// This file is part of Substrate.

// Copyright (C) Parity Technologies (UK) Ltd.

// SPDX-License-Identifier: Apache-2.0

// 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.

//! Various utilities that help interfacing with wasm runtime code.

/// Pack a pointer and length into an `u64`.

/// Unpacks an `u64` into the pointer and length.

///

/// Runtime API functions return a 64-bit value which encodes a pointer in the least-significant

/// 32-bits and a length in the most-significant 32 bits. This interprets the returned value as a

/// pointer, length tuple.

#[cfg(test)]

mod tests {

	use super::{pack_ptr_and_len, unpack_ptr_and_len};

	#[test]

	fn ptr_len_packing_unpacking() {

		const PTR: u32 = 0x1337;

		const LEN: u32 = 0x7f000000;

		let packed = pack_ptr_and_len(PTR, LEN);

		let (ptr, len) = unpack_ptr_and_len(packed);

		assert_eq!(PTR, ptr);

		assert_eq!(LEN, len);

	}

}