Split codec code (#128)

* move src/codec.rs -> src/codec/mod.rs
* Move traits Encoder and Decoder from src/framed_{read|write}.rs into src/codec/{encoder,decoder}.rs
* Move LinesCodec and BytesCodec from src/codecs.rs into src/codec/{lines,bytes}_codec.rs

9 files changed, 166 insertions, 149 deletions

diff --git a/tokio-io/src/codec/bytes_codec.rs b/tokio-io/src/codec/bytes_codec.rs
new file mode 100644
index 00000000..ce26b9e6
--- /dev/null
+++ b/tokio-io/src/codec/bytes_codec.rs
@@ -0,0 +1,37 @@
+use bytes::{Bytes, BufMut, BytesMut};
+use codec::{Encoder, Decoder};
+use std::io;
+
+/// A simple `Codec` implementation that just ships bytes around.
+#[derive(Copy, Clone, Debug, Eq, PartialEq, Ord, PartialOrd, Hash)]
+pub struct BytesCodec(());
+
+impl BytesCodec {
+    /// Creates a new `BytesCodec` for shipping around raw bytes.
+    pub fn new() -> BytesCodec { BytesCodec(())  }
+}
+
+impl Decoder for BytesCodec {
+    type Item = BytesMut;
+    type Error = io::Error;
+
+    fn decode(&mut self, buf: &mut BytesMut) -> Result<Option<BytesMut>, io::Error> {
+        if buf.len() > 0 {
+            let len = buf.len();
+            Ok(Some(buf.split_to(len)))
+        } else {
+            Ok(None)
+        }
+    }
+}
+
+impl Encoder for BytesCodec {
+    type Item = Bytes;
+    type Error = io::Error;
+
+    fn encode(&mut self, data: Bytes, buf: &mut BytesMut) -> Result<(), io::Error> {
+        buf.reserve(data.len());
+        buf.put(data);
+        Ok(())
+    }
+}
diff --git a/tokio-io/src/codec/decoder.rs b/tokio-io/src/codec/decoder.rs
new file mode 100644
index 00000000..e4c3d79e
--- /dev/null
+++ b/tokio-io/src/codec/decoder.rs
@@ -0,0 +1,86 @@
+use std::io;
+use bytes::BytesMut;
+
+/// Decoding of frames via buffers.
+///
+/// This trait is used when constructing an instance of `Framed` or
+/// `FramedRead`. An implementation of `Decoder` takes a byte stream that has
+/// already been buffered in `src` and decodes the data into a stream of
+/// `Self::Item` frames.
+///
+/// Implementations are able to track state on `self`, which enables
+/// implementing stateful streaming parsers. In many cases, though, this type
+/// will simply be a unit struct (e.g. `struct HttpDecoder`).
+pub trait Decoder {
+    /// The type of decoded frames.
+    type Item;
+
+    /// The type of unrecoverable frame decoding errors.
+    ///
+    /// If an individual message is ill-formed but can be ignored without
+    /// interfering with the processing of future messages, it may be more
+    /// useful to report the failure as an `Item`.
+    ///
+    /// `From<io::Error>` is required in the interest of making `Error` suitable
+    /// for returning directly from a `FramedRead`, and to enable the default
+    /// implementation of `decode_eof` to yield an `io::Error` when the decoder
+    /// fails to consume all available data.
+    ///
+    /// Note that implementors of this trait can simply indicate `type Error =
+    /// io::Error` to use I/O errors as this type.
+    type Error: From<io::Error>;
+
+    /// Attempts to decode a frame from the provided buffer of bytes.
+    ///
+    /// This method is called by `FramedRead` whenever bytes are ready to be
+    /// parsed.  The provided buffer of bytes is what's been read so far, and
+    /// this instance of `Decode` can determine whether an entire frame is in
+    /// the buffer and is ready to be returned.
+    ///
+    /// If an entire frame is available, then this instance will remove those
+    /// bytes from the buffer provided and return them as a decoded
+    /// frame. Note that removing bytes from the provided buffer doesn't always
+    /// necessarily copy the bytes, so this should be an efficient operation in
+    /// most circumstances.
+    ///
+    /// If the bytes look valid, but a frame isn't fully available yet, then
+    /// `Ok(None)` is returned. This indicates to the `Framed` instance that
+    /// it needs to read some more bytes before calling this method again.
+    ///
+    /// Note that the bytes provided may be empty. If a previous call to
+    /// `decode` consumed all the bytes in the buffer then `decode` will be
+    /// called again until it returns `None`, indicating that more bytes need to
+    /// be read.
+    ///
+    /// Finally, if the bytes in the buffer are malformed then an error is
+    /// returned indicating why. This informs `Framed` that the stream is now
+    /// corrupt and should be terminated.
+    fn decode(&mut self, src: &mut BytesMut) -> Result<Option<Self::Item>, Self::Error>;
+
+    /// A default method available to be called when there are no more bytes
+    /// available to be read from the underlying I/O.
+    ///
+    /// This method defaults to calling `decode` and returns an error if
+    /// `Ok(None)` is returned while there is unconsumed data in `buf`.
+    /// Typically this doesn't need to be implemented unless the framing
+    /// protocol differs near the end of the stream.
+    ///
+    /// Note that the `buf` argument may be empty. If a previous call to
+    /// `decode_eof` consumed all the bytes in the buffer, `decode_eof` will be
+    /// called again until it returns `None`, indicating that there are no more
+    /// frames to yield. This behavior enables returning finalization frames
+    /// that may not be based on inbound data.
+    fn decode_eof(&mut self, buf: &mut BytesMut) -> Result<Option<Self::Item>, Self::Error> {
+        match try!(self.decode(buf)) {
+            Some(frame) => Ok(Some(frame)),
+            None => {
+                if buf.is_empty() {
+                    Ok(None)
+                } else {
+                    Err(io::Error::new(io::ErrorKind::Other,
+                                       "bytes remaining on stream").into())
+                }
+            }
+        }
+    }
+}
diff --git a/tokio-io/src/codec/encoder.rs b/tokio-io/src/codec/encoder.rs
new file mode 100644
index 00000000..55056c1c
--- /dev/null
+++ b/tokio-io/src/codec/encoder.rs
@@ -0,0 +1,23 @@
+use std::io;
+use bytes::BytesMut;
+
+/// Trait of helper objects to write out messages as bytes, for use with
+/// `FramedWrite`.
+pub trait Encoder {
+    /// The type of items consumed by the `Encoder`
+    type Item;
+
+    /// The type of encoding errors.
+    ///
+    /// `FramedWrite` requires `Encoder`s errors to implement `From<io::Error>`
+    /// in the interest letting it return `Error`s directly.
+    type Error: From<io::Error>;
+
+    /// Encodes a frame into the buffer provided.
+    ///
+    /// This method will encode `item` into the byte buffer provided by `dst`.
+    /// The `dst` provided is an internal buffer of the `Framed` instance and
+    /// will be written out when possible.
+    fn encode(&mut self, item: Self::Item, dst: &mut BytesMut)
+              -> Result<(), Self::Error>;
+}
diff --git a/tokio-io/src/codecs.rs b/tokio-io/src/codec/lines_codec.rs
index f61448d1..2e1bea4a 100644
--- a/tokio-io/src/codecs.rs
+++ b/tokio-io/src/codec/lines_codec.rs
@@ -1,41 +1,7 @@
-use bytes::{Bytes, BufMut, BytesMut};
+use bytes::{BufMut, BytesMut};
 use codec::{Encoder, Decoder};
 use std::{io, str};
 
