tc_executor_common/
wasm_runtime.rs

1// This file is part of Tetcore.
2
3// Copyright (C) 2019-2021 Parity Technologies (UK) Ltd.
4// SPDX-License-Identifier: GPL-3.0-or-later WITH Classpath-exception-2.0
5
6// This program is free software: you can redistribute it and/or modify
7// it under the terms of the GNU General Public License as published by
8// the Free Software Foundation, either version 3 of the License, or
9// (at your option) any later version.
10
11// This program is distributed in the hope that it will be useful,
12// but WITHOUT ANY WARRANTY; without even the implied warranty of
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14// GNU General Public License for more details.
15
16// You should have received a copy of the GNU General Public License
17// along with this program. If not, see <https://www.gnu.org/licenses/>.
18
19//! Definitions for a wasm runtime.
20
21use crate::error::Error;
22use tetcore_wasm_interface::Value;
23
24/// A method to be used to find the entrypoint when calling into the runtime
25///
26/// Contains variants on how to resolve wasm function that will be invoked.
27pub enum InvokeMethod<'a> {
28	/// Call function exported with this name.
29	///
30	/// Located function should have (u32, u32) -> u64 signature.
31	Export(&'a str),
32	/// Call a function found in the exported table found under the given index.
33	///
34	/// Located function should have (u32, u32) -> u64 signature.
35	Table(u32),
36	/// Call function by reference from table through a wrapper.
37	///
38	/// Invoked function (`dispatcher_ref`) function
39	/// should have (u32, u32, u32) -> u64 signature.
40	///
41	/// `func` will be passed to the invoked function as a first argument.
42	TableWithWrapper {
43		/// Wrapper for the call.
44		///
45		/// Function pointer, index into runtime exported table.
46		dispatcher_ref: u32,
47		/// Extra argument for dispatch.
48		///
49		/// Common usage would be to use it as an actual wasm function pointer
50		/// that should be invoked, but can be used as any extra argument on the
51		/// callee side.
52		///
53		/// This is typically generated and invoked by the runtime itself.
54		func: u32,
55	},
56}
57
58impl<'a> From<&'a str> for InvokeMethod<'a> {
59	fn from(val: &'a str) -> InvokeMethod<'a> {
60		InvokeMethod::Export(val)
61	}
62}
63
64/// A trait that defines an abstract WASM runtime module.
65///
66/// This can be implemented by an execution engine.
67pub trait WasmModule: Sync + Send {
68	/// Create a new instance.
69	fn new_instance(&self) -> Result<Box<dyn WasmInstance>, Error>;
70}
71
72/// A trait that defines an abstract wasm module instance.
73///
74/// This can be implemented by an execution engine.
75pub trait WasmInstance: Send {
76	/// Call a method on this WASM instance.
77	///
78	/// Before execution, instance is reset.
79	///
80	/// Returns the encoded result on success.
81	fn call(&self, method: InvokeMethod, data: &[u8]) -> Result<Vec<u8>, Error>;
82
83	/// Call an exported method on this WASM instance.
84	///
85	/// Before execution, instance is reset.
86	///
87	/// Returns the encoded result on success.
88	fn call_export(&self, method: &str, data: &[u8]) -> Result<Vec<u8>, Error> {
89		self.call(method.into(), data)
90	}
91
92	/// Get the value from a global with the given `name`.
93	///
94	/// This method is only suitable for getting immutable globals.
95	fn get_global_const(&self, name: &str) -> Result<Option<Value>, Error>;
96}
tc_executor_common/wasm_runtime.rs

tc_executor_common/
wasm_runtime.rs
