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author | Valentin Popov <valentin@popov.link> | 2024-01-08 00:21:28 +0300 |
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committer | Valentin Popov <valentin@popov.link> | 2024-01-08 00:21:28 +0300 |
commit | 1b6a04ca5504955c571d1c97504fb45ea0befee4 (patch) | |
tree | 7579f518b23313e8a9748a88ab6173d5e030b227 /vendor/tiff/src/encoder/compression/lzw.rs | |
parent | 5ecd8cf2cba827454317368b68571df0d13d7842 (diff) | |
download | fparkan-1b6a04ca5504955c571d1c97504fb45ea0befee4.tar.xz fparkan-1b6a04ca5504955c571d1c97504fb45ea0befee4.zip |
Initial vendor packages
Signed-off-by: Valentin Popov <valentin@popov.link>
Diffstat (limited to 'vendor/tiff/src/encoder/compression/lzw.rs')
-rw-r--r-- | vendor/tiff/src/encoder/compression/lzw.rs | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/vendor/tiff/src/encoder/compression/lzw.rs b/vendor/tiff/src/encoder/compression/lzw.rs new file mode 100644 index 0000000..0e0f2aa --- /dev/null +++ b/vendor/tiff/src/encoder/compression/lzw.rs @@ -0,0 +1,47 @@ +use crate::{encoder::compression::*, tags::CompressionMethod}; +use std::io::Write; +use weezl::encode::Encoder as LZWEncoder; + +/// The LZW algorithm used to compress image data in TIFF files. +#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)] +pub struct Lzw; + +impl Compression for Lzw { + const COMPRESSION_METHOD: CompressionMethod = CompressionMethod::LZW; + + fn get_algorithm(&self) -> Compressor { + Compressor::Lzw(*self) + } +} + +impl CompressionAlgorithm for Lzw { + fn write_to<W: Write>(&mut self, writer: &mut W, bytes: &[u8]) -> Result<u64, io::Error> { + let mut encoder = LZWEncoder::with_tiff_size_switch(weezl::BitOrder::Msb, 8); + let result = encoder.into_stream(writer).encode_all(bytes); + let byte_count = result.bytes_written as u64; + result.status.map(|_| byte_count) + } +} + +#[cfg(test)] +mod tests { + use super::*; + use crate::encoder::compression::tests::TEST_DATA; + use std::io::Cursor; + + #[test] + fn test_lzw() { + const EXPECTED_COMPRESSED_DATA: [u8; 63] = [ + 0x80, 0x15, 0x0D, 0x06, 0x93, 0x98, 0x82, 0x08, 0x20, 0x30, 0x88, 0x0E, 0x67, 0x43, + 0x91, 0xA4, 0xDC, 0x67, 0x10, 0x19, 0x8D, 0xE7, 0x21, 0x01, 0x8C, 0xD0, 0x65, 0x31, + 0x9A, 0xE1, 0xD1, 0x03, 0xB1, 0x86, 0x1A, 0x6F, 0x3A, 0xC1, 0x4C, 0x66, 0xF3, 0x69, + 0xC0, 0xE4, 0x65, 0x39, 0x9C, 0xCD, 0x26, 0xF3, 0x74, 0x20, 0xD8, 0x67, 0x89, 0x9A, + 0x4E, 0x86, 0x83, 0x69, 0xCC, 0x5D, 0x01, + ]; + + let mut compressed_data = Vec::<u8>::new(); + let mut writer = Cursor::new(&mut compressed_data); + Lzw::default().write_to(&mut writer, TEST_DATA).unwrap(); + assert_eq!(EXPECTED_COMPRESSED_DATA, compressed_data.as_slice()); + } +} |