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
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107

use container_traits::MapContainer;
use fd;
use std::io;
use subfield::{subfield_length, write_subfield_length};
use Argdata;
use ArgdataRef;
use MapIterable;
use MapIterator;
use ReadError;
use Value;

#[derive(Clone, Copy, Debug)]
pub struct Map<'d, T: 'd> {
	items: &'d T,
	length: usize,
}

/// Create an argdata value representing a map.
///
/// Both a pair of lists and a list of pairs are acceptable containers for `map()`.
/// See [`container_trait::MapContainer`](container_traits/trait.MapContainer.html).
///
/// Examples:
///
///  - `map(&[(key, val), (key, val)])`
///  - `map(&[])`
///  - `let keys = vec![...]; let values = &[...]; map(&(keys, values))`
///
pub fn map<'d, T>(items: &'d T) -> Map<'d, T>
where
	T: MapContainer,
	<T as MapContainer>::Key: Argdata<'d>,
	<T as MapContainer>::Value: Argdata<'d>,
{
	let mut length = 1;
	for i in 0..items.len() {
		let (k, v) = items.get(i).unwrap();
		length += subfield_length(k.serialized_length());
		length += subfield_length(v.serialized_length());
	}
	Map { items, length }
}

impl<'d, T> Map<'d, T>
where
	T: MapContainer,
	<T as MapContainer>::Key: Argdata<'d>,
	<T as MapContainer>::Value: Argdata<'d>,
{
	pub fn elements(&self) -> &'d T {
		self.items
	}
}

impl<'d, T> Argdata<'d> for Map<'d, T>
where
	T: MapContainer,
	<T as MapContainer>::Key: Argdata<'d>,
	<T as MapContainer>::Value: Argdata<'d>,
{
	fn read<'a>(&'a self) -> Result<Value<'a, 'd>, ReadError>
	where
		'd: 'a,
	{
		Ok(Value::Map(MapIterator::new(self, 0)))
	}

	fn serialized_length(&self) -> usize {
		self.length
	}

	fn serialize(
		&self,
		writer: &mut io::Write,
		mut fd_map: Option<&mut fd::FdMapping>,
	) -> io::Result<()> {
		writer.write_all(&[6])?;
		for i in 0..self.items.len() {
			let (k, v) = self.items.get(i).unwrap();
			write_subfield_length(k.serialized_length(), writer)?;
			k.serialize(writer, fd_map.as_mut().map(|x| *x as _))?;
			write_subfield_length(v.serialized_length(), writer)?;
			v.serialize(writer, fd_map.as_mut().map(|x| *x as _))?;
		}
		Ok(())
	}
}

impl<'d, T> MapIterable<'d> for Map<'d, T>
where
	T: MapContainer,
	<T as MapContainer>::Key: Argdata<'d>,
	<T as MapContainer>::Value: Argdata<'d>,
{
	fn iter_map_next<'a>(
		&'a self,
		cookie: &mut usize,
	) -> Option<Result<(ArgdataRef<'a, 'd>, ArgdataRef<'a, 'd>), ReadError>>
	where
		'd: 'a,
	{
		self.items.get(*cookie).map(|(k, v)| {
			*cookie += 1;
			Ok((ArgdataRef::reference(k), ArgdataRef::reference(v)))
		})
	}
}