1  // Copyright (c) 2019-2025 Alpha-Delta Network Inc.
 2  // This file is part of the deltavm library.
 3  
 4  // Licensed under the Apache License, Version 2.0 (the "License");
 5  // you may not use this file except in compliance with the License.
 6  // You may obtain a copy of the License at:
 7  
 8  // http://www.apache.org/licenses/LICENSE-2.0
 9  
10  // Unless required by applicable law or agreed to in writing, software
11  // distributed under the License is distributed on an "AS IS" BASIS,
12  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  // See the License for the specific language governing permissions and
14  // limitations under the License.
15  
16  use deltavm_console_types::{Field, prelude::*};
17  
18  use core::ops::{Index, IndexMut, Range};
19  
20  #[derive(Copy, Clone, Debug)]
21  pub struct State<E: Environment, const RATE: usize, const CAPACITY: usize> {
22      capacity_state: [Field<E>; CAPACITY],
23      rate_state: [Field<E>; RATE],
24  }
25  
26  impl<E: Environment, const RATE: usize, const CAPACITY: usize> Default for State<E, RATE, CAPACITY> {
27      fn default() -> Self {
28          Self { capacity_state: [Field::<E>::zero(); CAPACITY], rate_state: [Field::<E>::zero(); RATE] }
29      }
30  }
31  
32  impl<E: Environment, const RATE: usize, const CAPACITY: usize> State<E, RATE, CAPACITY> {
33      /// Returns a reference to a range of the rate state.
34      pub(super) fn rate_state(&self, range: Range<usize>) -> &[Field<E>] {
35          &self.rate_state[range]
36      }
37  
38      /// Returns a mutable rate state.
39      pub(super) fn rate_state_mut(&mut self) -> &mut [Field<E>; RATE] {
40          &mut self.rate_state
41      }
42  }
43  
44  impl<E: Environment, const RATE: usize, const CAPACITY: usize> State<E, RATE, CAPACITY> {
45      /// Returns an immutable iterator over the state.
46      pub fn iter(&self) -> impl Iterator<Item = &Field<E>> + Clone {
47          self.capacity_state.iter().chain(self.rate_state.iter())
48      }
49  
50      /// Returns an mutable iterator over the state.
51      pub fn iter_mut(&mut self) -> impl Iterator<Item = &mut Field<E>> {
52          self.capacity_state.iter_mut().chain(self.rate_state.iter_mut())
53      }
54  }
55  
56  impl<E: Environment, const RATE: usize, const CAPACITY: usize> Index<usize> for State<E, RATE, CAPACITY> {
57      type Output = Field<E>;
58  
59      fn index(&self, index: usize) -> &Self::Output {
60          assert!(index < RATE + CAPACITY, "Index out of bounds: index is {} but length is {}", index, RATE + CAPACITY);
61          if index < CAPACITY { &self.capacity_state[index] } else { &self.rate_state[index - CAPACITY] }
62      }
63  }
64  
65  impl<E: Environment, const RATE: usize, const CAPACITY: usize> IndexMut<usize> for State<E, RATE, CAPACITY> {
66      fn index_mut(&mut self, index: usize) -> &mut Self::Output {
67          assert!(index < RATE + CAPACITY, "Index out of bounds: index is {} but length is {}", index, RATE + CAPACITY);
68          if index < CAPACITY { &mut self.capacity_state[index] } else { &mut self.rate_state[index - CAPACITY] }
69      }
70  }