MINOR: http-ana: Simplify creation/destruction of HTTP transactions

Now allocation and initialization of HTTP transactions are performed in a
unique function. Historically, there were two functions because the same TXN
was reset for K/A connections in the legacy HTTP mode. Now, in HTX, K/A
connections are handled at the mux level. A new stream, and thus a new TXN,
is created for each request. In addition, the function responsible to end
the TXN is now also reponsible to release it.

So, now, http_create_txn() and http_destroy_txn() must be used to create and
destroy an HTTP transaction.

include/haproxy/http_ana.h

@@ -57,9 +57,8 @@ int http_reply_to_htx(struct stream *s, struct htx *htx, struct http_reply *repl
 int http_reply_message(struct stream *s, struct http_reply *reply);
 int http_forward_proxy_resp(struct stream *s, int final);
 
-struct http_txn *http_alloc_txn(struct stream *s);
-void http_init_txn(struct stream *s);
-void http_end_txn(struct stream *s);
+struct http_txn *http_create_txn(struct stream *s);
+void http_destroy_txn(struct stream *s);
 
 /* for debugging, reports the HTTP/1 message state name (legacy version) */
 static inline const char *h1_msg_state_str(enum h1_state msg_state)

src/frontend.c

@@ -145,17 +145,8 @@ int frontend_accept(struct stream *s)
 			goto out_free_reqcap;	/* no memory */
 	}
 
-	if (fe->http_needed || IS_HTX_STRM(s)) {
-		/* we have to allocate header indexes only if we know
-		 * that we may make use of them. This of course includes
-		 * (mode == PR_MODE_HTTP).
-		 */
-		if (unlikely(!http_alloc_txn(s)))
-			goto out_free_rspcap; /* no memory */
-
-		/* and now initialize the HTTP transaction state */
-		http_init_txn(s);
-	}
+	if ((fe->http_needed || IS_HTX_STRM(s)) && !http_create_txn(s))
+		goto out_free_rspcap;
 
 	/* everything's OK, let's go on */
 	return 1;

src/http_ana.c

@@ -5044,15 +5044,20 @@ void http_txn_reset_res(struct http_txn *txn)
 }
 
 /*
- * Initialize a new HTTP transaction for stream <s>. It is assumed that all
- * the required fields are properly allocated and that we only need to (re)init
- * them. This should be used before processing any new request.
+ * Create and initialize a new HTTP transaction for stream <s>. This should be
+ * used before processing any new request. It returns the transaction or NLULL
+ * on error.
  */
-void http_init_txn(struct stream *s)
+struct http_txn *http_create_txn(struct stream *s)
 {
-	struct http_txn *txn = s->txn;
+	struct http_txn *txn;
 	struct conn_stream *cs = objt_cs(s->si[0].end);
 
+	txn = pool_alloc(pool_head_http_txn);
+	if (!txn)
+		return NULL;
+	s->txn = txn;
+
 	txn->flags = ((cs && cs->flags & CS_FL_NOT_FIRST) ? TX_NOT_FIRST : 0);
 	txn->status = -1;
 	txn->http_reply = NULL;
@@ -5075,10 +5080,12 @@ void http_init_txn(struct stream *s)
 
 	vars_init(&s->vars_txn,    SCOPE_TXN);
 	vars_init(&s->vars_reqres, SCOPE_REQ);
+
+	return txn;
 }
 
 /* to be used at the end of a transaction */
-void http_end_txn(struct stream *s)
+void http_destroy_txn(struct stream *s)
 {
 	struct http_txn *txn = s->txn;
 
@@ -5097,6 +5104,9 @@ void http_end_txn(struct stream *s)
 		vars_prune(&s->vars_txn, s->sess, s);
 	if (!LIST_ISEMPTY(&s->vars_reqres.head))
 		vars_prune(&s->vars_reqres, s->sess, s);
+
+	pool_free(pool_head_http_txn, txn);
+	s->txn = NULL;
 }
 
 

src/http_fetch.c

@@ -208,12 +208,8 @@ struct htx *smp_prefetch_htx(struct sample *smp, struct channel *chn, struct che
 		return NULL;
 	}
 
-	if (!s->txn) {
-		if (unlikely(!http_alloc_txn(s)))
-			return NULL; /* not enough memory */
-		http_init_txn(s);
-		txn = s->txn;
-	}
+	if (!s->txn && !http_create_txn(s))
+		return NULL;
 	txn = s->txn;
 	msg = (!(chn->flags & CF_ISRESP) ? &txn->req : &txn->rsp);
 

src/proxy.c

@@ -2145,13 +2145,8 @@ int stream_set_backend(struct stream *s, struct proxy *be)
 	/* If the target backend requires HTTP processing, we have to allocate
 	 * the HTTP transaction if we did not have one.
 	 */
-	if (unlikely(!s->txn && be->http_needed)) {
-		if (unlikely(!http_alloc_txn(s)))
-			return 0; /* not enough memory */
-
-		/* and now initialize the HTTP transaction state */
-		http_init_txn(s);
-	}
+	if (unlikely(!s->txn && be->http_needed && !http_create_txn(s)))
+			return 0;
 
 	if (s->txn) {
 		/* If we chain a TCP frontend to an HTX backend, we must upgrade

src/stream.c

@@ -658,7 +658,7 @@ static void stream_free(struct stream *s)
 	hlua_ctx_destroy(s->hlua);
 	s->hlua = NULL;
 	if (s->txn)
-		http_end_txn(s);
+		http_destroy_txn(s);
 
 	/* ensure the client-side transport layer is destroyed */
 	if (cli_cs)
@@ -671,11 +671,6 @@ static void stream_free(struct stream *s)
 		s->store[i].ts = NULL;
 	}
 
-	if (s->txn) {
-		pool_free(pool_head_http_txn, s->txn);
-		s->txn = NULL;
-	}
-
 	if (s->resolv_ctx.requester) {
 		__decl_thread(struct resolvers *resolvers = s->resolv_ctx.parent->arg.resolv.resolvers);