dec_stream.h

#ifndef QPACKDYN_DEC_STREAM_H
#define QPACKDYN_DEC_STREAM_H
 
#include "common/bytes/span/span.h"
 
/* RFC 9204 4.4. What this decoder owes the peer's encoder on its decoder
 * stream: Section Acknowledgments (4.4.1) queued as sections decode, and an
 * Insert Count Increment (4.4.3) for every insert no acknowledgment already
 * covered, and Stream Cancellations (4.4.2) for streams abandoned before
 * their sections were processed. */

#define QDYN_DEC_ACKS_MAX 512
#define QDYN_DEC_OUT_MAX (QDYN_DEC_ACKS_MAX + 10)

typedef struct {
  u8  acks[QDYN_DEC_ACKS_MAX]; 
  usz acks_len;                
  u64 acked; 
} qdyn_dec;
 
/* RFC 9204 4.4.1: queue a Section Acknowledgment for stream_id when its
 * section's Required Insert Count ric is non-zero. ponytail: the queue only
 * fills if the decoder stream's 64 KB send ring stays full for a step -- a
 * peer granting it no credit; the ack is then dropped (the peer's encoder
 * only keeps those entries pinned). A larger queue if that ever matters. */
void qdyn_dec_section_ack(qdyn_dec* d, u64 stream_id, u64 ric);
 
/* RFC 9204 4.4.2 / 2.2.2.2: queue a Stream Cancellation for stream_id -- a
 * stream reset or abandoned before its field sections were all processed
 * (same queue and full-queue ceiling as qdyn_dec_section_ack). */
void qdyn_dec_stream_cancel(qdyn_dec* d, u64 stream_id);
 
/* RFC 9204 4.4: write the owed bytes -- queued acks, then an Insert Count
 * Increment up to `inserts` (the table's total insert count) -- into out.
 * Consumes nothing; returns out->len. */
usz qdyn_dec_pending(const qdyn_dec* d, u64 inserts, wired_obuf* out);
 
/* The bytes qdyn_dec_pending produced for `inserts` were sent. */
void qdyn_dec_sent(qdyn_dec* d, u64 inserts);
 
#endif