feat!: decouple wasmer from Marine, replace it with generic backend interface (#219)

crates/wasm-backend-traits/src/module.rs

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2023 Fluence Labs Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+use crate::ModuleCreationResult;
+use crate::InstantiationResult;
+use crate::WasmBackend;
+
+/// A handle to compiled wasm module.
+pub trait Module<WB: WasmBackend>: Sized {
+    /// Compiles a wasm bytes into a module and extracts custom sections.
+    fn new(store: &mut <WB as WasmBackend>::Store, wasm: &[u8]) -> ModuleCreationResult<Self>;
+
+    /// Returns custom sections corresponding to `name`, empty slice if there is no sections.
+    fn custom_sections(&self, name: &str) -> &[Vec<u8>];
+
+    /// Instantiates module by allocating memory, VM state and linking imports with ones from `import` argument.
+    /// Does not call `_start` or `_initialize` functions.
+    ///
+    /// # Panics:
+    ///
+    ///     If the `Store` given is not the same with `Store` used to create `Imports` and this object.
+    fn instantiate(
+        &self,
+        store: &mut <WB as WasmBackend>::Store,
+        imports: &<WB as WasmBackend>::Imports,
+    ) -> InstantiationResult<<WB as WasmBackend>::Instance>;
+}