Active Record 抽象适配器¶ ↑

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 403
def self.database_exists?(config)
  new(config).database_exists?
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 128
def self.dbconsole(config, options = {})
  raise NotImplementedError.new("#{self.class} should define `dbconsole` that accepts a db config and options to implement connecting to the db console")
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 99
def self.find_cmd_and_exec(commands, *args) # :doc:
  commands = Array(commands)

  dirs_on_path = ENV["PATH"].to_s.split(File::PATH_SEPARATOR)
  unless (ext = RbConfig::CONFIG["EXEEXT"]).empty?
    commands = commands.map { |cmd| "#{cmd}#{ext}" }
  end

  full_path_command = nil
  found = commands.detect do |cmd|
    dirs_on_path.detect do |path|
      full_path_command = File.join(path, cmd)
      begin
        stat = File.stat(full_path_command)
      rescue SystemCallError
      else
        stat.file? && stat.executable?
      end
    end
  end

  if found
    exec full_path_command, *args
  else
    abort("Couldn't find database client: #{commands.join(', ')}. Check your $PATH and try again.")
  end
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 72
def self.type_cast_config_to_boolean(config)
  if config == "false"
    false
  else
    config
  end
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 62
def self.type_cast_config_to_integer(config)
  if config.is_a?(Integer)
    config
  elsif SIMPLE_INT.match?(config)
    config.to_i
  else
    config
  end
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 80
def self.validate_default_timezone(config)
  case config
  when nil
  when "utc", "local"
    config.to_sym
  else
    raise ArgumentError, "default_timezone must be either 'utc' or 'local'"
  end
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 705
def active?
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 398
def adapter_name
  self.class::ADAPTER_NAME
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 690
def check_all_foreign_keys_valid!
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 792
def clear_cache!(new_connection: false)
  if @statements
    @lock.synchronize do
      if new_connection
        @statements.reset
      else
        @statements.clear
      end
    end
  end
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 892
def close
  pool.checkin self
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 833
def connect!
  verify!
  self
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 698
def connected?
  !@raw_connection.nil?
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 221
def connection_retries
  (@config[:connection_retries] || 1).to_i
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 407
def database_exists?
  connect!
  true
rescue ActiveRecord::NoDatabaseError
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 237
def default_timezone
  @default_timezone || ActiveRecord.default_timezone
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 617
def disable_extension(name, **)
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 683
def disable_referential_integrity
  yield
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 767
def discard!
  # This should be overridden by concrete adapters.
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 752
def disconnect!
  @lock.synchronize do
    clear_cache!(new_connection: true)
    reset_transaction
    @raw_connection_dirty = false
    @connected_since = nil
  end
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 621
def enable_extension(name, **)
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 671
def extensions
  []
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 676
def index_algorithms
  {}
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 289
def lease
  if in_use?
    msg = +"Cannot lease connection, "
    if @owner == ActiveSupport::IsolatedExecutionState.context
      msg << "it is already leased by the current thread."
    else
      msg << "it is already in use by a different thread: #{@owner}. " \
             "Current thread: #{ActiveSupport::IsolatedExecutionState.context}."
    end
    raise ActiveRecordError, msg
  end

  @owner = ActiveSupport::IsolatedExecutionState.context
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 213
def max_jitter
  (@config[:pool_jitter] || 0.2).to_f.clamp(MAX_JITTER)
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 50
def pool=(value)
  return if value.eql?(@pool)
  @schema_cache = nil
  @pool = value
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 324
def pool_jitter(duration)
  duration * (1.0 - @pool_jitter)
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 447
def prefetch_primary_key?(table_name = nil)
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 252
def prepared_statements?
  @prepared_statements && !prepared_statements_disabled_cache.include?(object_id)
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 245
def preventing_writes?
  return true if replica?
  return false if connection_descriptor.nil?

  connection_descriptor.current_preventing_writes
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 860
def raw_connection
  with_raw_connection do |conn|
    disable_lazy_transactions!
    @raw_connection_dirty = true
    conn
  end
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 711
def reconnect!(restore_transactions: false)
  retries_available = connection_retries
  deadline = retry_deadline && Process.clock_gettime(Process::CLOCK_MONOTONIC) + retry_deadline

