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

use crate::varint;
use crate::{label, tags};
use desert::{ToBytesLE,FromBytesLE};
use failure::Error;

#[test]
fn peer_node() -> Result<(), Error> {
    let id = 1831881213;
    let lon = 12.253938100000001;
    let lat = 54.09006660000001;
    let tags = vec![("name", "Neu Broderstorf"), ("aerialway", "cable_car")];
    let node = Point::from_tags(id, (lon, lat), &tags)?;

    let bytes = node.to_bytes_le().unwrap();
    assert_eq!(
        hex::encode(&bytes),
        "0100fd93c1e906211044413a5c5842103d4e65752042726f64657273746f726600"
    );
    assert_eq!(
        Point::from_bytes_le(&bytes)?,
        (bytes.len(),node)
    );
    Ok(())
}

#[derive(Debug,Clone,PartialEq)]
pub struct Point {
    pub id: u64,
    pub point: (f32, f32),
    pub feature_type: u64,
    pub labels: Vec<u8>,
}

impl Point {
    pub fn from_tags(id: u64, point: (f32, f32), tags: &[(&str, &str)]) -> Result<Point, Error> {
        let (feature_type, labels) = tags::parse(tags)?;
        Ok(Point {
            id,
            point,
            feature_type,
            labels,
        })
    }
    pub fn new(id: u64, point: (f32, f32), feature_type: u64, labels: &[u8]) -> Point {
        Point {
            id,
            point,
            feature_type,
            labels: labels.to_vec(),
        }
    }
}

impl ToBytesLE for Point {
    fn to_bytes_le(&self) -> Result<Vec<u8>, Error> {
        let ft_length = varint::length(self.feature_type);
        let id_length = varint::length(self.id);
        let mut buf = vec![0u8; 1 + ft_length + id_length + 2 * 4 + self.labels.len()];
        buf[0] = 0x01;

        let mut offset = 1;
        offset += varint::encode(self.feature_type, &mut buf[offset..])?;
        offset += varint::encode(self.id, &mut buf[offset..])?;

        offset += self.point.0.write_bytes_le(&mut buf[offset..])?;
        offset += self.point.1.write_bytes_le(&mut buf[offset..])?;
        buf[offset..].copy_from_slice(&self.labels);
        Ok(buf)
    }
}

impl FromBytesLE for Point {
    fn from_bytes_le(buf: &[u8]) -> Result<(usize,Self), Error> {
        if buf[0] != 0x01 {
            failure::bail!["parsing node failed. expected 0x01, received 0x{:02x}", buf[0]];
        }
        let mut offset = 1;
        let (s,feature_type) = varint::decode(&buf[offset..])?;
        offset += s;
        let (s,id) = varint::decode(&buf[offset..])?;
        offset += s;
        let (s,lon) = f32::from_bytes_le(&buf[offset..])?;
        offset += s;
        let (s,lat) = f32::from_bytes_le(&buf[offset..])?;
        offset += s;
        let s = label::scan(&buf[offset..])?;
        let labels = buf[offset..offset+s].to_vec();
        offset += s;
        Ok((offset, Self { id, point: (lon,lat), feature_type, labels }))
    }
}