compression: remove wire_pos context parameter

src/libknot/packet/compr.c

@@ -125,13 +125,17 @@ int knot_compr_put_dname(const knot_dname_t *dname, uint8_t *dst, uint16_t max,
 		written += sizeof(uint16_t);
 	}
 
+	assert(dst >= compr->wire);
+	size_t wire_pos = dst - compr->wire;
+	assert(wire_pos < KNOT_WIRE_MAX_PKTSIZE);
+
 	/* Heuristics - expect similar names are grouped together. */
-	if (written > sizeof(uint16_t) && compr->wire_pos + written < KNOT_WIRE_PTR_MAX) {
-		compr->suffix.pos = compr->wire_pos;
+	if (written > sizeof(uint16_t) && wire_pos + written < KNOT_WIRE_PTR_MAX) {
+		compr->suffix.pos = wire_pos;
 		compr->suffix.labels = orig_labels;
 	}
 	dbg_packet("%s: compressed to %u bytes (match=%zu,@%zu)\n",
-		   __func__, written, dname - match_begin, compr->wire_pos);
+		   __func__, written, dname - match_begin, wire_pos);
 	return written;
 }
 

src/libknot/packet/compr.h

@@ -69,7 +69,6 @@ typedef struct {
  */
 typedef struct knot_compr {
 	uint8_t *wire;          /* Packet wireformat. */
-	size_t wire_pos;        /* Current wire position. */
 	knot_rrinfo_t *rrinfo;  /* Hints for current RRSet. */
 	struct {
 		uint16_t pos;   /* Position of current suffix. */

src/libknot/packet/pkt.c

@@ -495,7 +495,6 @@ int knot_pkt_put(knot_pkt_t *pkt, uint16_t compr_hint, const knot_rrset_t *rr,
 	/* Create compression context. */
 	knot_compr_t compr;
 	compr.wire = pkt->wire;
-	compr.wire_pos = pkt->size;
 	compr.rrinfo = rrinfo;
 	compr.suffix.pos = KNOT_WIRE_HEADER_SIZE;
 	compr.suffix.labels = knot_dname_labels(compr.wire + compr.suffix.pos,