cbor_no_std/
de.rs

1use alloc::collections::btree_map::BTreeMap;
2use alloc::vec::Vec;
3use value::Value;
4use bytes::bytes;
5use io::{Reader, VecReader};
6
7pub struct Deserializer<R: Reader>  {
8    pub reader: R,
9}
10
11pub fn from_bytes(bytes: Vec<u8>) -> Value
12{
13    let vec_reader = VecReader{input: bytes};
14    let mut d = Deserializer::from_vec_reader(vec_reader);
15    d.parse_value()
16}
17
18pub enum TestValue {
19    Int(u64),
20}
21
22#[inline]
23fn u8_slice_to_u16(slice: &[u8]) -> u16 {
24        ((slice[0] as u16) & 0xff) << 8 |
25        ((slice[1] as u16) & 0xff)
26}
27
28#[inline]
29fn u8_slice_to_u32(slice: &[u8]) -> u32 {
30        ((slice[0] as u32) & 0xff) << 24 |
31        ((slice[1] as u32) & 0xff) << 16 |
32        ((slice[2] as u32) & 0xff) << 8 |
33        ((slice[3] as u32) & 0xff)
34}
35
36
37impl<R> Deserializer<R> where R: Reader {
38    fn from_vec_reader(bytes: R) -> Deserializer<R> {
39        Deserializer{reader: bytes}
40    }
41
42    fn parse_value(&mut self) -> Value
43    {
44        let header_byte = self.reader.read_byte();
45        let major_type = bytes::major_type(header_byte);
46        let additional_type = bytes::additional_type(header_byte) as usize;
47
48        match major_type {
49            0b000 => self.deserialize_int(additional_type),
50            0b010 => self.deserialize_bytes(additional_type),
51            0b011 => self.deserialize_string(additional_type),
52            0b100 => self.deserialize_array(additional_type),
53            0b101 => self.deserialize_map(additional_type),
54            0b111 => self.deserialize_simple(additional_type),
55            _ => unreachable!(),
56        }
57    }
58
59    fn deserialize_int(&mut self, additional_type: usize) -> Value {
60        Value::Int(self.read_int(additional_type) as u64)
61    }
62
63    fn read_int(&mut self, additional_type: usize) -> usize {
64        match additional_type {
65            value @ 0b00000...0b10111 => value,
66            0b11000 => self.read_u8(),
67            0b11001 => self.read_u16(),
68            0b11010 => self.read_u32(),
69            _ => unreachable!(),
70        }
71    }
72
73    fn read_u8(&mut self) ->  usize{
74        self.reader.read_byte() as usize
75    }
76
77    fn read_u16(&mut self) -> usize {
78        let bytes = self.reader.read_n_bytes(2);
79        u8_slice_to_u16(bytes.as_slice()) as usize
80    }
81
82    fn read_u32(&mut self) -> usize {
83        let bytes = self.reader.read_n_bytes(4);
84        u8_slice_to_u32(bytes.as_slice()) as usize
85    }
86
87    fn deserialize_bytes(&mut self, additional_type: usize) -> Value{
88        let len = self.read_int(additional_type);
89        Value::Bytes(self.reader.read_n_bytes(len as usize))
90    }
91
92    fn deserialize_string(&mut self, len: usize) -> Value {
93        bytes::to_string(&self.reader.read_n_bytes(len as usize))
94    }
95
96    fn deserialize_array(&mut self, additional_type: usize) -> Value {
97        let len = self.read_int(additional_type);
98        let values = (0..len).map(|_| self.parse_value()).collect();
99        Value::Array(values)
100    }
101
102    fn deserialize_map(&mut self, len: usize) -> Value {
103        let mut map = BTreeMap::new();
104
105        for _ in 0..len {
106            let key = self.parse_value();
107            let value = self.parse_value();
108
109            map.insert(key, value);
110        }
111
112        Value::Map(map)
113    }
114
115    fn deserialize_simple(&mut self, value: usize) -> Value {
116        match value {
117            22 => Value::Null,
118            _ => unreachable!(),
119        }
120    }
121}
122
123#[test]
124fn deserialize_map() {
125    let mut test_map = BTreeMap::new();
126    test_map.insert("key1".into(), Value::String("value1".into()));
127    test_map.insert("key2".into(), Value::String("value2".into()));
128    let expected: Value = Value::Map(test_map);
129    assert_eq!(expected, from_bytes(vec![0xa2, 0x64, 0x6b, 0x65, 0x79, 0x31, 0x66, 0x76, 0x61, 0x6c, 0x75, 0x65, 0x31, 0x64, 0x6b, 0x65, 0x79, 0x32, 0x66, 0x76, 0x61, 0x6c, 0x75, 0x65, 0x32]));
130}
131
132#[test]
133fn deserialize_string() {
134    let expected: Value = Value::String("test".into());
135    assert_eq!(expected, from_bytes(vec![0x64, 0x74, 0x65, 0x73, 0x74]));
136}
137
138#[test]
139fn deserialize_array() {
140    let expected: Value = Value::Array(vec![Value::Int(1), Value::Int(2), Value::Int(3)]);
141    assert_eq!(expected, from_bytes(vec![0x83, 0x01, 0x02, 0x03]));
142}
143
144#[test]
145fn deserialize_bytes() {
146    let expected: Value = Value::Bytes(vec![1, 2, 3]);
147    assert_eq!(expected, from_bytes(vec![0x43, 0x01, 0x02, 0x03]));
148}
149
150#[test]
151fn deserialize_bytes_2() {
152    let mut range = (0..32).collect::<Vec<u8>>();
153    let expected: Value = Value::Bytes(range.clone());
154    let mut bytes_prefix = vec![0x58, 0x20];
155    bytes_prefix.append(&mut range);
156    assert_eq!(expected, from_bytes(bytes_prefix));
157}
158
159#[test]
160fn deserialize_u8() {
161    let expected: Value = Value::Int(1);
162    assert_eq!(expected, from_bytes(vec![0x01]));
163}
164
165#[test]
166fn deserialize_u8_2() {
167    let expected: Value = Value::Int(42);
168    assert_eq!(expected, from_bytes(vec![24, 42]));
169}
170
171#[test]
172fn deserialize_u16() {
173    let expected: Value = Value::Int(0x100);
174    assert_eq!(expected, from_bytes(vec![25, 1, 0]));
175}
176
177#[test]
178fn deserialize_u32() {
179    let expected: Value = Value::Int(0x1000000);
180    assert_eq!(expected, from_bytes(vec![26, 1, 0, 0, 0]));
181}
182
183#[test]
184fn deserialize_null() {
185    let expected: Value = Value::Null;
186    assert_eq!(expected, from_bytes(vec![246]));
187}
cbor_no_std/de.rs

cbor_no_std/
de.rs
