66 lines
2.2 KiB
Rust
66 lines
2.2 KiB
Rust
use error::PngError;
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use miniz_sys;
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use libc::c_int;
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use std::cmp::max;
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use zopfli;
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#[doc(hidden)]
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pub mod miniz_stream;
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/// Decompress a data stream using the DEFLATE algorithm
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pub fn inflate(data: &[u8]) -> Result<Vec<u8>, PngError> {
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let mut input = data.to_owned();
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let mut stream = miniz_stream::Stream::new_decompress();
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let mut output = Vec::with_capacity(data.len());
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loop {
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match stream.decompress_vec(input.as_mut(), output.as_mut()) {
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miniz_sys::MZ_OK => output.reserve(data.len()),
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miniz_sys::MZ_STREAM_END => break,
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c => return Err(PngError::new(&format!("Error code on decompress: {}", c))),
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}
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}
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output.shrink_to_fit();
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Ok(output)
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}
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/// Compress a data stream using the zlib implementation of the DEFLATE algorithm
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pub fn deflate(data: &[u8], zc: u8, zm: u8, zs: u8, zw: u8) -> Result<Vec<u8>, PngError> {
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let mut input = data.to_owned();
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// Compressed input should be smaller than decompressed, so allocate less than data.len()
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// However, it needs a minimum capacity in order to handle very small images
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let mut output = Vec::with_capacity(max(1024, data.len() / 20));
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let mut stream =
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miniz_stream::Stream::new_compress(zc as c_int, zw as c_int, zm as c_int, zs as c_int);
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loop {
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match stream.compress_vec(input.as_mut(), output.as_mut()) {
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miniz_sys::MZ_OK => output.reserve(max(1024, data.len() / 20)),
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miniz_sys::MZ_STREAM_END => break,
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c => return Err(PngError::new(&format!("Error code on compress: {}", c))),
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}
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}
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output.shrink_to_fit();
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Ok(output)
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}
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pub fn zopfli_deflate(data: &[u8]) -> Result<Vec<u8>, PngError> {
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let mut output = Vec::with_capacity(max(1024, data.len() / 20));
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let options = zopfli::Options::default();
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match zopfli::compress(&options, &zopfli::Format::Zlib, data, &mut output) {
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Ok(_) => (),
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Err(_) => return Err(PngError::new("Failed to compress in zopfli")),
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};
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output.shrink_to_fit();
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Ok(output)
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}
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#[derive(Clone, Copy, Debug, PartialEq)]
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/// DEFLATE algorithms supported by oxipng
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pub enum Deflaters {
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/// Use the Zlib DEFLATE implementation
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Zlib,
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/// Use the better but slower Zopfli implementation
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Zopfli,
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}
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