellationToken = null)
{
CancellationToken ct = cancellationToken ?? CancellationToken.None;
// Get or create the rate limit lock for the specified route
RateLimitLock routeLock;
if (!routeRateLimitLocks.TryGetValue(rateLimitRoute, out routeLock))
{
routeLock = new RateLimitLock();
routeRateLimitLocks[rateLimitRoute] = routeLock;
}
// Acquire route-specific lock
using (await routeLock.LockAsync(ct).ConfigureAwait(false))
{
HttpResponseMessage response;
RateLimitHeaders rateLimitHeaders;
bool retry = false;
int attempts = 0;
IDisposable globalLock = null;
do
{
retry = false;
attempts++;
// If the route-specific lock requires a wait, delay before continuing
await routeLock.WaitAsync(ct).ConfigureAwait(false);
// If we don't already have the global lock and the global rate limit is active, acquire it.
if (globalLock == null && globalRateLimitLock.RequiresWait)
{
globalLock = await globalRateLimitLock.LockAsync(ct).ConfigureAwait(false);
}
bool keepGlobalLock = false;
try
{
// If we have the global lock, delay if it requires a wait
if (globalLock != null)
{
await globalRateLimitLock.WaitAsync(ct).ConfigureAwait(false);
}
// Send request
if (globalHttpClient != null)
{
response = await globalHttpClient.SendAsync(requestCreate(), ct).ConfigureAwait(false);
}
else
{
using (HttpClient http = CreateHttpClient())
{
response = await http.SendAsync(requestCreate(), ct).ConfigureAwait(false);
}
}
// Check rate limit headers
rateLimitHeaders = RateLimitHeaders.ParseOrNull(response.Headers);
if (rateLimitHeaders != null)
{
if ((int)response.StatusCode == 429)
{
// Tell the appropriate lock to wait
if (rateLimitHeaders.IsGlobal)
{
globalRateLimitLock.ResetAfter(rateLimitHeaders.RetryAfter.Value);
}
else
{
routeLock.ResetAfter(rateLimitHeaders.RetryAfter.Value);
}
retry = RetryOnRateLimit && attempts < 20;
// If we are retrying from a global rate limit, don't release the lock
// so this request doesn't go to the back of the queue.
keepGlobalLock = retry && rateLimitHeaders.IsGlobal;
}
else
{
// If the request succeeded but we are out of calls, set the route lock
// to wait until the reset time.
if (rateLimitHeaders.Remaining == 0)
{
routeLock.ResetAt(rateLimitHeaders.Reset);
}
}
}
// Check if the request received a bad gateway
if (response.StatusCode == HttpStatusCode.BadGateway)
{
retry = attempts < 10;
}
// Release the global lock if necessary
if (globalLock != null && !keepGlobalLock)
{
globalLock.Dispose();
}
}
catch
{
// Always release the global lock if we ran into an exception
globalLock?.Dispose();
// Don't suppress the exception
throw;
}
}while (retry);
return(await ParseResponse(response, rateLimitHeaders).ConfigureAwait(false));
}
}
