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-rw-r--r--vendor/tiff/src/encoder/compression/mod.rs60
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diff --git a/vendor/tiff/src/encoder/compression/mod.rs b/vendor/tiff/src/encoder/compression/mod.rs
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+use crate::tags::CompressionMethod;
+use std::io::{self, Write};
+
+mod deflate;
+mod lzw;
+mod packbits;
+mod uncompressed;
+
+pub use self::deflate::{Deflate, DeflateLevel};
+pub use self::lzw::Lzw;
+pub use self::packbits::Packbits;
+pub use self::uncompressed::Uncompressed;
+
+/// An algorithm used for compression
+pub trait CompressionAlgorithm {
+ /// The algorithm writes data directly into the writer.
+ /// It returns the total number of bytes written.
+ fn write_to<W: Write>(&mut self, writer: &mut W, bytes: &[u8]) -> Result<u64, io::Error>;
+}
+
+/// An algorithm used for compression with associated enums and optional configurations.
+pub trait Compression: CompressionAlgorithm {
+ /// The corresponding tag to the algorithm.
+ const COMPRESSION_METHOD: CompressionMethod;
+
+ /// Method to optain a type that can store each variant of comression algorithm.
+ fn get_algorithm(&self) -> Compressor;
+}
+
+/// An enum to store each compression algorithm.
+pub enum Compressor {
+ Uncompressed(Uncompressed),
+ Lzw(Lzw),
+ Deflate(Deflate),
+ Packbits(Packbits),
+}
+
+impl Default for Compressor {
+ /// The default compression strategy does not apply any compression.
+ fn default() -> Self {
+ Compressor::Uncompressed(Uncompressed::default())
+ }
+}
+
+impl CompressionAlgorithm for Compressor {
+ fn write_to<W: Write>(&mut self, writer: &mut W, bytes: &[u8]) -> Result<u64, io::Error> {
+ match self {
+ Compressor::Uncompressed(algorithm) => algorithm.write_to(writer, bytes),
+ Compressor::Lzw(algorithm) => algorithm.write_to(writer, bytes),
+ Compressor::Deflate(algorithm) => algorithm.write_to(writer, bytes),
+ Compressor::Packbits(algorithm) => algorithm.write_to(writer, bytes),
+ }
+ }
+}
+
+#[cfg(test)]
+mod tests {
+ pub const TEST_DATA: &'static [u8] =
+ b"This is a string for checking various compression algorithms.";
+}