uuid.h

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/* Copyright (c) 2017, 2024, Oracle and/or its affiliates.
 
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License, version 2.0,
   as published by the Free Software Foundation.
 
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   as designated in a particular file or component or in included license
   documentation.  The authors of MySQL hereby grant you an additional
   permission to link the program and your derivative works with the
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   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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   You should have received a copy of the GNU General Public License
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   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */
 
#ifndef MYSQL_GTID_UUID_H
#define MYSQL_GTID_UUID_H
 
#include <stddef.h>
#include <stdio.h>
#include <string.h>
 
#include <array>
#include <string>
#include <utility>
 
#include "template_utils.h"
 
/// @addtogroup GroupLibsMysqlGtid
/// @{
 
namespace mysql::gtid {
 
/**
  @struct  Uuid
 
  Uuid is a trivial and of standard layout
  The structure contains the following components.
  <table>
  <caption>Structure gtid_info</caption>
 
  <tr>
    <th>Name</th>
    <th>Format</th>
    <th>Description</th>
  </tr>
  <tr>
    <td>byte</td>
    <td>unsigned char array</td>
    <td>This stores the Uuid of the server on which transaction
        is originated</td>
  </tr>
  </table>
*/
 
struct Uuid {
  /// Set to all zeros.
  void clear() { memset(bytes.data(), 0, BYTE_LENGTH); }
  /// Copies the given 16-byte data to this UUID.
  void copy_from(const unsigned char *data) {
    memcpy(bytes.data(), data, BYTE_LENGTH);
  }
 
  /// Copies the given UUID object to this UUID.
  void copy_to(unsigned char *data) const {
    memcpy(data, bytes.data(), BYTE_LENGTH);
  }
  /// Returns true if this UUID is equal the given UUID.
  bool equals(const Uuid &other) const {
    return memcmp(bytes.data(), other.bytes.data(), BYTE_LENGTH) == 0;
  }
 
  bool operator<(const Uuid &other) const {
    return memcmp(this->bytes.data(), other.bytes.data(), BYTE_LENGTH) < 0;
  }
  /**
    Returns true if parse() would succeed, but doesn't store the result.
 
     @param string String that needs to be checked.
     @param len    Length of that string.
 
     @retval true  valid string.
     @retval false invalid string.
  */
  static bool is_valid(const char *string, size_t len);
 
  /**
    Stores the UUID represented by a string of the form
    XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX or
    XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX or
    {XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX}
    in this object.
 
     @param string String to be parsed and stored.
     @param len    Length of that string.
 
     @retval   0   success.
     @retval  >0   failure.
  */
  int parse(const char *string, size_t len);
 
  /**
    Parses the UUID passed as argument in in_string and functions and writes
    the binary representation in out_binary_string.
    Depends on UUID's read_section method and the constants for text length.
 
     @param[in] in_string           String to be parsed.
     @param[in] len                 Length of that string.
     @param[out] out_binary_string  String where the binary UUID will be stored
 
     @retval   0   success.
     @retval  >0   failure.
  */
  static int parse(const char *in_string, size_t len,
                   const unsigned char *out_binary_string);
  /**
    Helper method used to validate and parse one section of a uuid.
    If the last parameter, out_binary_str, is NULL then the function will
    just validate the section.
 
     @param[in]      section_len      Length of the section to be parsed.
     @param[in,out]  section_str      Pointer to a string containing the
                                      section. It will be updated during the
                                      execution as the string is parsed.
     @param[out]     out_binary_str   String where the section will be stored
                                      in binary format. If null, the function
                                      will just validate the input string.
 
     @retval  false   success.
     @retval  true    failure.
  */
  static bool read_section(int section_len, const char **section_str,
                           const unsigned char **out_binary_str);
  /** The number of bytes in the data of a Uuid. */
  static constexpr std::size_t BYTE_LENGTH = 16;
 
  /** The data for this Uuid. */
  std::array<unsigned char, BYTE_LENGTH> bytes;
 
  /**
    Generates a 36+1 character long representation of this UUID object
    in the given string buffer.
 
    @retval 36 - the length of the resulting string.
  */
  size_t to_string(char *buf) const;
  /// Convert the given binary buffer to a UUID
  static size_t to_string(const unsigned char *bytes_arg, char *buf);
  std::string to_string() const {
    char buf[TEXT_LENGTH + 1];
    to_string(buf);
    return buf;
  }
  void print() const {
    char buf[TEXT_LENGTH + 1];
    to_string(buf);
    printf("%s\n", buf);
  }
  /// The number of bytes in the textual representation of a Uuid.
  static const size_t TEXT_LENGTH = 36;
  /// The number of bits in the data of a Uuid.
  static const size_t BIT_LENGTH = 128;
  static const int NUMBER_OF_SECTIONS = 5;
  static constexpr int bytes_per_section[NUMBER_OF_SECTIONS] = {4, 2, 2, 2, 6};
  static constexpr int hex_to_byte[256] = {
      -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
      -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
      -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 0,  1,  2,  3,  4,  5,
      6,  7,  8,  9,  -1, -1, -1, -1, -1, -1, -1, 10, 11, 12, 13, 14, 15, -1,
      -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
      -1, -1, -1, -1, -1, -1, -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1,
      -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
      -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
      -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
      -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
      -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
      -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
      -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
      -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
      -1, -1, -1, -1,
  };
};
 
static_assert(std::is_trivial_v<Uuid>);
static_assert(std::is_standard_layout_v<Uuid>);
 
struct Uuid_hash {
  size_t operator()(const Uuid &uuid) const {
    return std::hash<std::string>()(std::string(
        pointer_cast<const char *>(uuid.bytes.data()), Uuid::BYTE_LENGTH));
  }
};
 
inline bool operator==(const Uuid &a, const Uuid &b) { return a.equals(b); }
inline bool operator!=(const Uuid &a, const Uuid &b) { return !a.equals(b); }
 
}  // namespace mysql::gtid
 
namespace [[deprecated]] binary_log {
namespace [[deprecated]] gtids {
using namespace mysql::gtid;
}  // namespace gtids
}  // namespace binary_log
 
/// @}
 
#endif  // MYSQL_GTID_UUID_H