Commit 3f60b879 authored by David Gibson's avatar David Gibson

bytestring: Split bytestrings by a string delimiter

This introduces the functions bytestring_splitstr_first() and
bytestring_splitstr_next() which can be used to iterate through substrings
of a bytestring separated by a specified substring.
Signed-off-by: default avatarDavid Gibson <david@gibson.dropbear.id.au>
parent 309577c4
...@@ -104,3 +104,45 @@ struct bytestring bytestring_splitchrs_next(struct bytestring whole, ...@@ -104,3 +104,45 @@ struct bytestring bytestring_splitchrs_next(struct bytestring whole,
return _splitchrs(whole, delim, (prev.ptr - whole.ptr) + prev.len + 1); return _splitchrs(whole, delim, (prev.ptr - whole.ptr) + prev.len + 1);
} }
static struct bytestring _splitstr(struct bytestring whole,
struct bytestring delim, size_t start)
{
struct bytestring remainder, nextdelim;
assert(start <= whole.len);
remainder = bytestring_slice(whole, start, whole.len);
nextdelim = bytestring_bytestring(remainder, delim);
if (nextdelim.ptr)
return bytestring_slice(whole, start,
nextdelim.ptr - whole.ptr);
else
return remainder;
}
struct bytestring bytestring_splitstr_first(struct bytestring whole,
struct bytestring delim)
{
if (whole.len == 0)
return bytestring_NULL;
return _splitstr(whole, delim, 0);
}
struct bytestring bytestring_splitstr_next(struct bytestring whole,
struct bytestring 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 _splitstr(whole, delim,
(prev.ptr - whole.ptr) + prev.len + delim.len);
}
...@@ -276,4 +276,32 @@ struct bytestring bytestring_splitchrs_next(struct bytestring whole, ...@@ -276,4 +276,32 @@ struct bytestring bytestring_splitchrs_next(struct bytestring whole,
(_s).ptr; \ (_s).ptr; \
(_s) = bytestring_splitchrs_next((_w), (_delim), (_s))) (_s) = bytestring_splitchrs_next((_w), (_delim), (_s)))
/**
* bytestring_splitstr_first - split a bytestring on a delimiter string
* @whole: a bytestring
* @delim: delimiter substring
*
* Returns the first substring of @whole delimited by the substring in
* @delim.
*/
struct bytestring bytestring_splitstr_first(struct bytestring whole,
struct bytestring delim);
/**
* bytestring_splitstr_next - split a bytestring on a delimiter string
* @whole: a bytestring
* @delim: delimiter string
* @prev: last substring
*
* Returns the next @delim delimited substring of @whole after @prev.
*/
struct bytestring bytestring_splitstr_next(struct bytestring whole,
struct bytestring delim,
struct bytestring prev);
#define bytestring_foreach_splitstr(_s, _w, _delim) \
for ((_s) = bytestring_splitstr_first((_w), (_delim)); \
(_s).ptr; \
(_s) = bytestring_splitstr_next((_w), (_delim), (_s)))
#endif /* CCAN_BYTESTRING_H_ */ #endif /* CCAN_BYTESTRING_H_ */
...@@ -17,7 +17,7 @@ int main(void) ...@@ -17,7 +17,7 @@ int main(void)
int n; int n;
/* This is how many tests you plan to run */ /* This is how many tests you plan to run */
plan_tests(109); plan_tests(126);
bs = bytestring(str1, sizeof(str1) - 1); bs = bytestring(str1, sizeof(str1) - 1);
ok1(bs.ptr == str1); ok1(bs.ptr == str1);
...@@ -198,6 +198,39 @@ int main(void) ...@@ -198,6 +198,39 @@ int main(void)
} }
ok1(n == 6); ok1(n == 6);
bs7 = bytestring_splitstr_first(bs, BYTESTRING("t "));
ok1(bs7.ptr == bs.ptr);
ok1(bytestring_eq(bs7, BYTESTRING("tes")));
bs7 = bytestring_splitstr_next(bs, BYTESTRING("t "), bs7);
ok1(bs7.ptr == bs.ptr + 5);
ok1(bytestring_eq(bs7, BYTESTRING("string")));
bs7 = bytestring_splitstr_next(bs, BYTESTRING("t "), bs7);
ok1(!bs7.ptr);
bs7 = bytestring_splitstr_next(bs, BYTESTRING("t "), bs7);
ok1(!bs7.ptr);
bs7 = bytestring_splitstr_first(bs2, BYTESTRING("abc"));
ok1(bs7.ptr == bs2.ptr);
ok1(bs7.len == 0);
bs7 = bytestring_splitstr_next(bs2, BYTESTRING("abc"), bs7);
ok1(bs7.ptr == bs2.ptr + 3);
ok1(bytestring_eq(bs7, BYTESTRING("\0def")));
bs7 = bytestring_splitstr_next(bs2, BYTESTRING("t "), bs7);
ok1(!bs7.ptr);
bs7 = bytestring_splitstr_next(bs2, BYTESTRING("t "), bs7);
ok1(!bs7.ptr);
bs7 = bytestring_splitstr_first(BYTESTRING(""), BYTESTRING(""));
ok1(!bs7.ptr);
n = 0;
bytestring_foreach_splitstr(bs7, BYTESTRING("foofoo"),
BYTESTRING("foo")) {
n++;
ok1(bs7.ptr && !bs7.len);
}
ok1(n == 3);
/* This exits depending on whether all tests passed */ /* This exits depending on whether all tests passed */
return exit_status(); return exit_status();
} }
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment