exifsd 0.1.0

Provides JPEG file metadata manipulation, parsing, writing, and injection
Documentation 
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use crate::*;
use byteorder::WriteBytesExt;
use combine::{parser::*, *};
use std::io;

#[derive(Clone, Debug)]
pub enum JpegData<'a> {
    MarkedData(MarkedData<'a>),
    ScanSegment(ScanSegment<'a>),
}

impl<'a> JpegData<'a> {
    /// Parses any data in a JPEG between the Start of Image marker and the End of Image marker.
    pub fn parser<I: 'a>() -> impl Parser<Input = I, Output = JpegData<'a>> + 'a
    where
        I: RangeStream<Item = u8, Range = &'a [u8]>,
        I::Error: ParseError<I::Item, I::Range, I::Position>,
    {
        choice((
            attempt(ScanSegment::parser().map(JpegData::ScanSegment)),
            // If it wasn't a Scan Segment, the only other option is End of Image (0xD9).
            attempt(MarkedData::parser(none_of(std::iter::once(0xD9))).map(JpegData::MarkedData)),
        ))
    }

    /// Writes the binary representation of the `JpegData` out to a file.
    pub fn write<W: WriteBytesExt>(&self, writer: &mut W) -> io::Result<()> {
        match self {
            JpegData::MarkedData(md) => md.write(writer),
            JpegData::ScanSegment(ss) => ss.write(writer),
        }
    }
}