90 lines
2.0 KiB
C
90 lines
2.0 KiB
C
#include "mem_arena.h"
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#include "aliases.h"
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#include "mem_utils.h"
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#include <stdbool.h>
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#include <stdlib.h>
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#include <string.h>
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#ifndef DEFAULT_ALIGNMENT
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#define DEFAULT_ALIGNMENT (2 * sizeof(void *))
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#endif /* ifndef DEFAULT_ALIGNMENT */
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typedef struct base_arena BaseArena;
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struct base_arena {
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u8 *buf;
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u8 *offset;
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u64 capacity;
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BaseArena *prev;
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BaseArena *next;
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};
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internal bool base_arena_init(BaseArena *arena, u64 capacity);
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internal void *base_arena_alloc(BaseArena *arena, u64 size);
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internal void *base_arena_alloc_aligned(BaseArena *arena, u64 size,
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u64 alignment);
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internal void base_arena_clear(BaseArena *arena);
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internal void base_arena_free(BaseArena *arena);
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internal bool base_arena_init(BaseArena *arena, u64 capacity) {
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if (!arena || arena->buf) {
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return false;
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}
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u64 alloc_size = sizeof(u8) * capacity;
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arena->buf = (u8 *)malloc(alloc_size);
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if (!(arena->buf)) {
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return false;
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}
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memset(arena->buf, 0, alloc_size);
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arena->capacity = capacity;
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arena->offset = arena->buf;
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arena->prev = arena->next = NULL;
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return true;
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}
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internal void *base_arena_alloc(BaseArena *arena, u64 size) {
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return base_arena_alloc_aligned(arena, size, DEFAULT_ALIGNMENT);
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}
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internal void *base_arena_alloc_aligned(BaseArena *arena, u64 size,
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u64 alignment) {
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if (!arena) {
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return NULL;
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}
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u8 *output = mem_util_align_forward((void *)(arena->offset), alignment);
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if (output + size >= arena->buf + arena->capacity) {
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return NULL;
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}
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arena->offset += size;
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return (void *)output;
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}
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internal void base_arena_clear(BaseArena *arena) {
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if (!arena) {
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return;
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}
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memset(arena->buf, 0, arena->offset - arena->buf);
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arena->offset = arena->buf;
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}
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internal void base_arena_free(BaseArena *arena) {
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if (!arena) {
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return;
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}
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if (arena->buf) {
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free(arena->buf);
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}
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arena->buf = arena->offset = NULL;
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arena->capacity = 0;
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arena->prev = arena->next = NULL;
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}
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