/rust/registry/src/index.crates.io-6f17d22bba15001f/fdeflate-0.3.7/src/compress.rs

Source (jump to first uncovered line)
use simd_adler32::Adler32;
use std::io::{self, Seek, SeekFrom, Write};

use crate::tables::{
    BITMASKS, HUFFMAN_CODES, HUFFMAN_LENGTHS, LENGTH_TO_LEN_EXTRA, LENGTH_TO_SYMBOL,
};

/// Compressor that produces fdeflate compressed streams.
pub struct Compressor<W: Write> {
    checksum: Adler32,
    buffer: u64,
    nbits: u8,
    writer: W,
}
impl<W: Write> Compressor<W> {
    fn write_bits(&mut self, bits: u64, nbits: u8) -> io::Result<()> {
        debug_assert!(nbits <= 64);

        self.buffer |= bits << self.nbits;
        self.nbits += nbits;

        if self.nbits >= 64 {
            self.writer.write_all(&self.buffer.to_le_bytes())?;
            self.nbits -= 64;
            self.buffer = bits.checked_shr((nbits - self.nbits) as u32).unwrap_or(0);
        }
        debug_assert!(self.nbits < 64);
        Ok(())
    }

    fn flush(&mut self) -> io::Result<()> {
        if self.nbits % 8 != 0 {
            self.write_bits(0, 8 - self.nbits % 8)?;
        }
        if self.nbits > 0 {
            self.writer
                .write_all(&self.buffer.to_le_bytes()[..self.nbits as usize / 8])
                .unwrap();
            self.buffer = 0;
            self.nbits = 0;
        }
        Ok(())
    }

    fn write_run(&mut self, mut run: u32) -> io::Result<()> {
        self.write_bits(HUFFMAN_CODES[0] as u64, HUFFMAN_LENGTHS[0])?;
        run -= 1;

        while run >= 258 {
            self.write_bits(HUFFMAN_CODES[285] as u64, HUFFMAN_LENGTHS[285] + 1)?;
            run -= 258;
        }

        if run > 4 {
            let sym = LENGTH_TO_SYMBOL[run as usize - 3] as usize;
            self.write_bits(HUFFMAN_CODES[sym] as u64, HUFFMAN_LENGTHS[sym])?;

            let len_extra = LENGTH_TO_LEN_EXTRA[run as usize - 3];
            let extra = ((run - 3) & BITMASKS[len_extra as usize]) as u64;
            self.write_bits(extra, len_extra + 1)?;
        } else {
            debug_assert_eq!(HUFFMAN_CODES[0], 0);
            self.write_bits(0, run as u8 * HUFFMAN_LENGTHS[0])?;
        }

        Ok(())
    }

    /// Create a new Compressor.
    pub fn new(writer: W) -> io::Result<Self> {
        let mut compressor = Self {
            checksum: Adler32::new(),
            buffer: 0,
            nbits: 0,
            writer,
        };
        compressor.write_headers()?;
        Ok(compressor)
    }

    fn write_headers(&mut self) -> io::Result<()> {
        const HEADER: [u8; 54] = [
            120, 1, 237, 192, 3, 160, 36, 89, 150, 198, 241, 255, 119, 238, 141, 200, 204, 167,
            114, 75, 99, 174, 109, 219, 182, 109, 219, 182, 109, 219, 182, 109, 105, 140, 158, 150,
            74, 175, 158, 50, 51, 34, 238, 249, 118, 183, 106, 122, 166, 135, 59, 107, 213, 15,
        ];
        self.writer.write_all(&HEADER[..53]).unwrap();
        self.write_bits(HEADER[53] as u64, 5)?;

