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Simplify adapter construction; defer connect until first use
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@matthewd
matthewd committed Mar 31, 2022
1 parent 1c7f5dc commit feed930
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Showing 16 changed files with 190 additions and 166 deletions.
7 changes: 0 additions & 7 deletions activerecord/lib/active_record/connection_adapters/abstract/transaction.rb
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Original file line number Diff line number Diff line change
Expand Up @@ -382,13 +382,6 @@ def materialize_transactions
@has_unmaterialized_transactions = false
end
end

# As a logical simplification for now, we assume anything that requests
# materialization is about to dirty the transaction. Note this is just
# an assumption about the caller, not a direct property of this method.
# It can go away later when callers are able to handle dirtiness for
# themselves.
dirty_current_transaction
end

def commit_transaction
Expand Down
61 changes: 46 additions & 15 deletions activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
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Original file line number Diff line number Diff line change
Expand Up @@ -89,34 +89,51 @@ def self.quoted_table_names # :nodoc:
@quoted_table_names ||= {}
end

def initialize(connection, logger = nil, config = {}) # :nodoc:
def initialize(config_or_deprecated_connection, deprecated_logger = nil, deprecated_connection_options = nil, deprecated_config = nil) # :nodoc:
super()

@raw_connection = connection
@owner = nil
@instrumenter = ActiveSupport::Notifications.instrumenter
@logger = logger
@config = config
@pool = ActiveRecord::ConnectionAdapters::NullPool.new
@idle_since = Process.clock_gettime(Process::CLOCK_MONOTONIC)
if config_or_deprecated_connection.is_a?(Hash)
@raw_connection = nil
@config = config_or_deprecated_connection.symbolize_keys
@logger = ActiveRecord::Base.logger

if deprecated_logger || deprecated_connection_options || deprecated_config
raise ArgumentError, "new API accepts just one config hash"
end
else
# Soft-deprecated for now; we'll probably warn in future.

@raw_connection = config_or_deprecated_connection
@logger = deprecated_logger || ActiveRecord::Base.logger
if deprecated_config
@config = (deprecated_config || {}).symbolize_keys
@connection_parameters = deprecated_connection_options
else
@config = (deprecated_connection_options || {}).symbolize_keys
@connection_parameters = nil
end
end

@owner = nil
@instrumenter = ActiveSupport::Notifications.instrumenter
@pool = ActiveRecord::ConnectionAdapters::NullPool.new
@idle_since = Process.clock_gettime(Process::CLOCK_MONOTONIC)
@visitor = arel_visitor
@statements = build_statement_pool
@lock = ActiveSupport::Concurrency::LoadInterlockAwareMonitor.new

@prepared_statements = self.class.type_cast_config_to_boolean(
config.fetch(:prepared_statements, true)
@config.fetch(:prepared_statements, true)
)

@advisory_locks_enabled = self.class.type_cast_config_to_boolean(
config.fetch(:advisory_locks, true)
@config.fetch(:advisory_locks, true)
)

@default_timezone = self.class.validate_default_timezone(config[:default_timezone])
@default_timezone = self.class.validate_default_timezone(@config[:default_timezone])

@raw_connection_dirty = false
@verified = false

configure_connection
end

EXCEPTION_NEVER = { Exception => :never }.freeze # :nodoc:
Expand Down Expand Up @@ -320,7 +337,14 @@ def adapter_name

# Does the database for this adapter exist?
def self.database_exists?(config)
raise NotImplementedError
new(config).database_exists?
end

def database_exists?
connect!
true
rescue ActiveRecord::NoDatabaseError
false
end

# Does this adapter support DDL rollbacks in transactions? That is, would
Expand Down Expand Up @@ -663,6 +687,11 @@ def verify!
@verified = true
end

def connect!
verify!
self
end

def clean! # :nodoc:
@raw_connection_dirty = false
@verified = nil
Expand Down Expand Up @@ -865,6 +894,8 @@ def reconnect_can_restore_state?
#
def with_raw_connection(allow_retry: false, uses_transaction: true)
@lock.synchronize do
connect! if @raw_connection.nil? && reconnect_can_restore_state?

