Parse SRATIONAL fields.
This commit is contained in:
parent
0741492615
commit
2bb71cfefb
|
@ -32,7 +32,7 @@ pub use tag::Tag;
|
|||
pub use tiff::Field;
|
||||
pub use tiff::parse_exif;
|
||||
pub use value::Value;
|
||||
pub use value::Rational;
|
||||
pub use value::{Rational, SRational};
|
||||
|
||||
#[cfg(test)]
|
||||
#[macro_use]
|
||||
|
|
49
src/value.rs
49
src/value.rs
|
@ -52,6 +52,9 @@ pub enum Value<'a> {
|
|||
SShort(Vec<i16>),
|
||||
/// Vector of 32-bit signed integers.
|
||||
SLong(Vec<i32>),
|
||||
/// Vector of signed rationals.
|
||||
/// A signed rational number is a pair of 32-bit signed integers.
|
||||
SRational(Vec<SRational>),
|
||||
/// The type is unknown to this implementation.
|
||||
/// The associated values are the type and the count, and the
|
||||
/// offset of the "Value Offset" element.
|
||||
|
@ -67,6 +70,15 @@ impl fmt::Debug for Rational {
|
|||
}
|
||||
}
|
||||
|
||||
/// A signed rational number, which is a pair of 32-bit signed integers.
|
||||
pub struct SRational { pub num: i32, pub denom: i32 }
|
||||
|
||||
impl fmt::Debug for SRational {
|
||||
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
|
||||
write!(f, "SRational({}/{})", self.num, self.denom)
|
||||
}
|
||||
}
|
||||
|
||||
type Parser<'a> = fn(&'a [u8], usize, usize) -> Value<'a>;
|
||||
|
||||
// Return the length of a single value and the parser of the type.
|
||||
|
@ -82,6 +94,7 @@ pub fn get_type_info<'a, E>(typecode: u16)
|
|||
7 => (1, parse_undefined),
|
||||
8 => (2, parse_sshort::<E>),
|
||||
9 => (4, parse_slong::<E>),
|
||||
10 => (8, parse_srational::<E>),
|
||||
_ => (0, parse_unknown),
|
||||
}
|
||||
}
|
||||
|
@ -164,6 +177,18 @@ fn parse_slong<'a, E>(data: &'a [u8], offset: usize, count: usize)
|
|||
Value::SLong(val)
|
||||
}
|
||||
|
||||
fn parse_srational<'a, E>(data: &'a [u8], offset: usize, count: usize)
|
||||
-> Value<'a> where E: Endian {
|
||||
let mut val = Vec::with_capacity(count);
|
||||
for i in 0..count {
|
||||
val.push(SRational {
|
||||
num: E::loadu32(data, offset + i * 8) as i32,
|
||||
denom: E::loadu32(data, offset + i * 8 + 4) as i32,
|
||||
});
|
||||
}
|
||||
Value::SRational(val)
|
||||
}
|
||||
|
||||
// This is a dummy function and will never be called.
|
||||
#[allow(unused_variables)]
|
||||
fn parse_unknown<'a>(data: &'a [u8], offset: usize, count: usize)
|
||||
|
@ -334,4 +359,28 @@ mod tests {
|
|||
}
|
||||
}
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn srational() {
|
||||
let sets: &[(&[u8], Vec<SRational>)] = &[
|
||||
(b"x", vec![]),
|
||||
(b"x\xa1\x02\x03\x04\x05\x06\x07\x08\
|
||||
\x09\x0a\x0b\x0c\xbd\x0e\x0f\x10",
|
||||
vec![SRational { num: -0x5efdfcfc, denom: 0x05060708 },
|
||||
SRational { num: 0x090a0b0c, denom: -0x42f1f0f0 }]),
|
||||
];
|
||||
let (unitlen, parser) = get_type_info::<BigEndian>(10);
|
||||
for &(data, ref ans) in sets {
|
||||
assert!((data.len() - 1) % unitlen == 0);
|
||||
match parser(data, 1, (data.len() - 1) / unitlen) {
|
||||
Value::SRational(v) => {
|
||||
assert_eq!(v.len(), ans.len());
|
||||
for (x, y) in v.iter().zip(ans.iter()) {
|
||||
assert!(x.num == y.num && x.denom == y.denom);
|
||||
}
|
||||
},
|
||||
v => panic!("wrong variant {:?}", v),
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
|
Loading…
Reference in New Issue