BlockHeader.h

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/* -*- c++ -*-
 * Copyright (C) 2007-2015 Hypertable, Inc.
 *
 * This file is part of Hypertable.
 *
 * Hypertable 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; version 3 of the
 * License, or any later version.
 *
 * Hypertable 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 HYPERTABLE_BLOCKHEADER_H
#define HYPERTABLE_BLOCKHEADER_H

#include <utility>

namespace Hypertable {

  using namespace std::rel_ops;

  class BlockHeader {

  public:

    static const uint16_t LatestVersion = 1;    

    BlockHeader(uint16_t version=LatestVersion, const char *magic=0);

    virtual ~BlockHeader() { }

    void set_magic(const char *magic) { memcpy(m_magic, magic, 10); }

    const char *get_magic() { return (const char *)m_magic; }

    bool check_magic(const char *magic) { return !memcmp(magic, m_magic, 10); }

    void set_data_length(uint32_t length) { m_data_length = length; }

    uint32_t get_data_length() { return m_data_length; }

    void set_data_zlength(uint32_t zlength) { m_data_zlength = zlength; }

    uint32_t get_data_zlength() { return m_data_zlength; }

    void
    set_data_checksum(uint32_t checksum) { m_data_checksum = checksum; }

    uint32_t get_data_checksum() { return m_data_checksum; }

    void set_compression_type(uint16_t type) { m_compression_type = type; }

    uint16_t get_compression_type() { return m_compression_type; }

    void set_flags(uint16_t flags) { m_flags = flags; }

    uint16_t get_flags() { return m_flags; }

    void write_header_checksum(uint8_t *base);

    virtual size_t encoded_length();

    virtual void encode(uint8_t **bufp);

    virtual void decode(const uint8_t **bufp, size_t *remainp);

    bool equals(const BlockHeader &other) const;

  protected:

    char m_magic[10];

    uint16_t m_flags;

    uint32_t m_data_length;

    uint32_t m_data_zlength;

    uint32_t m_data_checksum;

    uint16_t m_compression_type;

  private:
    uint16_t m_version;
  };

  inline bool operator==(const BlockHeader &lhs, const BlockHeader &rhs) {
    return lhs.equals(rhs);
  }

}

#endif // HYPERTABLE_BLOCKHEADER_H