-/// A simple `Codec` implementation that just ships bytes around.
-#[derive(Copy, Clone, Debug, Eq, PartialEq, Ord, PartialOrd, Hash)]
-pub struct BytesCodec(());
-
-impl BytesCodec {
-    /// Creates a new `BytesCodec` for shipping around raw bytes.
-    pub fn new() -> BytesCodec { BytesCodec(())  }
-}
-
-impl Decoder for BytesCodec {
-    type Item = BytesMut;
-    type Error = io::Error;
-
-    fn decode(&mut self, buf: &mut BytesMut) -> Result<Option<BytesMut>, io::Error> {
-        if buf.len() > 0 {
-            let len = buf.len();
-            Ok(Some(buf.split_to(len)))
-        } else {
-            Ok(None)
-        }
-    }
-}
-
-impl Encoder for BytesCodec {
-    type Item = Bytes;
-    type Error = io::Error;
-
-    fn encode(&mut self, data: Bytes, buf: &mut BytesMut) -> Result<(), io::Error> {
-        buf.reserve(data.len());
-        buf.put(data);
-        Ok(())
-    }
-}
-
 /// A simple `Codec` implementation that splits up data into lines.
 #[derive(Clone, Debug, Eq, PartialEq, Ord, PartialOrd, Hash)]
 pub struct LinesCodec {
diff --git a/tokio-io/src/codec.rs b/tokio-io/src/codec/mod.rs
index aa91f224..3a80d6a3 100644
--- a/tokio-io/src/codec.rs
+++ b/tokio-io/src/codec/mod.rs
@@ -10,10 +10,19 @@
 //! [`Stream`]: #
 //! [transports]: #
 
