| // Original implementation taken from rust-memchr. |
| // Copyright 2015 Andrew Gallant, bluss and Nicolas Koch |
| |
| pub fn memchr(needle: u8, haystack: &[u8]) -> Option<usize> { |
| let p = unsafe { |
| libc::memchr( |
| haystack.as_ptr() as *const libc::c_void, |
| needle as libc::c_int, |
| haystack.len(), |
| ) |
| }; |
| if p.is_null() { None } else { Some(p.addr() - haystack.as_ptr().addr()) } |
| } |
| |
| pub fn memrchr(needle: u8, haystack: &[u8]) -> Option<usize> { |
| #[cfg(target_os = "linux")] |
| fn memrchr_specific(needle: u8, haystack: &[u8]) -> Option<usize> { |
| // GNU's memrchr() will - unlike memchr() - error if haystack is empty. |
| if haystack.is_empty() { |
| return None; |
| } |
| let p = unsafe { |
| libc::memrchr( |
| haystack.as_ptr() as *const libc::c_void, |
| needle as libc::c_int, |
| haystack.len(), |
| ) |
| }; |
| // FIXME: this should *likely* use `offset_from`, but more |
| // investigation is needed (including running tests in miri). |
| if p.is_null() { None } else { Some(p.addr() - haystack.as_ptr().addr()) } |
| } |
| |
| #[cfg(not(target_os = "linux"))] |
| fn memrchr_specific(needle: u8, haystack: &[u8]) -> Option<usize> { |
| core::slice::memchr::memrchr(needle, haystack) |
| } |
| |
| memrchr_specific(needle, haystack) |
| } |