Class: MysqlFramework::MysqlConnectionPool

Inherits:
Object
  • Object
show all
Defined in:
lib/mysql_framework/mysql_connection_pool.rb

Defined Under Namespace

Classes: ConnectionSanitizationError

Constant Summary collapse

CLEAN_IDLE_CONNECTIONS_THREAD_NAME = 
'clean-idle-connections'

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options) ⇒ void

Initializes a connection pool instance with MySQL client options.

Parameters:

  • options (Hash) —

    MySQL client options passed to each pooled connection



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# File 'lib/mysql_framework/mysql_connection_pool.rb', line 17

def initialize(options)
  @options = options
  @setup_mutex = Mutex.new
end

Instance Attribute Details

#connections ⇒ Object (readonly)

Returns the value of attribute connections.



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# File 'lib/mysql_framework/mysql_connection_pool.rb', line 11

def connections
  @connections
end

Instance Method Details

#check_in(client) ⇒ void

This method returns an undefined value.

Returns a MySQL client back to the pool or closes it when pooling is disabled.

Parameters:

  • client (Mysql2::Client, nil) —

    client to return or close



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# File 'lib/mysql_framework/mysql_connection_pool.rb', line 87

def check_in(client)
  return if client.nil?

  discard_current_connection! if client.closed?
  connections.checkin
end

#check_out ⇒ Mysql2::Client

Checks out a MySQL client, sanitizing it before use.

Returns:

  • (Mysql2::Client) —

    checked-out client

Raises:

  • (ConnectionSanitizationError) —

    when sanitization repeatedly fails

  • (Mysql2::Error) —

    when checkout or sanitization fails due to MySQL errors



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# File 'lib/mysql_framework/mysql_connection_pool.rb', line 66

def check_out
  sanitization_retries = 0
  begin
    conn = connections.checkout
    sanitize_connection!(conn)
    conn
  rescue ConnectionSanitizationError
    discard_current_connection!
    sanitization_retries += 1
    retry if sanitization_retries <= 1
    raise
  rescue Mysql2::Error
    discard_current_connection!
    raise
  end
end

#dispose ⇒ void

This method returns an undefined value.

Disposes of the connection pool and closes pooled connections.



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# File 'lib/mysql_framework/mysql_connection_pool.rb', line 40

def dispose
  @setup_mutex.synchronize do
    dispose_clean_idle_connections_thread
    connections&.shutdown(&:close)
    @connections = nil
  end
end

#pool_stats ⇒ Hash{Symbol => Integer}

Returns key connection-pool metrics for monitoring.

Returns:

  • (Hash{Symbol => Integer}) —

    pool size and availability metrics



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# File 'lib/mysql_framework/mysql_connection_pool.rb', line 51

def pool_stats
  return { size: 0, available: 0, idle: 0 } if connections.nil?

  {
    size: connections.size,
    available: connections.available,
    idle: connections.idle
  }
end

#setup ⇒ ConnectionPool

Sets up the MySQL connection pool. Idempotent — safe to call more than once.

Returns:

  • (ConnectionPool) —

    configured pool



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# File 'lib/mysql_framework/mysql_connection_pool.rb', line 25

def setup
  @setup_mutex.synchronize do
    return if connections

    @connections = ConnectionPool.new(size: max_pool_size, timeout: pool_timeout) do
      Mysql2::Client.new(@options)
    end

    start_clean_idle_connections_thread
  end
end

#with_client(discard_current_pool_connection: false) {|client| ... } ⇒ Object

Yields a MySQL client from the pool, or yields the provided client directly.

Parameters:

  • provided_client (Mysql2::Client, nil) —

    existing client to yield without pool checkout

  • discard_current_pool_connection (Boolean) (defaults to: false) —

    whether to discard the pooled connection after use

Yields:

  • (client) —

    block that performs work with a MySQL client

Yield Parameters:

  • client (Mysql2::Client)

Returns:

  • (Object) —

    block result

Raises:

  • (Mysql2::Error) —

    re-raises MySQL errors from the block



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# File 'lib/mysql_framework/mysql_connection_pool.rb', line 102

def with_client(discard_current_pool_connection: false)
  sanitization_retries = 0

  begin
    connections.with do |conn|
      sanitize_connection!(conn)
      yield conn
    rescue ConnectionSanitizationError, Mysql2::Error
      discard_current_connection!
      raise
    ensure
      discard_current_connection! if discard_current_pool_connection
    end
  rescue ConnectionSanitizationError
    sanitization_retries += 1
    retry if sanitization_retries <= 1
    raise
  end
end