newlib/winsup/cygwin/lsearch.cc

52 lines
1.5 KiB
C++

/* Initial implementation:
Copyright (c) 2002 Robert Drehmel
All rights reserved.
As long as the above copyright statement and this notice remain
unchanged, you can do what ever you want with this file. */
#include <stdint.h> /* for uint8_t */
#include <string.h> /* for memcpy () prototype */
static void *lwork (const void *, const void *, size_t *, size_t,
int (*) (const void *, const void *), int);
extern "C" void *
lsearch (const void *key, void *base, size_t *nelp, size_t width,
int (*compar) (const void *, const void *))
{
return lwork (key, base, nelp, width, compar, 1);
}
extern "C" void *
lfind (const void *key, const void *base, size_t *nelp, size_t width,
int (*compar) (const void *, const void *))
{
return lwork (key, base, nelp, width, compar, 0);
}
static void *
lwork (const void *key, const void *base, size_t *nelp, size_t width,
int (*compar) (const void *, const void *), int addelem)
{
uint8_t *ep, *endp;
/* Cast to an integer value first to avoid the warning for removing
'const' via a cast. */
ep = (uint8_t *) (uintptr_t)base;
for (endp = (uint8_t *) (ep + width * *nelp); ep < endp; ep += width)
if (compar (key, ep) == 0)
return ep;
/* lfind () shall return when the key was not found. */
if (!addelem)
return NULL;
/* lsearch () adds the key to the end of the table and increments
the number of elements. */
memcpy (endp, key, width);
++*nelp;
return endp;
}