-pub use codecs::{BytesCodec, LinesCodec};
+mod decoder;
+mod encoder;
+mod bytes_codec;
+mod lines_codec;
+
+pub use self::decoder::Decoder;
+pub use self::encoder::Encoder;
+pub use self::bytes_codec::BytesCodec;
+pub use self::lines_codec::LinesCodec;
+
 pub use framed::{Framed, FramedParts};
-pub use framed_read::{FramedRead, Decoder};
-pub use framed_write::{FramedWrite, Encoder};
+pub use framed_read::FramedRead;
+pub use framed_write::FramedWrite;
 
 pub mod length_delimited {
     //! Frame a stream of bytes based on a length prefix
diff --git a/tokio-io/src/framed.rs b/tokio-io/src/framed.rs
index e3255470..5a3c54a8 100644
--- a/tokio-io/src/framed.rs
+++ b/tokio-io/src/framed.rs
@@ -2,8 +2,9 @@ use std::io::{self, Read, Write};
 use std::fmt;
 
 use {AsyncRead, AsyncWrite};
-use framed_read::{framed_read2, framed_read2_with_buffer, FramedRead2, Decoder};
-use framed_write::{framed_write2, framed_write2_with_buffer, FramedWrite2, Encoder};
+use codec::{Decoder, Encoder};
+use framed_read::{framed_read2, framed_read2_with_buffer, FramedRead2};
+use framed_write::{framed_write2, framed_write2_with_buffer, FramedWrite2};
 
 use futures::{Stream, Sink, StartSend, Poll};
 use bytes::{BytesMut};
@@ -225,4 +226,4 @@ pub struct FramedParts<T>
     pub readbuf: BytesMut,
     /// A buffer with unprocessed data which are not written yet.
     pub writebuf: BytesMut
-}
\ No newline at end of file
+}
diff --git a/tokio-io/src/framed_read.rs b/tokio-io/src/framed_read.rs
index 6ccfd1aa..e04e3acf 100644
--- a/tokio-io/src/framed_read.rs
+++ b/tokio-io/src/framed_read.rs
@@ -1,95 +1,12 @@
-use std::{fmt, io};
+use std::fmt;
 
 use AsyncRead;
+use codec::Decoder;
 use framed::Fuse;
 
 use futures::{Async, Poll, Stream, Sink, StartSend};
 use bytes::BytesMut;
 