        Ok(())
    }

    /// Write data to the compressor.
    pub fn write_data(&mut self, data: &[u8]) -> io::Result<()> {
        self.checksum.write(data);

        let mut run = 0;
        let mut chunks = data.chunks_exact(8);
        for chunk in &mut chunks {
            let ichunk = u64::from_le_bytes(chunk.try_into().unwrap());

            if ichunk == 0 {
                run += 8;
                continue;
            } else if run > 0 {
                let run_extra = ichunk.trailing_zeros() / 8;
                self.write_run(run + run_extra)?;
                run = 0;

                if run_extra > 0 {
                    run = ichunk.leading_zeros() / 8;
                    for &b in &chunk[run_extra as usize..8 - run as usize] {
                        self.write_bits(
                            HUFFMAN_CODES[b as usize] as u64,
                            HUFFMAN_LENGTHS[b as usize],
                        )?;
                    }
                    continue;
                }
            }

            let run_start = ichunk.leading_zeros() / 8;
            if run_start > 0 {
                for &b in &chunk[..8 - run_start as usize] {
                    self.write_bits(
                        HUFFMAN_CODES[b as usize] as u64,
                        HUFFMAN_LENGTHS[b as usize],
                    )?;
                }
                run = run_start;
                continue;
            }

            let n0 = HUFFMAN_LENGTHS[chunk[0] as usize];
            let n1 = HUFFMAN_LENGTHS[chunk[1] as usize];
            let n2 = HUFFMAN_LENGTHS[chunk[2] as usize];
            let n3 = HUFFMAN_LENGTHS[chunk[3] as usize];
            let bits = HUFFMAN_CODES[chunk[0] as usize] as u64
                | ((HUFFMAN_CODES[chunk[1] as usize] as u64) << n0)
                | ((HUFFMAN_CODES[chunk[2] as usize] as u64) << (n0 + n1))
                | ((HUFFMAN_CODES[chunk[3] as usize] as u64) << (n0 + n1 + n2));
            self.write_bits(bits, n0 + n1 + n2 + n3)?;

            let n4 = HUFFMAN_LENGTHS[chunk[4] as usize];
            let n5 = HUFFMAN_LENGTHS[chunk[5] as usize];
            let n6 = HUFFMAN_LENGTHS[chunk[6] as usize];
            let n7 = HUFFMAN_LENGTHS[chunk[7] as usize];
            let bits2 = HUFFMAN_CODES[chunk[4] as usize] as u64
                | ((HUFFMAN_CODES[chunk[5] as usize] as u64) << n4)
                | ((HUFFMAN_CODES[chunk[6] as usize] as u64) << (n4 + n5))
                | ((HUFFMAN_CODES[chunk[7] as usize] as u64) << (n4 + n5 + n6));
            self.write_bits(bits2, n4 + n5 + n6 + n7)?;
        }

        if run > 0 {
            self.write_run(run)?;
        }

        for &b in chunks.remainder() {
            self.write_bits(
                HUFFMAN_CODES[b as usize] as u64,
                HUFFMAN_LENGTHS[b as usize],
            )?;
        }

        Ok(())
    }

    /// Write the remainder of the stream and return the inner writer.
    pub fn finish(mut self) -> io::Result<W> {
        // Write end of block
        self.write_bits(HUFFMAN_CODES[256] as u64, HUFFMAN_LENGTHS[256])?;
        self.flush()?;

        // Write Adler32 checksum
        let checksum: u32 = self.checksum.finish();
        self.writer
            .write_all(checksum.to_be_bytes().as_ref())
            .unwrap();
        Ok(self.writer)
    }
}

/// Compressor that only writes the stored blocks.
///
/// This is useful for writing files that are not compressed, but still need to be wrapped in a
/// zlib stream.
pub struct StoredOnlyCompressor<W> {
    writer: W,
    checksum: Adler32,
    block_bytes: u16,
}
impl<W: Write + Seek> StoredOnlyCompressor<W> {
    /// Creates a new `StoredOnlyCompressor` that writes to the given writer.
    pub fn new(mut writer: W) -> io::Result<Self> {
        writer.write_all(&[0x78, 0x01])?; // zlib header
        writer.write_all(&[0; 5])?; // placeholder stored block header

