Merge pull request #8 from GameAnalytics/faster_merge
Faster merging of hyper c arrays.
diff --git a/c_src/hyper_carray.c b/c_src/hyper_carray.c
index 7d78554..7eedc85 100644
--- a/c_src/hyper_carray.c
+++ b/c_src/hyper_carray.c
@@ -13,6 +13,7 @@
// You should have received a copy of the GNU Lesser General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
+#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <tgmath.h>
@@ -40,9 +41,11 @@
/*
* Array of items each one byte in size.
*/
- char *items;
+ uint8_t *items;
};
+typedef struct hyper_carray *restrict carray_ptr;
+
#define HYPER_CARRAY_SIZE sizeof(struct hyper_carray)
/*
@@ -58,8 +61,7 @@
/*
* Allocate a new hyper_carray for use as an Erlang NIF resource.
*/
-static void carray_alloc(unsigned int precision,
- struct hyper_carray *restrict * arr)
+static void carray_alloc(unsigned int precision, carray_ptr * arr)
{
unsigned int nitems = pow(2, precision);
size_t header_size = HYPER_CARRAY_SIZE;
@@ -78,13 +80,12 @@
* Given an hyper_carray and a valid index, set the value at that index to
* max(current value, given value).
*/
-static inline void carray_merge_item(struct hyper_carray *restrict arr,
+static inline void carray_merge_item(carray_ptr arr,
unsigned int index,
unsigned int value)
{
- char *item = arr->items + index;
- if (value > *item)
- *item = value;
+ uint8_t *item = arr->items + index;
+ *item = (value > *item) ? value : *item;
}
/*
@@ -97,7 +98,7 @@
if (!enif_get_uint(env, argv[0], &precision))
return enif_make_badarg(env);
- struct hyper_carray *restrict arr = NULL;
+ carray_ptr arr = NULL;
carray_alloc(precision, &arr);
memset(arr->items, 0, arr->size);
@@ -112,7 +113,7 @@
static ERL_NIF_TERM set(ErlNifEnv * env, int argc,
const ERL_NIF_TERM argv[])
{
- struct hyper_carray *restrict arr = NULL;
+ carray_ptr arr = NULL;
HYPER_CARRAY_OR_BADARG(argv[2], arr);
unsigned int index = 0;
@@ -151,39 +152,54 @@
if (narrays < 1)
return enif_make_badarg(env);
- void *tmp = NULL;
- struct hyper_carray *restrict first = NULL;
- struct hyper_carray *restrict acc = NULL;
- struct hyper_carray *restrict curr = NULL;
-
+ carray_ptr first = NULL;
HYPER_CARRAY_OR_BADARG(head, first);
+ carray_ptr acc = NULL;
carray_alloc(first->precision, &acc);
memcpy(acc->items, first->items, acc->size);
- unsigned int nitems = 0;
+ carray_ptr *arrays =
+ (carray_ptr *) enif_alloc(narrays * sizeof(carray_ptr));
+ arrays[0] = first;
+
+ // Validate arrays
for (int i = 1; i < narrays; ++i) {
+ void *tmp = NULL;
+
if (!enif_get_list_cell(env, tail, &head, &tail)
|| !enif_get_resource(env, head, carray_resource,
&tmp))
goto dealloc_and_badarg;
- curr = tmp;
+
+ arrays[i] = tmp;
// Require uniform precision.
- if (curr->precision != acc->precision)
+ if (arrays[i]->precision != acc->precision)
goto dealloc_and_badarg;
- nitems = curr->size;
- for (int j = 0; j < nitems; ++j)
- carray_merge_item(acc, j, curr->items[j]);
-
continue;
dealloc_and_badarg:
+ enif_free((void *) arrays);
dtor(env, acc);
return enif_make_badarg(env);
}
+ // Merge arrays
+ const unsigned int nitems = first->size;
+ for (carray_ptr * it = arrays + 1, *end = arrays + narrays;
+ it != end; ++it) {
+ carray_ptr curr = *it;
+
+ for (uint8_t * accitem = acc->items, *item = curr->items,
+ *enditem = curr->items + nitems;
+ item != enditem; ++item, ++accitem) {
+ *accitem = (*item > *accitem) ? *item : *accitem;
+ }
+ }
+
+ enif_free((void *) arrays);
return enif_make_resource(env, acc);
}
@@ -194,7 +210,7 @@
static ERL_NIF_TERM bytes(ErlNifEnv * env, int argc,
const ERL_NIF_TERM argv[])
{
- struct hyper_carray *restrict arr = NULL;
+ carray_ptr arr = NULL;
HYPER_CARRAY_OR_BADARG(argv[0], arr);
return enif_make_int(env, HYPER_CARRAY_SIZE + arr->size);
}
@@ -205,7 +221,7 @@
static ERL_NIF_TERM register_sum(ErlNifEnv * env, int argc,
const ERL_NIF_TERM argv[])
{
- struct hyper_carray *restrict arr = NULL;
+ carray_ptr arr = NULL;
HYPER_CARRAY_OR_BADARG(argv[0], arr);
int currval = 0;
@@ -226,7 +242,7 @@
static ERL_NIF_TERM zero_count(ErlNifEnv * env, int argc,
const ERL_NIF_TERM argv[])
{
- struct hyper_carray *restrict arr = NULL;
+ carray_ptr arr = NULL;
HYPER_CARRAY_OR_BADARG(argv[0], arr);
unsigned int nzeros = 0;
@@ -246,7 +262,7 @@
static ERL_NIF_TERM encode_registers(ErlNifEnv * env, int argc,
const ERL_NIF_TERM argv[])
{
- struct hyper_carray *restrict arr = NULL;
+ carray_ptr arr = NULL;
HYPER_CARRAY_OR_BADARG(argv[0], arr);
size_t nbytes = arr->size;
@@ -271,7 +287,7 @@
|| !enif_inspect_binary(env, argv[0], &bin))
return enif_make_badarg(env);
- struct hyper_carray *restrict arr = NULL;
+ carray_ptr arr = NULL;
carray_alloc(precision, &arr);
memcpy(arr->items, bin.data, arr->size);
