Added nxt_usts2str() to make C strings from nxt_str_t.str-v4

This function is identical to nxt_ustr2str(), except that it takes
a nxt_str_t structure as input, instead of a 'u_char *' and a size.

The documentation of the function:

/*
 * SYNOPSIS
 *      void nxt_usts2str(char dst[restrict .src->length+1],
 *                        const nxt_str_t *restrict src);
 *
 * ARGUMENTS
 *      dst     Pointer to the first byte of the destination buffer.
 *      src     Pointer to the source Unterminated STring Structure.
 *
 * DESCRIPTION
 *      Copy a string from the source nxt_str_t, which may be
 *      not-NUL-terminated, into a NUL-terminated string in the
 *      destination buffer.
 *
 * CAVEATS
 *      If the destination buffer is not wider than the source buffer
 *      at least by 1 byte, the behavior is undefined.
 *
 * EXAMPLES
 *      nxt_str_t  src = nxt_string("0123456789");
 *      char       dst[src.length + 1];
 *
 *      nxt_usts2str(dst, &src);
 *
 * SEE ALSO
 *      ustr2str(3), strlcpy(3), strscpy(9)
 */

Suggested-by: Andrew Clayton <a.clayton@nginx.com>
Signed-off-by: Alejandro Colomar <alx@nginx.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/src/nxt_string.h b/src/nxt_string.h
index 62459987..ae5d3179 100644
--- a/src/nxt_string.h
+++ b/src/nxt_string.h
@@ -122,6 +122,8 @@ typedef struct {
 
 NXT_EXPORT inline void nxt_ustr2str(char *restrict dst,
     const u_char *restrict src, size_t length);
+NXT_EXPORT inline void nxt_usts2str(char *restrict dst,
+    const nxt_str_t *restrict src);
 
 NXT_EXPORT nxt_str_t *nxt_str_alloc(nxt_mp_t *mp, size_t length);
 NXT_EXPORT nxt_str_t *nxt_str_dup(nxt_mp_t *mp, nxt_str_t *dst,
@@ -179,4 +181,11 @@ nxt_ustr2str(char *restrict dst, const u_char *restrict src, size_t length)
 }
 
 
+inline void
+nxt_usts2str(char *restrict dst, const nxt_str_t *restrict src)
+{
+    nxt_ustr2str(dst, src->start, src->length);
+}
+
+
 #endif /* _NXT_STRING_H_INCLUDED_ */