// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you 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.


#pragma once


namespace milvus {
namespace server {

template<typename T>
void
BlockingQueue<T>::Put(const T &task) {
    std::unique_lock<std::mutex> lock(mtx);
    full_.wait(lock, [this] {
        return (queue_.size() < capacity_);
    });

    queue_.push(task);
    empty_.notify_all();
}

template<typename T>
T
BlockingQueue<T>::Take() {
    std::unique_lock<std::mutex> lock(mtx);
    empty_.wait(lock, [this] {
        return !queue_.empty();
    });

    T front(queue_.front());
    queue_.pop();
    full_.notify_all();
    return front;
}

template<typename T>
size_t
BlockingQueue<T>::Size() {
    std::lock_guard<std::mutex> lock(mtx);
    return queue_.size();
}

template<typename T>
T
BlockingQueue<T>::Front() {
    std::unique_lock<std::mutex> lock(mtx);
    empty_.wait(lock, [this] {
        return !queue_.empty();
    });

    T front(queue_.front());
    return front;
}

template<typename T>
T
BlockingQueue<T>::Back() {
    std::unique_lock<std::mutex> lock(mtx);
    empty_.wait(lock, [this] {
        return !queue_.empty();
    });

    T back(queue_.back());
    return back;
}

template<typename T>
bool
BlockingQueue<T>::Empty() {
    std::unique_lock<std::mutex> lock(mtx);
    return queue_.empty();
}

template<typename T>
void
BlockingQueue<T>::SetCapacity(const size_t capacity) {
    capacity_ = (capacity > 0 ? capacity : capacity_);
}

} // namespace server
} // namespace milvus


