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require 'date'
require 'bigdecimal'
require 'bigdecimal/util'
require 'active_record/type'
require 'active_support/core_ext/benchmark'
require 'active_record/connection_adapters/schema_cache'
require 'active_record/connection_adapters/sql_type_metadata'
require 'active_record/connection_adapters/abstract/schema_dumper'
require 'active_record/connection_adapters/abstract/schema_creation'
require 'monitor'
require 'arel/collectors/bind'
require 'arel/collectors/sql_string'
module ActiveRecord
module ConnectionAdapters # :nodoc:
extend ActiveSupport::Autoload
autoload :Column
autoload :ConnectionSpecification
autoload_at 'active_record/connection_adapters/abstract/schema_definitions' do
autoload :IndexDefinition
autoload :ColumnDefinition
autoload :ChangeColumnDefinition
autoload :ForeignKeyDefinition
autoload :TableDefinition
autoload :Table
autoload :AlterTable
end
autoload_at 'active_record/connection_adapters/abstract/connection_pool' do
autoload :ConnectionHandler
autoload :ConnectionManagement
end
autoload_under 'abstract' do
autoload :SchemaStatements
autoload :DatabaseStatements
autoload :DatabaseLimits
autoload :Quoting
autoload :ConnectionPool
autoload :QueryCache
autoload :Savepoints
end
autoload_at 'active_record/connection_adapters/abstract/transaction' do
autoload :TransactionManager
autoload :NullTransaction
autoload :RealTransaction
autoload :SavepointTransaction
autoload :TransactionState
end
# Active Record supports multiple database systems. AbstractAdapter and
# related classes form the abstraction layer which makes this possible.
# An AbstractAdapter represents a connection to a database, and provides an
# abstract interface for database-specific functionality such as establishing
# a connection, escaping values, building the right SQL fragments for ':offset'
# and ':limit' options, etc.
#
# All the concrete database adapters follow the interface laid down in this class.
# ActiveRecord::Base.connection returns an AbstractAdapter object, which
# you can use.
#
# Most of the methods in the adapter are useful during migrations. Most
# notably, the instance methods provided by SchemaStatement are very useful.
class AbstractAdapter
ADAPTER_NAME = 'Abstract'.freeze
include Quoting, DatabaseStatements, SchemaStatements
include DatabaseLimits
include QueryCache
include ActiveSupport::Callbacks
include MonitorMixin
include ColumnDumper
SIMPLE_INT = /\A\d+\z/
define_callbacks :checkout, :checkin
attr_accessor :visitor, :pool
attr_reader :schema_cache, :owner, :logger
alias :in_use? :owner
def self.type_cast_config_to_integer(config)
if config =~ SIMPLE_INT
config.to_i
else
config
end
end
def self.type_cast_config_to_boolean(config)
if config == "false"
false
else
config
end
end
attr_reader :prepared_statements
def initialize(connection, logger = nil, pool = nil) #:nodoc:
super()
@connection = connection
@owner = nil
@instrumenter = ActiveSupport::Notifications.instrumenter
@logger = logger
@pool = pool
@schema_cache = SchemaCache.new self
@visitor = nil
@prepared_statements = false
end
class BindCollector < Arel::Collectors::Bind
def compile(bvs, conn)
casted_binds = conn.prepare_binds_for_database(bvs)
super(casted_binds.map { |value| conn.quote(value) })
end
end
class SQLString < Arel::Collectors::SQLString
def compile(bvs, conn)
super(bvs)
end
end
def collector
if prepared_statements
SQLString.new
else
BindCollector.new
end
end
def valid_type?(type)
true
end
def schema_creation
SchemaCreation.new self
end
def lease
synchronize do
unless in_use?
