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/*
*
* Hedera Rust SDK
*
* Copyright (C) 2022 - 2023 Hedera Hashgraph, LLC
*
* 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 std::os::raw::c_void;
use crate::ffi::error::Error;
/// Wrapper around a C callback handle and an associated opaque context pointer.
pub(super) struct Callback<T> {
handle: extern "C" fn(context: *const c_void, err: Error, value: T),
context: *const c_void,
}
impl<T> Callback<T> {
pub(super) fn new(
context: *const c_void,
handle: extern "C" fn(context: *const c_void, err: Error, value: T),
) -> Self {
Self { handle, context }
}
pub(super) fn call(&self, err: Error, value: T) {
(self.handle)(self.context, err, value);
}
}
// NOTE: The context pointer is referring to state that is never inspected, only passed
unsafe impl<T> Send for Callback<T> {}