MINOR: htx: Adapt htx_dump() to be used from traces

This function now dumps info about the HTX message into a buffer, passed as
argument. In addition, it is possible to only dump meta information, without the
message content.
diff --git a/include/common/htx.h b/include/common/htx.h
index b2ab134..aa0176f 100644
--- a/include/common/htx.h
+++ b/include/common/htx.h
@@ -805,16 +805,19 @@
 }
 
 /* For debugging purpose */
-static inline void htx_dump(struct htx *htx)
+static inline void htx_dump(struct buffer *chunk, const struct htx *htx, int full)
 {
 	int32_t pos;
 
-	fprintf(stderr, "htx:%p [ size=%u - data=%u - used=%u - wrap=%s - extra=%llu]\n",
-		htx, htx->size, htx->data, htx_nbblks(htx),
-		(!htx->head_addr) ? "NO" : "YES",
-		(unsigned long long)htx->extra);
-	fprintf(stderr, "\tfirst=%d - head=%d - tail=%d - tail_addr=%d - head_addr=%d, end_addr=%d\n",
-		htx->first, htx->head, htx->tail, htx->tail_addr, htx->head_addr, htx->end_addr);
+	chunk_appendf(chunk, " htx=%p(size=%u,data=%u,used=%u,wrap=%s,flags=0x%08x,extra=%llu,"
+		      "first=%d,head=%d,tail=%d,tail_addr=%d,head_addr=%d,end_addr=%d)",
+		      htx, htx->size, htx->data, htx_nbblks(htx), (!htx->head_addr) ? "NO" : "YES",
+		      htx->flags, (unsigned long long)htx->extra, htx->first, htx->head, htx->tail,
+		      htx->tail_addr, htx->head_addr, htx->end_addr);
+
+	if (!full || !htx_nbblks(htx))
+		return;
+	chunk_memcat(chunk, "\n", 1);
 
 	for (pos = htx_get_head(htx); pos != -1; pos = htx_get_next(htx, pos)) {
 		struct htx_sl     *sl;
@@ -828,23 +831,22 @@
 
 		if (type == HTX_BLK_REQ_SL || type == HTX_BLK_RES_SL) {
 			sl = htx_get_blk_ptr(htx, blk);
-			fprintf(stderr, "\t\t[%u] type=%-17s - size=%-6u - addr=%-6u\t%.*s %.*s %.*s\n",
-				pos, htx_blk_type_str(type), sz, blk->addr,
-				HTX_SL_P1_LEN(sl), HTX_SL_P1_PTR(sl),
-				HTX_SL_P2_LEN(sl), HTX_SL_P2_PTR(sl),
-				HTX_SL_P3_LEN(sl), HTX_SL_P3_PTR(sl));
+			chunk_appendf(chunk, "\t\t[%u] type=%-17s - size=%-6u - addr=%-6u\t%.*s %.*s %.*s\n",
+				      pos, htx_blk_type_str(type), sz, blk->addr,
+				      HTX_SL_P1_LEN(sl), HTX_SL_P1_PTR(sl),
+				      HTX_SL_P2_LEN(sl), HTX_SL_P2_PTR(sl),
+				      HTX_SL_P3_LEN(sl), HTX_SL_P3_PTR(sl));
 		}
 		else if (type == HTX_BLK_HDR || type == HTX_BLK_TLR)
-			fprintf(stderr, "\t\t[%u] type=%-17s - size=%-6u - addr=%-6u\t%.*s: %.*s\n",
-				pos, htx_blk_type_str(type), sz, blk->addr,
-				(int)n.len, n.ptr,
-				(int)v.len, v.ptr);
+			chunk_appendf(chunk, "\t\t[%u] type=%-17s - size=%-6u - addr=%-6u\t%.*s: %.*s\n",
+				      pos, htx_blk_type_str(type), sz, blk->addr,
+				      (int)n.len, n.ptr,
+				      (int)v.len, v.ptr);
 		else
-			fprintf(stderr, "\t\t[%u] type=%-17s - size=%-6u - addr=%-6u%s\n",
-				pos, htx_blk_type_str(type), sz, blk->addr,
-				(!v.len ? "\t<empty>" : ""));
+			chunk_appendf(chunk, "\t\t[%u] type=%-17s - size=%-6u - addr=%-6u%s\n",
+				      pos, htx_blk_type_str(type), sz, blk->addr,
+				      (!v.len ? "\t<empty>" : ""));
 	}
-	fprintf(stderr, "\n");
 }
 
 #endif /* _COMMON_HTX_H */