1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134


use ifd::{
    Entry,
    DataType,
};
use tag::AnyTag;
use image::{
    PhotometricInterpretation,
    BitsPerSample,
    BitsPerSampleError,
    ImageHeaderError,
};
use std::io;
use std::fmt::{
    self,
    Display,
};
use failure::{
    Context,
    Fail,
    Backtrace,
};

pub type DecodeResult<T> = ::std::result::Result<T, DecodeError>;

#[derive(Debug, Fail)]
pub enum DecodeErrorKind {
    #[fail(display = "IO Error: {:?}", error)]
    IO { error: io::Error },

    #[fail(display = "Incorrect header: No Byte Order")]
    NoByteOrder,

    #[fail(display = "Incorrect header: No Version")]
    NoVersion,

    #[fail(display = "Incorrect header: No IFD address")]
    NoIFDAddress,

    #[fail(display = "No Image address")]
    NoImage,

    #[fail(display = "Can't find the tag ({:?})", tag)]
    CannotFindTheTag { tag: AnyTag },

    #[fail(display = "Unsupported IFD Entry ({})\n  reason: {}", entry, reason)]
    UnsupportedIFDEntry{ entry: Entry, reason: String },

    #[fail(display = "Tag ({:?}) does not support data: ({:?})", tag, data)]
    UnsupportedMultipleData { tag: AnyTag, data: Vec<u32> },

    #[fail(display = "Tag ({:?}) does not support data: ({:?})", tag, data)]
    UnsupportedData { tag: AnyTag, data: u32 },

    #[fail(display = "Calculated from width and height: {}, sum: {}", calc, sum)]
    IncorrectBufferSize { calc: usize, sum: usize },

    #[fail(display = "Incompatible Data ({:?}/{:?}", photometric_interpretation, bits_per_sample)]
    IncompatibleData { photometric_interpretation: PhotometricInterpretation, bits_per_sample: BitsPerSample },

    #[fail(display = "Tag ({:?}) requires data, but you dont got any data", tag)]
    NoData { tag: AnyTag },

    #[fail(display = "Tag ({:?}) requires only one value, but you got extra data: {:?}.", tag, data)]
    ExtraData { tag: AnyTag, data: Vec<u32> },

    #[fail(display = "Tag ({:?}) doesn't support this datatype/count : {:?}/{}", tag, datatype, count)]
    NoSupportDataType { tag: AnyTag, datatype: DataType, count: usize },
}

#[derive(Debug)]
pub struct DecodeError {
    inner: Context<DecodeErrorKind>,
}

impl Fail for DecodeError {
    fn cause(&self) -> Option<&Fail> {
        self.inner.cause()
    }

    fn backtrace(&self) -> Option<&Backtrace> {
        self.inner.backtrace()
    }
}

impl Display for DecodeError {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        Display::fmt(&self.inner, f)
    }
}

impl DecodeError {
    fn new(kind: DecodeErrorKind) -> DecodeError {
        DecodeError { inner: Context::new(kind) }
    }
    
    pub fn kind(&self) -> &DecodeErrorKind {
        self.inner.get_context()
    }
}

impl From<io::Error> for DecodeError {
    fn from(err: io::Error) -> DecodeError {
        DecodeError::new(DecodeErrorKind::IO { error: err })
    }
}

impl From<BitsPerSampleError> for DecodeError {
    fn from(err: BitsPerSampleError) -> DecodeError {
        let kind = DecodeErrorKind::UnsupportedMultipleData { 
            tag: AnyTag::BitsPerSample,
            data: err.values().iter().map(|x| *x as u32).collect::<_>()
        };

        DecodeError::new(kind)
    }
}

impl From<ImageHeaderError> for DecodeError {
    fn from(err: ImageHeaderError) -> DecodeError {
        let (photometric_interpretation, bits_per_sample) = match err {
            ImageHeaderError::IncompatibleData { photometric_interpretation, bits_per_sample } => (photometric_interpretation, bits_per_sample)
        };
            
        DecodeError::new(DecodeErrorKind::IncompatibleData { photometric_interpretation, bits_per_sample })
    }
}

impl From<DecodeErrorKind> for DecodeError {
    fn from(kind: DecodeErrorKind) -> DecodeError {
        DecodeError { inner: Context::new(kind) }
    }
}