nautilus_core/ffi/
uuid.rs

1// -------------------------------------------------------------------------------------------------
2//  Copyright (C) 2015-2025 Posei Systems Pty Ltd. All rights reserved.
3//  https://poseitrader.io
4//
5//  Licensed under the GNU Lesser General Public License Version 3.0 (the "License");
6//  You may not use this file except in compliance with the License.
7//  You may obtain a copy of the License at https://www.gnu.org/licenses/lgpl-3.0.en.html
8//
9//  Unless required by applicable law or agreed to in writing, software
10//  distributed under the License is distributed on an "AS IS" BASIS,
11//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12//  See the License for the specific language governing permissions and
13//  limitations under the License.
14// -------------------------------------------------------------------------------------------------
15
16//! FFI helpers for the [`UUID4`] wrapper type.
17//!
18//! The functions exported here make it possible for C/Python code to create, compare, and hash
19//! UUID values *without* having to understand the internal representation chosen by
20//! PoseiTrader.
21
22use std::{
23    collections::hash_map::DefaultHasher,
24    ffi::{CStr, c_char},
25    hash::{Hash, Hasher},
26};
27
28use crate::UUID4;
29
30/// Generate a new random (version-4) UUID and return it by value.
31#[unsafe(no_mangle)]
32pub extern "C" fn uuid4_new() -> UUID4 {
33    UUID4::new()
34}
35
36/// Returns a [`UUID4`] from C string pointer.
37///
38/// # Safety
39///
40/// Assumes `ptr` is a valid C string pointer.
41///
42/// # Panics
43///
44/// Panics if `ptr` cannot be cast to a valid C string.
45#[unsafe(no_mangle)]
46pub unsafe extern "C" fn uuid4_from_cstr(ptr: *const c_char) -> UUID4 {
47    assert!(!ptr.is_null(), "`ptr` was NULL");
48    let cstr = unsafe { CStr::from_ptr(ptr) };
49    let value = cstr.to_str().expect("Failed to convert C string to UTF-8");
50    UUID4::from(value)
51}
52
53/// Return a borrowed *null-terminated* UTF-8 C string representing `uuid`.
54///
55/// The pointer remains valid for as long as the input `UUID4` reference lives – callers **must
56/// not** attempt to free it.
57#[unsafe(no_mangle)]
58pub extern "C" fn uuid4_to_cstr(uuid: &UUID4) -> *const c_char {
59    uuid.to_cstr().as_ptr()
60}
61
62/// Compare two UUID values, returning `1` when they are equal and `0` otherwise.
63#[unsafe(no_mangle)]
64pub extern "C" fn uuid4_eq(lhs: &UUID4, rhs: &UUID4) -> u8 {
65    u8::from(lhs == rhs)
66}
67
68/// Compute the stable [`u64`] hash of `uuid` using Rust’s default hasher.
69#[unsafe(no_mangle)]
70pub extern "C" fn uuid4_hash(uuid: &UUID4) -> u64 {
71    let mut h = DefaultHasher::new();
72    uuid.hash(&mut h);
73    h.finish()
74}
75
76////////////////////////////////////////////////////////////////////////////////
77// Tests
78////////////////////////////////////////////////////////////////////////////////
79#[cfg(test)]
80mod tests {
81    use std::ffi::CString;
82
83    use rstest::*;
84    use uuid::{self, Uuid};
85
86    use super::*;
87
88    #[rstest]
89    fn test_new() {
90        let uuid = uuid4_new();
91        let uuid_string = uuid.to_string();
92        let uuid_parsed = Uuid::parse_str(&uuid_string).expect("Uuid::parse_str failed");
93        assert_eq!(uuid_parsed.get_version().unwrap(), uuid::Version::Random);
94    }
95
96    #[rstest]
97    fn test_from_cstr() {
98        let uuid_string = "2d89666b-1a1e-4a75-b193-4eb3b454c757";
99        let uuid_cstring = CString::new(uuid_string).expect("CString::new failed");
100        let uuid_ptr = uuid_cstring.as_ptr();
101        let uuid = unsafe { uuid4_from_cstr(uuid_ptr) };
102        assert_eq!(uuid_string, uuid.to_string());
103    }
104
105    #[rstest]
106    fn test_to_cstr() {
107        let uuid_string = "2d89666b-1a1e-4a75-b193-4eb3b454c757";
108        let uuid = UUID4::from(uuid_string);
109        let uuid_ptr = uuid4_to_cstr(&uuid);
110        let uuid_cstr = unsafe { CStr::from_ptr(uuid_ptr) };
111        let uuid_result_string = uuid_cstr.to_str().expect("CStr::to_str failed").to_string();
112        assert_eq!(uuid_string, uuid_result_string);
113    }
114
115    #[rstest]
116    fn test_eq() {
117        let uuid1 = UUID4::from("2d89666b-1a1e-4a75-b193-4eb3b454c757");
118        let uuid2 = UUID4::from("2d89666b-1a1e-4a75-b193-4eb3b454c757");
119        let uuid3 = UUID4::from("2d89666b-1a1e-4a75-b193-4eb3b454c758");
120        assert_eq!(uuid4_eq(&uuid1, &uuid2), 1);
121        assert_eq!(uuid4_eq(&uuid1, &uuid3), 0);
122    }
123
124    #[rstest]
125    fn test_hash() {
126        let uuid1 = UUID4::from("2d89666b-1a1e-4a75-b193-4eb3b454c757");
127        let uuid2 = UUID4::from("2d89666b-1a1e-4a75-b193-4eb3b454c757");
128        let uuid3 = UUID4::from("2d89666b-1a1e-4a75-b193-4eb3b454c758");
129        assert_eq!(uuid4_hash(&uuid1), uuid4_hash(&uuid2));
130        assert_ne!(uuid4_hash(&uuid1), uuid4_hash(&uuid3));
131    }
132}
nautilus_core/ffi/uuid.rs

nautilus_core/ffi/
uuid.rs
