global_variable_attributes_bits.h

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/* Copyright (c) 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
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  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License, version 2.0, for more details.
 
  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 GLOBAL_VARIABLE_ATTRIBUTES_BITS_H
#define GLOBAL_VARIABLE_ATTRIBUTES_BITS_H
 
#include <cstddef>  // size_t
 
#include <mysql/components/service.h>
#include <mysql/components/services/mysql_string.h>
 
DEFINE_SERVICE_HANDLE(global_variable_attributes_iterator);
 
/**
  Initialize System Variable Attributes iterator object
  to enumerate key/value attributes attached to system variables, pointing to
  1st matching attribute
 
  @param variable_base Variable prefix or NULL if none.
  @param variable_name define system variable scope
  @param attribute_name Optional attribute name scope (NULL to iterate all
  attributes of a variable)
  @param [out] iterator iterator object
 
  @returns Result of iterator creation
    @retval false Success
    @retval true Failure
*/
typedef bool (*global_variable_attributes_iterator_create_t)(
    const char *variable_base, const char *variable_name,
    const char *attribute_name, global_variable_attributes_iterator *iterator);
 
/**
  Uninitialize System Variable Attributes iterator
 
  @param iterator iterator object
 
  @returns Result of iterator creation
    @retval false Success
    @retval true Failure
*/
typedef bool (*global_variable_attributes_iterator_destroy_t)(
    global_variable_attributes_iterator iterator);
 
/**
  Advance System Variable Attributes iterator to next element.
 
  @param iterator iterator object
 
  @returns Result of iterator creation
    @retval false Success
    @retval true Failure or no more elements
*/
typedef bool (*global_variable_attributes_iterator_advance_t)(
    global_variable_attributes_iterator iterator);
 
/**
  Return attribute name for the element pointed by
  System Variable Attributes iterator.
 
  @param iterator iterator object
  @param[out] out_name_handle pointer to receive name string content
 
  @returns Result of operation
    @retval false Success
    @retval true Failure or no more elements
*/
typedef bool (*global_variable_attributes_iterator_get_name_t)(
    global_variable_attributes_iterator iterator, my_h_string *out_name_handle);
 
/**
  Return attribute value for the element pointed by
  System Variable Attributes iterator.
 
  @param iterator iterator object
  @param[out] out_value_handle pointer to receive value string content
 
  @returns Result of operation
    @retval false Success
    @retval true Failure or no more elements
*/
typedef bool (*global_variable_attributes_iterator_get_value_t)(
    global_variable_attributes_iterator iterator,
    my_h_string *out_value_handle);
 
/**
  Attach a single key/value attribute to a given global system variable,
  or delete one or all attributes of a given variable.
 
  @param variable_base Variable prefix, NULL if none.
  @param variable_name Variable name.
  @param attribute_name Attribute name, if nullptr unset all attributes for the
  variable.
  @param attribute_value Attribute value, if nullptr unset the attribute.
 
  @returns Result of operation
    @retval false Success
    @retval true Failure or no more elements
*/
typedef bool (*global_variable_attributes_assign_t)(
    const char *variable_base, const char *variable_name,
    const char *attribute_name, const char *attribute_value);
 
/**
  Read a single global system variable attribute value, if exists.
 
  @param variable_base Variable prefix, NULL if none.
  @param variable_name Variable name.
  @param attribute_name Attribute name.
  @param attribute_value_buffer Pointer to buffer to receive the result.
  @param inout_attribute_value_length Buffer size, also used to return value
  string size.
 
  @returns Result of operation
    @retval false Success
    @retval true Failure or no more elements
*/
typedef bool (*global_variable_attributes_get_t)(
    const char *variable_base, const char *variable_name,
    const char *attribute_name, char *attribute_value_buffer,
    size_t *inout_attribute_value_length);
 
/**
  Read timestamp indicating when a global system variable was last modified.
 
  @param variable_base Variable prefix, NULL if none.
  @param variable_name Variable name.
  @param timestamp_value_buffer Pointer to buffer to receive the result.
  @param inout_timestamp_value_length Buffer size, also used to return value
  string size.
 
  @returns Result of operation
    @retval false Success
    @retval true Failure or no more elements
*/
typedef bool (*global_variable_attributes_get_time_t)(
    const char *variable_base, const char *variable_name,
    char *timestamp_value_buffer, size_t *inout_timestamp_value_length);
 
/**
  Read user name that last modified a global system variable.
 
  @param variable_base Variable prefix, NULL if none.
  @param variable_name Variable name.
  @param user_value_buffer Pointer to buffer to receive the result.
  @param inout_user_value_length Buffer size, also used to return value
  string size.
 
  @returns Result of operation
    @retval false Success
    @retval true Failure or no more elements
*/
typedef bool (*global_variable_attributes_get_user_t)(
    const char *variable_base, const char *variable_name,
    char *user_value_buffer, size_t *inout_user_value_length);
 
#endif /* GLOBAL_VARIABLE_ATTRIBUTES_BITS_H */