        Ok(Self {
            writer,
            checksum: Adler32::new(),
            block_bytes: 0,
        })
    }

    fn set_block_header(&mut self, size: u16, last: bool) -> io::Result<()> {
        self.writer.seek(SeekFrom::Current(-(size as i64 + 5)))?;
        self.writer.write_all(&[
            last as u8,
            (size & 0xFF) as u8,
            ((size >> 8) & 0xFF) as u8,
            (!size & 0xFF) as u8,
            ((!size >> 8) & 0xFF) as u8,
        ])?;
        self.writer.seek(SeekFrom::Current(size as i64))?;

        Ok(())
    }

    /// Writes the given data to the underlying writer.
    pub fn write_data(&mut self, mut data: &[u8]) -> io::Result<()> {
        self.checksum.write(data);
        while !data.is_empty() {
            if self.block_bytes == u16::MAX {
                self.set_block_header(u16::MAX, false)?;
                self.writer.write_all(&[0; 5])?; // placeholder stored block header
                self.block_bytes = 0;
            }

            let prefix_bytes = data.len().min((u16::MAX - self.block_bytes) as usize);
            self.writer.write_all(&data[..prefix_bytes])?;
            self.block_bytes += prefix_bytes as u16;
            data = &data[prefix_bytes..];
        }

        Ok(())
    }

    /// Finish writing the final block and return the underlying writer.
    pub fn finish(mut self) -> io::Result<W> {
        self.set_block_header(self.block_bytes, true)?;

        // Write Adler32 checksum
        let checksum: u32 = self.checksum.finish();
        self.writer
            .write_all(checksum.to_be_bytes().as_ref())
            .unwrap();

        Ok(self.writer)
    }
}
impl<W> StoredOnlyCompressor<W> {
    /// Return the number of bytes that will be written to the output stream
    /// for the given input size. Because this compressor only writes stored blocks,
    /// the output size is always slightly *larger* than the input size.
    pub fn compressed_size(raw_size: usize) -> usize {
        (raw_size.saturating_sub(1) / u16::MAX as usize) * (u16::MAX as usize + 5)
            + (raw_size % u16::MAX as usize + 5)
            + 6
    }
}

/// Compresses the given data.
pub fn compress_to_vec(input: &[u8]) -> Vec<u8> {
    let mut compressor = Compressor::new(Vec::with_capacity(input.len() / 4)).unwrap();
    compressor.write_data(input).unwrap();
    compressor.finish().unwrap()
}

#[cfg(test)]
mod tests {
    use super::*;
    use rand::Rng;

    fn roundtrip(data: &[u8]) {
        let compressed = compress_to_vec(data);
        let decompressed = miniz_oxide::inflate::decompress_to_vec_zlib(&compressed).unwrap();
        assert_eq!(&decompressed, data);
    }

    #[test]
    fn it_works() {
        roundtrip(b"Hello world!");
    }

    #[test]
    fn constant() {
        roundtrip(&vec![0; 2048]);
        roundtrip(&vec![5; 2048]);
        roundtrip(&vec![128; 2048]);
        roundtrip(&vec![254; 2048]);
    }

    #[test]
    fn random() {
        let mut rng = rand::thread_rng();
        let mut data = vec![0; 2048];
        for _ in 0..10 {
            for byte in &mut data {
                *byte = rng.gen();
            }
            roundtrip(&data);
        }
    }
}

