TsgcHTTP3Client › Methods › BlockedThenResumedCount
Returns how many response header sections were blocked on QPACK inserts and later resumed.
function BlockedThenResumedCount: Integer;Number of response field sections that had to wait for QPACK encoder-stream insertions before they could be decoded. (Integer)
A QPACK header block can reference dynamic-table entries that have not arrived yet, because the encoder stream and the request streams are delivered independently over QUIC. RFC 9204 Section 2.2.1 calls such a stream blocked. The client buffers the header block, and any DATA or trailer frames that follow it, until the missing insertions arrive on the encoder stream, then decodes it and delivers the response as usual.
This counter reports how many response header sections went through that block-and-resume path. Blocking is normal and handled transparently, so a non-zero value is not an error. A persistently high count means the peer encoder is referencing very recent insertions and adding latency, which can be reduced by lowering QPACKBlockedStreams in Settings.
The counter starts at zero when the component is created and is not reset per request. Use it together with QPACKDynamicInserts when verifying compression behaviour.
This member is currently available in the Delphi/C++Builder implementation only.
ShowMessage(Format('blocked then resumed: %d',
[oClient.BlockedThenResumedCount]));