Merge branch 'master' into master

src/decoder/ifd.rs

@@ -4,7 +4,7 @@ use std::io::{self, Read, Seek};
 use std::collections::{HashMap};
 
 use super::stream::{ByteOrder, SmartReader, EndianReader};
-use ::{TiffError, TiffResult};
+use ::{TiffError, TiffFormatError, TiffUnsupportedError, TiffResult};
 
 use self::Value::{Unsigned, List, Rational, Ascii};
 
@@ -86,7 +86,7 @@ pub enum Type {
 
 
 #[allow(unused_qualifications)]
-#[derive(Debug)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub enum Value {
     //Signed(i32),
     Unsigned(u32),
@@ -99,9 +99,7 @@ impl Value {
     pub fn into_u32(self) -> TiffResult<u32> {
         match self {
             Unsigned(val) => Ok(val),
-            val => Err(TiffError::FormatError(format!(
-                "Expected unsigned integer, {:?} found.", val
-            )))
+            val => Err(TiffError::FormatError(TiffFormatError::UnsignedIntegerExpected(val))),
         }
     }
     pub fn into_u32_vec(self) -> TiffResult<Vec<u32>> {
@@ -202,7 +200,7 @@ impl Entry {
                 let string = try!(decoder.read_string(n as usize));
                 Ok(Ascii(string))
             }
-            _ => Err(TiffError::UnsupportedError("Unsupported data type.".to_string()))
+            _ => Err(TiffError::UnsupportedError(TiffUnsupportedError::UnsupportedDataType))
         }
     }
 }

src/decoder/mod.rs

@@ -4,7 +4,7 @@ use num_traits::{FromPrimitive, Num};
 use std::collections::HashMap;
 use std::string::FromUtf8Error;
 
-use ::{ColorType, TiffError, TiffResult};
+use ::{ColorType, TiffError, TiffFormatError, TiffUnsupportedError, TiffResult};
 
 use self::ifd::Directory;
 
@@ -36,8 +36,8 @@ enum DecodingBuffer<'a> {
     U16(&'a mut [u16])
 }
 
-#[derive(Clone, Copy, Debug, PartialEq, FromPrimitive)]
-enum PhotometricInterpretation {
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, FromPrimitive)]
+pub enum PhotometricInterpretation {
     WhiteIsZero = 0,
     BlackIsZero = 1,
     RGB = 2,
@@ -48,8 +48,8 @@ enum PhotometricInterpretation {
     CIELab = 8,
 }
 
-#[derive(Clone, Copy, Debug, FromPrimitive)]
-enum CompressionMethod {
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, FromPrimitive)]
+pub enum CompressionMethod {
     None = 1,
     Huffman = 2,
     Fax3 = 3,
@@ -59,13 +59,13 @@ enum CompressionMethod {
     PackBits = 0x8005
 }
 
-#[derive(Clone, Copy, Debug, FromPrimitive)]
-enum PlanarConfiguration {
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, FromPrimitive)]
+pub enum PlanarConfiguration {
     Chunky = 1,
     Planar = 2
 }
 
-#[derive(Clone, Copy, Debug, FromPrimitive)]
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, FromPrimitive)]
 enum Predictor {
     None = 1,
     Horizontal = 2
@@ -126,9 +126,7 @@ fn rev_hpredict(image: DecodingResult, size: (u32, u32), color_type: ColorType)
         ColorType::Gray(8) | ColorType::Gray(16) => 1,
         ColorType::RGB(8) | ColorType::RGB(16) => 3,
         ColorType::RGBA(8) | ColorType::RGBA(16) | ColorType::CMYK(8) => 4,
-        _ => return Err(TiffError::UnsupportedError(format!(
-            "Horizontal predictor for {:?} is unsupported.", color_type
-        )))
+        _ => return Err(TiffError::UnsupportedError(TiffUnsupportedError::HorizontalPredictor(color_type)))
     };
     Ok(match image {
         DecodingResult::U8(buf) => {
@@ -172,9 +170,8 @@ impl<R: Read + Seek> Decoder<R> {
             PhotometricInterpretation::BlackIsZero | PhotometricInterpretation::WhiteIsZero
                                            if self.bits_per_sample.len() == 1 => Ok(ColorType::Gray(self.bits_per_sample[0])),
 
-            _ => Err(TiffError::UnsupportedError(format!(
-                "{:?} with {:?} bits per sample is unsupported", self.photometric_interpretation, self.bits_per_sample
-            ))) // TODO: this is bad we should not fail at this point}
+            // TODO: this is bad we should not fail at this point
+            _ => Err(TiffError::UnsupportedError(TiffUnsupportedError::InterpretationWithBits(self.photometric_interpretation, self.bits_per_sample.clone())))
         }
     }
 
