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#include <assert.h>
#include <kmalloc.h>
#include <lib/relist.h>
void relist_init(struct relist *list) {
list->bitmap_capacity = 100;
list->bitmap = kcalloc(sizeof(u64), list->bitmap_capacity);
if (!list->bitmap) {
goto relist_init_error;
}
list->entries = kallocarray(sizeof(void *), (sizeof(u64) * 8));
if (!list->entries) {
goto relist_init_error;
}
return;
// Can't allocate now but future appends can try to allocate anyways so
// there is no reason to "fail" the init.
relist_init_error:
list->bitmap_capacity = 0;
list->entries = NULL;
list->bitmap = NULL;
return;
}
void relist_reset(struct relist *list) {
memset(list->bitmap, 0, list->bitmap_capacity * sizeof(u64));
}
int relist_clone(struct relist *in, struct relist *out) {
relist_init(out);
for (int i = 0;; i++) {
void *output;
if (!relist_get(in, i, &output)) {
break;
}
if (!relist_add(out, output, NULL)) {
relist_free(out);
return 0;
}
}
return 1;
}
static int relist_find_free_entry(struct relist *list, u32 *entry) {
for (u32 i = 0; i < list->bitmap_capacity; i++) {
if (0 == ~(list->bitmap[i])) {
continue;
}
for (int c = 0; c < 64; c++) {
if (!(list->bitmap[i] & ((u64)1 << c))) {
*entry = i * 64 + c;
return 1;
}
}
}
*entry = 0;
return 0;
}
int relist_add(struct relist *list, void *value, u32 *index) {
u32 entry;
if (!relist_find_free_entry(list, &entry)) {
assert(0);
}
list->entries[entry] = value;
if (index) {
*index = entry;
}
list->bitmap[entry / 64] |= ((u64)1 << (entry % 64));
return 1;
}
int relist_remove(struct relist *list, u32 index) {
if ((index / 64) > list->bitmap_capacity) {
assert(0);
return 0;
}
int is_used = (list->bitmap[index / 64] & ((u64)1 << (index % 64)));
if (!is_used) {
assert(0);
return 0;
}
list->bitmap[index / 64] &= ~((u64)1 << (index % 64));
return 1;
}
int relist_set(struct relist *list, u32 index, void *value) {
assert(value);
if ((index / 64) > list->bitmap_capacity) {
assert(0);
return 0;
}
int is_used = (list->bitmap[index / 64] & ((u64)1 << (index % 64)));
assert(is_used);
list->entries[index] = value;
return 1;
}
int relist_get(const struct relist *list, u32 index, void **out) {
if ((index / 64) > list->bitmap_capacity) {
assert(0);
return 0;
}
int is_used = (list->bitmap[index / 64] & ((u64)1 << (index % 64)));
if (!is_used) {
return 0;
}
*out = list->entries[index];
return 1;
}
void relist_free(struct relist *list) {
list->bitmap_capacity = 0;
kfree(list->entries);
kfree(list->bitmap);
list->entries = NULL;
list->bitmap = NULL;
}
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