67 lines
1.5 KiB
Zig
67 lines
1.5 KiB
Zig
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const std = @import("std");
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const testing = std.testing;
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const mem = std.mem;
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const Allocator = mem.Allocator;
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pub const IDManager = struct {
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const Self = @This();
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allocator: *Allocator,
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nextID: usize = 0,
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availableIDs: std.ArrayList(usize),
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pub fn init(allocator: *Allocator) Self {
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return Self {
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.allocator = allocator,
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.availableIDs = std.ArrayList(usize).init(allocator),
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};
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}
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pub fn next(self: *Self) usize {
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if (self.availableIDs.items.len > 0)
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{
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return self.availableIDs.pop();
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}
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else
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{
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var result = self.nextID;
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self.nextID += 1;
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return result;
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}
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}
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pub fn free(self: *Self, id: usize) !void {
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self.availableIDs.append(id) catch |err| return err;
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}
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};
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test "next" {
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var arena = std.heap.ArenaAllocator.init(std.heap.page_allocator);
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defer arena.deinit();
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const allocator = &arena.allocator;
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var id_manager = IDManager.init(allocator);
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testing.expect(id_manager.next() == 0);
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testing.expect(id_manager.next() == 1);
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}
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test "free" {
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var arena = std.heap.ArenaAllocator.init(std.heap.page_allocator);
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defer arena.deinit();
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const allocator = &arena.allocator;
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var id_manager = IDManager.init(allocator);
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var id_zero = id_manager.next();
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var id_one = id_manager.next();
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var id_two = id_manager.next();
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try id_manager.free(id_one);
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testing.expect(id_manager.next() == id_one);
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testing.expect(id_manager.next() == 3);
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}
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