cbor_lite/
de.rs

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

cbor_lite/
de.rs
