private void OnRemoteSettingChanged(HTTP2SettingsRegistry registry, HTTP2Settings setting, uint oldValue, uint newValue)
{
switch (setting)
{
case HTTP2Settings.INITIAL_WINDOW_SIZE:
// https://httpwg.org/specs/rfc7540.html#InitialWindowSize
// "Prior to receiving a SETTINGS frame that sets a value for SETTINGS_INITIAL_WINDOW_SIZE,
// an endpoint can only use the default initial window size when sending flow-controlled frames."
// "In addition to changing the flow-control window for streams that are not yet active,
// a SETTINGS frame can alter the initial flow-control window size for streams with active flow-control windows
// (that is, streams in the "open" or "half-closed (remote)" state). When the value of SETTINGS_INITIAL_WINDOW_SIZE changes,
// a receiver MUST adjust the size of all stream flow-control windows that it maintains by the difference between the new value and the old value."
// So, if we created a stream before the remote peer's initial settings frame is received, we
// will adjust the window size. For example: initial window size by default is 65535, if we later
// receive a change to 1048576 (1 MB) we will increase the current remoteWindow by (1 048 576 - 65 535 =) 983 041
// But because initial window size in a setting frame can be smaller then the default 65535 bytes,
// the difference can be negative:
// "A change to SETTINGS_INITIAL_WINDOW_SIZE can cause the available space in a flow-control window to become negative.
// A sender MUST track the negative flow-control window and MUST NOT send new flow-controlled frames
// until it receives WINDOW_UPDATE frames that cause the flow-control window to become positive.
// For example, if the client sends 60 KB immediately on connection establishment
// and the server sets the initial window size to be 16 KB, the client will recalculate
// the available flow - control window to be - 44 KB on receipt of the SETTINGS frame.
// The client retains a negative flow-control window until WINDOW_UPDATE frames restore the
// window to being positive, after which the client can resume sending."
this.remoteWindow += newValue - oldValue;
HTTPManager.Logger.Information("HTTP2Stream", string.Format("[{0}] Remote Setting's Initial Window Updated from {1:N0} to {2:N0}, diff: {3:N0}, new remoteWindow: {4:N0}, total data sent: {5:N0}", this.Id, oldValue, newValue, newValue - oldValue, this.remoteWindow, this.sentData));
break;
}
}
private void OnRemoteSettingChanged(HTTP2SettingsRegistry registry, HTTP2Settings setting, uint oldValue, uint newValue)
{
switch (setting)
{
case HTTP2Settings.INITIAL_WINDOW_SIZE:
this.remoteWindow = newValue - (oldValue - this.remoteWindow);
break;
}
}
public void Merge(HTTP2SettingsRegistry from)
{
if (this.values != null)
{
this.values = new uint[from.values.Length];
}
for (int i = 0; i < this.values.Length; ++i)
{
this.values[i] = from.values[i];
}
}
public HeaderTable(HTTP2SettingsRegistry registry)
{
this.settingsRegistry = registry;
this.MaxDynamicTableSize = this.settingsRegistry[HTTP2Settings.HEADER_TABLE_SIZE];
}
