diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/sort.c | 34 |
1 files changed, 28 insertions, 6 deletions
diff --git a/lib/sort.c b/lib/sort.c index cf408aec3733..d54cf97e9548 100644 --- a/lib/sort.c +++ b/lib/sort.c @@ -144,6 +144,18 @@ static void do_swap(void *a, void *b, size_t size, swap_func_t swap_func) swap_func(a, b, (int)size); } +typedef int (*cmp_func_t)(const void *, const void *); +typedef int (*cmp_r_func_t)(const void *, const void *, const void *); +#define _CMP_WRAPPER ((cmp_r_func_t)0L) + +static int do_cmp(const void *a, const void *b, + cmp_r_func_t cmp, const void *priv) +{ + if (cmp == _CMP_WRAPPER) + return ((cmp_func_t)(priv))(a, b); + return cmp(a, b, priv); +} + /** * parent - given the offset of the child, find the offset of the parent. * @i: the offset of the heap element whose parent is sought. Non-zero. @@ -171,12 +183,13 @@ static size_t parent(size_t i, unsigned int lsbit, size_t size) } /** - * sort - sort an array of elements + * sort_r - sort an array of elements * @base: pointer to data to sort * @num: number of elements * @size: size of each element * @cmp_func: pointer to comparison function * @swap_func: pointer to swap function or NULL + * @priv: third argument passed to comparison function * * This function does a heapsort on the given array. You may provide * a swap_func function if you need to do something more than a memory @@ -188,9 +201,10 @@ static size_t parent(size_t i, unsigned int lsbit, size_t size) * O(n*n) worst-case behavior and extra memory requirements that make * it less suitable for kernel use. */ -void sort(void *base, size_t num, size_t size, - int (*cmp_func)(const void *, const void *), - void (*swap_func)(void *, void *, int size)) +void sort_r(void *base, size_t num, size_t size, + int (*cmp_func)(const void *, const void *, const void *), + void (*swap_func)(void *, void *, int size), + const void *priv) { /* pre-scale counters for performance */ size_t n = num * size, a = (num/2) * size; @@ -238,12 +252,12 @@ void sort(void *base, size_t num, size_t size, * average, 3/4 worst-case.) */ for (b = a; c = 2*b + size, (d = c + size) < n;) - b = cmp_func(base + c, base + d) >= 0 ? c : d; + b = do_cmp(base + c, base + d, cmp_func, priv) >= 0 ? c : d; if (d == n) /* Special case last leaf with no sibling */ b = c; /* Now backtrack from "b" to the correct location for "a" */ - while (b != a && cmp_func(base + a, base + b) >= 0) + while (b != a && do_cmp(base + a, base + b, cmp_func, priv) >= 0) b = parent(b, lsbit, size); c = b; /* Where "a" belongs */ while (b != a) { /* Shift it into place */ @@ -252,4 +266,12 @@ void sort(void *base, size_t num, size_t size, } } } +EXPORT_SYMBOL(sort_r); + +void sort(void *base, size_t num, size_t size, + int (*cmp_func)(const void *, const void *), + void (*swap_func)(void *, void *, int size)) +{ + return sort_r(base, num, size, _CMP_WRAPPER, swap_func, cmp_func); +} EXPORT_SYMBOL(sort); |