TsgcHTTP3Server › Methods › QPACKDynamicInserts
Reports how many QPACK dynamic-table insertions the response encoders have performed.
function QPACKDynamicInserts: Integer;The largest insertion count reported by any single connection's response encoder, or 0 when no connection has been established yet or no dynamic entry has been inserted. (Integer)
QPACK (RFC 9204) compresses HTTP/3 header fields against a static table and an optional per-connection dynamic table. The server enables dynamic-table encoding on the response direction once a client advertises a non-zero QPACK table capacity in its SETTINGS frame, bounded by a local maximum of 4096 bytes. Each field the encoder adds to that table is an insertion, and QPACKDynamicInserts exposes the running count.
The value is the maximum across all current connections rather than a sum, because the dynamic table is per connection: it answers "how deeply has dynamic encoding been used on the busiest connection", which is the useful signal when checking that dynamic compression is engaging at all. A value that stays at zero while clients are sending traffic means responses are being encoded against the static table only, typically because the client advertised a QPACK capacity of zero.
This is a diagnostic counter intended for verification, tests and logging. It has no effect on the protocol, and it is reset implicitly when connections close and their encoders are released.
This member is currently available in the Delphi/C++Builder implementation only.
Log('QPACK dynamic inserts: ' + IntToStr(oServer.QPACKDynamicInserts));