bytestring: Split bytestrings by a character delimiter

[ccan] / ccan / bytestring / bytestring.c

diff --git a/ccan/bytestring/bytestring.c b/ccan/bytestring/bytestring.c
index 69e2b32bcebcc2067cddfd816ab54257646191b1..ddc5dcd06e9e1427b6776fc8a7b92c5164f51f5a 100644 (file)
--- 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);
+}