From 86e9c9aa2358a74bcc5e63f9fc69c2d01e64c002 Mon Sep 17 00:00:00 2001 From: Jeremy Sowden Date: Tue, 20 Jun 2023 19:11:00 +0100 Subject: [PATCH] lib/ts_bm: add helper to reduce indentation and improve readability 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. Fix indentation and trailing white-space in preceding debug logging statement. Signed-off-by: Jeremy Sowden Signed-off-by: Florian Westphal --- lib/ts_bm.c | 43 ++++++++++++++++++++++++++++++------------- 1 file changed, 30 insertions(+), 13 deletions(-) diff --git a/lib/ts_bm.c b/lib/ts_bm.c index c8ecbf7..e5f30f9 100644 --- a/lib/ts_bm.c +++ b/lib/ts_bm.c @@ -55,6 +55,24 @@ struct ts_bm unsigned int good_shift[]; }; +static unsigned int matchpat(const u8 *pattern, unsigned int patlen, + const u8 *text, bool icase) +{ + unsigned int i; + + for (i = 0; i < patlen; i++) { + u8 t = *(text-i); + + if (icase) + t = toupper(t); + + if (t != *(pattern-i)) + break; + } + + return i; +} + static unsigned int bm_find(struct ts_config *conf, struct ts_state *state) { struct ts_bm *bm = ts_config_priv(conf); @@ -72,19 +90,18 @@ 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]); + + i = matchpat(&bm->pattern[bm->patlen-1], bm->patlen, + &text[shift], icase); + if (i == bm->patlen) { + /* 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]); -- 2.7.4