bjoernager/rust
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Make use of slice::strip_prefix and slice pattern

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This commit is contained in:
Lzu Tao 2020-07-10 15:59:25 +00:00
parent 90a7d2470a
commit 27a966a149
2 changed files with 25 additions and 27 deletions
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1
src/libstd/lib.rs
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@ -306,6 +306,7 @@
#![feature(shrink_to)]
#![feature(slice_concat_ext)]
#![feature(slice_internals)]
#![feature(slice_strip)]
#![feature(staged_api)]
#![feature(std_internals)]
#![feature(stdsimd)]

45
src/libstd/sys/windows/path.rs
View file

@ -29,23 +29,20 @@ pub fn is_valid_drive_letter(disk: u8) -> bool {
}
pub fn parse_prefix(path: &OsStr) -> Option<Prefix<'_>> {
use crate::path::Prefix::*;
use Prefix::{DeviceNS, Disk, Verbatim, VerbatimDisk, VerbatimUNC, UNC};
unsafe {
// The unsafety here stems from converting between &OsStr and &[u8]
// and back. This is safe to do because (1) we only look at ASCII
// contents of the encoding and (2) new &OsStr values are produced
// only from ASCII-bounded slices of existing &OsStr values.
let mut path = os_str_as_u8_slice(path);
let path = os_str_as_u8_slice(path);
if path.starts_with(br"\\") {
// \\
path = &path[2..];
if path.starts_with(br"?\") {
if let Some(path) = path.strip_prefix(br"\\") {
// \\?\
path = &path[2..];
if path.starts_with(br"UNC\") {
if let Some(path) = path.strip_prefix(br"?\") {
// \\?\UNC\server\share
path = &path[4..];
if let Some(path) = path.strip_prefix(br"UNC\") {
let (server, share) = match parse_two_comps(path, is_verbatim_sep) {
Some((server, share)) => {
(u8_slice_as_os_str(server), u8_slice_as_os_str(share))
@ -55,22 +52,23 @@ pub fn parse_prefix(path: &OsStr) -> Option<Prefix<'_>> {
return Some(VerbatimUNC(server, share));
} else {
// \\?\path
let idx = path.iter().position(|&b| b == b'\\');
if idx == Some(2) && path[1] == b':' {
let c = path[0];
if is_valid_drive_letter(c) {
// \\?\C:\ path
match path {
// \\?\C:\path
[c, b':', b'\\', ..] if is_valid_drive_letter(*c) => {
return Some(VerbatimDisk(c.to_ascii_uppercase()));
}
}
let slice = &path[..idx.unwrap_or(path.len())];
// \\?\cat_pics
_ => {
let idx = path.iter().position(|&b| b == b'\\').unwrap_or(path.len());
let slice = &path[..idx];
return Some(Verbatim(u8_slice_as_os_str(slice)));
}
} else if path.starts_with(b".\\") {
// \\.\path
path = &path[2..];
let pos = path.iter().position(|&b| b == b'\\');
let slice = &path[..pos.unwrap_or(path.len())];
}
}
} else if let Some(path) = path.strip_prefix(b".\\") {
// \\.\COM42
let idx = path.iter().position(|&b| b == b'\\').unwrap_or(path.len());
let slice = &path[..idx];
return Some(DeviceNS(u8_slice_as_os_str(slice)));
}
match parse_two_comps(path, is_sep_byte) {
@ -78,12 +76,11 @@ pub fn parse_prefix(path: &OsStr) -> Option<Prefix<'_>> {
// \\server\share
return Some(UNC(u8_slice_as_os_str(server), u8_slice_as_os_str(share)));
}
_ => (),
_ => {}
}
} else if path.get(1) == Some(&b':') {
} else if let [c, b':', ..] = path {
// C:
let c = path[0];
if is_valid_drive_letter(c) {
if is_valid_drive_letter(*c) {
return Some(Disk(c.to_ascii_uppercase()));
}
}