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require 'benchmark'
require 'date'
require 'bigdecimal'
require 'bigdecimal/util'
require 'active_record/connection_adapters/abstract/schema_definitions'
require 'active_record/connection_adapters/abstract/schema_statements'
require 'active_record/connection_adapters/abstract/database_statements'
require 'active_record/connection_adapters/abstract/quoting'
require 'active_record/connection_adapters/abstract/connection_pool'
require 'active_record/connection_adapters/abstract/connection_specification'
require 'active_record/connection_adapters/abstract/query_cache'
module ActiveRecord
module ConnectionAdapters # :nodoc:
# All the concrete database adapters follow the interface laid down in this class.
# You can use this interface directly by borrowing the database connection from the Base with
# Base.connection.
#
# Most of the methods in the adapter are useful during migrations. Most
# notably, SchemaStatements#create_table, SchemaStatements#drop_table,
# SchemaStatements#add_index, SchemaStatements#remove_index,
# SchemaStatements#add_column, SchemaStatements#change_column and
# SchemaStatements#remove_column are very useful.
class AbstractAdapter
include Quoting, DatabaseStatements, SchemaStatements
include QueryCache
include ActiveSupport::Callbacks
define_callbacks :checkout, :checkin
checkout :reset!
@@row_even = true
def initialize(connection, logger = nil) #:nodoc:
@connection, @logger = connection, logger
@runtime = 0
@last_verification = 0
@query_cache_enabled = false
end
# Returns the human-readable name of the adapter. Use mixed case - one
# can always use downcase if needed.
def adapter_name
'Abstract'
end
# Does this adapter support migrations? Backend specific, as the
# abstract adapter always returns +false+.
def supports_migrations?
false
end
# Does this adapter support using DISTINCT within COUNT? This is +true+
# for all adapters except sqlite.
def supports_count_distinct?
true
end
# Does this adapter support DDL rollbacks in transactions? That is, would
# CREATE TABLE or ALTER TABLE get rolled back by a transaction? PostgreSQL,
# SQL Server, and others support this. MySQL and others do not.
def supports_ddl_transactions?
false
end
# Should primary key values be selected from their corresponding
# sequence before the insert statement? If true, next_sequence_value
# is called before each insert to set the record's primary key.
# This is false for all adapters but Firebird.
def prefetch_primary_key?(table_name = nil)
false
end
def reset_runtime #:nodoc:
rt, @runtime = @runtime, 0
rt
end
# QUOTING ==================================================
# Override to return the quoted table name. Defaults to column quoting.
def quote_table_name(name)
quote_column_name(name)
end
# REFERENTIAL INTEGRITY ====================================
# Override to turn off referential integrity while executing <tt>&block</tt>.
def disable_referential_integrity(&block)
yield
end
# CONNECTION MANAGEMENT ====================================
# Is this connection active and ready to perform queries?
def active?
@active != false
end
# Close this connection and open a new one in its place.
def reconnect!
@active = true
end
# Close this connection
def disconnect!
@active = false
end
# Reset the state of this connection, directing the DBMS to clear
# transactions and other connection-related server-side state. Usually a
# database-dependent operation; the default method simply executes a
# ROLLBACK and swallows any exceptions which is probably not enough to
# ensure the connection is clean.
def reset!
# this should be overridden by concrete adapters
end
# Returns true if its safe to reload the connection between requests for development mode.
# This is not the case for Ruby/MySQL and it's not necessary for any adapters except SQLite.
def requires_reloading?
false
end
# Verify this connection by calling <tt>active?</tt> and reconnecting if
# the connection is no longer active.
def verify!(*ignored)
reconnect! unless active?
end
# Provides access to the underlying database connection. Useful for
# when you need to call a proprietary method such as postgresql's lo_*
# methods
def raw_connection
@connection
end
def open_transactions
@open_transactions ||= 0
end
def increment_open_transactions
@open_transactions ||= 0
@open_transactions += 1
end
def decrement_open_transactions
@open_transactions -= 1
end
def log_info(sql, name, seconds)
if @logger && @logger.debug?
name = "#{name.nil? ? "SQL" : name} (#{sprintf("%.1f", seconds * 1000)}ms)"
@logger.debug(format_log_entry(name, sql.squeeze(' ')))
end
end
protected
def log(sql, name)
if block_given?
result = nil
seconds = Benchmark.realtime { result = yield }
@runtime += seconds
log_info(sql, name, seconds)
result
else
log_info(sql, name, 0)
nil
end
rescue Exception => e
# Log message and raise exception.
# Set last_verification to 0, so that connection gets verified
# upon reentering the request loop
@last_verification = 0
message = "#{e.class.name}: #{e.message}: #{sql}"
log_info(message, name, 0)
raise ActiveRecord::StatementInvalid, message
end
def format_log_entry(message, dump = nil)
if ActiveRecord::Base.colorize_logging
if @@row_even
@@row_even = false
message_color, dump_color = "4;36;1", "0;1"
else
@@row_even = true
message_color, dump_color = "4;35;1", "0"
end
log_entry = " \e[#{message_color}m#{message}\e[0m "
log_entry << "\e[#{dump_color}m%#{String === dump ? 's' : 'p'}\e[0m" % dump if dump
log_entry
else
"%s %s" % [message, dump]
end
end
end
end
end
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