worterbuch_codec/decode/
server.rs

1use crate::{
2    error::{DecodeError, DecodeResult},
3    Handshake, Key, KeyLength, KeyValuePairs, MetaData, MetaDataLength, NumKeyValuePairs,
4    ProtocolVersion, ProtocolVersionSegment, RequestPattern, RequestPatternLength, TransactionId,
5    Value, ValueLength, ERROR_CODE_BYTES, HSHK, KEY_LENGTH_BYTES, MESSAGE_LENGTH_BYTES,
6    METADATA_LENGTH_BYTES, MULTI_WILDCARD_BYTES, NUM_KEY_VALUE_PAIRS_BYTES,
7    PROTOCOL_VERSION_SEGMENT_BYTES, REQUEST_PATTERN_LENGTH_BYTES, SEPARATOR_BYTES,
8    TRANSACTION_ID_BYTES, VALUE_LENGTH_BYTES, WILDCARD_BYTES,
9    {Ack, Err, PState, ServerMessage as SM, State, ACK, ERR, PSTA, STA},
10};
11use std::io::Read;
12
13pub fn read_server_message(mut data: impl Read) -> DecodeResult<SM> {
14    let mut buf = [0; MESSAGE_LENGTH_BYTES];
15    data.read_exact(&mut buf)?;
16    let mut buf = [0];
17    data.read_exact(&mut buf)?;
18    match buf[0] {
19        PSTA => read_pstate_message(data).map(SM::PState),
20        ACK => read_ack_message(data).map(SM::Ack),
21        STA => read_state_message(data).map(SM::State),
22        ERR => read_err_message(data).map(SM::Err),
23        HSHK => read_handshake_message(data).map(SM::Handshake),
24        _ => Err(DecodeError::UndefinedType(buf[0])),
25    }
26}
27
28fn read_pstate_message(mut data: impl Read) -> DecodeResult<PState> {
29    let mut buf = [0; TRANSACTION_ID_BYTES];
30    data.read_exact(&mut buf)?;
31    let transaction_id = TransactionId::from_be_bytes(buf);
32
33    let mut buf = [0; REQUEST_PATTERN_LENGTH_BYTES];
34    data.read_exact(&mut buf)?;
35    let request_pattern_length = RequestPatternLength::from_be_bytes(buf);
36
37    let mut buf = [0; NUM_KEY_VALUE_PAIRS_BYTES];
38    data.read_exact(&mut buf)?;
39    let num_key_val_pairs = NumKeyValuePairs::from_be_bytes(buf);
40
41    let mut key_value_lengths = Vec::new();
42
43    for _ in 0..num_key_val_pairs {
44        let mut buf = [0; KEY_LENGTH_BYTES];
45        data.read_exact(&mut buf)?;
46        let key_length = KeyLength::from_be_bytes(buf);
47
48        let mut buf = [0; VALUE_LENGTH_BYTES];
49        data.read_exact(&mut buf)?;
50        let value_length = ValueLength::from_be_bytes(buf);
51
52        key_value_lengths.push((key_length, value_length));
53    }
54
55    let mut buf = vec![0; request_pattern_length as usize];
56    data.read_exact(&mut buf)?;
57    let request_pattern = RequestPattern::from_utf8_lossy(&buf).to_string();
58
59    let mut key_value_pairs = KeyValuePairs::new();
60
61    for (key_length, value_length) in key_value_lengths {
62        let mut buf = vec![0; key_length as usize];
63        data.read_exact(&mut buf)?;
64        let key = Key::from_utf8(buf)?;
65
66        let mut buf = vec![0; value_length as usize];
67        data.read_exact(&mut buf)?;
68        let value = Value::from_utf8_lossy(&buf).to_string();
69
70        key_value_pairs.push((key, value).into());
71    }
72
73    Ok(PState {
74        transaction_id,
75        request_pattern,
76        key_value_pairs,
77    })
78}
79
80fn read_handshake_message(mut data: impl Read) -> DecodeResult<Handshake> {
81    let mut buf = [0; PROTOCOL_VERSION_SEGMENT_BYTES];
82    data.read_exact(&mut buf)?;
83    let major = ProtocolVersionSegment::from_be_bytes(buf);
84
85    let mut buf = [0; PROTOCOL_VERSION_SEGMENT_BYTES];
86    data.read_exact(&mut buf)?;
87    let minor = ProtocolVersionSegment::from_be_bytes(buf);
88
89    let protocol_version = ProtocolVersion { major, minor };
90
91    let mut buf = vec![0; SEPARATOR_BYTES];
92    data.read_exact(&mut buf)?;
93    let separator = buf[0] as char;
94
