mysql_handler/hton/
flags.rs

1// Copyright (C) 2026 ren-yamanashi
2//
3// This program is free software; you can redistribute it and/or modify
4// it under the terms of the GNU General Public License, version 2.0,
5// as published by the Free Software Foundation.
6//
7// This program is designed to work with certain software (including
8// but not limited to OpenSSL) that is licensed under separate terms,
9// as designated in a particular file or component or in included license
10// documentation. The authors of this program hereby grant you an additional
11// permission to link the program and your derivative works with the
12// separately licensed software that they have either included with
13// the program or referenced in the documentation.
14//
15// This program is distributed in the hope that it will be useful,
16// but WITHOUT ANY WARRANTY; without even the implied warranty of
17// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18// GNU General Public License for more details.
19//
20// You should have received a copy of the GNU General Public License
21// along with this program; if not, see <https://www.gnu.org/licenses/>.
22
23//! Engine-level `handlerton` flags (the `HTON_*` bits).
24
25use crate::sys;
26
27/// A set of `handlerton` flags (the `HTON_*` bits from `sql/handler.h`).
28///
29/// Returned from [`Handlerton::flags`](crate::hton::Handlerton::flags). The
30/// zero-config engine sets [`HtonFlags::CAN_RECREATE`], which is therefore the
31/// trait default; return [`HtonFlags::NONE`] to clear it.
32///
33/// ```
34/// use mysql_handler::hton::HtonFlags;
35///
36/// let f = HtonFlags::NONE | HtonFlags::CAN_RECREATE;
37/// assert!(f.contains(HtonFlags::CAN_RECREATE));
38/// ```
39#[derive(Debug, Clone, Copy, PartialEq, Eq)]
40#[non_exhaustive]
41pub struct HtonFlags(u32);
42
43impl HtonFlags {
44    /// No flags set (`HTON_NO_FLAGS`)
45    pub const NONE: Self = Self(0);
46    /// `HTON_CAN_RECREATE`: the engine implements `TRUNCATE` by recreating the
47    /// table. The flag the zero-config engine sets today.
48    pub const CAN_RECREATE: Self = Self(sys::HTON_CAN_RECREATE);
49
50    /// An empty flag set
51    #[must_use]
52    pub const fn empty() -> Self {
53        Self(0)
54    }
55
56    /// The raw bits, for handing the set across the FFI boundary
57    #[must_use]
58    pub const fn bits(self) -> u32 {
59        self.0
60    }
61
62    /// Whether every flag in `other` is set in `self`
63    #[must_use]
64    pub const fn contains(self, other: Self) -> bool {
65        self.0 & other.0 == other.0
66    }
67
68    /// The union of two flag sets
69    #[must_use]
70    pub const fn union(self, other: Self) -> Self {
71        Self(self.0 | other.0)
72    }
73}
74
75impl core::ops::BitOr for HtonFlags {
76    type Output = Self;
77
78    fn bitor(self, rhs: Self) -> Self {
79        self.union(rhs)
80    }
81}
82
83#[cfg(test)]
84mod tests {
85    use super::*;
86
87    #[test]
88    fn can_recreate_matches_sys_constant() {
89        assert_eq!(HtonFlags::CAN_RECREATE.bits(), sys::HTON_CAN_RECREATE);
90    }
91
92    #[test]
93    fn none_is_empty() {
94        assert_eq!(HtonFlags::NONE, HtonFlags::empty());
95        assert_eq!(HtonFlags::empty().bits(), 0);
96    }
97
98    #[test]
99    fn union_and_contains() {
100        let f = HtonFlags::NONE | HtonFlags::CAN_RECREATE;
101        assert!(f.contains(HtonFlags::CAN_RECREATE));
102        assert!(HtonFlags::NONE.contains(HtonFlags::NONE));
103        assert!(!HtonFlags::NONE.contains(HtonFlags::CAN_RECREATE));
104    }
105}
mysql_handler/hton/flags.rs

mysql_handler/hton/
flags.rs
