1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
|
#![allow(dead_code)] // TODO
use std::{
io, mem,
pin::Pin,
task::{Context, Poll},
};
use async_compression::tokio::bufread::{BzDecoder, GzipDecoder, XzDecoder};
use futures::ready;
use pin_project::pin_project;
use tokio::io::{AsyncBufRead, AsyncRead, BufReader, ReadBuf};
const GZIP_MAGIC: [u8; 2] = [0x1f, 0x8b];
const BZIP2_MAGIC: [u8; 3] = *b"BZh";
const XZ_MAGIC: [u8; 6] = [0xfd, 0x37, 0x7a, 0x58, 0x5a, 0x00];
const BYTES_NEEDED: usize = 6;
#[derive(Debug, Clone, Copy)]
enum Algorithm {
Gzip,
Bzip2,
Xz,
}
impl Algorithm {
fn from_magic(magic: &[u8]) -> Option<Self> {
if magic.starts_with(&GZIP_MAGIC) {
Some(Self::Gzip)
} else if magic.starts_with(&BZIP2_MAGIC) {
Some(Self::Bzip2)
} else if magic.starts_with(&XZ_MAGIC) {
Some(Self::Xz)
} else {
None
}
}
}
#[pin_project]
struct WithPreexistingBuffer<R> {
buffer: Vec<u8>,
#[pin]
inner: R,
}
impl<R> AsyncRead for WithPreexistingBuffer<R>
where
R: AsyncRead,
{
fn poll_read(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &mut ReadBuf<'_>,
) -> Poll<io::Result<()>> {
let this = self.project();
if !this.buffer.is_empty() {
// TODO: check if the buffer fits first
buf.put_slice(this.buffer);
this.buffer.clear();
}
this.inner.poll_read(cx, buf)
}
}
#[pin_project(project = DecompressedReaderInnerProj)]
enum DecompressedReaderInner<R> {
Unknown {
buffer: Vec<u8>,
#[pin]
inner: Option<R>,
},
Gzip(#[pin] GzipDecoder<BufReader<WithPreexistingBuffer<R>>>),
Bzip2(#[pin] BzDecoder<BufReader<WithPreexistingBuffer<R>>>),
Xz(#[pin] XzDecoder<BufReader<WithPreexistingBuffer<R>>>),
}
impl<R> DecompressedReaderInner<R>
where
R: AsyncBufRead,
{
fn switch_to(&mut self, algorithm: Algorithm) {
let (buffer, inner) = match self {
DecompressedReaderInner::Unknown { buffer, inner } => {
(mem::take(buffer), inner.take().unwrap())
}
DecompressedReaderInner::Gzip(_)
| DecompressedReaderInner::Bzip2(_)
| DecompressedReaderInner::Xz(_) => unreachable!(),
};
let inner = BufReader::new(WithPreexistingBuffer { buffer, inner });
*self = match algorithm {
Algorithm::Gzip => Self::Gzip(GzipDecoder::new(inner)),
Algorithm::Bzip2 => Self::Bzip2(BzDecoder::new(inner)),
Algorithm::Xz => Self::Xz(XzDecoder::new(inner)),
}
}
}
impl<R> AsyncRead for DecompressedReaderInner<R>
where
R: AsyncBufRead,
{
fn poll_read(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &mut ReadBuf<'_>,
) -> Poll<io::Result<()>> {
match self.project() {
DecompressedReaderInnerProj::Unknown { .. } => {
unreachable!("Can't call poll_read on Unknown")
}
DecompressedReaderInnerProj::Gzip(inner) => inner.poll_read(cx, buf),
DecompressedReaderInnerProj::Bzip2(inner) => inner.poll_read(cx, buf),
DecompressedReaderInnerProj::Xz(inner) => inner.poll_read(cx, buf),
}
}
}
#[pin_project]
pub struct DecompressedReader<R> {
#[pin]
inner: DecompressedReaderInner<R>,
switch_to: Option<Algorithm>,
}
impl<R> DecompressedReader<R> {
pub fn new(inner: R) -> Self {
Self {
inner: DecompressedReaderInner::Unknown {
buffer: vec![0; BYTES_NEEDED],
inner: Some(inner),
},
switch_to: None,
}
}
}
impl<R> AsyncRead for DecompressedReader<R>
where
R: AsyncBufRead + Unpin,
{
fn poll_read(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &mut ReadBuf<'_>,
) -> Poll<io::Result<()>> {
let mut this = self.project();
let (buffer, inner) = match this.inner.as_mut().project() {
DecompressedReaderInnerProj::Gzip(inner) => return inner.poll_read(cx, buf),
DecompressedReaderInnerProj::Bzip2(inner) => return inner.poll_read(cx, buf),
DecompressedReaderInnerProj::Xz(inner) => return inner.poll_read(cx, buf),
DecompressedReaderInnerProj::Unknown { buffer, inner } => (buffer, inner),
};
let mut our_buf = ReadBuf::new(buffer);
if let Err(e) = ready!(inner.as_pin_mut().unwrap().poll_read(cx, &mut our_buf)) {
return Poll::Ready(Err(e));
}
let data = our_buf.filled();
if data.len() >= BYTES_NEEDED {
if let Some(algorithm) = Algorithm::from_magic(data) {
this.inner.as_mut().switch_to(algorithm);
} else {
return Poll::Ready(Err(io::Error::new(
io::ErrorKind::InvalidData,
"tar data not gz, bzip2, or xz compressed",
)));
}
this.inner.poll_read(cx, buf)
} else {
cx.waker().wake_by_ref();
Poll::Pending
}
}
}
#[cfg(test)]
mod tests {
use std::path::Path;
use async_compression::tokio::bufread::GzipEncoder;
use futures::TryStreamExt;
use test_case::test_case;
use tokio::io::{AsyncReadExt, BufReader};
use tokio_tar::Archive;
use super::*;
#[tokio::test]
async fn gzip() {
let data = b"abcdefghijk";
let mut enc = GzipEncoder::new(&data[..]);
let mut gzipped = vec![];
enc.read_to_end(&mut gzipped).await.unwrap();
let mut reader = DecompressedReader::new(BufReader::new(&gzipped[..]));
let mut round_tripped = vec![];
reader.read_to_end(&mut round_tripped).await.unwrap();
assert_eq!(data[..], round_tripped[..]);
}
#[test_case(include_bytes!("tests/blob.tar.gz"); "gzip")]
#[test_case(include_bytes!("tests/blob.tar.bz2"); "bzip2")]
#[test_case(include_bytes!("tests/blob.tar.xz"); "xz")]
#[tokio::test]
async fn compressed_tar(data: &[u8]) {
let reader = DecompressedReader::new(BufReader::new(data));
let mut archive = Archive::new(reader);
let mut entries: Vec<_> = archive.entries().unwrap().try_collect().await.unwrap();
assert_eq!(entries.len(), 1);
assert_eq!(entries[0].path().unwrap().as_ref(), Path::new("empty"));
let mut data = String::new();
entries[0].read_to_string(&mut data).await.unwrap();
assert_eq!(data, "");
}
}
|
