orc_format/read/decode/
float.rs

1use crate::error::Error;
2
3/// Sealead trait to generically represent f32 and f64.
4pub trait Float: Default + Copy + private::Sealed {
5    type Bytes: AsRef<[u8]> + AsMut<[u8]> + Default;
6    fn from_le_bytes(bytes: Self::Bytes) -> Self;
7}
8
9mod private {
10    pub trait Sealed {} // Users in other crates cannot name this trait.
11    impl Sealed for f32 {}
12    impl Sealed for f64 {}
13}
14
15impl Float for f32 {
16    type Bytes = [u8; 4];
17
18    #[inline]
19    fn from_le_bytes(bytes: Self::Bytes) -> Self {
20        Self::from_le_bytes(bytes)
21    }
22}
23
24impl Float for f64 {
25    type Bytes = [u8; 8];
26
27    #[inline]
28    fn from_le_bytes(bytes: Self::Bytes) -> Self {
29        Self::from_le_bytes(bytes)
30    }
31}
32
33/// An iterator
34pub struct FloatIter<T: Float, R: std::io::Read> {
35    reader: R,
36    remaining: usize,
37    phantom: std::marker::PhantomData<T>,
38}
39
40impl<T: Float, R: std::io::Read> FloatIter<T, R> {
41    /// Returns a new [`FloatIter`]
42    #[inline]
43    pub fn new(reader: R, length: usize) -> Self {
44        Self {
45            reader,
46            remaining: length,
47            phantom: Default::default(),
48        }
49    }
50
51    /// The number of items remaining
52    #[inline]
53    pub fn len(&self) -> usize {
54        self.remaining
55    }
56
57    /// Whether the iterator is empty
58    #[must_use]
59    pub fn is_empty(&self) -> bool {
60        self.len() == 0
61    }
62
63    /// Returns its internal reader
64    pub fn into_inner(self) -> R {
65        self.reader
66    }
67}
68
69impl<T: Float, R: std::io::Read> Iterator for FloatIter<T, R> {
70    type Item = Result<T, Error>;
71
72    #[inline]
73    fn next(&mut self) -> Option<Self::Item> {
74        if self.remaining == 0 {
75            return None;
76        }
77        let mut chunk: T::Bytes = Default::default();
78        let error = self.reader.read_exact(chunk.as_mut());
79        if error.is_err() {
80            return Some(Err(Error::DecodeFloat));
81        };
82        self.remaining -= 1;
83        Some(Ok(T::from_le_bytes(chunk)))
84    }
85
86    #[inline]
87    fn size_hint(&self) -> (usize, Option<usize>) {
88        let remaining = self.len();
89        (remaining, Some(remaining))
90    }
91}
orc_format/read/decode/float.rs

orc_format/read/decode/
float.rs
