From 52acddf36c8cb3778ab2098a0d95cc2e375a4069 Mon Sep 17 00:00:00 2001 From: Taylor Blau Date: Mon, 24 Apr 2023 18:20:10 -0400 Subject: [PATCH] string-list: multi-delimiter `string_list_split_in_place()` Enhance `string_list_split_in_place()` to accept multiple characters as delimiters instead of a single character. Instead of using `strchr(2)` to locate the first occurrence of the given delimiter character, `string_list_split_in_place_multi()` uses `strcspn(2)` to move past the initial segment of characters comprised of any characters in the delimiting set. When only a single delimiting character is provided, `strpbrk(2)` (which is implemented with `strcspn(2)`) has equivalent performance to `strchr(2)`. Modern `strcspn(2)` implementations treat an empty delimiter or the singleton delimiter as a special case and fall back to calling strchrnul(). Both glibc[1] and musl[2] implement `strcspn(2)` this way. This change is one step to removing `strtok(2)` from the tree. Note that `string_list_split_in_place()` is not a strict replacement for `strtok()`, since it will happily turn sequential delimiter characters into empty entries in the resulting string_list. For example: string_list_split_in_place(&xs, "foo:;:bar:;:baz", ":;", -1) would yield a string list of: ["foo", "", "", "bar", "", "", "baz"] Callers that wish to emulate the behavior of strtok(2) more directly should call `string_list_remove_empty_items()` after splitting. To avoid regressions for the new multi-character delimter cases, update t0063 in this patch as well. [1]: https://sourceware.org/git/?p=glibc.git;a=blob;f=string/strcspn.c;hb=glibc-2.37#l35 [2]: https://git.musl-libc.org/cgit/musl/tree/src/string/strcspn.c?h=v1.2.3#n11 Signed-off-by: Taylor Blau Signed-off-by: Junio C Hamano --- builtin/gc.c | 4 +-- diff.c | 2 +- notes.c | 2 +- refs/packed-backend.c | 2 +- string-list.c | 4 +-- string-list.h | 2 +- t/helper/test-string-list.c | 4 +-- t/t0063-string-list.sh | 51 +++++++++++++++++++++++++++++++++++++ 8 files changed, 61 insertions(+), 10 deletions(-) diff --git a/builtin/gc.c b/builtin/gc.c index edd98d35a5..f68e976704 100644 --- a/builtin/gc.c +++ b/builtin/gc.c @@ -1687,11 +1687,11 @@ static int get_schedule_cmd(const char **cmd, int *is_available) if (is_available) *is_available = 0; - string_list_split_in_place(&list, testing, ',', -1); + string_list_split_in_place(&list, testing, ",", -1); for_each_string_list_item(item, &list) { struct string_list pair = STRING_LIST_INIT_NODUP; - if (string_list_split_in_place(&pair, item->string, ':', 2) != 2) + if (string_list_split_in_place(&pair, item->string, ":", 2) != 2) continue; if (!strcmp(*cmd, pair.items[0].string)) { diff --git a/diff.c b/diff.c index 78b0fdd8ca..378a0248e1 100644 --- a/diff.c +++ b/diff.c @@ -134,7 +134,7 @@ static int parse_dirstat_params(struct diff_options *options, const char *params int i; if (*params_copy) - string_list_split_in_place(¶ms, params_copy, ',', -1); + string_list_split_in_place(¶ms, params_copy, ",", -1); for (i = 0; i < params.nr; i++) { const char *p = params.items[i].string; if (!strcmp(p, "changes")) { diff --git a/notes.c b/notes.c index 45fb7f22d1..eee806f626 100644 --- a/notes.c +++ b/notes.c @@ -963,7 +963,7 @@ void string_list_add_refs_from_colon_sep(struct string_list *list, char *globs_copy = xstrdup(globs); int i; - string_list_split_in_place(&split, globs_copy, ':', -1); + string_list_split_in_place(&split, globs_copy, ":", -1); string_list_remove_empty_items(&split, 0); for (i = 0; i < split.nr; i++) diff --git a/refs/packed-backend.c b/refs/packed-backend.c index 1eba1015dd..cc903baa7e 100644 --- a/refs/packed-backend.c +++ b/refs/packed-backend.c @@ -650,7 +650,7 @@ static struct snapshot *create_snapshot(struct packed_ref_store *refs) snapshot->buf, snapshot->eof - snapshot->buf); - string_list_split_in_place(&traits, p, ' ', -1); + string_list_split_in_place(&traits, p, " ", -1); if (unsorted_string_list_has_string(&traits, "fully-peeled")) snapshot->peeled = PEELED_FULLY; diff --git a/string-list.c b/string-list.c index db473f273e..5f5b60fe1c 100644 --- a/string-list.c +++ b/string-list.c @@ -301,7 +301,7 @@ int string_list_split(struct string_list *list, const char *string, } int string_list_split_in_place(struct string_list *list, char *string, - int delim, int maxsplit) + const char *delim, int maxsplit) { int count = 0; char *p = string, *end; @@ -315,7 +315,7 @@ int string_list_split_in_place(struct string_list *list, char *string, string_list_append(list, p); return count; } - end = strchr(p, delim); + end = strpbrk(p, delim); if (end) { *end = '\0'; string_list_append(list, p); diff --git a/string-list.h b/string-list.h index c7b0d5d000..77854840f7 100644 --- a/string-list.h +++ b/string-list.h @@ -270,5 +270,5 @@ int string_list_split(struct string_list *list, const char *string, * list->strdup_strings must *not* be set. */ int string_list_split_in_place(struct string_list *list, char *string, - int delim, int maxsplit); + const char *delim, int maxsplit); #endif /* STRING_LIST_H */ diff --git a/t/helper/test-string-list.c b/t/helper/test-string-list.c index 2123dda85b..63df88575c 100644 --- a/t/helper/test-string-list.c +++ b/t/helper/test-string-list.c @@ -62,7 +62,7 @@ int cmd__string_list(int argc, const char **argv) struct string_list list = STRING_LIST_INIT_NODUP; int i; char *s = xstrdup(argv[2]); - int delim = *argv[3]; + const char *delim = argv[3]; int maxsplit = atoi(argv[4]); i = string_list_split_in_place(&list, s, delim, maxsplit); @@ -111,7 +111,7 @@ int cmd__string_list(int argc, const char **argv) */ if (sb.len && sb.buf[sb.len - 1] == '\n') strbuf_setlen(&sb, sb.len - 1); - string_list_split_in_place(&list, sb.buf, '\n', -1); + string_list_split_in_place(&list, sb.buf, "\n", -1); string_list_sort(&list); diff --git a/t/t0063-string-list.sh b/t/t0063-string-list.sh index 46d4839194..1fee6d9010 100755 --- a/t/t0063-string-list.sh +++ b/t/t0063-string-list.sh @@ -18,6 +18,14 @@ test_split () { " } +test_split_in_place() { + cat >expected && + test_expect_success "split (in place) $1 at $2, max $3" " + test-tool string-list split_in_place '$1' '$2' '$3' >actual && + test_cmp expected actual + " +} + test_split "foo:bar:baz" ":" "-1" <