/// <summary>
/// Asynchronously obtains a grant of <paramref name="requestedBytes"/> for the requesting <paramref name="username"/>.
/// </summary>
/// <remarks>
/// This operation completes when any number of bytes can be granted. The amount returned may be smaller than the
/// requested amount.
/// </remarks>
/// <param name="username">The username of the requesting user.</param>
/// <param name="requestedBytes">The number of requested bytes.</param>
/// <param name="cancellationToken">The token to monitor for cancellation.</param>
/// <returns>The operation context, including the number of bytes granted.</returns>
public Task <int> GetBytesAsync(string username, int requestedBytes, CancellationToken cancellationToken)
{
var group = Users.GetGroup(username);
var bucket = TokenBuckets.GetValueOrDefault(group ?? string.Empty, TokenBuckets[Application.DefaultGroup]);
return(bucket.GetAsync(requestedBytes, cancellationToken));
}
/// <summary>
/// Returns wasted bytes for redistribution.
/// </summary>
/// <param name="username">The username of the user that generated the waste.</param>
/// <param name="attemptedBytes">The number of bytes that were attempted to be transferred.</param>
/// <param name="grantedBytes">The number of bytes granted by all governors in the system.</param>
/// <param name="actualBytes">The actual number of bytes transferred.</param>
public void ReturnBytes(string username, int attemptedBytes, int grantedBytes, int actualBytes)
{
var waste = Math.Max(0, grantedBytes - actualBytes);
if (waste == 0)
{
return;
}
var group = Users.GetGroup(username);
var bucket = TokenBuckets.GetValueOrDefault(group ?? string.Empty, TokenBuckets[Application.DefaultGroup]);
// we don't have enough information to tell whether grantedBytes was reduced by the global limiter within
// Soulseek.NET, so we just return the bytes that we know for sure that were wasted, which is grantedBytes - actualBytes.
// example: we grant 1000 bytes. Soulseek.NET grants only 500. 250 bytes are written. ideally we would return 750
// bytes, but instead we return 250. this discrepancy doesn't really matter because Soulseek.NET is the constraint in
// this scenario and the additional tokens we would return would never be used.
bucket.Return(waste);
}