implement filter transform

xxchan · xxchan · Feb 26, 2023 · Feb 26, 2023 · Apr 9, 2023 · Feb 26, 2023
commit 7a300061f072df1061489c09604f646b554f21a7
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/crates/fluvio-smartengine/Cargo.toml b/crates/fluvio-smartengine/Cargo.toml
@@ -28,7 +28,8 @@ wasmtime-wasi = { version = "7.0.0", optional = true }
 serde = { version = "1", features = ['derive'] }
 serde_json = { version = "1.0", optional = true }
 serde_yaml = { version = "0.9", default-features = false, optional = true }
-wasmedge-sdk = { version = "0.7", optional = true }
+# Use the Clone trait
+wasmedge-sdk = { git = "https://github.com/WasmEdge/WasmEdge", rev = "fe5fe2c", optional = true }
 
 cfg-if = "1.0.0"
 derive_builder = { workspace = true }

diff --git a/crates/fluvio-smartengine/src/config.rs b/crates/fluvio-smartengine/src/config.rs
@@ -1,5 +1,5 @@
 use derive_builder::Builder;
-use fluvio_smartmodule::dataplane::smartmodule::{SmartModuleExtraParams};
+use fluvio_smartmodule::dataplane::smartmodule::SmartModuleExtraParams;
 
 const DEFAULT_SMARTENGINE_VERSION: i16 = 17;
 

