Add another BSEARCH function that lets you search through an array of objects.

If you give it a value x, the macro lets you pull a value out of each object
that you want to compare to x.
This commit is contained in:
Dana Jansens 2011-01-27 17:23:47 -05:00
parent 30fe9697df
commit 7d32190a4c
2 changed files with 16 additions and 7 deletions

View file

@ -23,13 +23,22 @@
G_BEGIN_DECLS
/*! Setup to do a binary search on an array holding elements of type @t */
#define BSEARCH_SETUP(t) \
register t l_BSEARCH, r_BSEARCH, out_BSEARCH;
/*! Setup to do a binary search on an array. */
#define BSEARCH_SETUP() \
register guint l_BSEARCH, r_BSEARCH, out_BSEARCH;
/*! Helper macro that just returns the input */
#define BSEARCH_IS_T(t) (t)
/*! Search an array @ar holding elements of type @t, starting at index @start,
with @size elements, looking for value @val. */
#define BSEARCH(t, ar, start, size, val) \
BSEARCH_CMP(t, ar, start, size, val, BSEARCH_IS_T)
/*! Search an array @ar, starting at index @start,
with @size elements, looking for value @val of type @t,
using the macro @to_t to convert values in the arrau @ar to type @t.*/
#define BSEARCH_CMP(t, ar, start, size, val, to_t) \
{ \
l_BSEARCH = (start); \
r_BSEARCH = (start)+(size)-1; \
@ -37,10 +46,10 @@ G_BEGIN_DECLS
/* m is in the middle, but to the left if there's an even number \
of elements */ \
out_BSEARCH = l_BSEARCH + (r_BSEARCH - l_BSEARCH)/2; \
if ((val) == (ar)[out_BSEARCH]) { \
if ((val) == to_t((ar)[out_BSEARCH])) { \
break; \
} \
else if ((val) < (ar)[out_BSEARCH] && out_BSEARCH > 0) { \
else if ((val) < to_t((ar)[out_BSEARCH]) && out_BSEARCH > 0) { \
r_BSEARCH = out_BSEARCH-1; /* search to the left side */ \
} \
else \

View file

@ -335,7 +335,7 @@ static inline gboolean try_exec(const ObtPaths *const p,
const gchar *const path)
{
struct stat st;
BSEARCH_SETUP(guint);
BSEARCH_SETUP();
if (stat(path, &st) != 0)
return FALSE;