@matheusbsbs / matheus-bagliano / commits / fa59e7beb2

pickaxe -G: terminate early on matching lines

Solve a long-standing item for "git log -Grx" of us e.g. finding "+ str" in the diff context and noting that we had a "hit", but xdiff diligently continuing to generate and spew the rest of the diff at us. This makes use of a new "early return" xdiff interface added by preceding commits. The TODO item (or, the NEEDSWORK comment) has been there since "git log -G" was implemented. See f506b8e8b5f (git log/diff: add -G<regexp> that greps in the patch text, 2010-08-23). But now with the support added in the preceding changes to the xdiff-interface we can return early. Let's assert the behavior of that new early-return xdiff-interface by having a BUG() call here to die if it ever starts handing us needless work again. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Ævar Arnfjörð Bjarmason committed Apr 12, 2021 at 19:15 UTC fa59e7beb2a61d9cd1312b212075edf12935fdc6

2 files changed +23 -11

diffcore-pickaxe.c

+19 -11

@@ -27,13 +27,12 @@ static int diffgrep_consume(void *priv, char *line, unsigned long len)

27 if (line[0] != '+' && line[0] != '-')

28 return 0;

29 if (data->hit)

30 - /*

31 - * NEEDSWORK: we should have a way to terminate the

32 - * caller early.

33 - */

34 - return 0;

35 - data->hit = !regexec_buf(data->regexp, line + 1, len - 1, 1,

36 - &regmatch, 0);

30 + BUG("Already matched in diffgrep_consume! Broken xdiff_emit_line_fn?");

31 + if (!regexec_buf(data->regexp, line + 1, len - 1, 1,

32 + &regmatch, 0)) {

33 + data->hit = 1;

34 + return 1;

35 + }

36 return 0;

37 }

@@ -45,6 +44,7 @@ static int diff_grep(mmfile_t *one, mmfile_t *two,

44 struct diffgrep_cb ecbdata;

45 xpparam_t xpp;

46 xdemitconf_t xecfg;

47 + int ret;

49 if (!one)

50 return !regexec_buf(regexp, two->ptr, two->size,

@@ -63,10 +63,18 @@ static int diff_grep(mmfile_t *one, mmfile_t *two,

63 ecbdata.hit = 0;

64 xecfg.ctxlen = o->context;

65 xecfg.interhunkctxlen = o->interhunkcontext;

66 - if (xdi_diff_outf(one, two, discard_hunk_line, diffgrep_consume,

67 - &ecbdata, &xpp, &xecfg))

68 - return 0;

69 - return ecbdata.hit;

66 +

67 + /*

68 + * An xdiff error might be our "data->hit" from above. See the

69 + * comment for xdiff_emit_line_fn in xdiff-interface.h

70 + */

71 + ret = xdi_diff_outf(one, two, discard_hunk_line, diffgrep_consume,

72 + &ecbdata, &xpp, &xecfg);

73 + if (ecbdata.hit)

74 + return 1;

75 + if (ret)

76 + return ret;

77 + return 0;

78 }

80 static unsigned int contains(mmfile_t *mf, regex_t *regexp, kwset_t kws,

xdiff-interface.h

@@ -27,6 +27,10 @@

27 * doing so will currently make your early return indistinguishable

28 * from an error internal to xdiff, xdiff itself will see that

29 * non-zero return and translate it to -1.

30 + *

31 + * See "diff_grep" in diffcore-pickaxe.c for a trick to work around

32 + * this, i.e. using the "consume_callback_data" to note the desired

33 + * early return.

34 */

35 typedef int (*xdiff_emit_line_fn)(void *, char *, unsigned long);

36 typedef void (*xdiff_emit_hunk_fn)(void *data,