summaryrefslogtreecommitdiffstats
path: root/third_party/rust/flate2/src/gz/read.rs
blob: cfeb992e8a4bce8a2af552985e39fdc52f8fd89a (plain)
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
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
use std::io;
use std::io::prelude::*;

use super::bufread;
use super::{GzBuilder, GzHeader};
use crate::bufreader::BufReader;
use crate::Compression;

/// A gzip streaming encoder
///
/// This structure exposes a [`Read`] interface that will read uncompressed data
/// from the underlying reader and expose the compressed version as a [`Read`]
/// interface.
///
/// [`Read`]: https://doc.rust-lang.org/std/io/trait.Read.html
///
/// # Examples
///
/// ```
/// use std::io::prelude::*;
/// use std::io;
/// use flate2::Compression;
/// use flate2::read::GzEncoder;
///
/// // Return a vector containing the GZ compressed version of hello world
///
/// fn gzencode_hello_world() -> io::Result<Vec<u8>> {
///     let mut ret_vec = [0;100];
///     let bytestring = b"hello world";
///     let mut gz = GzEncoder::new(&bytestring[..], Compression::fast());
///     let count = gz.read(&mut ret_vec)?;
///     Ok(ret_vec[0..count].to_vec())
/// }
/// ```
#[derive(Debug)]
pub struct GzEncoder<R> {
    inner: bufread::GzEncoder<BufReader<R>>,
}

pub fn gz_encoder<R: Read>(inner: bufread::GzEncoder<BufReader<R>>) -> GzEncoder<R> {
    GzEncoder { inner }
}

impl<R: Read> GzEncoder<R> {
    /// Creates a new encoder which will use the given compression level.
    ///
    /// The encoder is not configured specially for the emitted header. For
    /// header configuration, see the `GzBuilder` type.
    ///
    /// The data read from the stream `r` will be compressed and available
    /// through the returned reader.
    pub fn new(r: R, level: Compression) -> GzEncoder<R> {
        GzBuilder::new().read(r, level)
    }
}

impl<R> GzEncoder<R> {
    /// Acquires a reference to the underlying reader.
    pub fn get_ref(&self) -> &R {
        self.inner.get_ref().get_ref()
    }

    /// Acquires a mutable reference to the underlying reader.
    ///
    /// Note that mutation of the reader may result in surprising results if
    /// this encoder is continued to be used.
    pub fn get_mut(&mut self) -> &mut R {
        self.inner.get_mut().get_mut()
    }

    /// Returns the underlying stream, consuming this encoder
    pub fn into_inner(self) -> R {
        self.inner.into_inner().into_inner()
    }
}

impl<R: Read> Read for GzEncoder<R> {
    fn read(&mut self, into: &mut [u8]) -> io::Result<usize> {
        self.inner.read(into)
    }
}

impl<R: Read + Write> Write for GzEncoder<R> {
    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
        self.get_mut().write(buf)
    }

    fn flush(&mut self) -> io::Result<()> {
        self.get_mut().flush()
    }
}

/// A gzip streaming decoder
///
/// This structure exposes a [`Read`] interface that will consume compressed
/// data from the underlying reader and emit uncompressed data.
///
/// [`Read`]: https://doc.rust-lang.org/std/io/trait.Read.html
///
/// # Examples
///
/// ```
///
/// use std::io::prelude::*;
/// use std::io;
/// # use flate2::Compression;
/// # use flate2::write::GzEncoder;
/// use flate2::read::GzDecoder;
///
/// # fn main() {
/// #    let mut e = GzEncoder::new(Vec::new(), Compression::default());
/// #    e.write_all(b"Hello World").unwrap();
/// #    let bytes = e.finish().unwrap();
/// #    println!("{}", decode_reader(bytes).unwrap());
/// # }
/// #
/// // Uncompresses a Gz Encoded vector of bytes and returns a string or error
/// // Here &[u8] implements Read
///
/// fn decode_reader(bytes: Vec<u8>) -> io::Result<String> {
///    let mut gz = GzDecoder::new(&bytes[..]);
///    let mut s = String::new();
///    gz.read_to_string(&mut s)?;
///    Ok(s)
/// }
/// ```
#[derive(Debug)]
pub struct GzDecoder<R> {
    inner: bufread::GzDecoder<BufReader<R>>,
}

impl<R: Read> GzDecoder<R> {
    /// Creates a new decoder from the given reader, immediately parsing the
    /// gzip header.
    pub fn new(r: R) -> GzDecoder<R> {
        GzDecoder {
            inner: bufread::GzDecoder::new(BufReader::new(r)),
        }
    }
}

impl<R> GzDecoder<R> {
    /// Returns the header associated with this stream, if it was valid.
    pub fn header(&self) -> Option<&GzHeader> {
        self.inner.header()
    }

