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use libstomper::{huffman::Huffman, lzw::LZW, Compressor};
use std::error;
use std::fs::File;
use std::io::prelude::*;
use std::io::{BufReader, BufWriter, Error, ErrorKind};
use std::path::PathBuf;
use structopt::StructOpt;
pub fn run(args: Args) -> Result<(), Box<dyn error::Error>> {
let mut input = BufReader::new(File::open(&args.input)?);
let out_filename = if let Some(path) = args.output {
path
} else {
if !args.input.is_file() {
return Err(Box::new(Error::new(ErrorKind::InvalidInput, "input is not a file")));
}
let mut default = PathBuf::new();
let compressor = &args.compressor;
let decompress = if args.decompress {
"decomp"
} else {
"comp"
};
default.set_file_name(format!("stomped.{}.{}",compressor, decompress));
default
};
let mut output = BufWriter::new(File::create(out_filename)?);
choose_compression(args.compressor.as_str(), args.decompress, &mut input, &mut output)?;
Ok(())
}
fn choose_compression<R, W>(comp: &str, decomp: bool, inp: &mut R, out: &mut W) -> Result<(), Box<dyn error::Error>>
where R: Read + Seek,
W: Write + Seek
{
match comp {
"lzw" => match decomp {
true => LZW::decode(inp, out),
false => LZW::encode(inp, out),
},
"huffman" | "huff" => match decomp{
true => Huffman::decode(inp, out),
false => Huffman::encode(inp, out),
},
s => {
return Err(Box::new(Error::new(
ErrorKind::InvalidInput,
format!("{} is not a compression type", s),
)))
}
}?;
Ok(())
}
#[derive(StructOpt)]
pub struct Args {
#[structopt(short, long)]
pub decompress: bool,
pub compressor: String,
#[structopt(parse(from_os_str))]
pub input: PathBuf,
#[structopt(short, long)]
pub output: Option<PathBuf>,
}