@@ -188,12 +185,10 @@ impl<R: Read + Seek> Decoder<R> {
             b"MM" => {
                 self.byte_order = ByteOrder::BigEndian;
                 self.reader.byte_order = ByteOrder::BigEndian;  },
-            _ => return Err(TiffError::FormatError(
-                "TIFF signature not found.".to_string()
-            ))
+            _ => return Err(TiffError::FormatError(TiffFormatError::TiffSignatureNotFound))
         }
         if try!(self.read_short()) != 42 {
-            return Err(TiffError::FormatError("TIFF signature invalid.".to_string()))
+            return Err(TiffError::FormatError(TiffFormatError::TiffSignatureInvalid))
         }
         self.next_ifd = match try!(self.read_long()) {
             0 => None,
@@ -219,18 +214,14 @@ impl<R: Read + Seek> Decoder<R> {
             try!(self.get_tag_u32(ifd::Tag::PhotometricInterpretation))
         ) {
             Some(val) => val,
-            None => return Err(TiffError::UnsupportedError(
-                "The image is using an unknown photometric interpretation.".to_string()
-            ))
+            None => return Err(TiffError::UnsupportedError(TiffUnsupportedError::UnknownInterpretation))
         };
         if let Some(val) = try!(self.find_tag_u32(ifd::Tag::Compression)) {
             match FromPrimitive::from_u32(val) {
                 Some(method) =>  {
                     self.compression_method = method
                 },
-                None => return Err(TiffError::UnsupportedError(
-                    "Unknown compression method.".to_string()
-                ))
+                None => return Err(TiffError::UnsupportedError(TiffUnsupportedError::UnknownCompressionMethod))
             }
         }
         if let Some(val) = try!(self.find_tag_u32(ifd::Tag::SamplesPerPixel)) {
@@ -248,9 +239,7 @@ impl<R: Read + Seek> Decoder<R> {
                 }
 
             }
-            _ => return Err(TiffError::UnsupportedError(
-                format!("{} samples per pixel is supported.", self.samples)
-            ))
+            _ => return Err(TiffError::UnsupportedError(TiffUnsupportedError::UnsupportedSampleDepth(self.samples)))
         }
         Ok(self)
     }
@@ -334,9 +323,7 @@ impl<R: Read + Seek> Decoder<R> {
     fn read_ifd(&mut self) -> TiffResult<Directory> {
         let mut dir: Directory = HashMap::new();
         match self.next_ifd {
-            None => return Err(TiffError::FormatError(
-                "Image file directory not found.".to_string())
-            ),
+            None => return Err(TiffError::FormatError(TiffFormatError::ImageFileDirectoryNotFound)),
             Some(offset) => try!(self.goto_offset(offset))
         }
         for _ in 0..try!(self.read_short()) {
@@ -390,9 +377,7 @@ impl<R: Read + Seek> Decoder<R> {
     pub fn get_tag(&mut self, tag: ifd::Tag) -> TiffResult<ifd::Value> {
         match try!(self.find_tag(tag)) {
             Some(val) => Ok(val),
-            None => Err(TiffError::FormatError(format!(
-                "Required tag `{:?}` not found.", tag
-            )))
+            None => Err(TiffError::FormatError(TiffFormatError::RequiredTagNotFound(tag))),
         }
     }
 
@@ -425,13 +410,11 @@ impl<R: Read + Seek> Decoder<R> {
                 let (bytes, reader) = try!(PackBitsReader::new(&mut self.reader, order, length as usize));
                 (bytes, Box::new(reader))
             },
-            method => return Err(TiffError::UnsupportedError(format!(
-                "Compression method {:?} is unsupported", method
-            )))
+            method => return Err(TiffError::UnsupportedError(TiffUnsupportedError::UnsupportedCompressionMethod(method)))
         };
         Ok(match (color_type, buffer) {
             (ColorType:: RGB(8), DecodingBuffer::U8(ref mut buffer)) |
-            (ColorType::RGBA(8), DecodingBuffer::U8(ref mut buffer)) | 
+            (ColorType::RGBA(8), DecodingBuffer::U8(ref mut buffer)) |
             (ColorType::CMYK(8), DecodingBuffer::U8(ref mut buffer)) => {
                 try!(reader.read(&mut buffer[..bytes]))
             }
@@ -460,9 +443,7 @@ impl<R: Read + Seek> Decoder<R> {
                 }
                 bytes
             }
-            (type_, _) => return Err(TiffError::UnsupportedError(format!(
-                "Color type {:?} is unsupported", type_
-            )))
+            (type_, _) => return Err(TiffError::UnsupportedError(TiffUnsupportedError::UnsupportedColorType(type_))),
         })
     }
 
