enc_stream.h

#ifndef QPACKDYN_ENC_STREAM_H
#define QPACKDYN_ENC_STREAM_H
 
#include "app/qpack/qpack/dyntable.h"
 
/* RFC 9204 4.3. Decode the one encoder-stream instruction at buf's head and
 * apply it to t: Set Dynamic Table Capacity (4.3.1, bounded by the server's
 * advertised max, 5), Insert With Name Reference (4.3.2, static or dynamic
 * name), Insert With Literal Name (4.3.3) or Duplicate (4.3.4). Returns the
 * bytes consumed; 0 with *err untouched while the instruction is not whole
 * in buf yet; 0 with *err = QPACK_ENCODER_STREAM_ERROR when it is invalid --
 * a capacity past max, an entry larger than the capacity, a name/duplicate
 * reference to no live entry, or a bad string. */
usz qdyn_enc_apply(wired_span buf, qpack_dyn* t, u64 max, u16* err);

#define QDYN_ENCRX_CAP 49152

typedef struct {
  u8 buf[QDYN_ENCRX_CAP]; 
  u8  have[QDYN_ENCRX_CAP / 8];
  u64 base; 
  usz hi;   
  u64 stream_id;
  usz type_len;
} qdyn_encrx;
 
/* Start holding stream_id's bytes (0: none), dropping anything held. */
void qdyn_encrx_take(qdyn_encrx* rx, u64 stream_id);
 
/* Land d at stream offset off of the held stream. While unidentified, once
 * the leading type varint is whole: the encoder type (RFC 9204 4.2) claims
 * the stream, any other type lets it go (qdyn_encrx_take(rx, 0)). Once
 * claimed, apply every whole instruction now contiguous from base to t.
 * Returns 1 ok, 0 with *err = QPACK_ENCODER_STREAM_ERROR when a claimed
 * stream's d reaches past the window (only a flow-control violation can) or
 * an instruction is invalid (qdyn_enc_apply). */
int qdyn_encrx_feed(
    qdyn_encrx* rx, u64 off, wired_span d, qpack_dyn* t, u64 max, u16* err);
 
/* RFC 9000 4.1 / 19.10: the claimed encoder stream's flow-control limit --
 * base + QDYN_ENCRX_CAP, which grows only as instructions are consumed. */
u64 qdyn_encrx_credit(const qdyn_encrx* rx);
 
#endif