colla/arena.h
snarmph 6d36aa4442 .
2025-03-21 19:09:14 +01:00

73 lines
No EOL
2 KiB
C

#ifndef COLLA_ARENA_H
#define COLLA_ARENA_H
#include "core.h"
#if COLLA_WIN && !COLLA_TCC
#define alignof __alignof
#endif
typedef enum arena_type_e {
ARENA_TYPE_NONE, // only here so that a 0 initialised arena is valid
ARENA_VIRTUAL,
ARENA_MALLOC,
ARENA_MALLOC_ALWAYS,
ARENA_STATIC,
} arena_type_e;
typedef enum alloc_flags_e {
ALLOC_FLAGS_NONE = 0,
ALLOC_NOZERO = 1 << 0,
ALLOC_SOFT_FAIL = 1 << 1,
} alloc_flags_e;
typedef struct arena_t arena_t;
struct arena_t {
u8 *beg;
u8 *cur;
u8 *end;
arena_type_e type;
};
typedef struct arena_desc_t arena_desc_t;
struct arena_desc_t {
arena_type_e type;
usize size;
u8 *static_buffer;
};
typedef struct arena_alloc_desc_t arena_alloc_desc_t;
struct arena_alloc_desc_t {
arena_t *arena;
usize count;
alloc_flags_e flags;
usize align;
usize size;
};
// arena_type_e type, usize allocation, [ byte *static_buffer ]
#define arena_make(...) arena_init(&(arena_desc_t){ __VA_ARGS__ })
// arena_t *arena, T type, [ usize count, alloc_flags_e flags, usize align, usize size ]
#define alloc(arenaptr, type, ...) arena_alloc(&(arena_alloc_desc_t){ .size = sizeof(type), .count = 1, .align = alignof(type), .arena = arenaptr, __VA_ARGS__ })
// simple arena that always calls malloc internally, this is useful if you need
// malloc for some reason but want to still use the arena interface
// WARN: most arena functions outside of alloc/scratch won't work!
// you also need to each allocation afterwards! this is still
// malloc
extern arena_t malloc_arena;
arena_t arena_init(const arena_desc_t *desc);
void arena_cleanup(arena_t *arena);
arena_t arena_scratch(arena_t *arena, usize size);
void *arena_alloc(const arena_alloc_desc_t *desc);
usize arena_tell(arena_t *arena);
usize arena_remaining(arena_t *arena);
usize arena_capacity(arena_t *arena);
void arena_rewind(arena_t *arena, usize from_start);
void arena_pop(arena_t *arena, usize amount);
#endif