solana_program/sysvar/
recent_blockhashes.rs

1//! Information about recent blocks and their fee calculators.
2//!
3//! The _recent blockhashes sysvar_ provides access to the [`RecentBlockhashes`],
4//! which contains recent blockhahes and their [`FeeCalculator`]s.
5//!
6//! [`RecentBlockhashes`] does not implement [`Sysvar::get`].
7//!
8//! This sysvar is deprecated and should not be used. Transaction fees should be
9//! determined with the [`getFeeForMessage`] RPC method. For additional context
10//! see the [Comprehensive Compute Fees proposal][ccf].
11//!
12//! [`getFeeForMessage`]: https://solana.com/docs/rpc/http/getfeeformessage
13//! [ccf]: https://docs.solanalabs.com/proposals/comprehensive-compute-fees
14//!
15//! See also the Solana [documentation on the recent blockhashes sysvar][sdoc].
16//!
17//! [sdoc]: https://docs.solanalabs.com/runtime/sysvars#recentblockhashes
18
19#![allow(deprecated)]
20#![allow(clippy::arithmetic_side_effects)]
21use {
22    crate::{fee_calculator::FeeCalculator, hash::Hash, sysvar::Sysvar},
23    solana_sysvar_id::declare_deprecated_sysvar_id,
24    std::{cmp::Ordering, collections::BinaryHeap, iter::FromIterator, ops::Deref},
25};
26
27#[deprecated(
28    since = "1.9.0",
29    note = "Please do not use, will no longer be available in the future"
30)]
31pub const MAX_ENTRIES: usize = 150;
32
33declare_deprecated_sysvar_id!(
34    "SysvarRecentB1ockHashes11111111111111111111",
35    RecentBlockhashes
36);
37
38#[deprecated(
39    since = "1.9.0",
40    note = "Please do not use, will no longer be available in the future"
41)]
42#[repr(C)]
43#[derive(Serialize, Deserialize, Clone, Debug, Default, PartialEq, Eq)]
44pub struct Entry {
45    pub blockhash: Hash,
46    pub fee_calculator: FeeCalculator,
47}
48impl Entry {
49    pub fn new(blockhash: &Hash, lamports_per_signature: u64) -> Self {
50        Self {
51            blockhash: *blockhash,
52            fee_calculator: FeeCalculator::new(lamports_per_signature),
53        }
54    }
55}
56
57#[deprecated(
58    since = "1.9.0",
59    note = "Please do not use, will no longer be available in the future"
60)]
61#[derive(Clone, Debug)]
62pub struct IterItem<'a>(pub u64, pub &'a Hash, pub u64);
63
64impl<'a> Eq for IterItem<'a> {}
65
66impl<'a> PartialEq for IterItem<'a> {
67    fn eq(&self, other: &Self) -> bool {
68        self.0 == other.0
69    }
70}
71
72impl<'a> Ord for IterItem<'a> {
73    fn cmp(&self, other: &Self) -> Ordering {
74        self.0.cmp(&other.0)
75    }
76}
77
78impl<'a> PartialOrd for IterItem<'a> {
79    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
80        Some(self.cmp(other))
81    }
82}
83
84/// Contains recent block hashes and fee calculators.
85///
86/// The entries are ordered by descending block height, so the first entry holds
87/// the most recent block hash, and the last entry holds an old block hash.
88#[deprecated(
89    since = "1.9.0",
90    note = "Please do not use, will no longer be available in the future"
91)]
92#[repr(C)]
93#[derive(Serialize, Deserialize, Clone, Debug, PartialEq, Eq)]
94pub struct RecentBlockhashes(Vec<Entry>);
95
96impl Default for RecentBlockhashes {
97    fn default() -> Self {
98        Self(Vec::with_capacity(MAX_ENTRIES))
99    }
100}
101
102impl<'a> FromIterator<IterItem<'a>> for RecentBlockhashes {
103    fn from_iter<I>(iter: I) -> Self
104    where
105        I: IntoIterator<Item = IterItem<'a>>,
106    {
107        let mut new = Self::default();
108        for i in iter {
109            new.0.push(Entry::new(i.1, i.2))
110        }
111        new
112    }
113}
114
115// This is cherry-picked from HEAD of rust-lang's master (ref1) because it's
116// a nightly-only experimental API.
117// (binary_heap_into_iter_sorted [rustc issue #59278])
118// Remove this and use the standard API once BinaryHeap::into_iter_sorted (ref2)
119// is stabilized.
120// ref1: https://github.com/rust-lang/rust/blob/2f688ac602d50129388bb2a5519942049096cbff/src/liballoc/collections/binary_heap.rs#L1149
121// ref2: https://doc.rust-lang.org/std/collections/struct.BinaryHeap.html#into_iter_sorted.v
122
123#[derive(Clone, Debug)]
124pub struct IntoIterSorted<T> {
125    inner: BinaryHeap<T>,
126}
127impl<T> IntoIterSorted<T> {
128    pub fn new(binary_heap: BinaryHeap<T>) -> Self {
129        Self { inner: binary_heap }
130    }
131}
132
133impl<T: Ord> Iterator for IntoIterSorted<T> {
134    type Item = T;
135
136    #[inline]
137    fn next(&mut self) -> Option<T> {
138        self.inner.pop()
139    }
140
141    #[inline]
142    fn size_hint(&self) -> (usize, Option<usize>) {
143        let exact = self.inner.len();
144        (exact, Some(exact))
145    }
146}
147
148impl Sysvar for RecentBlockhashes {
149    fn size_of() -> usize {
150        // hard-coded so that we don't have to construct an empty
151        6008 // golden, update if MAX_ENTRIES changes
152    }
153}
154
155impl Deref for RecentBlockhashes {
156    type Target = Vec<Entry>;
157    fn deref(&self) -> &Self::Target {
158        &self.0
159    }
160}
161
162#[cfg(test)]
163mod tests {
164    use {super::*, solana_clock::MAX_PROCESSING_AGE};
165
166    #[test]
167    #[allow(clippy::assertions_on_constants)]
168    fn test_sysvar_can_hold_all_active_blockhashes() {
169        // Ensure we can still hold all of the active entries in `BlockhashQueue`
170        assert!(MAX_PROCESSING_AGE <= MAX_ENTRIES);
171    }
172
173    #[test]
174    fn test_size_of() {
175        let entry = Entry::new(&Hash::default(), 0);
176        assert_eq!(
177            bincode::serialized_size(&RecentBlockhashes(vec![entry; MAX_ENTRIES])).unwrap()
178                as usize,
179            RecentBlockhashes::size_of()
180        );
181    }
182}
solana_program/sysvar/recent_blockhashes.rs

solana_program/sysvar/
recent_blockhashes.rs
