//! Input and output of images.

use std::io;

use std::io::Read as _;

/// The decoder traits.

pub(crate) mod decoder;

/// The encoder traits.

pub(crate) mod encoder;

pub(crate) mod format;

pub(crate) mod free_functions;

pub(crate) mod image_reader_type;

pub(crate) mod limits;

#[deprecated(note = "this type has been moved and renamed to image::ImageReader")]

/// Deprecated re-export of `ImageReader` as `Reader`

pub type Reader<R> = ImageReader<R>;

#[deprecated(note = "this type has been moved to image::Limits")]

/// Deprecated re-export of `Limits`

pub type Limits = limits::Limits;

#[deprecated(note = "this type has been moved to image::LimitSupport")]

/// Deprecated re-export of `LimitSupport`

pub type LimitSupport = limits::LimitSupport;

pub(crate) use self::image_reader_type::ImageReader;

/// Adds `read_exact_vec`

pub(crate) trait ReadExt {

    fn read_exact_vec(&mut self, vec: &mut Vec<u8>, len: usize) -> io::Result<()>;

}

impl<R: io::Read> ReadExt for R {

    fn read_exact_vec(&mut self, vec: &mut Vec<u8>, len: usize) -> io::Result<()> {

        let initial_len = vec.len();

        vec.try_reserve(len)?;

        match self.take(len as u64).read_to_end(vec) {

            Ok(read) if read == len => Ok(()),

            fail => {

                vec.truncate(initial_len);

                Err(fail.err().unwrap_or(io::ErrorKind::UnexpectedEof.into()))

            }

        }

    }

}