MEDIUM: log: optimizing tmp->type handling in sess_build_logline()

Instead of chaining 2 switchcases and performing encoding checks for all
nodes let's actually split the logic in 2: first handle simple node types
(text/separator), and then handle dynamic node types (tag, expr). Encoding
options are only evaluated for dynamic node types.

Also, last_isspace is always set to 0 after next_fmt label, since next_fmt
label is only used for dynamic nodes, thus != LOG_FMT_SEPARATOR.

Since LF_NODE_WITH_OPT() macro (which was introduced recently) is now
unused, let's get rid of it.

No functional change should be expected.

(Use diff -w to check patch changes since reindentation makes the patch
look heavy, but in fact it remains fairly small)

include/haproxy/log-t.h

@@ -174,10 +174,6 @@ struct logformat_node {
 	const struct logformat_tag *tag; // set if ->type == LOG_FMT_TAG
 };
 
-/* returns true if the node options may be set (according to it's type) */
-#define LF_NODE_WITH_OPT(node) \
-  (node->type == LOG_FMT_EXPR || node->type == LOG_FMT_TAG)
-
 enum lf_expr_flags {
 	LF_FL_NONE     = 0x00,
 	LF_FL_COMPILED = 0x01

src/log.c

@@ -3644,16 +3644,43 @@ int sess_build_logline(struct session *sess, struct stream *s, char *dst, size_t
 		struct sample *key;
 		const struct buffer empty = { };
 
+		/* first start with basic types (use continue statement to skip
+		 * the current node)
+		 */
+		if (tmp->type == LOG_FMT_SEPARATOR) {
+			if (g_options & LOG_OPT_ENCODE) {
+				/* ignored when global encoding is set */
+				continue;
+			}
+			if (!last_isspace) {
+				LOGCHAR(' ');
+				last_isspace = 1;
+			}
+			continue;
+		}
+		else if (tmp->type == LOG_FMT_TEXT) {
+			/* text */
+			if (g_options & LOG_OPT_ENCODE) {
+				/* ignored when global encoding is set */
+				continue;
+			}
+			src = tmp->arg;
+			iret = strlcpy2(tmplog, src, dst + maxsize - tmplog);
+			if (iret == 0)
+				goto out;
+			tmplog += iret;
+			last_isspace = 0; /* data was written */
+			continue;
+		}
+
+		/* dynamic types handling (use "goto next_fmt" statement to skip
+		 * the current node)
+		 */
+
 		if (g_options & LOG_OPT_ENCODE) {
 			/* only consider global ctx for key encoding */
 			lf_buildctx_prepare(&ctx, g_options, NULL);
 
-			/* types that cannot be named such as text or separator are ignored
-			 * when encoding is set
-			 */
-			if (!LF_NODE_WITH_OPT(tmp))
-				goto next_fmt;
-
 			if (!tmp->name)
 				goto next_fmt; /* cannot represent anonymous field, ignore */
 
@@ -3692,24 +3719,8 @@ int sess_build_logline(struct session *sess, struct stream *s, char *dst, size_t
 		 */
 		lf_buildctx_prepare(&ctx, g_options, tmp);
 
-		switch (tmp->type) {
+		if (tmp->type == LOG_FMT_EXPR) {
-			case LOG_FMT_SEPARATOR:
+			/* sample expression, may be request or response */
-				if (!last_isspace) {
-					LOGCHAR(' ');
-					last_isspace = 1;
-				}
-				break;
-
-			case LOG_FMT_TEXT: // text
-				src = tmp->arg;
-				iret = strlcpy2(tmplog, src, dst + maxsize - tmplog);
-				if (iret == 0)
-					goto out;
-				tmplog += iret;
-				break;
-
-			case LOG_FMT_EXPR: // sample expression, may be request or response
-			{
 			int type;
 
 			key = NULL;
@@ -3761,7 +3772,6 @@ int sess_build_logline(struct session *sess, struct stream *s, char *dst, size_t
 
 			if (key && !sample_convert(key, type))
 				key = NULL;
-
 			if (ctx.options & LOG_OPT_HTTP)
 				ret = lf_encode_chunk(tmplog, dst + maxsize,
 				                      '%', http_encode_map, key ? &key->data.u.str : &empty, &ctx);
@@ -3787,12 +3797,10 @@ int sess_build_logline(struct session *sess, struct stream *s, char *dst, size_t
 			if (ret == NULL)
 				goto out;
 			tmplog = ret;
-				break;
+			goto next_fmt;
-			}
 		}
 
-		if (tmp->type != LOG_FMT_TAG)
+		BUG_ON(tmp->type != LOG_FMT_TAG);
-			goto next_fmt;
 
 		/* logformat tag */
 		switch (tmp->tag->type) {
@@ -4748,8 +4756,7 @@ int sess_build_logline(struct session *sess, struct stream *s, char *dst, size_t
 
 		}
  next_fmt:
-		if (tmp->type != LOG_FMT_SEPARATOR)
+		last_isspace = 0;
-			last_isspace = 0; // not a separator, hence not a space
 
 		if (value_beg == tmplog) {
 			/* handle the case where no data was generated for the value after