Coverage Report

Created: 2025-07-18 06:49

Line	Count	Source (jump to first uncovered line)
1		use simd_adler32::Adler32;
2		use std::io::{self, Seek, SeekFrom, Write};
3
4		use crate::tables::{
5		BITMASKS, HUFFMAN_CODES, HUFFMAN_LENGTHS, LENGTH_TO_LEN_EXTRA, LENGTH_TO_SYMBOL,
6		};
7
8		/// Compressor that produces fdeflate compressed streams.
9		pub struct Compressor<W: Write> {
10		checksum: Adler32,
11		buffer: u64,
12		nbits: u8,
13		writer: W,
14		}
15		impl<W: Write> Compressor<W> {
16	0	fn write_bits(&mut self, bits: u64, nbits: u8) -> io::Result<()> {
17	0	debug_assert!(nbits <= 64);
18
19	0	self.buffer \|= bits << self.nbits;
20	0	self.nbits += nbits;
21	0
22	0	if self.nbits >= 64 {
23	0	self.writer.write_all(&self.buffer.to_le_bytes())?;
24	0	self.nbits -= 64;
25	0	self.buffer = bits.checked_shr((nbits - self.nbits) as u32).unwrap_or(0);
26	0	}
27	0	debug_assert!(self.nbits < 64);
28	0	Ok(())
29	0	} Unexecuted instantiation: <fdeflate::compress::Compressor<std::io::cursor::Cursor<alloc::vec::Vec<u8>>>>::write_bits Unexecuted instantiation: <fdeflate::compress::Compressor<alloc::vec::Vec<u8>>>::write_bits
30
31	0	fn flush(&mut self) -> io::Result<()> {
32	0	if self.nbits % 8 != 0 {
33	0	self.write_bits(0, 8 - self.nbits % 8)?;
34	0	}
35	0	if self.nbits > 0 {
36	0	self.writer
37	0	.write_all(&self.buffer.to_le_bytes()[..self.nbits as usize / 8])
38	0	.unwrap();
39	0	self.buffer = 0;
40	0	self.nbits = 0;
41	0	}
42	0	Ok(())
43	0	} Unexecuted instantiation: <fdeflate::compress::Compressor<std::io::cursor::Cursor<alloc::vec::Vec<u8>>>>::flush Unexecuted instantiation: <fdeflate::compress::Compressor<alloc::vec::Vec<u8>>>::flush
44
45	0	fn write_run(&mut self, mut run: u32) -> io::Result<()> {
46	0	self.write_bits(HUFFMAN_CODES[0] as u64, HUFFMAN_LENGTHS[0])?;
47	0	run -= 1;
48
49	0	while run >= 258 {
50	0	self.write_bits(HUFFMAN_CODES[285] as u64, HUFFMAN_LENGTHS[285] + 1)?;
51	0	run -= 258;
52		}
53
54	0	if run > 4 {
55	0	let sym = LENGTH_TO_SYMBOL[run as usize - 3] as usize;
56	0	self.write_bits(HUFFMAN_CODES[sym] as u64, HUFFMAN_LENGTHS[sym])?;
57
58	0	let len_extra = LENGTH_TO_LEN_EXTRA[run as usize - 3];
59	0	let extra = ((run - 3) & BITMASKS[len_extra as usize]) as u64;
60	0	self.write_bits(extra, len_extra + 1)?;
61		} else {
62	0	debug_assert_eq!(HUFFMAN_CODES[0], 0);
63	0	self.write_bits(0, run as u8 * HUFFMAN_LENGTHS[0])?;
64		}
65
66	0	Ok(())
67	0	} Unexecuted instantiation: <fdeflate::compress::Compressor<std::io::cursor::Cursor<alloc::vec::Vec<u8>>>>::write_run Unexecuted instantiation: <fdeflate::compress::Compressor<alloc::vec::Vec<u8>>>::write_run
68
69		/// Create a new Compressor.
70	0	pub fn new(writer: W) -> io::Result<Self> {
71	0	let mut compressor = Self {
72	0	checksum: Adler32::new(),
73	0	buffer: 0,
74	0	nbits: 0,
75	0	writer,
76	0	};
77	0	compressor.write_headers()?;
78	0	Ok(compressor)
