60 lines
2.1 KiB
Rust
60 lines
2.1 KiB
Rust
use atomicmin::AtomicMin;
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use error::PngError;
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use miniz_oxide::deflate::core::*;
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pub fn compress_to_vec_oxipng(input: &[u8], level: u8, window_bits: i32, strategy: i32, max_size: &AtomicMin) -> Result<Vec<u8>, PngError> {
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// The comp flags function sets the zlib flag if the window_bits parameter is > 0.
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let flags = create_comp_flags_from_zip_params(level.into(), window_bits, strategy);
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let mut compressor = CompressorOxide::new(flags);
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// if max size is known, then expect that much data (but no more than input.len())
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let mut output = Vec::with_capacity(max_size.get().unwrap_or(input.len() / 2).min(input.len()));
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// # Unsafe
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// We trust compress to not read the uninitialized bytes.
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unsafe {
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let cap = output.capacity();
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output.set_len(cap);
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}
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let mut in_pos = 0;
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let mut out_pos = 0;
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loop {
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let (status, bytes_in, bytes_out) = compress(
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&mut compressor,
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&input[in_pos..],
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&mut output[out_pos..],
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TDEFLFlush::Finish,
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);
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out_pos += bytes_out;
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in_pos += bytes_in;
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match status {
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TDEFLStatus::Done => {
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output.truncate(out_pos);
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break;
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}
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TDEFLStatus::Okay => {
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if let Some(max) = max_size.get() {
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if output.len() > max {
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return Err(PngError::DeflatedDataTooLong(output.len()))
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}
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}
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// We need more space, so extend the vector.
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if output.len().saturating_sub(out_pos) < 30 {
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let current_len = output.len();
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output.reserve(current_len);
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// # Unsafe
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// We trust compress to not read the uninitialized bytes.
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unsafe {
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let cap = output.capacity();
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output.set_len(cap);
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}
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}
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}
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// Not supposed to happen unless there is a bug.
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_ => panic!("Bug! Unexpectedly failed to compress!"),
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}
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}
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Ok(output)
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}
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