materialize_transactions if uses_transaction

retries_available = allow_retry ? connection_retries : 0
Expand Down Expand Up @@ -943,7 +974,7 @@ def reconnect
# to both be thread-safe and not rely upon actual server communication.
# This is useful for e.g. string escaping methods.
def any_raw_connection
@raw_connection
@raw_connection || valid_raw_connection
end

# Similar to any_raw_connection, but ensures it is validated and
Expand Down
4 changes: 0 additions & 4 deletions activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
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Original file line number Diff line number Diff line change
Expand Up @@ -51,10 +51,6 @@ def dealloc(stmt)
end
end

def initialize(connection, logger, connection_options, config)
super(connection, logger, config)
end

def get_database_version # :nodoc:
full_version_string = get_full_version
version_string = version_string(full_version_string)
Expand Down
62 changes: 25 additions & 37 deletions activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb
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Original file line number Diff line number Diff line change
Expand Up @@ -10,21 +10,7 @@ module ActiveRecord
module ConnectionHandling # :nodoc:
# Establishes a connection to the database that's used by all Active Record objects.
def mysql2_connection(config)
config = config.symbolize_keys
config[:flags] ||= 0

if config[:flags].kind_of? Array
config[:flags].push "FOUND_ROWS"
else
config[:flags] |= Mysql2::Client::FOUND_ROWS
end

ConnectionAdapters::Mysql2Adapter.new(
ConnectionAdapters::Mysql2Adapter.new_client(config),
logger,
nil,
config,
)
ConnectionAdapters::Mysql2Adapter.new(config)
end
end

Expand Down Expand Up @@ -55,16 +41,25 @@ def new_client(config)
end
end

def initialize(connection, logger, connection_options, config)
check_prepared_statements_deprecation(config)
superclass_config = config.reverse_merge(prepared_statements: false)
super(connection, logger, connection_options, superclass_config)
end
def initialize(...)
super

@config[:flags] ||= 0

def self.database_exists?(config)
!!ActiveRecord::Base.mysql2_connection(config)
rescue ActiveRecord::NoDatabaseError
false
if @config[:flags].kind_of? Array
@config[:flags].push "FOUND_ROWS"
else
@config[:flags] |= Mysql2::Client::FOUND_ROWS
end

unless @config.key?(:prepared_statements)
ActiveSupport::Deprecation.warn(<<-MSG.squish)
The default value of `prepared_statements` for the mysql2 adapter will be changed from +false+ to +true+ in Rails 7.2.
MSG
@config[:prepared_statements] = false
end

@connection_parameters ||= @config
end

def supports_json?
Expand Down Expand Up @@ -120,7 +115,7 @@ def quote_string(string)
#++

def active?
@raw_connection.ping
!!@raw_connection&.ping
end

alias :reset! :reconnect!
Expand All @@ -129,30 +124,23 @@ def active?
# Otherwise, this method does nothing.
def disconnect!
super
@raw_connection.close
@raw_connection&.close
@raw_connection = nil
end

def discard! # :nodoc:
super
@raw_connection.automatic_close = false
@raw_connection&.automatic_close = false
@raw_connection = nil
end

private
def check_prepared_statements_deprecation(config)
if !config.key?(:prepared_statements)
ActiveSupport::Deprecation.warn(<<-MSG.squish)
The default value of `prepared_statements` for the mysql2 adapter will be changed from +false+ to +true+ in Rails 7.2.
MSG
end
end

def connect
@raw_connection = self.class.new_client(@config)
@raw_connection = self.class.new_client(@connection_parameters)
end

def reconnect
@raw_connection.close
@raw_connection&.close
connect
end

Expand Down
63 changes: 31 additions & 32 deletions activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
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Original file line number Diff line number Diff line change
Expand Up @@ -23,22 +23,7 @@ module ActiveRecord
module ConnectionHandling # :nodoc:
# Establishes a connection to the database that's used by all Active Record objects
def postgresql_connection(config)
conn_params = config.symbolize_keys.compact