79	0	} Unexecuted instantiation: <fdeflate::compress::Compressor<std::io::cursor::Cursor<alloc::vec::Vec<u8>>>>::new Unexecuted instantiation: <fdeflate::compress::Compressor<alloc::vec::Vec<u8>>>::new
80
81	0	fn write_headers(&mut self) -> io::Result<()> {
82		const HEADER: [u8; 54] = [
83		120, 1, 237, 192, 3, 160, 36, 89, 150, 198, 241, 255, 119, 238, 141, 200, 204, 167,
84		114, 75, 99, 174, 109, 219, 182, 109, 219, 182, 109, 219, 182, 109, 105, 140, 158, 150,
85		74, 175, 158, 50, 51, 34, 238, 249, 118, 183, 106, 122, 166, 135, 59, 107, 213, 15,
86		];
87	0	self.writer.write_all(&HEADER[..53]).unwrap();
88	0	self.write_bits(HEADER[53] as u64, 5)?;
89
90	0	Ok(())
91	0	} Unexecuted instantiation: <fdeflate::compress::Compressor<std::io::cursor::Cursor<alloc::vec::Vec<u8>>>>::write_headers Unexecuted instantiation: <fdeflate::compress::Compressor<alloc::vec::Vec<u8>>>::write_headers
92
93		/// Write data to the compressor.
94	0	pub fn write_data(&mut self, data: &[u8]) -> io::Result<()> {
95	0	self.checksum.write(data);
96	0
97	0	let mut run = 0;
98	0	let mut chunks = data.chunks_exact(8);
99	0	for chunk in &mut chunks {
100	0	let ichunk = u64::from_le_bytes(chunk.try_into().unwrap());
101	0
102	0	if ichunk == 0 {
103	0	run += 8;
104	0	continue;
105	0	} else if run > 0 {
106	0	let run_extra = ichunk.trailing_zeros() / 8;
107	0	self.write_run(run + run_extra)?;
108	0	run = 0;
109	0
110	0	if run_extra > 0 {
111	0	run = ichunk.leading_zeros() / 8;
112	0	for &b in &chunk[run_extra as usize..8 - run as usize] {
113	0	self.write_bits(
114	0	HUFFMAN_CODES[b as usize] as u64,
115	0	HUFFMAN_LENGTHS[b as usize],
116	0	)?;
117		}
118	0	continue;
119	0	}
120	0	}
121
122	0	let run_start = ichunk.leading_zeros() / 8;
123	0	if run_start > 0 {
124	0	for &b in &chunk[..8 - run_start as usize] {
125	0	self.write_bits(
126	0	HUFFMAN_CODES[b as usize] as u64,
127	0	HUFFMAN_LENGTHS[b as usize],
128	0	)?;
129		}
130	0	run = run_start;
131	0	continue;
132	0	}
133	0
134	0	let n0 = HUFFMAN_LENGTHS[chunk[0] as usize];
135	0	let n1 = HUFFMAN_LENGTHS[chunk[1] as usize];
136	0	let n2 = HUFFMAN_LENGTHS[chunk[2] as usize];
137	0	let n3 = HUFFMAN_LENGTHS[chunk[3] as usize];
138	0	let bits = HUFFMAN_CODES[chunk[0] as usize] as u64
139	0	\| ((HUFFMAN_CODES[chunk[1] as usize] as u64) << n0)
140	0	\| ((HUFFMAN_CODES[chunk[2] as usize] as u64) << (n0 + n1))
141	0	\| ((HUFFMAN_CODES[chunk[3] as usize] as u64) << (n0 + n1 + n2));
142	0	self.write_bits(bits, n0 + n1 + n2 + n3)?;
143
144	0	let n4 = HUFFMAN_LENGTHS[chunk[4] as usize];
145	0	let n5 = HUFFMAN_LENGTHS[chunk[5] as usize];
146	0	let n6 = HUFFMAN_LENGTHS[chunk[6] as usize];
147	0	let n7 = HUFFMAN_LENGTHS[chunk[7] as usize];
148	0	let bits2 = HUFFMAN_CODES[chunk[4] as usize] as u64
149	0	\| ((HUFFMAN_CODES[chunk[5] as usize] as u64) << n4)
150	0	\| ((HUFFMAN_CODES[chunk[6] as usize] as u64) << (n4 + n5))
151	0	\| ((HUFFMAN_CODES[chunk[7] as usize] as u64) << (n4 + n5 + n6));
152	0	self.write_bits(bits2, n4 + n5 + n6 + n7)?;