  @lock.synchronize do
    @allow_preconnect = false

    reconnect

    enable_lazy_transactions!
    @raw_connection_dirty = false
    @last_activity = @connected_since = Process.clock_gettime(Process::CLOCK_MONOTONIC)
    @verified = true
    @allow_preconnect = true

    reset_transaction(restore: restore_transactions) do
      clear_cache!(new_connection: true)
      attempt_configure_connection
    end
  rescue => original_exception
    translated_exception = translate_exception_class(original_exception, nil, nil)
    retry_deadline_exceeded = deadline && deadline < Process.clock_gettime(Process::CLOCK_MONOTONIC)

    if !retry_deadline_exceeded && retries_available > 0
      retries_available -= 1

      if retryable_connection_error?(translated_exception)
        backoff(connection_retries - retries_available)
        retry
      end
    end

    @last_activity = nil
    @verified = false

    raise translated_exception
  end
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 217
def replica?
  @config[:replica] || false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 805
def requires_reloading?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 779
def reset!
  clear_cache!(new_connection: true)
  reset_transaction
  attempt_configure_connection
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 229
def retry_deadline
  if @config[:retry_deadline]
    @config[:retry_deadline].to_f
  else
    nil
  end
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 310
def role
  @pool.role
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 431
def savepoint_errors_invalidate_transactions?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 320
def schema_cache
  @pool.schema_cache || (@schema_cache ||= BoundSchemaReflection.for_lone_connection(@pool.schema_reflection, self))
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 927
def schema_version
  pool.migration_context.current_version
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 316
def shard
  @pool.shard
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 440
def supports_advisory_locks?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 420
def supports_bulk_alter?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 512
def supports_check_constraints?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 547
def supports_comments?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 552
def supports_comments_in_create?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 571
def supports_common_table_expressions?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 595
def supports_concurrent_connections?
  true
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 537
def supports_datetime_with_precision?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 416
def supports_ddl_transactions?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 507
def supports_deferrable_constraints?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 603
def supports_disabling_indexes?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 517
def supports_exclusion_constraints?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 476
def supports_explain?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 471
def supports_expression_index?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 486
def supports_extensions?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 497
def supports_foreign_keys?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 562
def supports_foreign_tables?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 466
def supports_index_include?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 456
def supports_index_sort_order?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 492
def supports_indexes_in_create?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 591
def supports_insert_conflict_target?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 583
def supports_insert_on_duplicate_skip?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 587
def supports_insert_on_duplicate_update?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 579
def supports_insert_returning?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 542
def supports_json?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 575
def supports_lazy_transactions?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 532
def supports_materialized_views?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 599
def supports_nulls_not_distinct?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 567
def supports_optimizer_hints?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 461
def supports_partial_index?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 451
def supports_partitioned_indexes?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 435
def supports_restart_db_transaction?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 425
def supports_savepoints?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 481
def supports_transaction_isolation?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 522
def supports_unique_constraints?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 502
def supports_validate_constraints?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 527
def supports_views?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 557
def supports_virtual_columns?
  false
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 786
def throw_away!
  pool.remove self
  disconnect!
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 389
def unprepared_statement
  cache = prepared_statements_disabled_cache.add?(object_id) if @prepared_statements
  yield
ensure
  cache&.delete(object_id)
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 812
def verify!
  unless active?
    @lock.synchronize do
      if @unconfigured_connection
        @raw_connection = @unconfigured_connection
        @unconfigured_connection = nil
        attempt_configure_connection
        @last_activity = Process.clock_gettime(Process::CLOCK_MONOTONIC)
        @verified = true
        @allow_preconnect = true
        return
      end

      reconnect!(restore_transactions: true)
    end
  end

  @last_activity = Process.clock_gettime(Process::CLOCK_MONOTONIC)
  @verified = true
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 225
def verify_timeout
  (@config[:verify_timeout] || 2).to_i
end

# File activerecord/lib/active_record/connection_adapters/abstract_adapter.rb, line 1200
def log(sql, name = "SQL", binds = [], type_casted_binds = [], async: false, allow_retry: false, &block) # :doc:
  instrumenter.instrument(
    "sql.active_record",
    sql:               sql,
    name:              name,
    binds:             binds,
    type_casted_binds: type_casted_binds,
    async:             async,
    allow_retry:       allow_retry,
    connection:        self,
    transaction:       current_transaction.user_transaction.presence,
    affected_rows:     0,
    row_count:         0,
    &block
  )
rescue ActiveRecord::StatementInvalid => ex
  raise ex.set_query(sql, binds)
end