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 }
109 }
110
111 #[test]
112 fn postcard_blueprint_snapshot_roundtrip() {
113 let codec = PostcardCodec;
114 let delta = TickDelta {
115 tick: 1,
116 entities: vec![],
117 resource_nodes: vec![],
118 buildings: vec![],
119 doors: vec![],
120 npcs: vec![],
121 inventory: vec![],
122 blueprints: vec![BlueprintView {
123 id: "oak_to_lumber".into(),
124 label: "Saw Planks".into(),
125 output: "lumber".into(),
126 output_qty: 1,
127 craft_ticks: 60,
128 station: Some("woodworking".into()),
129 category: Some("woodworking".into()),
130 required_tools: vec![ToolRequirementView {
131 item: "handsaw".into(),
132 consumed: false,
133 }],
134 skill: None,
135 failure_chance: 0.0,
136 worker_train_copper: 0,
137 inputs: vec![BlueprintIngredientView {
138 template_id: "oak_log".into(),
139 quantity: 2,
140 consumed: true,
141 }],
142 }],
143 world_clock: WorldClock::default(),
144 ground_drops: vec![],
145 placed_containers: vec![],
146 combat: None,
147 interior_map: None,
148 quest_log: vec![],
149 hired_workers: Vec::new(),
150 interactables: vec![],
151 };
152 let bytes = codec.encode(&Envelope::new(delta.clone())).unwrap();
153 let decoded: Envelope<TickDelta> = codec.decode(&bytes).unwrap();
154 assert_eq!(decoded.payload, delta);
155 }
156
157 #[test]
158 fn postcard_roundtrip_tick_delta() {
159 let codec = PostcardCodec;
160 let original = Envelope::new(sample_tick_delta());
161 let bytes = codec.encode(&original).expect("encode");
162 let decoded: Envelope<TickDelta> = codec.decode(&bytes).expect("decode");
163 assert_eq!(original, decoded);
164 }
165
166 #[test]
167 fn bincode_roundtrip_tick_delta() {
168 let codec = BincodeCodec;
169 let original = Envelope::new(sample_tick_delta());
170 let bytes = codec.encode(&original).expect("encode");
171 let decoded: Envelope<TickDelta> = codec.decode(&bytes).expect("decode");
172 assert_eq!(original, decoded);
173 }
174
175 #[test]
176 fn postcard_many_entities_vitals_none() {
177 let delta = TickDelta {
178 tick: 42,
179 entities: (0..15)
180 .map(|i| EntityState {
181 id: i + 1,
182 label: String::new(),
183 transform: Transform {
184 position: WorldCoord::surface(i as f32, i as f32 * 0.5),
185 yaw: 1.25,
186 velocity: crate::types::Velocity2D { vx: 0.5, vy: -0.2 },
187 },
188 vitals: None,
189 attributes: None,
190 skills: None,
191 inside_building: None,
192 tile_id: None,
193 presentation_state: None,
194 sprite_mode: None,
195 progression_xp: None,
196 })
197 .collect(),
198 resource_nodes: vec![],
199 buildings: vec![],
200 doors: vec![],
201 npcs: vec![],
202 inventory: vec![],
203 blueprints: vec![],
204 world_clock: WorldClock::default(),
205 ground_drops: vec![],
206 placed_containers: vec![],
207 combat: None,
208 interior_map: None,
209 quest_log: vec![],
210 hired_workers: Vec::new(),
211 interactables: vec![],
212 };
213 let codec = PostcardCodec;
214 let bytes = codec.encode(&Envelope::new(delta.clone())).unwrap();
215 let decoded: Envelope<TickDelta> = codec.decode(&bytes).unwrap();
216 assert_eq!(decoded.payload, delta);
217 }
218}