    /// Acquires a reference to the underlying reader.
    pub fn get_ref(&self) -> &R {
        self.inner.get_ref().get_ref()
    }

    /// Acquires a mutable reference to the underlying stream.
    ///
    /// Note that mutation of the stream may result in surprising results if
    /// this decoder is continued to be used.
    pub fn get_mut(&mut self) -> &mut R {
        self.inner.get_mut().get_mut()
    }

    /// Consumes this decoder, returning the underlying reader.
    pub fn into_inner(self) -> R {
        self.inner.into_inner().into_inner()
    }
}

impl<R: Read> Read for GzDecoder<R> {
    fn read(&mut self, into: &mut [u8]) -> io::Result<usize> {
        self.inner.read(into)
    }
}

impl<R: Read + Write> Write for GzDecoder<R> {
    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
        self.get_mut().write(buf)
    }

    fn flush(&mut self) -> io::Result<()> {
        self.get_mut().flush()
    }
}

/// A gzip streaming decoder that decodes all members of a multistream
///
/// A gzip member consists of a header, compressed data and a trailer. The [gzip
/// specification](https://tools.ietf.org/html/rfc1952), however, allows multiple
/// gzip members to be joined in a single stream.  `MultiGzDecoder` will
/// decode all consecutive members while `GzDecoder` will only decompress the
/// first gzip member. The multistream format is commonly used in bioinformatics,
/// for example when using the BGZF compressed data.
///
/// This structure exposes a [`Read`] interface that will consume all gzip members
/// from the underlying reader and emit uncompressed data.
///
/// [`Read`]: https://doc.rust-lang.org/std/io/trait.Read.html
///
/// # Examples
///
/// ```
/// use std::io::prelude::*;
/// use std::io;
/// # use flate2::Compression;
/// # use flate2::write::GzEncoder;
/// use flate2::read::MultiGzDecoder;
///
/// # fn main() {
/// #    let mut e = GzEncoder::new(Vec::new(), Compression::default());
/// #    e.write_all(b"Hello World").unwrap();
/// #    let bytes = e.finish().unwrap();
/// #    println!("{}", decode_reader(bytes).unwrap());
/// # }
/// #
/// // Uncompresses a Gz Encoded vector of bytes and returns a string or error
/// // Here &[u8] implements Read
///
/// fn decode_reader(bytes: Vec<u8>) -> io::Result<String> {
///    let mut gz = MultiGzDecoder::new(&bytes[..]);
///    let mut s = String::new();
///    gz.read_to_string(&mut s)?;
///    Ok(s)
/// }
/// ```
#[derive(Debug)]
pub struct MultiGzDecoder<R> {
    inner: bufread::MultiGzDecoder<BufReader<R>>,
}

impl<R: Read> MultiGzDecoder<R> {
    /// Creates a new decoder from the given reader, immediately parsing the
    /// (first) gzip header. If the gzip stream contains multiple members all will
    /// be decoded.
    pub fn new(r: R) -> MultiGzDecoder<R> {
        MultiGzDecoder {
            inner: bufread::MultiGzDecoder::new(BufReader::new(r)),
        }
    }
}

impl<R> MultiGzDecoder<R> {
    /// Returns the current header associated with this stream, if it's valid.
    pub fn header(&self) -> Option<&GzHeader> {
        self.inner.header()
    }

    /// Acquires a reference to the underlying reader.
    pub fn get_ref(&self) -> &R {
        self.inner.get_ref().get_ref()
    }

    /// Acquires a mutable reference to the underlying stream.
    ///
    /// Note that mutation of the stream may result in surprising results if
    /// this decoder is continued to be used.
    pub fn get_mut(&mut self) -> &mut R {
        self.inner.get_mut().get_mut()
    }

    /// Consumes this decoder, returning the underlying reader.
    pub fn into_inner(self) -> R {
        self.inner.into_inner().into_inner()
    }
}

impl<R: Read> Read for MultiGzDecoder<R> {
    fn read(&mut self, into: &mut [u8]) -> io::Result<usize> {
        self.inner.read(into)
    }
}

impl<R: Read + Write> Write for MultiGzDecoder<R> {
    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
        self.get_mut().write(buf)
    }

    fn flush(&mut self) -> io::Result<()> {
        self.get_mut().flush()
    }
}