@@ -480,18 +461,12 @@ impl<R: Read + Seek> Decoder<R> {
         let mut result = match self.bits_per_sample.iter().cloned().max().unwrap_or(8) {
             n if n <= 8 => DecodingResult::U8(Vec::with_capacity(buffer_size)),
             n if n <= 16 => DecodingResult::U16(Vec::with_capacity(buffer_size)),
-            n => return Err(
-                TiffError::UnsupportedError(
-                    format!("{} bits per channel not supported", n)
-                )
-            )
+            n => return Err(TiffError::UnsupportedError(TiffUnsupportedError::UnsupportedBitsPerChannel(n))),
         };
         if let Ok(config) = self.get_tag_u32(ifd::Tag::PlanarConfiguration) {
             match FromPrimitive::from_u32(config) {
                 Some(PlanarConfiguration::Chunky) => {},
-                config => return Err(TiffError::UnsupportedError(
-                    format!("Unsupported planar configuration “{:?}”.", config)
-                ))
+                config => return Err(TiffError::UnsupportedError(TiffUnsupportedError::UnsupportedPlanarConfig(config)))
             }
         }
         // Safe since the uninitialized values are never read.
@@ -544,9 +519,7 @@ impl<R: Read + Seek> Decoder<R> {
                         try!(self.colortype())
                     ))
                 },
-                None => return Err(TiffError::FormatError(
-                    format!("Unknown predictor “{}” encountered", predictor)
-                ))
+                None => return Err(TiffError::FormatError(TiffFormatError::UnknownPredictor(predictor))),
             }
         }
         Ok(result)

src/error.rs

@@ -3,19 +3,81 @@ use std::fmt;
 use std::io;
 use std::string;
 
+use decoder::ifd::{Tag, Value};
+use decoder::{PhotometricInterpretation, CompressionMethod, PlanarConfiguration};
+use ColorType;
+
 /// Tiff error kinds.
 #[derive(Debug)]
 pub enum TiffError {
     /// The Image is not formatted properly
-    FormatError(String),
+    FormatError(TiffFormatError),
 
     /// The Decoder does not support this image format
-    UnsupportedError(String),
+    UnsupportedError(TiffUnsupportedError),
 
     /// An I/O Error occurred while decoding the image
     IoError(io::Error),
 }
 
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub enum TiffFormatError {
+    TiffSignatureNotFound,
+    TiffSignatureInvalid,
+    ImageFileDirectoryNotFound,
+    RequiredTagNotFound(Tag),
+    UnknownPredictor(u32),
+    UnsignedIntegerExpected(Value),
+}
+
+impl fmt::Display for TiffFormatError {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+        use self::TiffFormatError::*;
+        match *self {
+            TiffSignatureNotFound => write!(fmt, "TIFF signature not found."),
+            TiffSignatureInvalid => write!(fmt, "TIFF signature invalid."),
+            ImageFileDirectoryNotFound => write!(fmt, "Image file directory not found."),
+            RequiredTagNotFound(ref tag) => write!(fmt, "Required tag `{:?}` not found.", tag),
+            UnknownPredictor(ref predictor) => write!(fmt, "Unknown predictor “{}” encountered", predictor),
+            UnsignedIntegerExpected(ref val) => write!(fmt,  "Expected unsigned integer, {:?} found.", val),
+        }
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub enum TiffUnsupportedError {
+    HorizontalPredictor(ColorType),
+    InterpretationWithBits(PhotometricInterpretation, Vec<u8>),
+    UnknownInterpretation,
+    UnknownCompressionMethod,
+    UnsupportedCompressionMethod(CompressionMethod),
+    UnsupportedSampleDepth(u8),
+    UnsupportedColorType(ColorType),
+    UnsupportedBitsPerChannel(u8),
+    UnsupportedPlanarConfig(Option<PlanarConfiguration>),
+    UnsupportedDataType,
+}
+
+impl fmt::Display for TiffUnsupportedError {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+        use self::TiffUnsupportedError::*;
+        match *self {
+            HorizontalPredictor(color_type) => write!(fmt, "Horizontal predictor for {:?} is unsupported.", color_type),
+            InterpretationWithBits(ref photometric_interpretation, ref bits_per_sample) => {
+                write!(fmt, "{:?} with {:?} bits per sample is unsupported", photometric_interpretation, bits_per_sample)
+            },
+            UnknownInterpretation => write!(fmt, "The image is using an unknown photometric interpretation."),
+            UnknownCompressionMethod => write!(fmt, "Unknown compression method."),
+            UnsupportedCompressionMethod(method) => write!(fmt, "Compression method {:?} is unsupported", method),
+            UnsupportedSampleDepth(samples) => write!(fmt, "{} samples per pixel is supported.", samples),
+            UnsupportedColorType(color_type) => write!(fmt, "Color type {:?} is unsupported", color_type),
+            UnsupportedBitsPerChannel(bits) => write!(fmt, "{} bits per channel not supported", bits),
+            UnsupportedPlanarConfig(config) => write!(fmt, "Unsupported planar configuration “{:?}”.", config),
+            UnsupportedDataType => write!(fmt, "Unsupported data type."),
+        }
+    }
+}
+
 impl fmt::Display for TiffError {
     fn fmt(&self, fmt: &mut fmt::Formatter) -> Result<(), fmt::Error> {
         match *self {

src/lib.rs

@@ -14,7 +14,7 @@ extern crate num_traits;
 pub mod decoder;
 mod error;
 
-pub use self::error::{TiffError, TiffResult};
+pub use self::error::{TiffError, TiffFormatError, TiffUnsupportedError, TiffResult};
 
 /// An enumeration over supported color types and their bit depths
 #[derive(Copy, PartialEq, Eq, Debug, Clone, Hash)]