On 2023-06-20, at 19:09:25 +0100, Jeremy Sowden wrote:
> 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@xxxxxxxxxx>
> ---
> lib/ts_bm.c | 42 +++++++++++++++++++++++++++++-------------
> 1 file changed, 29 insertions(+), 13 deletions(-)
Sent the wrong version. Apologies.
J.
> 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
>
Attachment:
signature.asc
Description: PGP signature
