const physMemory = @import("mem/phys.zig");
const log = @import("debug.zig").log;
const mem = @import("mem.zig");

pub const Arena = struct {
    physBase: mem.PhysicalAddress,
    capacity: usize,
    len: usize,

    pub fn setup(cap: usize) ?Arena {
        const base = physMemory.allocateChunk(cap / 0x1000) orelse return null;
        return .{
            .physBase = .{ .raw = base },
            .capacity = cap,
            .len = 0,
        };
    }

    pub fn create(self: *@This(), comptime T: type) *T {
        if (self.len + @sizeOf(T) > self.capacity) {
            log.panic("Out of memory. Cannot allocate {} bytes", .{ @sizeOf(T) });
        }

        const v = self.physBase.add(self.len).virtualize();
        const ptr = @as(*T, @ptrFromInt(v));
        self.len += @sizeOf(T);

        return ptr;
    }
};