-/// Decoding of frames via buffers.
-///
-/// This trait is used when constructing an instance of `Framed` or
-/// `FramedRead`. An implementation of `Decoder` takes a byte stream that has
-/// already been buffered in `src` and decodes the data into a stream of
-/// `Self::Item` frames.
-///
-/// Implementations are able to track state on `self`, which enables
-/// implementing stateful streaming parsers. In many cases, though, this type
-/// will simply be a unit struct (e.g. `struct HttpDecoder`).
-pub trait Decoder {
-    /// The type of decoded frames.
-    type Item;
-
-    /// The type of unrecoverable frame decoding errors.
-    ///
-    /// If an individual message is ill-formed but can be ignored without
-    /// interfering with the processing of future messages, it may be more
-    /// useful to report the failure as an `Item`.
-    ///
-    /// `From<io::Error>` is required in the interest of making `Error` suitable
-    /// for returning directly from a `FramedRead`, and to enable the default
-    /// implementation of `decode_eof` to yield an `io::Error` when the decoder
-    /// fails to consume all available data.
-    ///
-    /// Note that implementors of this trait can simply indicate `type Error =
-    /// io::Error` to use I/O errors as this type.
-    type Error: From<io::Error>;
-
-    /// Attempts to decode a frame from the provided buffer of bytes.
-    ///
-    /// This method is called by `FramedRead` whenever bytes are ready to be
-    /// parsed.  The provided buffer of bytes is what's been read so far, and
-    /// this instance of `Decode` can determine whether an entire frame is in
-    /// the buffer and is ready to be returned.
-    ///
-    /// If an entire frame is available, then this instance will remove those
-    /// bytes from the buffer provided and return them as a decoded
-    /// frame. Note that removing bytes from the provided buffer doesn't always
-    /// necessarily copy the bytes, so this should be an efficient operation in
-    /// most circumstances.
-    ///
-    /// If the bytes look valid, but a frame isn't fully available yet, then
-    /// `Ok(None)` is returned. This indicates to the `Framed` instance that
-    /// it needs to read some more bytes before calling this method again.
-    ///
-    /// Note that the bytes provided may be empty. If a previous call to
-    /// `decode` consumed all the bytes in the buffer then `decode` will be
-    /// called again until it returns `None`, indicating that more bytes need to
-    /// be read.
-    ///
-    /// Finally, if the bytes in the buffer are malformed then an error is
-    /// returned indicating why. This informs `Framed` that the stream is now
-    /// corrupt and should be terminated.
-    fn decode(&mut self, src: &mut BytesMut) -> Result<Option<Self::Item>, Self::Error>;
-
-    /// A default method available to be called when there are no more bytes
-    /// available to be read from the underlying I/O.
-    ///
-    /// This method defaults to calling `decode` and returns an error if
-    /// `Ok(None)` is returned while there is unconsumed data in `buf`.
-    /// Typically this doesn't need to be implemented unless the framing
-    /// protocol differs near the end of the stream.
-    ///
-    /// Note that the `buf` argument may be empty. If a previous call to
-    /// `decode_eof` consumed all the bytes in the buffer, `decode_eof` will be
-    /// called again until it returns `None`, indicating that there are no more
-    /// frames to yield. This behavior enables returning finalization frames
-    /// that may not be based on inbound data.
-    fn decode_eof(&mut self, buf: &mut BytesMut) -> Result<Option<Self::Item>, Self::Error> {
-        match try!(self.decode(buf)) {
-            Some(frame) => Ok(Some(frame)),
-            None => {
-                if buf.is_empty() {
-                    Ok(None)
-                } else {
-                    Err(io::Error::new(io::ErrorKind::Other,
-                                       "bytes remaining on stream").into())
-                }
-            }
-        }
-    }
-}
-
 /// A `Stream` of messages decoded from an `AsyncRead`.
 pub struct FramedRead<T, D> {
     inner: FramedRead2<Fuse<T, D>>,
diff --git a/tokio-io/src/framed_write.rs b/tokio-io/src/framed_write.rs
index f9d0edcb..e16ad3f8 100644
--- a/tokio-io/src/framed_write.rs
+++ b/tokio-io/src/framed_write.rs
@@ -2,33 +2,12 @@ use std::io::{self, Read};
 use std::fmt;
 
 use {AsyncRead, AsyncWrite};
-use codec::Decoder;
+use codec::{Decoder, Encoder};
 use framed::Fuse;
 
 use futures::{Async, AsyncSink, Poll, Stream, Sink, StartSend};
 use bytes::BytesMut;
 
-/// Trait of helper objects to write out messages as bytes, for use with
-/// `FramedWrite`.
-pub trait Encoder {
-    /// The type of items consumed by the `Encoder`
-    type Item;
-
-    /// The type of encoding errors.
-    ///
-    /// `FramedWrite` requires `Encoder`s errors to implement `From<io::Error>`
-    /// in the interest letting it return `Error`s directly.
-    type Error: From<io::Error>;
-
-    /// Encodes a frame into the buffer provided.
-    ///
-    /// This method will encode `item` into the byte buffer provided by `dst`.
-    /// The `dst` provided is an internal buffer of the `Framed` instance and
-    /// will be written out when possible.
-    fn encode(&mut self, item: Self::Item, dst: &mut BytesMut)
-              -> Result<(), Self::Error>;
-}
-
 /// A `Sink` of frames encoded to an `AsyncWrite`.
 pub struct FramedWrite<T, E> {
     inner: FramedWrite2<Fuse<T, E>>,
diff --git a/tokio-io/src/lib.rs b/tokio-io/src/lib.rs
index 4c6d67ef..58dbeedf 100644
--- a/tokio-io/src/lib.rs
+++ b/tokio-io/src/lib.rs
@@ -49,7 +49,6 @@ pub mod io;
 pub mod codec;
 
 mod allow_std;
-mod codecs;
 mod copy;
 mod flush;
 mod framed;