# Map ActiveRecords param names to PGs.
conn_params[:user] = conn_params.delete(:username) if conn_params[:username]
conn_params[:dbname] = conn_params.delete(:database) if conn_params[:database]

# Forward only valid config params to PG::Connection.connect.
valid_conn_param_keys = PG::Connection.conndefaults_hash.keys + [:requiressl]
conn_params.slice!(*valid_conn_param_keys)

ConnectionAdapters::PostgreSQLAdapter.new(
ConnectionAdapters::PostgreSQLAdapter.new_client(conn_params),
logger,
conn_params,
config,
)
ConnectionAdapters::PostgreSQLAdapter.new(config)
end
end

Expand Down Expand Up @@ -282,26 +267,31 @@ def dealloc(key)
end

# Initializes and connects a PostgreSQL adapter.
def initialize(connection, logger, connection_parameters, config)
@connection_parameters = connection_parameters || {}
def initialize(...)
super

conn_params = @config.compact

# Map ActiveRecords param names to PGs.
conn_params[:user] = conn_params.delete(:username) if conn_params[:username]
conn_params[:dbname] = conn_params.delete(:database) if conn_params[:database]

# Forward only valid config params to PG::Connection.connect.
valid_conn_param_keys = PG::Connection.conndefaults_hash.keys + [:requiressl]
conn_params.slice!(*valid_conn_param_keys)

@connection_parameters = conn_params

@max_identifier_length = nil
@type_map = nil

super(connection, logger, config)

@use_insert_returning = @config.key?(:insert_returning) ? self.class.type_cast_config_to_boolean(@config[:insert_returning]) : true
end

def self.database_exists?(config)
!!ActiveRecord::Base.postgresql_connection(config)
rescue ActiveRecord::NoDatabaseError
false
end

# Is this connection alive and ready for queries?
def active?
@lock.synchronize do
return false unless @raw_connection
@raw_connection.query ";"
end
true
Expand All @@ -323,6 +313,8 @@ def reload_type_map # :nodoc:

def reset!
@lock.synchronize do
return connect! unless @raw_connection

unless @raw_connection.transaction_status == ::PG::PQTRANS_IDLE
@raw_connection.query "ROLLBACK"
end
Expand All @@ -337,13 +329,14 @@ def reset!
def disconnect!
@lock.synchronize do
super
@raw_connection.close rescue nil
@raw_connection&.close rescue nil
@raw_connection = nil
end
end

def discard! # :nodoc:
super
@raw_connection.socket_io.reopen(IO::NULL) rescue nil
@raw_connection&.socket_io&.reopen(IO::NULL) rescue nil
@raw_connection = nil
end

Expand Down Expand Up @@ -861,9 +854,13 @@ def connect
end

def reconnect
@raw_connection.reset
rescue PG::ConnectionBad
connect
begin
@raw_connection&.reset
rescue PG::ConnectionBad
@raw_connection = nil
end

connect unless @raw_connection
end

# Configures the encoding, verbosity, schema search path, and time zone of the connection.
Expand Down Expand Up @@ -995,7 +992,7 @@ def add_pg_encoders
end

def update_typemap_for_default_timezone
if @mapped_default_timezone != default_timezone && @timestamp_decoder
if @raw_connection && @mapped_default_timezone != default_timezone && @timestamp_decoder
decoder_class = default_timezone == :utc ?
PG::TextDecoder::TimestampUtc :
PG::TextDecoder::TimestampWithoutTimeZone
Expand All @@ -1008,6 +1005,8 @@ def update_typemap_for_default_timezone
# if default timezone has changed, we need to reconfigure the connection
# (specifically, the session time zone)
reconfigure_connection_timezone

true
end
end

Expand Down

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