fluvio_smartengine/engine/wasmtime/
look_back.rs

1use std::convert::TryFrom;
2use std::fmt::Debug;
3
4use anyhow::{Result, Ok};
5use fluvio_smartmodule::dataplane::smartmodule::{
6    SmartModuleLookbackOutput, SmartModuleLookbackErrorStatus, SmartModuleInput,
7};
8use wasmtime::{AsContextMut, TypedFunc};
9
10use super::instance::SmartModuleInstanceContext;
11
12const LOOKBACK_FN_NAME: &str = "look_back";
13type LookBackFn = TypedFunc<(i32, i32, u32), i32>;
14
15pub(crate) struct SmartModuleLookBack(LookBackFn);
16
17impl Debug for SmartModuleLookBack {
18    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
19        write!(f, "LookBackFn")
20    }
21}
22
23impl SmartModuleLookBack {
24    pub fn try_instantiate(
25        ctx: &SmartModuleInstanceContext,
26        store: &mut impl AsContextMut,
27    ) -> Result<Option<Self>> {
28        match ctx.get_wasm_func(store, LOOKBACK_FN_NAME) {
29            // check type signature
30            Some(func) => func
31                .typed(&mut *store)
32                .or_else(|_| func.typed(store))
33                .map(Self)
34                .map(Some),
35            None => Ok(None),
36        }
37    }
38
39    pub(crate) fn call(
40        &mut self,
41        input: SmartModuleInput,
42        ctx: &mut SmartModuleInstanceContext,
43        store: &mut impl AsContextMut,
44    ) -> Result<()> {
45        let slice = ctx.write_input(&input, &mut *store)?;
46        let output = self.0.call(&mut *store, slice)?;
47
48        if output < 0 {
49            let internal_error = SmartModuleLookbackErrorStatus::try_from(output)
50                .unwrap_or(SmartModuleLookbackErrorStatus::UnknownError);
51
52            match internal_error {
53                SmartModuleLookbackErrorStatus::PropagatedError => {
54                    let output: SmartModuleLookbackOutput = ctx.read_output(store)?;
55                    Err(output.error.into())
56                }
57                _ => Err(internal_error.into()),
58            }
59        } else {
60            Ok(())
61        }
62    }
63}
fluvio_smartengine/engine/wasmtime/look_back.rs

fluvio_smartengine/engine/wasmtime/
look_back.rs