153		}
154
155	0	if run > 0 {
156	0	self.write_run(run)?;
157	0	}
158
159	0	for &b in chunks.remainder() {
160	0	self.write_bits(
161	0	HUFFMAN_CODES[b as usize] as u64,
162	0	HUFFMAN_LENGTHS[b as usize],
163	0	)?;
164		}
165
166	0	Ok(())
167	0	} Unexecuted instantiation: <fdeflate::compress::Compressor<std::io::cursor::Cursor<alloc::vec::Vec<u8>>>>::write_data Unexecuted instantiation: <fdeflate::compress::Compressor<alloc::vec::Vec<u8>>>::write_data
168
169		/// Write the remainder of the stream and return the inner writer.
170	0	pub fn finish(mut self) -> io::Result<W> {
171	0	// Write end of block
172	0	self.write_bits(HUFFMAN_CODES[256] as u64, HUFFMAN_LENGTHS[256])?;
173	0	self.flush()?;
174
175		// Write Adler32 checksum
176	0	let checksum: u32 = self.checksum.finish();
177	0	self.writer
178	0	.write_all(checksum.to_be_bytes().as_ref())
179	0	.unwrap();
180	0	Ok(self.writer)
181	0	} Unexecuted instantiation: <fdeflate::compress::Compressor<std::io::cursor::Cursor<alloc::vec::Vec<u8>>>>::finish Unexecuted instantiation: <fdeflate::compress::Compressor<alloc::vec::Vec<u8>>>::finish
182		}
183
184		/// Compressor that only writes the stored blocks.
185		///
186		/// This is useful for writing files that are not compressed, but still need to be wrapped in a
187		/// zlib stream.
188		pub struct StoredOnlyCompressor<W> {
189		writer: W,
190		checksum: Adler32,
191		block_bytes: u16,
192		}
193		impl<W: Write + Seek> StoredOnlyCompressor<W> {
194		/// Creates a new `StoredOnlyCompressor` that writes to the given writer.
195	0	pub fn new(mut writer: W) -> io::Result<Self> {
196	0	writer.write_all(&[0x78, 0x01])?; // zlib header
197	0	writer.write_all(&[0; 5])?; // placeholder stored block header
198
199	0	Ok(Self {
200	0	writer,
201	0	checksum: Adler32::new(),
202	0	block_bytes: 0,
203	0	})
204	0	} Unexecuted instantiation: <fdeflate::compress::StoredOnlyCompressor<std::io::cursor::Cursor<alloc::vec::Vec<u8>>>>::new Unexecuted instantiation: <fdeflate::compress::StoredOnlyCompressor<_>>::new
205
206	0	fn set_block_header(&mut self, size: u16, last: bool) -> io::Result<()> {
207	0	self.writer.seek(SeekFrom::Current(-(size as i64 + 5)))?;
208	0	self.writer.write_all(&[
209	0	last as u8,
210	0	(size & 0xFF) as u8,
211	0	((size >> 8) & 0xFF) as u8,
212	0	(!size & 0xFF) as u8,
213	0	((!size >> 8) & 0xFF) as u8,
214	0	])?;
215	0	self.writer.seek(SeekFrom::Current(size as i64))?;
216
217	0	Ok(())
218	0	} Unexecuted instantiation: <fdeflate::compress::StoredOnlyCompressor<std::io::cursor::Cursor<alloc::vec::Vec<u8>>>>::set_block_header Unexecuted instantiation: <fdeflate::compress::StoredOnlyCompressor<_>>::set_block_header
219
220		/// Writes the given data to the underlying writer.
221	0	pub fn write_data(&mut self, mut data: &[u8]) -> io::Result<()> {
222	0	self.checksum.write(data);
223	0	while !data.is_empty() {
224	0	if self.block_bytes == u16::MAX {
