[PATCH nf-next] lib/ts_bm: add helper to reduce indentation and improve readability

[Jeremy Sowden <jeremy@azazel.net>]

The flow-control of `bm_find` is very deeply nested with a conditional
comparing a ternary expression against the pattern inside a for-loop
inside a while-loop inside a for-loop.

Move the inner for-loop into a helper function to reduce the amount of
indentation and make the code easier to read.

Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
---
 lib/ts_bm.c | 42 +++++++++++++++++++++++++++++-------------
 1 file changed, 29 insertions(+), 13 deletions(-)

diff --git a/lib/ts_bm.c b/lib/ts_bm.c
index 1f2234221dd1..d74fdb87d269 100644
--- a/lib/ts_bm.c
+++ b/lib/ts_bm.c
@@ -55,6 +55,24 @@ struct ts_bm
 	unsigned int	good_shift[];
 };
 
+static bool patmtch(const u8 *pattern, const u8 *text, unsigned int patlen,
+		    bool icase)
+{
+	unsigned int i;
+
+	for (i = 0; i < patlen; i++) {
+		u8 t = *(text-i);
+
+		if (icase)
+			t = toupper(t);
+
+		if (t != *(pattern-i))
+			return false;
+	}
+
+	return true;
+}
+
 static unsigned int bm_find(struct ts_config *conf, struct ts_state *state)
 {
 	struct ts_bm *bm = ts_config_priv(conf);
@@ -70,19 +88,17 @@ static unsigned int bm_find(struct ts_config *conf, struct ts_state *state)
 			break;
 
 		while (shift < text_len) {
-			DEBUGP("Searching in position %d (%c)\n", 
-				shift, text[shift]);
-			for (i = 0; i < bm->patlen; i++) 
-				if ((icase ? toupper(text[shift-i])
-				    : text[shift-i])
-					!= bm->pattern[bm->patlen-1-i])
-				     goto next;
-
-			/* London calling... */
-			DEBUGP("found!\n");
-			return consumed + (shift-(bm->patlen-1));
-
-next:			bs = bm->bad_shift[text[shift-i]];
+			DEBUGP("Searching in position %d (%c)\n",
+			       shift, text[shift]);
+
+			if (patmtch(&bm->pattern[bm->patlen-1], &text[shift],
+				    bm->patlen, icase)) {
+				/* London calling... */
+				DEBUGP("found!\n");
+				return consumed + (shift-(bm->patlen-1));
+			}
+
+			bs = bm->bad_shift[text[shift-i]];
 
 			/* Now jumping to... */
 			shift = max_t(int, shift-i+bs, shift+bm->good_shift[i]);
-- 
2.39.2