@owner = Thread.current
end
end
end
def schema_cache=(cache)
cache.connection = self
@schema_cache = cache
end
def expire
@owner = nil
end
def unprepared_statement
old_prepared_statements, @prepared_statements = @prepared_statements, false
yield
ensure
@prepared_statements = old_prepared_statements
end
# Returns the human-readable name of the adapter. Use mixed case - one
# can always use downcase if needed.
def adapter_name
self.class::ADAPTER_NAME
end
# Does this adapter support migrations?
def supports_migrations?
false
end
# Can this adapter determine the primary key for tables not attached
# to an Active Record class, such as join tables?
def supports_primary_key?
false
end
# Does this adapter support DDL rollbacks in transactions? That is, would
# CREATE TABLE or ALTER TABLE get rolled back by a transaction?
def supports_ddl_transactions?
false
end
def supports_bulk_alter?
false
end
# Does this adapter support savepoints?
def supports_savepoints?
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.
def prefetch_primary_key?(table_name = nil)
false
end
# Does this adapter support index sort order?
def supports_index_sort_order?
false
end
# Does this adapter support partial indices?
def supports_partial_index?
false
end
# Does this adapter support explain?
def supports_explain?
false
end
# Does this adapter support setting the isolation level for a transaction?
def supports_transaction_isolation?
false
end
# Does this adapter support database extensions?
def supports_extensions?
false
end
# Does this adapter support creating indexes in the same statement as
# creating the table?
def supports_indexes_in_create?
false
end
# Does this adapter support creating foreign key constraints?
def supports_foreign_keys?
false
end
# Does this adapter support views?
def supports_views?
false
end
# Does this adapter support datetime with precision?
def supports_datetime_with_precision?
false
end
# This is meant to be implemented by the adapters that support extensions
def disable_extension(name)
end
# This is meant to be implemented by the adapters that support extensions
def enable_extension(name)
end
# A list of extensions, to be filled in by adapters that support them.
def extensions
[]
end
# A list of index algorithms, to be filled by adapters that support them.
def index_algorithms
{}
end
# Returns a bind substitution value given a bind +column+
# NOTE: The column param is currently being used by the sqlserver-adapter
def substitute_at(column, _unused = 0)
Arel::Nodes::BindParam.new
end
# REFERENTIAL INTEGRITY ====================================
# Override to turn off referential integrity while executing <tt>&block</tt>.
def disable_referential_integrity
yield
end
# CONNECTION MANAGEMENT ====================================
# Checks whether the connection to the database is still active. This includes
# checking whether the database is actually capable of responding, i.e. whether
# the connection isn't stale.
def active?
end
# Disconnects from the database if already connected, and establishes a
# new connection with the database. Implementors should call super if they
# override the default implementation.
def reconnect!
clear_cache!
reset_transaction
end
# Disconnects from the database if already connected. Otherwise, this
# method does nothing.
def disconnect!
clear_cache!
reset_transaction
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 implementation does nothing; the implementation should be
# overridden by concrete adapters.
def reset!
# this should be overridden by concrete adapters
end
###
# Clear any caching the database adapter may be doing, for example
# clearing the prepared statement cache. This is database specific.
def clear_cache!
# this should be overridden by concrete adapters
end
# Returns true if its required to reload the connection between requests for development mode.
def requires_reloading?
false
end
# Checks whether the connection to the database is still active (i.e. not stale).
# This is done under the hood by calling <tt>active?</tt>. If the connection
# is no longer active, then this method will reconnect to the database.
def verify!(*ignored)
reconnect! unless active?
end
# Provides access to the underlying database driver for this adapter. For
# example, this method returns a Mysql object in case of MysqlAdapter,
# and a PGconn object in case of PostgreSQLAdapter.
#
# This is useful for when you need to call a proprietary method such as
# PostgreSQL's lo_* methods.
def raw_connection
@connection
end
def create_savepoint(name = nil)
end
def release_savepoint(name = nil)
end
def case_sensitive_modifier(node, table_attribute)
node
end
def case_sensitive_comparison(table, attribute, column, value)
table_attr = table[attribute]
value = case_sensitive_modifier(value, table_attr) unless value.nil?
table_attr.eq(value)
end
def case_insensitive_comparison(table, attribute, column, value)
if can_perform_case_insensitive_comparison_for?(column)
table[attribute].lower.eq(table.lower(value))
else
case_sensitive_comparison(table, attribute, column, value)
end
end
def can_perform_case_insensitive_comparison_for?(column)
true
end
private :can_perform_case_insensitive_comparison_for?
