Mercurial > code
changeset 22:ecdf21f1d0c6
Added a new function array_swap() that swap elements by index
| author | David Demelier <markand@malikania.fr> |
|---|---|
| date | Wed, 14 Sep 2011 20:24:14 +0200 |
| parents | ae4128d16c92 |
| children | 216b6e6a539c |
| files | array.c array.h |
| diffstat | 2 files changed, 41 insertions(+), 5 deletions(-) [+] |
line wrap: on
line diff
--- a/array.c Fri Sep 09 17:32:53 2011 +0200 +++ b/array.c Wed Sep 14 20:24:14 2011 +0200 @@ -34,11 +34,12 @@ if (unit == 0 || !(arr = malloc(sizeof (struct array)))) return NULL; + arr->tmp = NULL; + arr->length = 0; + arr->flags = flags; arr->bsize = (bsize == 0) ? ARRAY_DEFAULT_BSIZE : bsize; - arr->flags = flags; arr->unit = unit; - arr->size = SIZE(bsize); - arr->length = 0; + arr->size = SIZE(arr->bsize); if (!(arr->data = malloc(arr->size))) { free(arr); @@ -165,6 +166,35 @@ } /* + * Swap the two elements referenced by index `i1' and `i2'. This function needs + * to allocate data to swap elements thus if the functions fails it returns -1 + * otherwise 0 is returned. + */ + +int +array_swap(struct array *arr, int i1, int i2) +{ + /* Out of bounds */ + if (i1 > arr->length - 1|| i1 < 0 || i2 > arr->length - 1|| i2 < 0) + return -1; + + /* + * Only allocate at this time, the user may do not want to use this + * function. + */ + + if (!arr->tmp && !(arr->tmp = malloc(arr->unit))) + return -1; + + memcpy(arr->tmp, arr->data + SIZE(i1), arr->unit); + memcpy(arr->data + SIZE(i1), arr->data + SIZE(i2), arr->unit); + memcpy(arr->data + SIZE(i2), arr->tmp, arr->unit); + + return 0; +} + + +/* * Apply the function `fn' on each object and give the optional `udata' * argument to the function too. */ @@ -225,7 +255,11 @@ { array_clear(arr); - free(arr->data); + if (arr->data) + free(arr->data); + if (arr->tmp) + free(arr->tmp); + free(arr); }
--- a/array.h Fri Sep 09 17:32:53 2011 +0200 +++ b/array.h Wed Sep 14 20:24:14 2011 +0200 @@ -23,11 +23,12 @@ struct array { char *data; /* array of data */ + char *tmp; /* only used for array_swap() */ int length; /* number of element inside */ #define ARRAY_FIXED 0x00000000 #define ARRAY_AUTO 0x00000001 - int flags; /* array's flags (default FIXED) */ + int flags; /* array's flags (default FIXED) */ /* Private should not be modified by user */ size_t size; /* current buffer size */ @@ -45,6 +46,7 @@ void *array_pop(struct array *); void *array_unqueue(struct array *); void *array_remove(struct array *, int); +int array_swap(struct array *, int, int); void array_map(struct array *, void (*fn)(void *, void *), void *); void *array_find(struct array *, int (*fn)(void *, void *), void *, int *); void array_clear(struct array *);