fn copy_and_capture<R: Read, W: Write>(
    r: &mut R,
    w: &mut W,
    tag_buffer: &mut Cursor<Vec<u8>>,
) -> Option<io::Result<usize>> {
    use self::CopyUntilResult::*;
    debug!("copy_and_capture");

    // Find the opening byte.
    match copy_until(r, w, b'{') {
        // The end of the reader was reached without finding the opening tag.
        // (either with or without having copied data to the writer)
        // Return None indicating that we are done.
        ReaderEmpty | DelimiterNotFound(_) => None,

        // Something went wrong.
        ReadError(e) | WriteError(e) => Some(Err(e)),

        // The opening byte was found.
        // (either with or without having copied data to the writer)
        DelimiterFound(_) => {
            // Lets reset the buffer first and find out how long it is.
            tag_buffer.set_position(0);
            let buffer_size = tag_buffer.get_ref().len();

            // Find the closing byte,limiting the reader to the length of the buffer.
            let mut rb = r.take(buffer_size as u64);
            match copy_until(&mut rb, tag_buffer, b'}') {
                // We were already at the end of the reader.
                // Return None indicating that we are done.
                ReaderEmpty => None,

                // The closing tag was found.
                // Return the tag_length.
                DelimiterFound(tag_length) => Some(Ok(tag_length)),

                // The end of the reader was found without finding the closing tag.
                // Write the opening byte and captured text to the writer.
                // Return 0 indicating that nothing was captured but the reader still contains data.
                DelimiterNotFound(not_tag_length) => match w.write(b"{") {
                    Err(e) => Some(Err(e)),
                    _ => match w.write(&tag_buffer.get_ref()[0..not_tag_length]) {
                        Err(e) => Some(Err(e)),
                        _ => Some(Ok(0)),
                    },
                },

                ReadError(e) | WriteError(e) => Some(Err(e)),
            }
        }
    }
}
/// Copies the contents of a reader into a writer until a {tag} is found,
/// copying the tag content to a buffer and returning its size.
/// In addition to errors, there are three possible outputs:
///   - `None`: The reader was consumed.
///   - `Some(Ok(0))`: No tag was captured but the reader still contains data.
///   - `Some(Ok(length>0))`: a tag with `length` was captured to the `tag_buffer`.
Copies the contents of a reader into a writer until a {tag} is found,
copying the tag content to a buffer and returning its size.
In addition to errors, there are three possible outputs:
`None`: The reader was consumed.
`Some(Ok(0))`: No tag was captured but the reader still contains data.
Copies the contents of a reader into a writer until a { tag } is found copying the tag content to a buffer and returning its size . In addition to errors there are three possible outputs : ` None ` : The reader was consumed . ` Some ( Ok ( 0 )) ` : No tag was captured but the reader still contains data .
fn copy_and_capture<R: Read, W: Write>(
    r: &mut R,
    w: &mut W,
    tag_buffer: &mut Cursor<Vec<u8>>,
) -> Option<io::Result<usize>> {
    use self::CopyUntilResult::*;
    debug!("copy_and_capture");
    // Find the opening byte.
    match copy_until(r, w, b'{') {
        // The end of the reader was reached without finding the opening tag.
        // (either with or without having copied data to the writer)
        // Return None indicating that we are done.
        ReaderEmpty | DelimiterNotFound(_) => None,
        // Something went wrong.
        ReadError(e) | WriteError(e) => Some(Err(e)),
        // The opening byte was found.
        // (either with or without having copied data to the writer)
        DelimiterFound(_) => {
            // Lets reset the buffer first and find out how long it is.
            tag_buffer.set_position(0);
            let buffer_size = tag_buffer.get_ref().len();
            // Find the closing byte,limiting the reader to the length of the buffer.
            let mut rb = r.take(buffer_size as u64);
            match copy_until(&mut rb, tag_buffer, b'}') {
                // We were already at the end of the reader.
                // Return None indicating that we are done.
                ReaderEmpty => None,
                // The closing tag was found.
                // Return the tag_length.
                DelimiterFound(tag_length) => Some(Ok(tag_length)),
                // The end of the reader was found without finding the closing tag.
                // Write the opening byte and captured text to the writer.
                // Return 0 indicating that nothing was captured but the reader still contains data.
                DelimiterNotFound(not_tag_length) => match w.write(b"{") {
                    Err(e) => Some(Err(e)),
                    _ => match w.write(&tag_buffer.get_ref()[0..not_tag_length]) {
                        Err(e) => Some(Err(e)),
                        _ => Some(Ok(0)),
                    },
                },
                ReadError(e) | WriteError(e) => Some(Err(e)),
            }
        }
    }
}
fn copy_and_capture < R : Read , W : Write > ( r : & mut R , w : & mut W , tag_buffer : & mut Cursor < Vec < u8 > > , ) -> Option < io :: Result < usize > > { use self :: CopyUntilResult :: * ; debug ! ( " " ) ; // Find the opening byte. match copy_until ( r , w , b'{' ) { // The end of the reader was reached without finding the opening tag. // (either with or without having copied data to the writer) // Return None indicating that we are done. ReaderEmpty | DelimiterNotFound ( _ ) => None , // Something went wrong. ReadError ( e ) | WriteError ( e ) => Some ( Err ( e ) ) , // The opening byte was found. // (either with or without having copied data to the writer) DelimiterFound ( _ ) => { // Lets reset the buffer first and find out how long it is. tag_buffer . set_position ( 0 ) ; let buffer_size = tag_buffer . get_ref ( ) . len ( ) ; // Find the closing byte,limiting the reader to the length of the buffer. let mut rb = r . take ( buffer_size as u64 ) ; match copy_until ( & mut rb , tag_buffer , b'}' ) { // We were already at the end of the reader. // Return None indicating that we are done. ReaderEmpty => None , // The closing tag was found. // Return the tag_length. DelimiterFound ( tag_length ) => Some ( Ok ( tag_length ) ) , // The end of the reader was found without finding the closing tag. // Write the opening byte and captured text to the writer. // Return 0 indicating that nothing was captured but the reader still contains data. DelimiterNotFound ( not_tag_length ) => match w . write ( b" " ) { Err ( e ) => Some ( Err ( e ) ) , _ => match w . write ( & tag_buffer . get_ref ( ) [ 0 .. not_tag_length ] ) { Err ( e ) => Some ( Err ( e ) ) , _ => Some ( Ok ( 0 ) ) , } , } , ReadError ( e ) | WriteError ( e ) => Some ( Err ( e ) ) , } } } }
Copies the contents of a reader into a writer until a {tag} is found,
copying the tag content to a buffer and returning its size.
Copies the contents of a reader into a writer until a { tag } is found copying the tag content to a buffer and returning its size .
r
&mut R
w
&mut W
tag_buffer
&mut Cursor<Vec<u8>>
r
&mut R
w
&mut W
tag_buffer
&mut Cursor<Vec<u8>>