/*
  +----------------------------------------------------------------------+
  | Swoole                                                               |
  +----------------------------------------------------------------------+
  | This source file is subject to version 2.0 of the Apache license,    |
  | that is bundled with this package in the file LICENSE, and is        |
  | available through the world-wide-web at the following url:           |
  | http://www.apache.org/licenses/LICENSE-2.0.html                      |
  | If you did not receive a copy of the Apache2.0 license and are unable|
  | to obtain it through the world-wide-web, please send a note to       |
  | license@php.net so we can mail you a copy immediately.               |
  +----------------------------------------------------------------------+
  | Author: Tianfeng Han  <rango@swoole.com>                             |
  +----------------------------------------------------------------------+
*/

#pragma once

#include <queue>
#include <sys/uio.h>

namespace swoole {

struct BufferChunk {
    enum Type {
        TYPE_DATA,
        TYPE_SENDFILE,
        TYPE_CLOSE,
    };

    Type type;
    uint32_t length = 0;
    uint32_t offset = 0;
    union {
        char *str;
        void *ptr;
        uint32_t u32;
        uint64_t u64;
    } value{};
    uint32_t size = 0;

    BufferChunk(Type type, uint32_t size);
    ~BufferChunk();

    void (*destroy)(BufferChunk *chunk) = nullptr;
};

class Buffer {
    // 0: don't use chunk
    uint32_t chunk_size;
    uint32_t total_length = 0;
    std::queue<BufferChunk *> queue_;

  public:
    explicit Buffer(uint32_t _chunk_size);
    ~Buffer();

    BufferChunk *alloc(BufferChunk::Type type, uint32_t size);

    BufferChunk *front() const {
        return queue_.front();
    }

    void pop();
    void append(const char *data, uint32_t size);
    void append(const struct iovec *iov, size_t iovcnt, off_t offset);

    uint32_t length() const {
        return total_length;
    }

    size_t count() const {
        return queue_.size();
    }

    bool empty() const {
        return queue_.empty();
    }

    static bool empty(const Buffer *buffer) {
        return buffer == nullptr || buffer->queue_.empty();
    }
};

}  // namespace swoole
