async_tar_wasm/
pax.rs

1use std::{slice, str};
2
3use async_std::io;
4
5use crate::other;
6
7/// An iterator over the pax extensions in an archive entry.
8///
9/// This iterator yields structures which can themselves be parsed into
10/// key/value pairs.
11pub struct PaxExtensions<'entry> {
12    data: slice::Split<'entry, u8, fn(&u8) -> bool>,
13}
14
15/// A key/value pair corresponding to a pax extension.
16pub struct PaxExtension<'entry> {
17    key: &'entry [u8],
18    value: &'entry [u8],
19}
20
21pub fn pax_extensions(a: &[u8]) -> PaxExtensions {
22    PaxExtensions {
23        data: a.split(|a| *a == b'\n'),
24    }
25}
26
27impl<'entry> Iterator for PaxExtensions<'entry> {
28    type Item = io::Result<PaxExtension<'entry>>;
29
30    fn next(&mut self) -> Option<io::Result<PaxExtension<'entry>>> {
31        let line = match self.data.next() {
32            Some(line) if line.is_empty() => return None,
33            Some(line) => line,
34            None => return None,
35        };
36
37        Some(
38            line.iter()
39                .position(|b| *b == b' ')
40                .and_then(|i| {
41                    str::from_utf8(&line[..i])
42                        .ok()
43                        .and_then(|len| len.parse::<usize>().ok().map(|j| (i + 1, j)))
44                })
45                .and_then(|(kvstart, reported_len)| {
46                    if line.len() + 1 == reported_len {
47                        line[kvstart..]
48                            .iter()
49                            .position(|b| *b == b'=')
50                            .map(|equals| (kvstart, equals))
51                    } else {
52                        None
53                    }
54                })
55                .map(|(kvstart, equals)| PaxExtension {
56                    key: &line[kvstart..kvstart + equals],
57                    value: &line[kvstart + equals + 1..],
58                })
59                .ok_or_else(|| other("malformed pax extension")),
60        )
61    }
62}
63
64impl<'entry> PaxExtension<'entry> {
65    /// Returns the key for this key/value pair parsed as a string.
66    ///
67    /// May fail if the key isn't actually utf-8.
68    pub fn key(&self) -> Result<&'entry str, str::Utf8Error> {
69        str::from_utf8(self.key)
70    }
71
72    /// Returns the underlying raw bytes for the key of this key/value pair.
73    pub fn key_bytes(&self) -> &'entry [u8] {
74        self.key
75    }
76
77    /// Returns the value for this key/value pair parsed as a string.
78    ///
79    /// May fail if the value isn't actually utf-8.
80    pub fn value(&self) -> Result<&'entry str, str::Utf8Error> {
81        str::from_utf8(self.value)
82    }
83
84    /// Returns the underlying raw bytes for this value of this key/value pair.
85    pub fn value_bytes(&self) -> &'entry [u8] {
86        self.value
87    }
88}
async_tar_wasm/pax.rs

async_tar_wasm/
pax.rs
