40 lines
1.2 KiB
C
40 lines
1.2 KiB
C
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#include "arena_allocator.h"
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#include "assert.h"
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#include "vector.h"
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#include <stdlib.h>
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#include <string.h>
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static ArenaBlock arena_block_alloc(size_t size) {
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size = size < ARENA_BLOCK_SIZE ? ARENA_BLOCK_SIZE : size;
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byte *ptr = malloc(size);
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assert_alloc(ptr);
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return (ArenaBlock){.data = ptr, .size = size, .end = ptr + size};
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}
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void arena_block_drop(ArenaBlock block) { free(block.data); }
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ArenaAllocator arena_init() {
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ArenaBlock block = arena_block_alloc(ARENA_BLOCK_SIZE);
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ArenaBlockVec blocks = vec_init();
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vec_grow(&blocks, 256);
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vec_push(&blocks, block);
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ArenaBlock *last = blocks.data;
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return (ArenaAllocator){.blocks = blocks, .ptr = last->data, .last = last};
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}
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void *arena_alloc(ArenaAllocator *alloc, size_t size) {
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if (alloc->ptr + size > alloc->last->end) {
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ArenaBlock block = arena_block_alloc(size);
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vec_push(&alloc->blocks, block);
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ArenaBlock *last = &alloc->blocks.data[alloc->blocks.len - 1];
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alloc->ptr = last->data;
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alloc->last = last;
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}
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byte *ptr = alloc->ptr;
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alloc->ptr += size;
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return ptr;
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}
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void arena_drop(ArenaAllocator arena) { vec_drop(arena.blocks); }
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