225	0	self.set_block_header(u16::MAX, false)?;
226	0	self.writer.write_all(&[0; 5])?; // placeholder stored block header
227	0	self.block_bytes = 0;
228	0	}
229
230	0	let prefix_bytes = data.len().min((u16::MAX - self.block_bytes) as usize);
231	0	self.writer.write_all(&data[..prefix_bytes])?;
232	0	self.block_bytes += prefix_bytes as u16;
233	0	data = &data[prefix_bytes..];
234		}
235
236	0	Ok(())
237	0	} Unexecuted instantiation: <fdeflate::compress::StoredOnlyCompressor<std::io::cursor::Cursor<alloc::vec::Vec<u8>>>>::write_data Unexecuted instantiation: <fdeflate::compress::StoredOnlyCompressor<_>>::write_data
238
239		/// Finish writing the final block and return the underlying writer.
240	0	pub fn finish(mut self) -> io::Result<W> {
241	0	self.set_block_header(self.block_bytes, true)?;
242
243		// Write Adler32 checksum
244	0	let checksum: u32 = self.checksum.finish();
245	0	self.writer
246	0	.write_all(checksum.to_be_bytes().as_ref())
247	0	.unwrap();
248	0
249	0	Ok(self.writer)
250	0	} Unexecuted instantiation: <fdeflate::compress::StoredOnlyCompressor<std::io::cursor::Cursor<alloc::vec::Vec<u8>>>>::finish Unexecuted instantiation: <fdeflate::compress::StoredOnlyCompressor<_>>::finish
251		}
252		impl<W> StoredOnlyCompressor<W> {
253		/// Return the number of bytes that will be written to the output stream
254		/// for the given input size. Because this compressor only writes stored blocks,
255		/// the output size is always slightly larger than the input size.
256	0	pub fn compressed_size(raw_size: usize) -> usize {
257	0	(raw_size.saturating_sub(1) / u16::MAX as usize) * (u16::MAX as usize + 5)
258	0	+ (raw_size % u16::MAX as usize + 5)
259	0	+ 6
260	0	} Unexecuted instantiation: <fdeflate::compress::StoredOnlyCompressor<()>>::compressed_size Unexecuted instantiation: <fdeflate::compress::StoredOnlyCompressor<_>>::compressed_size
261		}
262
263		/// Compresses the given data.
264	0	pub fn compress_to_vec(input: &[u8]) -> Vec<u8> {
265	0	let mut compressor = Compressor::new(Vec::with_capacity(input.len() / 4)).unwrap();
266	0	compressor.write_data(input).unwrap();
267	0	compressor.finish().unwrap()
268	0	}
269
270		#[cfg(test)]
271		mod tests {
272		use super::*;
273		use rand::Rng;
274
275		fn roundtrip(data: &[u8]) {
276		let compressed = compress_to_vec(data);
277		let decompressed = miniz_oxide::inflate::decompress_to_vec_zlib(&compressed).unwrap();
278		assert_eq!(&decompressed, data);
279		}
280
281		#[test]
282		fn it_works() {
283		roundtrip(b"Hello world!");
284		}
285
286		#[test]
287		fn constant() {
288		roundtrip(&vec![0; 2048]);
289		roundtrip(&vec![5; 2048]);
290		roundtrip(&vec![128; 2048]);
291		roundtrip(&vec![254; 2048]);
292		}
293
294		#[test]
295		fn random() {
296		let mut rng = rand::thread_rng();
297		let mut data = vec![0; 2048];
298		for _ in 0..10 {
299		for byte in &mut data {
300		*byte = rng.gen();
301		}
302		roundtrip(&data);
303		}
304		}
305		}