95    let mut buf = vec![0; WILDCARD_BYTES];
96    data.read_exact(&mut buf)?;
97    let wildcard = buf[0] as char;
98
99    let mut buf = vec![0; MULTI_WILDCARD_BYTES];
100    data.read_exact(&mut buf)?;
101    let multi_wildcard = buf[0] as char;
102
103    Ok(Handshake {
104        protocol_version,
105        separator,
106        wildcard,
107        multi_wildcard,
108    })
109}
110
111fn read_ack_message(mut data: impl Read) -> DecodeResult<Ack> {
112    let mut buf = [0; TRANSACTION_ID_BYTES];
113    data.read_exact(&mut buf)?;
114    let transaction_id = TransactionId::from_be_bytes(buf);
115
116    Ok(Ack { transaction_id })
117}
118
119fn read_state_message(mut data: impl Read) -> DecodeResult<State> {
120    let mut buf = [0; TRANSACTION_ID_BYTES];
121    data.read_exact(&mut buf)?;
122    let transaction_id = TransactionId::from_be_bytes(buf);
123
124    let mut buf = [0; KEY_LENGTH_BYTES];
125    data.read_exact(&mut buf)?;
126    let key_length = KeyLength::from_be_bytes(buf);
127
128    let mut buf = [0; VALUE_LENGTH_BYTES];
129    data.read_exact(&mut buf)?;
130    let value_length = ValueLength::from_be_bytes(buf);
131
132    let mut buf = vec![0; key_length as usize];
133    data.read_exact(&mut buf)?;
134    let key = Key::from_utf8_lossy(&buf).to_string();
135
136    let mut buf = vec![0; value_length as usize];
137    data.read_exact(&mut buf)?;
138    let value = Value::from_utf8_lossy(&buf).to_string();
139
140    Ok(State {
141        transaction_id,
142        key_value: (key, value).into(),
143    })
144}
145
146fn read_err_message(mut data: impl Read) -> DecodeResult<Err> {
147    let mut buf = [0; TRANSACTION_ID_BYTES];
148    data.read_exact(&mut buf)?;
149    let transaction_id = TransactionId::from_be_bytes(buf);
150
151    let mut buf = [0; ERROR_CODE_BYTES];
152    data.read_exact(&mut buf)?;
153    let error_code = buf[0];
154
155    let mut buf = [0; METADATA_LENGTH_BYTES];
156    data.read_exact(&mut buf)?;
157    let metadata_length = MetaDataLength::from_be_bytes(buf);
158
159    let mut buf = vec![0; metadata_length as usize];
160    data.read_exact(&mut buf)?;
161    let metadata = MetaData::from_utf8_lossy(&buf).to_string();
162
163    Ok(Err {
164        transaction_id,
165        error_code,
166        metadata,
167    })
168}
169
170#[cfg(test)]
171mod test {
172
173    use super::*;
174
175    #[test]
176    fn handshake_message_is_read_correctly() {
177        let data = [
178            0b00000000, 0b00000000, 0b00000000, 0b00001000, // message length
179            HSHK, 0b00000000, 0b00000001, 0b00000000, 0b00000000, b'/', b'?', b'#',
180        ];
181
182        let result = read_server_message(&data[..]).unwrap();
183
184        assert_eq!(
185            result,
186            SM::Handshake(Handshake {
187                protocol_version: ProtocolVersion { major: 1, minor: 0 },
188                separator: '/',
189                wildcard: '?',
190                multi_wildcard: '#',
191            })
192        );
193    }
194
195    #[test]
196    fn pstate_message_is_read_correctly() {
197        let data = [
198            0b00000000, 0b00000000, 0b00000000, 0b10010010, // message length
199            PSTA, 0b11111111, 0b11111111, 0b11111111, 0b11111111, 0b11111111, 0b11111111,
200            0b11111111, 0b11111111, 0b00000000, 0b00001111, 0b00000000, 0b00000000, 0b00000000,
201            0b00000010, 0b00000000, 0b00100010, 0b00000000, 0b00000000, 0b00000000, 0b00011010,
202            0b00000000, 0b00010100, 0b00000000, 0b00000000, 0b00000000, 0b00011000, b'w', b'h',
203            b'o', b'/', b'l', b'e', b't', b'/', b't', b'h', b'e', b'/', b'?', b'/', b'#', b'w',
