63 lines
1.6 KiB
Plaintext
Executable File
63 lines
1.6 KiB
Plaintext
Executable File
#import "modules/std.sx";
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#import "modules/std/mem.sx";
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// --- State(T) — a handle to persistent storage ---
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State :: struct ($T: Type) {
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ptr: *T;
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get :: (self: State(T)) -> T { self.ptr.* }
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set :: (self: State(T), val: T) { self.ptr.* = val; }
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}
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// --- StateEntry — type-erased storage ---
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StateEntry :: struct {
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id: s64;
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data: [*]u8;
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size: s64;
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generation: s64;
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}
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// --- StateStore — manages persistent state ---
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StateStore :: struct {
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entries: List(StateEntry);
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current_generation: s64;
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parent_allocator: Allocator;
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init :: (self: *StateStore) {
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self.entries = List(StateEntry).{};
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self.current_generation = 0;
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self.parent_allocator = context.allocator;
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}
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get_or_create :: (self: *StateStore, id: s64, $T: Type, default: T) -> State(T) {
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// Search for existing entry
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i : s64 = 0;
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while i < self.entries.len {
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if self.entries.items[i].id == id {
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self.entries.items[i].generation = self.current_generation;
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return State(T).{ ptr = xx self.entries.items[i].data };
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}
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i += 1;
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}
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// Create new entry
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data : [*]u8 = xx self.parent_allocator.alloc_bytes(size_of(T));
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memcpy(data, @default, size_of(T));
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self.entries.append(.{
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id = id,
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data = data,
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size = size_of(T),
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generation = self.current_generation
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}, self.parent_allocator);
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State(T).{ ptr = xx data }
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}
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next_frame :: (self: *StateStore) {
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self.current_generation += 1;
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}
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}
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