simplify pxar module structure

src/pxar/decoder.rs

@@ -22,14 +22,14 @@ use nix::errno::Errno;
 use nix::NixPath;
 
 // This one need Read, but works without Seek
-pub struct PxarDecoder<'a, R: Read> {
+pub struct SequentialDecoder<'a, R: Read> {
     reader: &'a mut R,
     skip_buffer: Vec<u8>,
 }
 
 const HEADER_SIZE: u64 = std::mem::size_of::<CaFormatHeader>() as u64;
 
-impl <'a, R: Read> PxarDecoder<'a, R> {
+impl <'a, R: Read> SequentialDecoder<'a, R> {
 
     pub fn new(reader: &'a mut R) -> Self {
         let skip_buffer = vec![0u8; 64*1024];

src/pxar/encoder.rs

@@ -27,7 +27,7 @@ use nix::sys::stat::FileStat;
 /// maximum memory usage.
 pub const MAX_DIRECTORY_ENTRIES: usize = 256*1024;
 
-pub struct PxarEncoder<'a, W: Write> {
+pub struct Encoder<'a, W: Write> {
     current_path: PathBuf, // used for error reporting
     writer: &'a mut W,
     writer_pos: usize,
@@ -38,7 +38,7 @@ pub struct PxarEncoder<'a, W: Write> {
     verbose: bool,
 }
 
-impl <'a, W: Write> PxarEncoder<'a, W> {
+impl <'a, W: Write> Encoder<'a, W> {
 
     pub fn encode(
         path: PathBuf,