61 lines
1.6 KiB
Odin
61 lines
1.6 KiB
Odin
/*
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The default arena allocator Odin provides does fragmented resizes even for the last most allocated block getting resized.
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This is an alternative to alleviates that.
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*/
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package sectr
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import "core:mem"
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// Initialize a sub-section of our virtual memory as a sub-arena
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sub_arena_init :: proc( address : ^ byte, size : int ) -> ( ^ Arena) {
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Arena :: mem.Arena
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arena_size :: size_of( Arena)
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sub_arena := cast( ^ Arena ) address
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mem_slice := slice_ptr( ptr_offset( address, arena_size), size )
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arena_init( sub_arena, mem_slice )
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return sub_arena
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}
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// TODO(Ed) : Once this is done (ArenaFixed), rename to just Arena as we're not going to use the core implementation
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ArenaFixedHeader :: struct {
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data : []byte,
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offset : uint,
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peak_used : uint,
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}
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ArenaFixed :: struct {
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using header : ^ArenaFixedHeader,
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}
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arena_fixed_init :: proc( backing : []byte ) -> (arena : ArenaFixed) {
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header_size := size_of(ArenaFixedHeader)
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verify(len(backing) >= (header_size + Kilobyte), "Attempted to init an arena with less than kilobyte of memory...")
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arena.header = cast(^ArenaFixedHeader) raw_data(backing)
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using arena.header
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data_ptr := cast([^]byte) (cast( [^]ArenaFixedHeader) arena.header)[ 1:]
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data = slice_ptr( data_ptr, len(backing) - header_size )
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offset = 0
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peak_used = 0
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return
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}
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arena_fixed_allocator_proc :: proc(
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allocator_data : rawptr,
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mode : AllocatorMode,
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size : int,
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alignment : int,
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old_memory : rawptr,
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old_size : int,
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location := #caller_location
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) -> ([]byte, AllocatorError)
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{
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return nil, .Out_Of_Memory
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}
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