def current_savepoint_name
current_transaction.savepoint_name
end
# Check the connection back in to the connection pool
def close
pool.checkin self
end
def type_map # :nodoc:
@type_map ||= Type::TypeMap.new.tap do |mapping|
initialize_type_map(mapping)
end
end
def new_column(name, default, sql_type_metadata = nil, null = true)
Column.new(name, default, sql_type_metadata, null)
end
def lookup_cast_type(sql_type) # :nodoc:
type_map.lookup(sql_type)
end
def column_name_for_operation(operation, node) # :nodoc:
visitor.accept(node, collector).value
end
protected
def initialize_type_map(m) # :nodoc:
register_class_with_limit m, %r(boolean)i, Type::Boolean
register_class_with_limit m, %r(char)i, Type::String
register_class_with_limit m, %r(binary)i, Type::Binary
register_class_with_limit m, %r(text)i, Type::Text
register_class_with_precision m, %r(date)i, Type::Date
register_class_with_precision m, %r(time)i, Type::Time
register_class_with_precision m, %r(datetime)i, Type::DateTime
register_class_with_limit m, %r(float)i, Type::Float
register_class_with_limit m, %r(int)i, Type::Integer
m.alias_type %r(blob)i, 'binary'
m.alias_type %r(clob)i, 'text'
m.alias_type %r(timestamp)i, 'datetime'
m.alias_type %r(numeric)i, 'decimal'
m.alias_type %r(number)i, 'decimal'
m.alias_type %r(double)i, 'float'
m.register_type(%r(decimal)i) do |sql_type|
scale = extract_scale(sql_type)
precision = extract_precision(sql_type)
if scale == 0
# FIXME: Remove this class as well
Type::DecimalWithoutScale.new(precision: precision)
else
Type::Decimal.new(precision: precision, scale: scale)
end
end
end
def reload_type_map # :nodoc:
type_map.clear
initialize_type_map(type_map)
end
def register_class_with_limit(mapping, key, klass) # :nodoc:
mapping.register_type(key) do |*args|
limit = extract_limit(args.last)
klass.new(limit: limit)
end
end
def register_class_with_precision(mapping, key, klass) # :nodoc:
mapping.register_type(key) do |*args|
precision = extract_precision(args.last)
klass.new(precision: precision)
end
end
def extract_scale(sql_type) # :nodoc:
case sql_type
when /\((\d+)\)/ then 0
when /\((\d+)(,(\d+))\)/ then $3.to_i
end
end
def extract_precision(sql_type) # :nodoc:
$1.to_i if sql_type =~ /\((\d+)(,\d+)?\)/
end
def extract_limit(sql_type) # :nodoc:
case sql_type
when /^bigint/i
8
when /\((.*)\)/
$1.to_i
end
end
def translate_exception_class(e, sql)
begin
message = "#{e.class.name}: #{e.message}: #{sql}"
rescue Encoding::CompatibilityError
message = "#{e.class.name}: #{e.message.force_encoding sql.encoding}: #{sql}"
end
exception = translate_exception(e, message)
exception.set_backtrace e.backtrace
exception
end
def log(sql, name = "SQL", binds = [], statement_name = nil)
@instrumenter.instrument(
"sql.active_record",
:sql => sql,
:name => name,
:connection_id => object_id,
:statement_name => statement_name,
:binds => binds) { yield }
rescue => e
raise translate_exception_class(e, sql)
end
def translate_exception(exception, message)
# override in derived class
ActiveRecord::StatementInvalid.new(message, exception)
end
def without_prepared_statement?(binds)
!prepared_statements || binds.empty?
end
def column_for(table_name, column_name) # :nodoc:
column_name = column_name.to_s
columns(table_name).detect { |c| c.name == column_name } ||
raise(ActiveRecordError, "No such column: #{table_name}.#{column_name}")
end
end
end
end
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