xz-skill 0.1.0

Skill plugin system — skill registration, execution, and sandbox
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132

#[cfg(feature = "wasm-runtime")]
use std::collections::HashMap;
#[cfg(feature = "wasm-runtime")]
use std::sync::RwLock;

#[cfg(feature = "wasm-runtime")]
use crate::error::SkillError;

#[cfg(feature = "wasm-runtime")]
#[derive(Debug)]
pub struct WasmConfig {
    pub memory_limit_mb: u64,
    pub default_timeout_ms: u64,
    pub max_instances: usize,
}

#[cfg(feature = "wasm-runtime")]
impl Default for WasmConfig {
    fn default() -> Self {
        Self {
            memory_limit_mb: 64,
            default_timeout_ms: 5000,
            max_instances: 10,
        }
    }
}

#[cfg(feature = "wasm-runtime")]
pub struct WasmRuntime {
    engine: wasmtime::Engine,
    module_cache: RwLock<HashMap<String, wasmtime::Module>>,
    config: WasmConfig,
}

#[cfg(feature = "wasm-runtime")]
impl std::fmt::Debug for WasmRuntime {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        f.debug_struct("WasmRuntime")
            .field("engine", &"<wasmtime::Engine>")
            .field("module_cache", &self.module_cache)
            .field("config", &self.config)
            .finish()
    }
}

#[cfg(feature = "wasm-runtime")]
impl WasmRuntime {
    pub fn new(config: WasmConfig) -> Result<Self, SkillError> {
        let mut engine_config = wasmtime::Config::default();
        engine_config
            .consume_fuel(true)
            .epoch_interruption(true);

        let engine = wasmtime::Engine::new(&engine_config)
            .map_err(|e| SkillError::Wasm(e.to_string()))?;

        Ok(Self {
            engine,
            module_cache: RwLock::new(HashMap::new()),
            config,
        })
    }

    /// Compile and execute a WASM module.
    pub async fn execute(
        &self,
        module_bytes: &[u8],
        tool: &str,
        _args: serde_json::Value,
    ) -> Result<serde_json::Value, SkillError> {
        let cache_key = format!("{}:{}", tool, hex::encode(&module_bytes[..module_bytes.len().min(32)]));

        let module = {
            let cache = self.module_cache.read().unwrap();
            cache.get(&cache_key).cloned()
        };

        let module = match module {
            Some(m) => m,
            None => {
                let m = wasmtime::Module::new(&self.engine, module_bytes)
                    .map_err(|e| SkillError::Wasm(e.to_string()))?;
                self.module_cache
                    .write()
                    .unwrap()
                    .insert(cache_key.clone(), m.clone());
                m
            }
        };

        let mut store = wasmtime::Store::new(&self.engine, ());
        store.set_fuel(1_000_000)
            .map_err(|e| SkillError::Wasm(e.to_string()))?;

        let linker = wasmtime::Linker::new(&self.engine);
        let instance = linker
            .instantiate_async(&mut store, &module)
            .await
            .map_err(|e| SkillError::Wasm(e.to_string()))?;

        let result = if let Ok(func) = instance.get_typed_func::<(), i32>(&mut store, tool) {
            let ret = func.call_async(&mut store, ())
                .await
                .map_err(|e| SkillError::Wasm(e.to_string()))?;
            serde_json::json!({"exit_code": ret})
        } else if let Ok(func) = instance.get_typed_func::<(), ()>(&mut store, tool) {
            func.call_async(&mut store, ())
                .await
                .map_err(|e| SkillError::Wasm(e.to_string()))?;
            serde_json::json!({"status": "ok"})
        } else if let Ok(func) = instance.get_typed_func::<(), ()>(&mut store, "_start") {
            func.call_async(&mut store, ())
                .await
                .map_err(|e| SkillError::Wasm(e.to_string()))?;
            serde_json::json!({"status": "started"})
        } else {
            return Err(SkillError::Wasm(format!(
                "Function '{}' not found in WASM module", tool
            )));
        };

        Ok(result)
    }
}

// Simple hex encoding helper for cache key
#[cfg(feature = "wasm-runtime")]
mod hex {
    pub fn encode(bytes: &[u8]) -> String {
        bytes.iter().map(|b| format!("{:02x}", b)).collect()
    }
}