tiff/encoder/compression/
mod.rs

1use crate::tags::CompressionMethod;
2use std::io::{self, Write};
3
4mod deflate;
5mod lzw;
6mod packbits;
7mod uncompressed;
8
9pub use self::deflate::{Deflate, DeflateLevel};
10pub use self::lzw::Lzw;
11pub use self::packbits::Packbits;
12pub use self::uncompressed::Uncompressed;
13
14/// An algorithm used for compression
15pub trait CompressionAlgorithm {
16    /// The algorithm writes data directly into the writer.
17    /// It returns the total number of bytes written.
18    fn write_to<W: Write>(&mut self, writer: &mut W, bytes: &[u8]) -> Result<u64, io::Error>;
19}
20
21/// An algorithm used for compression with associated enums and optional configurations.
22pub trait Compression: CompressionAlgorithm {
23    /// The corresponding tag to the algorithm.
24    const COMPRESSION_METHOD: CompressionMethod;
25
26    /// Method to optain a type that can store each variant of comression algorithm.
27    fn get_algorithm(&self) -> Compressor;
28}
29
30/// An enum to store each compression algorithm.
31pub enum Compressor {
32    Uncompressed(Uncompressed),
33    Lzw(Lzw),
34    Deflate(Deflate),
35    Packbits(Packbits),
36}
37
38impl Default for Compressor {
39    /// The default compression strategy does not apply any compression.
40    fn default() -> Self {
41        Compressor::Uncompressed(Uncompressed)
42    }
43}
44
45impl CompressionAlgorithm for Compressor {
46    fn write_to<W: Write>(&mut self, writer: &mut W, bytes: &[u8]) -> Result<u64, io::Error> {
47        match self {
48            Compressor::Uncompressed(algorithm) => algorithm.write_to(writer, bytes),
49            Compressor::Lzw(algorithm) => algorithm.write_to(writer, bytes),
50            Compressor::Deflate(algorithm) => algorithm.write_to(writer, bytes),
51            Compressor::Packbits(algorithm) => algorithm.write_to(writer, bytes),
52        }
53    }
54}
55
56#[cfg(test)]
57mod tests {
58    pub const TEST_DATA: &[u8] = b"This is a string for checking various compression algorithms.";
59}
tiff/encoder/compression/mod.rs

tiff/encoder/compression/
mod.rs
