typed_store/
util.rs

1// Copyright (c) Mysten Labs, Inc.
2// SPDX-License-Identifier: Apache-2.0
3
4use crate::StorageType;
5use bincode::Options;
6use serde::Serialize;
7use std::ops::{Bound, RangeBounds};
8use std::path::Path;
9
10#[inline]
11pub fn be_fix_int_ser<S>(t: &S) -> Vec<u8>
12where
13    S: ?Sized + serde::Serialize,
14{
15    bincode::DefaultOptions::new()
16        .with_big_endian()
17        .with_fixint_encoding()
18        .serialize(t)
19        .expect("failed to serialize via be_fix_int_ser method")
20}
21
22/// Serialize `t` in big-endian fixed-int encoding directly into `buf`,
23/// returning the number of bytes written.
24#[inline]
25pub fn be_fix_int_ser_into<S>(buf: &mut Vec<u8>, t: &S) -> usize
26where
27    S: ?Sized + serde::Serialize,
28{
29    let before = buf.len();
30    bincode::DefaultOptions::new()
31        .with_big_endian()
32        .with_fixint_encoding()
33        .serialize_into(&mut *buf, t)
34        .expect("failed to serialize via be_fix_int_ser_into method");
35    buf.len() - before
36}
37
38pub(crate) fn iterator_bounds<K>(
39    lower_bound: Option<K>,
40    upper_bound: Option<K>,
41) -> (Option<Vec<u8>>, Option<Vec<u8>>)
42where
43    K: Serialize,
44{
45    (
46        lower_bound.map(|b| be_fix_int_ser(&b)),
47        upper_bound.map(|b| be_fix_int_ser(&b)),
48    )
49}
50
51pub(crate) fn iterator_bounds_with_range<K>(
52    range: impl RangeBounds<K>,
53) -> (Option<Vec<u8>>, Option<Vec<u8>>)
54where
55    K: Serialize,
56{
57    let iterator_lower_bound = match range.start_bound() {
58        Bound::Included(lower_bound) => {
59            // Rocksdb lower bound is inclusive by default so nothing to do
60            Some(be_fix_int_ser(&lower_bound))
61            // readopts.set_iterate_lower_bound(key_buf);
62        }
63        Bound::Excluded(lower_bound) => {
64            let mut key_buf = be_fix_int_ser(&lower_bound);
65
66            // Since we want exclusive, we need to increment the key to exclude the previous
67            big_endian_saturating_add_one(&mut key_buf);
68            Some(key_buf)
69            // readopts.set_iterate_lower_bound(key_buf);
70        }
71        Bound::Unbounded => None,
72    };
73    let iterator_upper_bound = match range.end_bound() {
74        Bound::Included(upper_bound) => {
75            let mut key_buf = be_fix_int_ser(&upper_bound);
76
77            // If the key is already at the limit, there's nowhere else to go, so no upper bound
78            if !is_max(&key_buf) {
79                // Since we want exclusive, we need to increment the key to get the upper bound
80                big_endian_saturating_add_one(&mut key_buf);
81                // readopts.set_iterate_upper_bound(key_buf);
82            }
83            Some(key_buf)
84        }
85        Bound::Excluded(upper_bound) => {
86            // Rocksdb upper bound is inclusive by default so nothing to do
87            Some(be_fix_int_ser(&upper_bound))
88            // readopts.set_iterate_upper_bound(key_buf);
89        }
90        Bound::Unbounded => None,
91    };
92    (iterator_lower_bound, iterator_upper_bound)
93}
94
95/// Given a vec<u8>, find the value which is one more than the vector
96/// if the vector was a big endian number.
97/// If the vector is already minimum, don't change it.
98fn big_endian_saturating_add_one(v: &mut [u8]) {
99    if is_max(v) {
100        return;
101    }
102    for i in (0..v.len()).rev() {
103        if v[i] == u8::MAX {
104            v[i] = 0;
105        } else {
106            v[i] += 1;
107            break;
108        }
109    }
110}
111
112/// Check if all the bytes in the vector are 0xFF
113fn is_max(v: &[u8]) -> bool {
114    v.iter().all(|&x| x == u8::MAX)
115}
116
117pub(crate) fn ensure_database_type<P: AsRef<Path>>(
118    path: P,
119    storage_type: StorageType,
120) -> std::io::Result<()> {
121    if !path.as_ref().exists() {
122        return Ok(());
123    }
124    for entry in std::fs::read_dir(path)? {
125        let filepath = entry?.path();
126        if filepath.extension().is_some_and(|ext| ext == "sst")
127            && storage_type != StorageType::Rocks
128        {
129            panic!(
130                "DB type mismatch: expected {:?}, found RocksDB",
131                storage_type
132            );
133        }
134        if filepath
135            .file_name()
136            .is_some_and(|n| n.to_string_lossy().starts_with("wal_"))
137            && storage_type != StorageType::TideHunter
138        {
139            panic!(
140                "DB type mismatch: expected {:?}, found TideHunter",
141                storage_type
142            );
143        }
144    }
145    Ok(())
146}
147
148#[allow(clippy::assign_op_pattern, clippy::manual_div_ceil)]
149#[test]
150fn test_helpers() {
151    let v = vec![];
152    assert!(is_max(&v));
153
154    fn check_add(v: Vec<u8>) {
155        let mut v = v;
156        let num = Num32::from_big_endian(&v);
157        big_endian_saturating_add_one(&mut v);
158        assert!(num + 1 == Num32::from_big_endian(&v));
159    }
160
161    uint::construct_uint! {
162        // 32 byte number
163        struct Num32(4);
164    }
165
166    let mut v = vec![255; 32];
167    big_endian_saturating_add_one(&mut v);
168    assert!(Num32::MAX == Num32::from_big_endian(&v));
169
170    check_add(vec![1; 32]);
171    check_add(vec![6; 32]);
172    check_add(vec![254; 32]);
173
174    // TBD: More tests coming with randomized arrays
175}
typed_store/util.rs

typed_store/
util.rs
