39 lines
1.2 KiB
Rust
39 lines
1.2 KiB
Rust
// Original implementation taken from rust-memchr.
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// Copyright 2015 Andrew Gallant, bluss and Nicolas Koch
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pub fn memchr(needle: u8, haystack: &[u8]) -> Option<usize> {
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let p = unsafe {
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libc::memchr(
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haystack.as_ptr() as *const libc::c_void,
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needle as libc::c_int,
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haystack.len(),
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)
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};
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if p.is_null() { None } else { Some(p as usize - (haystack.as_ptr() as usize)) }
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}
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pub fn memrchr(needle: u8, haystack: &[u8]) -> Option<usize> {
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#[cfg(target_os = "linux")]
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fn memrchr_specific(needle: u8, haystack: &[u8]) -> Option<usize> {
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// GNU's memrchr() will - unlike memchr() - error if haystack is empty.
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if haystack.is_empty() {
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return None;
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}
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let p = unsafe {
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libc::memrchr(
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haystack.as_ptr() as *const libc::c_void,
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needle as libc::c_int,
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haystack.len(),
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)
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};
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if p.is_null() { None } else { Some(p as usize - (haystack.as_ptr() as usize)) }
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}
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#[cfg(not(target_os = "linux"))]
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fn memrchr_specific(needle: u8, haystack: &[u8]) -> Option<usize> {
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core::slice::memchr::memrchr(needle, haystack)
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}
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memrchr_specific(needle, haystack)
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}
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