fuchsia_archive/
async_utf8_reader.rs

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1// Copyright 2022 The Fuchsia Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5use crate::error::Error;
6use fuchsia_fs::file::{AsyncGetSize, AsyncReadAt};
7
8/// A struct to open and read a FAR-formatted archive asynchronously.
9/// Requires that all paths are valid UTF-8.
10#[derive(Debug)]
11pub struct AsyncUtf8Reader<T>
12where
13    T: AsyncReadAt + AsyncGetSize + Unpin,
14{
15    reader: crate::async_read::AsyncReader<T>,
16}
17
18impl<T> AsyncUtf8Reader<T>
19where
20    T: AsyncReadAt + AsyncGetSize + Unpin,
21{
22    /// Create a new AsyncUtf8Reader for the provided source.
23    pub async fn new(source: T) -> Result<Self, Error> {
24        let ret = Self { reader: crate::async_read::AsyncReader::new(source).await? };
25        let () = ret.try_list().try_for_each(|r| r.map(|_| ()))?;
26        Ok(ret)
27    }
28
29    /// Return a list of the items in the archive.
30    /// Individual items will error if their paths are not valid UTF-8.
31    fn try_list(&self) -> impl ExactSizeIterator<Item = Result<crate::Utf8Entry<'_>, Error>> {
32        self.reader.list().map(|e| {
33            Ok(crate::Utf8Entry {
34                path: std::str::from_utf8(e.path).map_err(|err| Error::PathDataInvalidUtf8 {
35                    source: err,
36                    path: e.path.into(),
37                })?,
38                offset: e.offset,
39                length: e.length,
40            })
41        })
42    }
43
44    /// Return a list of the items in the archive.
45    pub fn list(&self) -> impl ExactSizeIterator<Item = crate::Utf8Entry<'_>> {
46        self.try_list().map(|r| {
47            r.expect("AsyncUtf8Reader::new only succeeds if try_list succeeds for every element")
48        })
49    }
50
51    /// Read the entire contents of an entry with the specified path.
52    /// O(log(# directory entries))
53    pub async fn read_file(&mut self, path: &str) -> Result<Vec<u8>, Error> {
54        self.reader.read_file(path.as_bytes()).await
55    }
56}
57
58#[cfg(test)]
59mod tests {
60    use super::*;
61    use assert_matches::assert_matches;
62    use fuchsia_async as fasync;
63    use fuchsia_fs::file::Adapter;
64    use futures::io::Cursor;
65
66    #[fasync::run_singlethreaded(test)]
67    async fn new_rejects_non_utf8_path() {
68        let mut far_bytes = vec![];
69        let () = crate::write::write(
70            &mut far_bytes,
71            std::collections::BTreeMap::from_iter([(
72                b"\xff",
73                (0, Box::new("".as_bytes()) as Box<dyn std::io::Read>),
74            )]),
75        )
76        .unwrap();
77
78        assert_matches!(
79            AsyncUtf8Reader::new(Adapter::new(Cursor::new(far_bytes))).await,
80            Err(crate::Error::PathDataInvalidUtf8{source: _, path}) if path == b"\xff".to_vec()
81        );
82    }
83
84    #[fasync::run_singlethreaded(test)]
85    async fn list_does_not_panic() {
86        let mut far_bytes = vec![];
87        let () = crate::write::write(
88            &mut far_bytes,
89            std::collections::BTreeMap::from_iter([(
90                "valid-utf8",
91                (0, Box::new("".as_bytes()) as Box<dyn std::io::Read>),
92            )]),
93        )
94        .unwrap();
95
96        itertools::assert_equal(
97            AsyncUtf8Reader::new(Adapter::new(Cursor::new(far_bytes))).await.unwrap().list(),
98            [crate::Utf8Entry { path: "valid-utf8", offset: 4096, length: 0 }],
99        );
100    }
101
102    #[fasync::run_singlethreaded(test)]
103    async fn read_file() {
104        let mut far_bytes = vec![];
105        let () = crate::write::write(
106            &mut far_bytes,
107            std::collections::BTreeMap::from_iter([(
108                "valid-utf8",
109                (12, Box::new("test-content".as_bytes()) as Box<dyn std::io::Read>),
110            )]),
111        )
112        .unwrap();
113
114        assert_eq!(
115            AsyncUtf8Reader::new(Adapter::new(Cursor::new(far_bytes)))
116                .await
117                .unwrap()
118                .read_file("valid-utf8")
119                .await
120                .unwrap(),
121            b"test-content".to_vec()
122        );
123    }
124}
fuchsia_archive/async_utf8_reader.rs

fuchsia_archive/
async_utf8_reader.rs
