From cb2d540f764b225a068a3cdd1396df4fc8dc6824 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Mon, 28 Jul 2014 19:31:11 +1000 Subject: [PATCH] bytestring: Split bytestrings by a character delimiter This introduces the functions bytestring_splitchr_first() and bytestring_splitchr_next() which can be used to iterate through substrings of a bytestring separated by a single, specified delimiter character. Signed-off-by: David Gibson --- ccan/bytestring/bytestring.c | 42 ++++++++++++++++++++++ ccan/bytestring/bytestring.h | 26 ++++++++++++++ ccan/bytestring/test/run.c | 69 ++++++++++++++++++++++++++++++++++-- 3 files changed, 135 insertions(+), 2 deletions(-) diff --git a/ccan/bytestring/bytestring.c b/ccan/bytestring/bytestring.c index 69e2b32b..ddc5dcd0 100644 --- a/ccan/bytestring/bytestring.c +++ b/ccan/bytestring/bytestring.c @@ -24,3 +24,45 @@ size_t bytestring_cspn(struct bytestring s, struct bytestring reject) return s.len; } + +static struct bytestring _splitchr(struct bytestring whole, char delim, + size_t start) +{ + const char *p; + + assert(start <= whole.len); + + /* Check this first, in case memchr() is not safe with zero length */ + if (start == whole.len) + return bytestring(whole.ptr + start, 0); + + p = memchr(whole.ptr + start, delim, whole.len - start); + if (p) + return bytestring_slice(whole, start, p - whole.ptr); + else + return bytestring_slice(whole, start, whole.len); +} + +struct bytestring bytestring_splitchr_first(struct bytestring whole, + char delim) +{ + if (whole.len == 0) + return bytestring_NULL; + + return _splitchr(whole, delim, 0); +} + +struct bytestring bytestring_splitchr_next(struct bytestring whole, + char delim, struct bytestring prev) +{ + if (!prev.ptr) + return bytestring_NULL; + + /* prev has to be a substring of whole */ + assert(prev.ptr >= whole.ptr); + + if ((prev.ptr + prev.len) == (whole.ptr + whole.len)) + return bytestring_NULL; + + return _splitchr(whole, delim, (prev.ptr - whole.ptr) + prev.len + 1); +} diff --git a/ccan/bytestring/bytestring.h b/ccan/bytestring/bytestring.h index 34d81af2..8aa27275 100644 --- a/ccan/bytestring/bytestring.h +++ b/ccan/bytestring/bytestring.h @@ -220,4 +220,30 @@ size_t bytestring_spn(struct bytestring s, struct bytestring accept); */ size_t bytestring_cspn(struct bytestring s, struct bytestring reject); +/** + * bytestring_splitchr_first - split a bytestring on a single character delimiter + * @whole: a bytestring + * @delim: delimiter character + * + * Returns the first @delim delimited substring of @whole. + */ +struct bytestring bytestring_splitchr_first(struct bytestring whole, + char delim); + +/** + * bytestring_splitchr_next - split a bytestring on a single character delimiter + * @whole: a bytestring + * @delim: delimiter character + * @prev: last substring + * + * Returns the next @delim delimited substring of @whole after @prev. + */ +struct bytestring bytestring_splitchr_next(struct bytestring