public void ReplenishUpToMaximum()
{
now = DateTime.UtcNow;
var b = new LeakyBucket(10, 2, () => now);
Assert.Equal(10, b.ComputedCurrentlyAvailable);
Assert.True(b.WaitForAvailableAsync(5).IsCompleted);
Assert.Equal(5, b.ComputedCurrentlyAvailable);
now = now.AddSeconds(1);
Assert.Equal(7, b.ComputedCurrentlyAvailable);
now = now.AddSeconds(1);
Assert.Equal(9, b.ComputedCurrentlyAvailable);
now = now.AddSeconds(1);
Assert.Equal(10, b.ComputedCurrentlyAvailable);
b.SetState(20, 3, b.ComputedCurrentlyAvailable);
now = now.AddSeconds(1);
Assert.Equal(13, b.ComputedCurrentlyAvailable);
now = now.AddSeconds(2);
Assert.Equal(19, b.ComputedCurrentlyAvailable);
now = now.AddSeconds(1);
Assert.Equal(20, b.ComputedCurrentlyAvailable);
}
public async Task <RequestResult <T> > Run <T>(CloneableRequestMessage baseRequest, ExecuteRequestAsync <T> executeRequestAsync, CancellationToken cancellationToken)
{
var accessToken = GetAccessToken(baseRequest);
LeakyBucket bucket = null;
if (accessToken != null)
{
bucket = _shopAccessTokenToLeakyBucket.GetOrAdd(accessToken, _ => new LeakyBucket());
}
while (true)
{
var request = baseRequest.Clone();
if (accessToken != null)
{
await bucket.GrantAsync();
}
try
{
var fullResult = await executeRequestAsync(request);
var bucketState = LeakyBucketState.Get(fullResult.Response);
if (bucketState != null)
{
bucket?.SetState(bucketState);
}
return(fullResult);
}
catch (ShopifyRateLimitException ex) when(ex.Reason == ShopifyRateLimitReason.BucketFull || !_retryOnlyIfLeakyBucketFull)
{
//Only retry if breach caused by full bucket
//Other limits will bubble the exception because it's not clear how long the program should wait
//Even if there is a Retry-After header, we probably don't want the thread to sleep for potentially many hours
//
//An exception may still occur:
//-Shopify may have a slightly different algorithm
//-Shopify may change to a different algorithm in the future
//-There may be timing and latency delays
//-Multiple programs may use the same access token
//-Multiple instances of the same program may use the same access token
await Task.Delay(THROTTLE_DELAY, cancellationToken);
}
}
}
public async Task <T> Run <T>(CloneableRequestMessage baseRequest, ExecuteRequestAsync <T> executeRequestAsync)
{
var accessToken = GetAccessToken(baseRequest);
LeakyBucket bucket = null;
if (accessToken != null)
{
bucket = _shopAccessTokenToLeakyBucket.GetOrAdd(accessToken, _ => new LeakyBucket());
}
while (true)
{
var request = baseRequest.Clone();
if (accessToken != null)
{
await bucket.GrantAsync();
}
try
{
var fullResult = await executeRequestAsync(request);
var bucketState = GetBucketState(fullResult.Response);
if (bucketState != null)
{
bucket?.SetState(bucketState);
}
return(fullResult.Result);
}
catch (SquareSpaceRateLimitException)
{
//An exception may still occur:
//-SquareSpace may have a slightly different algorithm
//-SquareSpace may change to a different algorithm in the future
//-There may be timing and latency delays
//-Multiple programs may use the same access token
//-Multiple instances of the same program may use the same access token
await Task.Delay(THROTTLE_DELAY);
}
}
}
