[ccan] [PATCH 07/11] bytestring: Split bytestrings by a character delimiter
David Gibson
david at gibson.dropbear.id.au
Sun Oct 12 03:43:32 AEDT 2014
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 <david at gibson.dropbear.id.au>
---
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 2e205b7..45c1297 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 6ca7197..98d7edb 100644
--- a/ccan/bytestring/bytestring.h
+++ b/ccan/bytestring/bytestring.h
@@ -201,4 +201,30 @@ 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 0f9ceaa..74406c1 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(46);
+ plan_tests(82);
bs = bytestring(str1, sizeof(str1) - 1);
ok1(bs.ptr == str1);
@@ -92,6 +93,70 @@ 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();
}
--
1.9.3
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