whole, + char delim, struct bytestring prev); + +#define bytestring_foreach_splitchr(_s, _w, _delim) \ + for ((_s) = bytestring_splitchr_first((_w), (_delim)); \ + (_s).ptr; \ + (_s) = bytestring_splitchr_next((_w), (_delim), (_s))) + #endif /* CCAN_BYTESTRING_H_ */ diff --git a/ccan/bytestring/test/run.c b/ccan/bytestring/test/run.c index 23415df5..3b563de3 100644 --- a/ccan/bytestring/test/run.c +++ b/ccan/bytestring/test/run.c @@ -13,10 +13,11 @@ const char *str2 = TEST_STRING; int main(void) { - struct bytestring bs, bs1, bs2, bs3, bs4, bs5, bs6; + struct bytestring bs, bs1, bs2, bs3, bs4, bs5, bs6, bs7; + int n; /* This is how many tests you plan to run */ - plan_tests(53); + plan_tests(89); bs = bytestring(str1, sizeof(str1) - 1); ok1(bs.ptr == str1); @@ -100,6 +101,70 @@ int main(void) ok1(bytestring_spn(bs1, BYTESTRING("eginrst ")) == bs1.len); ok1(bytestring_cspn(bs2, BYTESTRING("z")) == bs2.len); + bs7 = bytestring_splitchr_first(bs, ' '); + ok1(bs7.ptr == bs.ptr); + ok1(bytestring_eq(bs7, BYTESTRING("test"))); + bs7 = bytestring_splitchr_next(bs, ' ', bs7); + ok1(bs7.ptr == bs.ptr + 5); + ok1(bytestring_eq(bs7, BYTESTRING("string"))); + bs7 = bytestring_splitchr_next(bs, ' ', bs7); + ok1(!bs7.ptr); + bs7 = bytestring_splitchr_next(bs, ' ', bs7); + ok1(!bs7.ptr); + + bs7 = bytestring_splitchr_first(bs2, '\0'); + ok1(bs7.ptr = bs2.ptr); + ok1(bytestring_eq(bs7, BYTESTRING("abc"))); + bs7 = bytestring_splitchr_next(bs2, '\0', bs7); + ok1(bs7.ptr == bs2.ptr + 4); + ok1(bytestring_eq(bs7, BYTESTRING("def"))); + bs7 = bytestring_splitchr_next(bs2, '\0', bs7); + ok1(!bs7.ptr); + bs7 = bytestring_splitchr_next(bs2, ' ', bs7); + ok1(!bs7.ptr); + + bs7 = bytestring_splitchr_first(bs, 's'); + ok1(bs7.ptr == bs.ptr); + ok1(bytestring_eq(bs7, BYTESTRING("te"))); + bs7 = bytestring_splitchr_next(bs, 's', bs7); + ok1(bs7.ptr == bs.ptr + 3); + ok1(bytestring_eq(bs7, BYTESTRING("t "))); + bs7 = bytestring_splitchr_next(bs, 's', bs7); + ok1(bs7.ptr == bs.ptr + 6); + ok1(bytestring_eq(bs7, BYTESTRING("tring"))); + bs7 = bytestring_splitchr_next(bs, 's', bs7); + ok1(!bs7.ptr); + bs7 = bytestring_splitchr_next(bs, ' ', bs7); + ok1(!bs7.ptr); + + bs7 = bytestring_splitchr_first(bs2, 'f'); + ok1(bs7.ptr = bs2.ptr); + ok1(bytestring_eq(bs7, BYTESTRING("abc\0de"))); + bs7 = bytestring_splitchr_next(bs2, 'f', bs7); + ok1(bs7.ptr == bs2.ptr + 7); + ok1(bs7.len == 0); + bs7 = bytestring_splitchr_next(bs2, 'f', bs7); + ok1(!bs7.ptr); + bs7 = bytestring_splitchr_next(bs2, 'f', bs7); + ok1(!bs7.ptr); + + bs7 = bytestring_splitchr_first(BYTESTRING(""), 'q'); + ok1(!bs7.ptr); + + n = 0; + bytestring_foreach_splitchr(bs7, BYTESTRING(" "), ' ') { + n++; + ok1(bs7.ptr && !bs7.len); + } + ok1(n == 3); + + n = 0; + bytestring_foreach_splitchr(bs7, BYTESTRING("\0\0\0"), '\0') { + n++; + ok1(bs7.ptr && !bs7.len); + } + ok1(n == 4); + /* This exits depending on whether all tests passed */ return exit_status(); } -- 2.39.2