diff --git a/crates/fluvio-smartengine/src/wasmedge_engine/init.rs b/crates/fluvio-smartengine/src/wasmedge_engine/init.rs
@@ -0,0 +1 @@
+pub struct SmartModuleInit {}
diff --git a/crates/fluvio-smartengine/src/wasmedge_engine/instance.rs b/crates/fluvio-smartengine/src/wasmedge_engine/instance.rs
@@ -0,0 +1,223 @@
+use fluvio_protocol::{Decoder, Encoder};
+use tracing::debug;
+use wasmedge_sdk::error::HostFuncError;
+use wasmedge_sdk::types::Val;
+use wasmedge_sdk::{
+    host_function, Caller, CallingFrame, Engine, Executor, Func, ImportObjectBuilder, Instance,
+    Memory, Module, Store, WasmValue,
+};
+
+use super::init::SmartModuleInit;
+use crate::error::EngineError;
+use crate::metrics::SmartModuleChainMetrics;
+use crate::wasmedge_engine::memory;
+use crate::{config::*, WasmSlice};
+use anyhow::Result;
+use fluvio_smartmodule::dataplane::smartmodule::{SmartModuleInput, SmartModuleOutput};
+use std::any::Any;
+use std::fmt::{self, Debug};
+use std::sync::{Arc, Mutex};
+
+pub struct SmartModuleInstance {
+    ctx: SmartModuleInstanceContext,
+    transform: Box<dyn DowncastableTransform>,
+    // init: Option<SmartModuleInit>,
+}
+
+impl SmartModuleInstance {
+    #[cfg(test)]
+    #[allow(clippy::borrowed_box)]
+    pub(crate) fn transform(&self) -> &Box<dyn DowncastableTransform> {
+        &self.transform
+    }
+
+    #[cfg(test)]
+    pub(crate) fn get_init(&self) -> &Option<SmartModuleInit> {
+        &None
+    }
+
+    pub(crate) fn new(
+        ctx: SmartModuleInstanceContext,
+        // init: Option<SmartModuleInit>,
+        transform: Box<dyn DowncastableTransform>,
+    ) -> Self {
+        Self {
+            ctx,
+            // init,
+            transform,
+        }
+    }
+
+    pub(crate) fn process(
+        &mut self,
+        input: SmartModuleInput,
+        engine: &mut Executor,
+    ) -> Result<SmartModuleOutput> {
+        self.transform.process(input, &mut self.ctx, engine)
+    }
+}
+
+pub struct SmartModuleInstanceContext {
+    instance: Instance,
+    records_cb: Arc<RecordsCallBack>,
+    // params: SmartModuleExtraParams,
+    version: i16,
+}
+
+impl SmartModuleInstanceContext {
+    /// get wasm function from instance
+    pub(crate) fn get_wasm_func(&self, name: &str) -> Option<Func> {
+        self.instance.func(name)
+    }
+
+    /// instantiate new module instance that contain context
+    pub(crate) fn instantiate(
+        store: &mut Store,
+        executor: &mut Executor,
+        module: Module,
+        // params: SmartModuleExtraParams,
+        version: i16,
+    ) -> Result<Self, EngineError> {
+        debug!("creating WasmModuleInstance");
+        let cb = Arc::new(RecordsCallBack::new());
+        let records_cb = cb.clone();
+
+        // See crates/fluvio-smartmodule-derive/src/generator/transform.rs for copy_records
+        let copy_records_fn = move |caller: CallingFrame,
+                                    inputs: Vec<WasmValue>|
+              -> Result<Vec<WasmValue>, HostFuncError> {
+            assert_eq!(inputs.len(), 2);
+            let ptr = inputs[0].to_i32() as u32;
+            let len = inputs[1].to_i32() as u32;
+
+            debug!(len, "callback from wasm filter");
+            let caller = Caller::new(caller);
+            let memory = caller.memory(0).unwrap();
+
+            let records = RecordsMemory { ptr, len, memory };
+            cb.set(records);
+            Ok(vec![])
+        };
+
+        let import = ImportObjectBuilder::new()
+            .with_func::<(i32, i32), ()>("copy_records", copy_records_fn)
+            .map_err(|e| EngineError::Instantiate(e.into()))?
+            .build("env")
+            .map_err(|e| EngineError::Instantiate(e.into()))?;
+
+        debug!("instantiating WASMtime");
+        store
+            .register_import_module(executor, &import)
+            .map_err(|e| EngineError::Instantiate(e.into()))?;
+        let instance = store
+            .register_active_module(executor, &module)
+            .map_err(|e| EngineError::Instantiate(e.into()))?;
+
+        // This is a hack to avoid them being dropped
+        // FIXME: manage their lifetimes
+        std::mem::forget(import);
+        std::mem::forget(module);
+
+        Ok(Self {
+            instance,
+            records_cb,
+            // params,
+            version,
+        })
+    }
+
+    pub(crate) fn write_input<E: Encoder>(
+        &mut self,
+        input: &E,
+        engine: &mut impl Engine,
+    ) -> Result<Vec<WasmValue>> {
+        self.records_cb.clear();
+        let mut input_data = Vec::new();
+        input.encode(&mut input_data, self.version)?;
+        debug!(
+            len = input_data.len(),
+            version = self.version,
+            "input encoded"
+        );
+        let array_ptr = memory::copy_memory_to_instance(engine, &self.instance, &input_data)?;
+        let length = input_data.len();
+        Ok(vec![
+            Val::I32(array_ptr as i32).into(),
+            Val::I32(length as i32).into(),
+            Val::I32(self.version as i32).into(),
+        ])
+    }
+
+    pub(crate) fn read_output<D: Decoder + Default>(&mut self) -> Result<D> {
+        let bytes = self
+            .records_cb
+            .get()
+            .and_then(|m| m.copy_memory_from().ok())
+            .unwrap_or_default();
+        let mut output = D::default();
+        output.decode(&mut std::io::Cursor::new(bytes), self.version)?;
+        Ok(output)
+    }
+}
+
+// TODO: revise later to see whether Clone is necessary
+#[derive(Clone)]
+pub struct RecordsMemory {
+    ptr: u32,
+    len: u32,
+    memory: Memory,
+}
+
+impl RecordsMemory {
+    fn copy_memory_from(&self) -> Result<Vec<u8>> {
+        let mut bytes = self.memory.read(self.ptr, self.len)?;
+        Ok(bytes)
+    }
+}
+
+pub struct RecordsCallBack(Mutex<Option<RecordsMemory>>);
+
+impl RecordsCallBack {
+    pub(crate) fn new() -> Self {
+        Self(Mutex::new(None))
+    }
+
+    pub(crate) fn set(&self, records: RecordsMemory) {
+        let mut write_inner = self.0.lock().unwrap();
+        write_inner.replace(records);
+    }
+
+    pub(crate) fn clear(&self) {
+        let mut write_inner = self.0.lock().unwrap();
+        write_inner.take();
+    }
+
+    pub(crate) fn get(&self) -> Option<RecordsMemory> {
+        let reader = self.0.lock().unwrap();
+        reader.clone()
+    }
+}
+
+pub(crate) trait SmartModuleTransform: Send + Sync {
+    /// transform records
+    fn process(
+        &mut self,
+        input: SmartModuleInput,
+        ctx: &mut SmartModuleInstanceContext,
+        engine: &mut Executor,
+    ) -> Result<SmartModuleOutput>;
+
+    /// return name of transform, this is used for identifying transform and debugging
+    fn name(&self) -> &str;
+}
+
+// In order turn to any, need following magic trick
+pub(crate) trait DowncastableTransform: SmartModuleTransform + Any {
+    fn as_any(&self) -> &dyn Any;
+}
+
+impl<T: SmartModuleTransform + Any> DowncastableTransform for T {
+    fn as_any(&self) -> &dyn Any {
+        self
+    }
+}
diff --git a/crates/fluvio-smartengine/src/wasmedge_engine/memory.rs b/crates/fluvio-smartengine/src/wasmedge_engine/memory.rs
@@ -0,0 +1,43 @@
+use anyhow::{anyhow, Error, Result};
+use wasmedge_sdk::{types::Val, Engine, Instance};
+
+const ALLOC_FN: &str = "alloc";
+const MEMORY: &str = "memory";
+// const ARRAY_SUM_FN: &str = "array_sum";
+// const UPPER_FN: &str = "upper";
+// const DEALLOC_FN: &str = "dealloc";
+
+/// Copy a byte array into an instance's linear memory
+/// and return the offset relative to the module's memory.
+pub(crate) fn copy_memory_to_instance(
+    engine: &mut impl Engine,
+    instance: &Instance,
+    bytes: &[u8],
+) -> Result<i32, Error> {
+    // Get the "memory" export of the module.
+    // If the module does not export it, just panic,
+    // since we are not going to be able to copy the data.
+    let mut memory = instance
+        .memory(MEMORY)
+        .ok_or_else(|| anyhow!("Missing memory"))?;
+
+    // The module is not using any bindgen libraries,
+    // so it should export its own alloc function.
+    //
+    // Get the guest's exported alloc function, and call it with the
+    // length of the byte array we are trying to copy.
+    // The result is an offset relative to the module's linear memory,
+    // which is used to copy the bytes into the module's memory.
+    // Then, return the offset.
+    let alloc = instance
+        .func(ALLOC_FN)
+        .ok_or_else(|| anyhow!("missing alloc"))?;
+
+    let alloc_result = alloc.call(engine, [Val::I32(bytes.len() as i32).into()])?;
+
+    let guest_ptr_offset = alloc_result[0].to_i32();
+
+    memory.write(bytes, guest_ptr_offset as u32)?;
+
+    Ok(guest_ptr_offset)
+}