ThreadInputStream.hxx

Go to the documentation of this file.

/*
 * Copyright 2003-2017 The Music Player Daemon Project
 * http://www.musicpd.org
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#ifndef MPD_THREAD_INPUT_STREAM_HXX
#define MPD_THREAD_INPUT_STREAM_HXX

#include "check.h"
#include "InputStream.hxx"
#include "thread/Thread.hxx"
#include "thread/Cond.hxx"

#include <exception>

#include <assert.h>
#include <stdint.h>

template<typename T> class CircularBuffer;

class ThreadInputStream : public InputStream {
        const char *const plugin;

        Thread thread;

        Cond wake_cond;

        std::exception_ptr postponed_exception;

        const size_t buffer_size;
        CircularBuffer<uint8_t> *buffer = nullptr;

        bool close = false;

        bool eof = false;

public:
        ThreadInputStream(const char *_plugin,
                          const char *_uri, Mutex &_mutex, Cond &_cond,
                          size_t _buffer_size)
                :InputStream(_uri, _mutex, _cond),
                 plugin(_plugin),
                 thread(BIND_THIS_METHOD(ThreadFunc)),
                 buffer_size(_buffer_size) {}

#ifndef NDEBUG
        ~ThreadInputStream() override {
                /* Stop() must have been called already */
                assert(!thread.IsDefined());
                assert(buffer == nullptr);
        }
#endif

        void Start();

        /* virtual methods from InputStream */
        void Check() override final;
        bool IsEOF() noexcept final;
        bool IsAvailable() noexcept final;
        size_t Read(void *ptr, size_t size) override final;

protected:
        void Stop() noexcept;

        void SetMimeType(const char *_mime) {
                assert(thread.IsInside());

                InputStream::SetMimeType(_mime);
        }

        /* to be implemented by the plugin */

        virtual void Open() {
        }

        virtual size_t ThreadRead(void *ptr, size_t size) = 0;

        virtual void Close() {}

        virtual void Cancel() {}

private:
        void ThreadFunc();
};

#endif