1use serde::{de::DeserializeOwned, Serialize};
2
3use crate::Envelope;
4
5#[derive(Debug, thiserror::Error)]
6pub enum CodecError {
7 #[error("postcard encode failed: {0}")]
8 PostcardEncode(postcard::Error),
9 #[error("postcard decode failed: {0}")]
10 PostcardDecode(postcard::Error),
11 #[error("bincode encode failed: {0}")]
12 BincodeEncode(bincode::Error),
13 #[error("bincode decode failed: {0}")]
14 BincodeDecode(bincode::Error),
15}
16
17pub trait Codec {
18 fn encode<T: Serialize>(&self, value: &T) -> Result<Vec<u8>, CodecError>;
19 fn decode<T: DeserializeOwned>(&self, bytes: &[u8]) -> Result<T, CodecError>;
20}
21
22#[derive(Debug, Clone, Copy, Default)]
24pub struct PostcardCodec;
25
26impl Codec for PostcardCodec {
27 fn encode<T: Serialize>(&self, value: &T) -> Result<Vec<u8>, CodecError> {
28 postcard::to_allocvec(value).map_err(CodecError::PostcardEncode)
29 }
30
31 fn decode<T: DeserializeOwned>(&self, bytes: &[u8]) -> Result<T, CodecError> {
32 postcard::from_bytes(bytes).map_err(CodecError::PostcardDecode)
33 }
34}
35
36#[derive(Debug, Clone, Copy, Default)]
38pub struct BincodeCodec;
39
40impl Codec for BincodeCodec {
41 fn encode<T: Serialize>(&self, value: &T) -> Result<Vec<u8>, CodecError> {
42 bincode::serialize(value).map_err(CodecError::BincodeEncode)
43 }
44
45 fn decode<T: DeserializeOwned>(&self, bytes: &[u8]) -> Result<T, CodecError> {
46 bincode::deserialize(bytes).map_err(CodecError::BincodeDecode)
47 }
48}
49
50pub fn encode_envelope<T: Serialize>(
51 codec: &impl Codec,
52 payload: T,
53) -> Result<Vec<u8>, CodecError> {
54 codec.encode(&Envelope::new(payload))
55}
56
57pub fn decode_envelope<T: DeserializeOwned>(
58 codec: &impl Codec,
59 bytes: &[u8],
60) -> Result<Envelope<T>, CodecError> {
61 codec.decode(bytes)
62}
63
64#[cfg(test)]
65mod tests {
66 use super::*;
67 use crate::types::{
68 BlueprintIngredientView, BlueprintView, EntityState, TickDelta, ToolRequirementView,
69 Transform, WorldClock, WorldCoord,
70 };
71
72 fn sample_tick_delta() -> TickDelta {
73 TickDelta {
74 tick: 42,
75 entities: (0..15)
76 .map(|i| EntityState {
77 id: i + 1,
78 label: String::new(),
79 transform: Transform {
80 position: WorldCoord::surface(i as f32, i as f32 * 0.5),
81 yaw: 1.25,
82 velocity: crate::types::Velocity2D { vx: 0.5, vy: -0.2 },
83 },
84 vitals: None,
85 attributes: None,
86 skills: None,
87 inside_building: None,
88 tile_id: None,
89 presentation_state: None,
90 sprite_mode: None,
91 progression_xp: None,
92 })
93 .collect(),
94 resource_nodes: Vec::new(),
95 buildings: Vec::new(),
96 doors: Vec::new(),
97 npcs: Vec::new(),
98 inventory: Vec::new(),
99 blueprints: Vec::new(),
100 world_clock: WorldClock::default(),
101 ground_drops: Vec::new(),
102 placed_containers: Vec::new(),
103 combat: None,
104 interior_map: None,
105 quest_log: vec![],
106 hired_workers: Vec::new(),
107 interactables: vec![],
108 ledger: None,
109 career: None,
110 }
111 }
112
113 #[test]
114 fn postcard_blueprint_snapshot_roundtrip() {
115 let codec = PostcardCodec;
116 let delta = TickDelta {
117 tick: 1,
118 entities: vec![],
119 resource_nodes: vec![],
120 buildings: vec![],
121 doors: vec![],
122 npcs: vec![],
123 inventory: vec![],
124 blueprints: vec![BlueprintView {
125 id: "oak_to_lumber".into(),
126 label: "Saw Planks".into(),
127 output: "lumber".into(),
128 output_qty: 1,
129 craft_ticks: 60,
130 station: Some("woodworking".into()),
131 category: Some("woodworking".into()),
132 required_tools: vec![ToolRequirementView {
133 item: "handsaw".into(),
134 consumed: false,
135 }],
136 skill: None,
137 failure_chance: 0.0,
138 worker_train_copper: 0,
139 inputs: vec![BlueprintIngredientView {
140 template_id: "oak_log".into(),
141 quantity: 2,
142 consumed: true,
143 }],
144 }],
145 world_clock: WorldClock::default(),
146 ground_drops: vec![],
147 placed_containers: vec![],
148 combat: None,
149 interior_map: None,
150 quest_log: vec![],
151 hired_workers: Vec::new(),
152 interactables: vec![],
153 ledger: None,
154 career: None,
155 };
156 let bytes = codec.encode(&Envelope::new(delta.clone())).unwrap();
157 let decoded: Envelope<TickDelta> = codec.decode(&bytes).unwrap();
158 assert_eq!(decoded.payload, delta);
159 }
160
161 #[test]
162 fn postcard_roundtrip_tick_delta() {
163 let codec = PostcardCodec;
164 let original = Envelope::new(sample_tick_delta());
165 let bytes = codec.encode(&original).expect("encode");
166 let decoded: Envelope<TickDelta> = codec.decode(&bytes).expect("decode");
167 assert_eq!(original, decoded);
168 }
169
170 #[test]
171 fn bincode_roundtrip_tick_delta() {
172 let codec = BincodeCodec;
173 let original = Envelope::new(sample_tick_delta());
174 let bytes = codec.encode(&original).expect("encode");
175 let decoded: Envelope<TickDelta> = codec.decode(&bytes).expect("decode");
176 assert_eq!(original, decoded);
177 }
178
179 #[test]
180 fn postcard_many_entities_vitals_none() {
181 let delta = TickDelta {
182 tick: 42,
183 entities: (0..15)
184 .map(|i| EntityState {
185 id: i + 1,
186 label: String::new(),
187 transform: Transform {
188 position: WorldCoord::surface(i as f32, i as f32 * 0.5),
189 yaw: 1.25,
190 velocity: crate::types::Velocity2D { vx: 0.5, vy: -0.2 },
191 },
192 vitals: None,
193 attributes: None,
194 skills: None,
195 inside_building: None,
196 tile_id: None,
197 presentation_state: None,
198 sprite_mode: None,
199 progression_xp: None,
200 })
201 .collect(),
202 resource_nodes: vec![],
203 buildings: vec![],
204 doors: vec![],
205 npcs: vec![],
206 inventory: vec![],
207 blueprints: vec![],
208 world_clock: WorldClock::default(),
209 ground_drops: vec![],
210 placed_containers: vec![],
211 combat: None,
212 interior_map: None,
213 quest_log: vec![],
214 hired_workers: Vec::new(),
215 interactables: vec![],
216 ledger: None,
217 career: None,
218 };
219 let codec = PostcardCodec;
220 let bytes = codec.encode(&Envelope::new(delta.clone())).unwrap();
221 let decoded: Envelope<TickDelta> = codec.decode(&bytes).unwrap();
222 assert_eq!(decoded.payload, delta);
223 }
224}