204            b'h', b'o', b'/', b'l', b'e', b't', b'/', b't', b'h', b'e', b'/', b'c', b'h', b'i',
205            b'c', b'k', b'e', b'n', b'/', b'c', b'r', b'o', b's', b's', b'/', b't', b'h', b'e',
206            b'/', b'r', b'o', b'a', b'd', b'y', b'e', b'a', b'h', b',', b' ', b't', b'h', b'a',
207            b't', b' ', b'w', b'a', b's', b' ', b'm', b'e', b',', b' ', b'I', b' ', b'g', b'u',
208            b'e', b's', b's', b'w', b'h', b'o', b'/', b'l', b'e', b't', b'/', b't', b'h', b'e',
209            b'/', b'd', b'o', b'g', b's', b'/', b'o', b'u', b't', b'W', b'h', b'o', b'?', b' ',
210            b'W', b'h', b'o', b'?', b' ', b'W', b'h', b'o', b'?', b' ', b'W', b'h', b'o', b'?',
211            b' ', b'W', b'h', b'o', b'?',
212        ];
213
214        let result = read_server_message(&data[..]).unwrap();
215
216        assert_eq!(
217            result,
218            SM::PState(PState {
219                transaction_id: u64::MAX,
220                request_pattern: "who/let/the/?/#".to_owned(),
221                key_value_pairs: vec![
222                    (
223                        "who/let/the/chicken/cross/the/road".to_owned(),
224                        "yeah, that was me, I guess".to_owned()
225                    )
226                        .into(),
227                    (
228                        "who/let/the/dogs/out".to_owned(),
229                        "Who? Who? Who? Who? Who?".to_owned()
230                    )
231                        .into()
232                ]
233            })
234        )
235    }
236
237    #[test]
238    fn ack_message_is_read_correctly() {
239        let data = [
240            0b00000000, 0b00000000, 0b00000000, 0b00001001, // message length
241            ACK, 0b00000000, 0b00000000, 0b00000000, 0b00000000, 0b00000000, 0b00000000,
242            0b00000000, 0b00101010,
243        ];
244
245        let result = read_server_message(&data[..]).unwrap();
246
247        assert_eq!(result, SM::Ack(Ack { transaction_id: 42 }))
248    }
249
250    #[test]
251    fn state_message_is_read_correctly() {
252        let data = [
253            0b00000000, 0b00000000, 0b00000000, 0b00010101, // message length
254            STA, 0b00000000, 0b00000000, 0b00000000, 0b00000000, 0b00000000, 0b00000000,
255            0b00000000, 0b00101010, 0b00000000, 0b00000101, 0b00000000, 0b00000000, 0b00000000,
256            0b00000001, b'1', b'/', b'2', b'/', b'3', b'4',
257        ];
258
259        let result = read_server_message(&data[..]).unwrap();
260
261        assert_eq!(
262            result,
263            SM::State(State {
264                transaction_id: 42,
265                key_value: ("1/2/3", "4").into()
266            })
267        )
268    }
269
270    #[test]
271    fn err_message_is_read_correctly() {
272        let data = [
273            0b00000000, 0b00000000, 0b00000000, 0b00011111, // message length
274            ERR, 0b00000000, 0b00000000, 0b00000000, 0b00000000, 0b00000000, 0b00000000,
275            0b00000000, 0b00101010, 0b00000101, 0b00000000, 0b00000000, 0b00000000, 0b00010001,
276            b'T', b'H', b'I', b'S', b' ', b'I', b'S', b' ', b'M', b'E', b'T', b'A', b'A', b'A',
277            b'!', b'!', b'!',
278        ];
279
280        let result = read_server_message(&data[..]).unwrap();
281
282        assert_eq!(
283            result,
284            SM::Err(Err {
285                transaction_id: 42,
286                error_code: 5,
287                metadata: "THIS IS METAAA!!!".to_owned()
288            })
289        )
290    }
291}
worterbuch_codec/decode/server.rs

worterbuch_codec/decode/
server.rs
