zksync_vm2 0.5.0-4

High-performance rewrite of the out-of-circuit VM for ZKsync Era
Documentation 
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
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167

use std::collections::{BTreeMap, BTreeSet};

/// A trait for things that can be rolled back to snapshots
pub(crate) trait Rollback {
    type Snapshot;
    fn snapshot(&self) -> Self::Snapshot;
    fn rollback(&mut self, snapshot: Self::Snapshot);
    fn delete_history(&mut self);
}

#[derive(Debug, Default)]
pub(crate) struct RollbackableMap<K: Ord, V> {
    map: BTreeMap<K, V>,
    old_entries: Vec<(K, Option<V>)>,
}

impl<K: Ord + Clone, V: Clone> RollbackableMap<K, V> {
    pub(crate) fn insert(&mut self, key: K, value: V) -> Option<V> {
        let old_value = self.map.insert(key.clone(), value);
        self.old_entries.push((key, old_value.clone()));
        old_value
    }

    pub(crate) fn changes_after(
        &self,
        snapshot: <Self as Rollback>::Snapshot,
    ) -> BTreeMap<K, (Option<V>, V)> {
        let mut changes = BTreeMap::new();
        for (key, old_value) in self.old_entries[snapshot..].iter().rev() {
            changes
                .entry(key.clone())
                .and_modify(|(old, _): &mut (Option<V>, V)| old.clone_from(old_value))
                .or_insert((old_value.clone(), self.map.get(key).unwrap().clone()));
        }
        changes
    }
}

impl<K: Ord, V> Rollback for RollbackableMap<K, V> {
    type Snapshot = usize;

    fn snapshot(&self) -> Self::Snapshot {
        self.old_entries.len()
    }

    fn rollback(&mut self, snapshot: Self::Snapshot) {
        for (k, v) in self.old_entries.drain(snapshot..).rev() {
            if let Some(old_value) = v {
                self.map.insert(k, old_value);
            } else {
                self.map.remove(&k);
            }
        }
    }

    fn delete_history(&mut self) {
        self.old_entries.clear();
    }
}

impl<K: Ord, V> AsRef<BTreeMap<K, V>> for RollbackableMap<K, V> {
    fn as_ref(&self) -> &BTreeMap<K, V> {
        &self.map
    }
}

#[derive(Debug, Default)]
pub(crate) struct RollbackableSet<K: Ord> {
    map: BTreeSet<K>,
    old_entries: Vec<K>,
}

impl<T: Ord + Clone> RollbackableSet<T> {
    /// Adds `key` to the set and returns if it was added (not present earlier).
    pub(crate) fn add(&mut self, key: T) -> bool {
        let is_new = self.map.insert(key.clone());
        if is_new {
            self.old_entries.push(key);
        }
        is_new
    }
}

impl<K: Ord> Rollback for RollbackableSet<K> {
    type Snapshot = usize;

    fn snapshot(&self) -> Self::Snapshot {
        self.old_entries.len()
    }

    fn rollback(&mut self, snapshot: Self::Snapshot) {
        for k in self.old_entries.drain(snapshot..) {
            self.map.remove(&k);
        }
    }

    fn delete_history(&mut self) {
        self.old_entries.clear();
    }
}

impl<K: Ord> AsRef<BTreeSet<K>> for RollbackableSet<K> {
    fn as_ref(&self) -> &BTreeSet<K> {
        &self.map
    }
}

#[derive(Debug)]
pub(crate) struct RollbackableLog<T> {
    entries: Vec<T>,
}

impl<T> Default for RollbackableLog<T> {
    fn default() -> Self {
        Self {
            entries: Vec::default(),
        }
    }
}

impl<T> Rollback for RollbackableLog<T> {
    type Snapshot = usize;

    fn snapshot(&self) -> Self::Snapshot {
        self.entries.len()
    }

    fn rollback(&mut self, snapshot: Self::Snapshot) {
        self.entries.truncate(snapshot);
    }

    fn delete_history(&mut self) {}
}

impl<T> RollbackableLog<T> {
    pub(crate) fn push(&mut self, entry: T) {
        self.entries.push(entry);
    }

    pub(crate) fn logs_after(&self, snapshot: <RollbackableLog<T> as Rollback>::Snapshot) -> &[T] {
        &self.entries[snapshot..]
    }
}

impl<T> AsRef<[T]> for RollbackableLog<T> {
    fn as_ref(&self) -> &[T] {
        &self.entries
    }
}

/// Rollbackable Plain Old Data simply stores copies of itself in snapshots.
#[derive(Debug, Default, Copy, Clone)]
pub(crate) struct RollbackablePod<T: Copy>(pub(crate) T);

impl<T: Copy> Rollback for RollbackablePod<T> {
    type Snapshot = T;

    fn snapshot(&self) -> Self::Snapshot {
        self.0
    }

    fn rollback(&mut self, snapshot: Self::Snapshot) {
        self.0 = snapshot;
    }

    fn delete_history(&mut self) {}
}