polars_arrow/bitmap/utils/
fmt.rs

1use std::fmt::Write;
2
3use super::is_set;
4
5/// Formats `bytes` taking into account an offset and length of the form
6pub fn fmt(
7    bytes: &[u8],
8    offset: usize,
9    length: usize,
10    f: &mut std::fmt::Formatter<'_>,
11) -> std::fmt::Result {
12    assert!(offset < 8);
13
14    write!(f, "Bitmap {{ len: {length}, offset: {offset}, bytes: [")?;
15    let mut remaining = length;
16    if remaining == 0 {
17        f.write_str("] }")?;
18        return Ok(());
19    }
20
21    let first = bytes[0];
22    let bytes = &bytes[1..];
23    let empty_before = 8usize.saturating_sub(remaining + offset);
24    f.write_str("0b")?;
25    for _ in 0..empty_before {
26        f.write_char('_')?;
27    }
28    let until = std::cmp::min(8, offset + remaining);
29    for i in offset..until {
30        if is_set(first, offset + until - 1 - i) {
31            f.write_char('1')?;
32        } else {
33            f.write_char('0')?;
34        }
35    }
36    for _ in 0..offset {
37        f.write_char('_')?;
38    }
39    remaining -= until - offset;
40
41    if remaining == 0 {
42        f.write_str("] }")?;
43        return Ok(());
44    }
45
46    let number_of_bytes = remaining / 8;
47    for byte in &bytes[..number_of_bytes] {
48        f.write_str(", ")?;
49        f.write_fmt(format_args!("{byte:#010b}"))?;
50    }
51    remaining -= number_of_bytes * 8;
52    if remaining == 0 {
53        f.write_str("] }")?;
54        return Ok(());
55    }
56
57    let last = bytes[std::cmp::min((length + offset + 7) / 8, bytes.len() - 1)];
58    let remaining = (length + offset) % 8;
59    f.write_str(", ")?;
60    f.write_str("0b")?;
61    for _ in 0..(8 - remaining) {
62        f.write_char('_')?;
63    }
64    for i in 0..remaining {
65        if is_set(last, remaining - 1 - i) {
66            f.write_char('1')?;
67        } else {
68            f.write_char('0')?;
69        }
70    }
71    f.write_str("] }")
72}
polars_arrow/bitmap/utils/fmt.rs

polars_arrow/bitmap/utils/
fmt.rs
