solana_sdk/
hard_forks.rs

1//! The `hard_forks` module is used to maintain the list of slot boundaries for when a hard fork
2//! should occur.
3
4#![cfg(feature = "full")]
5
6use {
7    byteorder::{ByteOrder, LittleEndian},
8    solana_sdk::clock::Slot,
9};
10
11#[derive(Default, Clone, Debug, Deserialize, Serialize, AbiExample, PartialEq, Eq)]
12pub struct HardForks {
13    hard_forks: Vec<(Slot, usize)>,
14}
15impl HardForks {
16    // Register a fork to occur at all slots >= `slot` with a parent slot < `slot`
17    pub fn register(&mut self, new_slot: Slot) {
18        if let Some(i) = self
19            .hard_forks
20            .iter()
21            .position(|(slot, _)| *slot == new_slot)
22        {
23            self.hard_forks[i] = (new_slot, self.hard_forks[i].1.saturating_add(1));
24        } else {
25            self.hard_forks.push((new_slot, 1));
26        }
27        #[allow(clippy::stable_sort_primitive)]
28        self.hard_forks.sort();
29    }
30
31    // Returns a sorted-by-slot iterator over the registered hark forks
32    pub fn iter(&self) -> std::slice::Iter<(Slot, usize)> {
33        self.hard_forks.iter()
34    }
35
36    // Returns data to include in the bank hash for the given slot if a hard fork is scheduled
37    pub fn get_hash_data(&self, slot: Slot, parent_slot: Slot) -> Option<[u8; 8]> {
38        // The expected number of hard forks in a cluster is small.
39        // If this turns out to be false then a more efficient data
40        // structure may be needed here to avoid this linear search
41        let fork_count: usize = self
42            .hard_forks
43            .iter()
44            .map(|(fork_slot, fork_count)| {
45                if parent_slot < *fork_slot && slot >= *fork_slot {
46                    *fork_count
47                } else {
48                    0
49                }
50            })
51            .sum();
52
53        if fork_count > 0 {
54            let mut buf = [0u8; 8];
55            LittleEndian::write_u64(&mut buf[..], fork_count as u64);
56            Some(buf)
57        } else {
58            None
59        }
60    }
61}
62
63#[cfg(test)]
64mod tests {
65    use super::*;
66
67    #[test]
68    fn iter_is_sorted() {
69        let mut hf = HardForks::default();
70        hf.register(30);
71        hf.register(20);
72        hf.register(10);
73        hf.register(20);
74
75        assert_eq!(hf.hard_forks, vec![(10, 1), (20, 2), (30, 1)]);
76    }
77
78    #[test]
79    fn multiple_hard_forks_since_parent() {
80        let mut hf = HardForks::default();
81        hf.register(10);
82        hf.register(20);
83
84        assert_eq!(hf.get_hash_data(9, 0), None);
85        assert_eq!(hf.get_hash_data(10, 0), Some([1, 0, 0, 0, 0, 0, 0, 0,]));
86        assert_eq!(hf.get_hash_data(19, 0), Some([1, 0, 0, 0, 0, 0, 0, 0,]));
87        assert_eq!(hf.get_hash_data(20, 0), Some([2, 0, 0, 0, 0, 0, 0, 0,]));
88        assert_eq!(hf.get_hash_data(20, 10), Some([1, 0, 0, 0, 0, 0, 0, 0,]));
89        assert_eq!(hf.get_hash_data(20, 11), Some([1, 0, 0, 0, 0, 0, 0, 0,]));
90        assert_eq!(hf.get_hash_data(21, 11), Some([1, 0, 0, 0, 0, 0, 0, 0,]));
91        assert_eq!(hf.get_hash_data(21, 20), None);
92    }
93}
solana_sdk/hard_forks.rs

solana_sdk/
hard_forks.rs
