Keyring component metadata query service provides APIs to obtain component specific metadata in string format. More...

#include <keyring_metadata_query.h>

Public Attributes
mysql_service_status_t(*	init )(my_h_keyring_component_metadata_iterator *metadata_iterator)
	Initialize metadata iterator. More...

mysql_service_status_t(*	deinit )(my_h_keyring_component_metadata_iterator metadata_iterator)
	Deinitialize metadata iterator. More...

mysql_service_status_t(*	is_valid )(my_h_keyring_component_metadata_iterator metadata_iterator)
	Check validity of iterator. More...

mysql_service_status_t(*	next )(my_h_keyring_component_metadata_iterator metadata_iterator)
	Move iterator forward. More...

mysql_service_status_t(*	get_length )(my_h_keyring_component_metadata_iterator metadata_iterator, size_t key_buffer_length, size_t value_buffer_length)
	Get length information about metadata key and value. More...

mysql_service_status_t(*	get )(my_h_keyring_component_metadata_iterator metadata_iterator, char key_buffer, size_t key_buffer_len, char value_buffer, size_t value_buffer_len)
	Get name and value of metadata at current position. More...

Detailed Description

Keyring component metadata query service provides APIs to obtain component specific metadata in string format.

Metadata would be in (key, value) pair.

Implementor can decide what metadata should be exposed through these APIs.

One of the primary consumer of this metadata is Performance schema table keyring_component_status.

bool print_component_status() {
  bool next_status = false;
  my_h_keyring_component_metadata_iterator iterator = nullptr;
  my_service<SERVICE_TYPE(keyring_component_metadata_query)>
      metadata_query_service("keyring_component_metadata_query",
                             m_reg_srv);
  if (!metadata_query_service.valid()) {
    return false;
  }
 
  if (metadata_query_service->init(&iterator) == true) {
    return false;
  }
 
  bool ok = true;
  for (; metadata_query_service->is_valid(iterator) && next_status;
       next_status = metadata_query_service->next(iterator)) {
    size_t key_buffer_length = 0;
    size_t value_buffer_length = 0;
    if (metadata_query_service->get_length(iterator, &key_buffer_length,
                                           &value_buffer_length) == true) {
      ok = false;
      break;
    }
 
    std::unique_ptr<char[]> key_buffer(new char[key_buffer_length]);
    std::unique_ptr<char[]> value_buffer(new char[value_buffer_length]);
 
    if (key_buffer.get() == nullptr || value_buffer.get() == nullptr) break;
 
    memset(key_buffer.get(), 0, key_buffer_length);
    memset(value_buffer.get(), 0, value_buffer_length);
 
    if (metadata_query_service->get(
            iterator, key_buffer.get(), key_buffer_length, value_buffer.get(),
            value_buffer_length) == true) {
      ok = false;
      break;
    }
 
    std::cout << "Metadata key: " << key_buffer.get()
              << ". Metadata value: " << value_buffer.get.get() << std::endl;
  }
 
  if (metadata_query_service->deinit(iterator) {
    return false;
  }
 
  return ok;
}

Member Data Documentation

◆ deinit

mysql_service_status_t(* s_mysql_keyring_component_metadata_query::deinit) (my_h_keyring_component_metadata_iterator metadata_iterator)

Deinitialize metadata iterator.

Parameters

[in,out] metadata_iterator Metadata iterator handle

Returns: Status of iterator deinitialization

Return values

false	Success
true	Failure

◆ get

mysql_service_status_t(* s_mysql_keyring_component_metadata_query::get) (my_h_keyring_component_metadata_iterator metadata_iterator, char *key_buffer, size_t key_buffer_len, char *value_buffer, size_t value_buffer_len)

Get name and value of metadata at current position.

Parameters

[in]	metadata_iterator	Metadata iterator handle
[out]	key_buffer	Output buffer for key. Byte string.
[in]	key_buffer_length	Length of key buffer
[out]	value_buffer	Output buffer for value. Byte string.
[in]	value_buffer_length	Length of value buffer

Returns: Status of fetch operation

Return values

false	Success
true	Failure

◆ get_length

mysql_service_status_t(* s_mysql_keyring_component_metadata_query::get_length) (my_h_keyring_component_metadata_iterator metadata_iterator, size_t *key_buffer_length, size_t *value_buffer_length)

Get length information about metadata key and value.

Parameters

[in]	metadata_iterator	Metadata iterator handle
[out]	key_buffer_length	Length of the key buffer
[out]	value_buffer_length	Length of the value buffer

Returns: Get length information about key and value

Return values

false	Success
true	Failure

◆ init

mysql_service_status_t(* s_mysql_keyring_component_metadata_query::init) (my_h_keyring_component_metadata_iterator *metadata_iterator)

Initialize metadata iterator.

deinit should be called for clean-up.

Parameters

[out] metadata_iterator Metadata iterator handle

Returns: Status of iterator initialization

Return values

false	Success
true	Failure

◆ is_valid

mysql_service_status_t(* s_mysql_keyring_component_metadata_query::is_valid) (my_h_keyring_component_metadata_iterator metadata_iterator)

Check validity of iterator.

Parameters

[in] metadata_iterator Metadata iterator handle

Returns: Validity of the the iterator

Return values

true	Iterator valid
false	Iterator invalid

◆ next

mysql_service_status_t(* s_mysql_keyring_component_metadata_query::next) (my_h_keyring_component_metadata_iterator metadata_iterator)

Move iterator forward.

Parameters

[in,out] metadata_iterator Metadata iterator handle

Returns: Status of operation

Return values

false	Success
true	Failure. Either iterator already reached end position or some other error was encountered.

The documentation for this struct was generated from the following file:

include/mysql/components/services/keyring_metadata_query.h

Public Attributes

Detailed Description

Member Data Documentation

◆ deinit

◆ get

◆ get_length

◆ init

◆ is_valid

◆ next