oxipng/src/deflate/deflater.rs
2022-10-29 15:05:08 +13:00

38 lines
1.4 KiB
Rust

use crate::atomicmin::AtomicMin;
use crate::{PngError, PngResult};
use libdeflater::*;
pub fn deflate(data: &[u8], level: u8, max_size: &AtomicMin) -> PngResult<Vec<u8>> {
let mut compressor = Compressor::new(CompressionLvl::new(level.into()).unwrap());
// If adhering to a max_size we need to include at least 9 extra bytes of slack space (as specified in docs).
let capacity = max_size
.get()
.unwrap_or_else(|| compressor.zlib_compress_bound(data.len()))
+ 9;
let mut dest = vec![0; capacity];
let len = compressor
.zlib_compress(data, &mut dest)
.map_err(|err| match err {
CompressionError::InsufficientSpace => PngError::DeflatedDataTooLong(capacity),
})?;
if let Some(max) = max_size.get() {
if len > max {
return Err(PngError::DeflatedDataTooLong(max));
}
}
dest.truncate(len);
Ok(dest)
}
pub fn inflate(data: &[u8], out_size: usize) -> PngResult<Vec<u8>> {
let mut decompressor = Decompressor::new();
let mut dest = vec![0; out_size];
let len = decompressor
.zlib_decompress(data, &mut dest)
.map_err(|err| match err {
DecompressionError::BadData => PngError::InvalidData,
DecompressionError::InsufficientSpace => PngError::new("inflated data too long"),
})?;
dest.truncate(len);
Ok(dest)
}