1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106

use intuicio_data::{
    data_heap::DataHeap,
    data_stack::{DataStack, DataStackMode, DataStackRegisterAccess},
};
use std::{any::Any, collections::HashMap};

pub struct Context {
    stack: DataStack,
    registers: DataStack,
    registers_barriers: Vec<usize>,
    heap: DataHeap,
    custom: HashMap<String, Box<dyn Any>>,
}

impl Context {
    pub fn new(
        stack_capacity: usize,
        registers_capacity: usize,
        heap_page_capacity: usize,
    ) -> Self {
        Self {
            stack: DataStack::new(stack_capacity, DataStackMode::Values),
            registers: DataStack::new(registers_capacity, DataStackMode::Registers),
            registers_barriers: vec![],
            heap: DataHeap::new(heap_page_capacity),
            custom: Default::default(),
        }
    }

    pub fn fork(&self) -> Self {
        Self::new(
            self.stack.size(),
            self.registers.size(),
            self.heap.page_capacity(),
        )
    }

    pub fn stack_capacity(&self) -> usize {
        self.stack.size()
    }

    pub fn registers_capacity(&self) -> usize {
        self.registers.size()
    }

    pub fn heap_page_capacity(&self) -> usize {
        self.heap.page_capacity()
    }

    pub fn stack(&mut self) -> &mut DataStack {
        &mut self.stack
    }

    pub fn registers(&mut self) -> &mut DataStack {
        &mut self.registers
    }

    pub fn heap(&mut self) -> &mut DataHeap {
        &mut self.heap
    }

    pub fn stack_and_registers(&mut self) -> (&mut DataStack, &mut DataStack) {
        (&mut self.stack, &mut self.registers)
    }

    pub fn store_registers(&mut self) {
        self.registers_barriers
            .push(self.registers.registers_count());
    }

    pub fn restore_registers(&mut self) {
        if let Some(count) = self.registers_barriers.pop() {
            while self.registers.registers_count() > count {
                self.registers.drop_register();
            }
        }
    }

    pub fn registers_barriers(&self) -> &[usize] {
        &self.registers_barriers
    }

    pub fn absolute_register_index(&self, index: usize) -> usize {
        self.registers_barriers
            .last()
            .map(|count| index + count)
            .unwrap_or(index)
    }

    pub fn access_register(&mut self, index: usize) -> Option<DataStackRegisterAccess> {
        let index = self.absolute_register_index(index);
        self.registers.access_register(index)
    }

    pub fn custom<T: 'static>(&self, name: &str) -> Option<&T> {
        self.custom.get(name)?.downcast_ref::<T>()
    }

    pub fn custom_mut<T: 'static>(&mut self, name: &str) -> Option<&mut T> {
        self.custom.get_mut(name)?.downcast_mut::<T>()
    }

    pub fn set_custom<T: 'static>(&mut self, name: impl ToString, data: T) {
        self.custom.insert(name.to_string(), Box::new(data));
    }
}