/*
 * Copyright The OpenTelemetry Authors
 *
 * 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
 *
 *      https://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.
 */
import { Deferred } from './promise';
/**
 * Bind the callback and only invoke the callback once regardless how many times `BindOnceFuture.call` is invoked.
 */
export class BindOnceFuture {
    constructor(_callback, _that) {
        this._callback = _callback;
        this._that = _that;
        this._isCalled = false;
        this._deferred = new Deferred();
    }
    get isCalled() {
        return this._isCalled;
    }
    get promise() {
        return this._deferred.promise;
    }
    call(...args) {
        if (!this._isCalled) {
            this._isCalled = true;
            try {
                Promise.resolve(this._callback.call(this._that, ...args)).then(val => this._deferred.resolve(val), err => this._deferred.reject(err));
            }
            catch (err) {
                this._deferred.reject(err);
            }
        }
        return this._deferred.promise;
    }
}
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