require "active_record/connection_adapters/abstract_adapter"
require "active_record/connection_adapters/postgresql/column"
require "active_record/connection_adapters/postgresql/database_statements"
require "active_record/connection_adapters/postgresql/oid"
require "active_record/connection_adapters/postgresql/quoting"
require "active_record/connection_adapters/postgresql/referential_integrity"
require "active_record/connection_adapters/postgresql/schema_definitions"
require "active_record/connection_adapters/postgresql/schema_statements"
require "active_record/connection_adapters/postgresql/type_metadata"
require "active_record/connection_adapters/postgresql/utils"
require "active_record/connection_adapters/statement_pool"
require 'arel/visitors/bind_visitor'
# Make sure we're using pg high enough for PGResult#values
gem 'pg', '~> 0.15'
require 'pg'
require 'ipaddr'
module ActiveRecord
module ConnectionHandling # :nodoc:
VALID_CONN_PARAMS = [:host, :hostaddr, :port, :dbname, :user, :password, :connect_timeout,
:client_encoding, :options, :application_name, :fallback_application_name,
:keepalives, :keepalives_idle, :keepalives_interval, :keepalives_count,
:tty, :sslmode, :requiressl, :sslcompression, :sslcert, :sslkey,
:sslrootcert, :sslcrl, :requirepeer, :krbsrvname, :gsslib, :service]
# Establishes a connection to the database that's used by all Active Record objects
def postgresql_connection(config)
conn_params = config.symbolize_keys
conn_params.delete_if { |_, v| v.nil? }
# 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 PGconn.connect.
conn_params.keep_if { |k, _| VALID_CONN_PARAMS.include?(k) }
# The postgres drivers don't allow the creation of an unconnected PGconn object,
# so just pass a nil connection object for the time being.
ConnectionAdapters::PostgreSQLAdapter.new(nil, logger, conn_params, config)
end
end
module ConnectionAdapters
# The PostgreSQL adapter works with the native C (https://bitbucket.org/ged/ruby-pg) driver.
#
# Options:
#
# * <tt>:host</tt> - Defaults to a Unix-domain socket in /tmp. On machines without Unix-domain sockets,
# the default is to connect to localhost.
# * <tt>:port</tt> - Defaults to 5432.
# * <tt>:username</tt> - Defaults to be the same as the operating system name of the user running the application.
# * <tt>:password</tt> - Password to be used if the server demands password authentication.
# * <tt>:database</tt> - Defaults to be the same as the user name.
# * <tt>:schema_search_path</tt> - An optional schema search path for the connection given
# as a string of comma-separated schema names. This is backward-compatible with the <tt>:schema_order</tt> option.
# * <tt>:encoding</tt> - An optional client encoding that is used in a <tt>SET client_encoding TO
# <encoding></tt> call on the connection.
# * <tt>:min_messages</tt> - An optional client min messages that is used in a
# <tt>SET client_min_messages TO <min_messages></tt> call on the connection.
# * <tt>:variables</tt> - An optional hash of additional parameters that
# will be used in <tt>SET SESSION key = val</tt> calls on the connection.
# * <tt>:insert_returning</tt> - An optional boolean to control the use of <tt>RETURNING</tt> for <tt>INSERT</tt> statements
# defaults to true.
#
# Any further options are used as connection parameters to libpq. See
# http://www.postgresql.org/docs/9.1/static/libpq-connect.html for the
# list of parameters.
#
# In addition, default connection parameters of libpq can be set per environment variables.
# See http://www.postgresql.org/docs/9.1/static/libpq-envars.html .
class PostgreSQLAdapter < AbstractAdapter
ADAPTER_NAME = 'PostgreSQL'.freeze
NATIVE_DATABASE_TYPES = {
primary_key: "serial primary key",
bigserial: "bigserial",
string: { name: "character varying" },
text: { name: "text" },
integer: { name: "integer" },
float: { name: "float" },
decimal: { name: "decimal" },
datetime: { name: "timestamp" },
time: { name: "time" },
date: { name: "date" },
daterange: { name: "daterange" },
numrange: { name: "numrange" },
tsrange: { name: "tsrange" },
tstzrange: { name: "tstzrange" },
int4range: { name: "int4range" },
int8range: { name: "int8range" },
binary: { name: "bytea" },
boolean: { name: "boolean" },
bigint: { name: "bigint" },
xml: { name: "xml" },
tsvector: { name: "tsvector" },
hstore: { name: "hstore" },
inet: { name: "inet" },
cidr: { name: "cidr" },
macaddr: { name: "macaddr" },
uuid: { name: "uuid" },
json: { name: "json" },
jsonb: { name: "jsonb" },
ltree: { name: "ltree" },
citext: { name: "citext" },
point: { name: "point" },
bit: { name: "bit" },
bit_varying: { name: "bit varying" },
money: { name: "money" },
}
OID = PostgreSQL::OID #:nodoc:
include PostgreSQL::Quoting
include PostgreSQL::ReferentialIntegrity
include PostgreSQL::SchemaStatements
include PostgreSQL::DatabaseStatements
include Savepoints
def schema_creation # :nodoc:
PostgreSQL::SchemaCreation.new self
end
def column_spec_for_primary_key(column)
spec = {}
if column.serial?
return unless column.sql_type == 'bigint'
spec[:id] = ':bigserial'
elsif column.type == :uuid
spec[:id] = ':uuid'
spec[:default] = column.default_function.inspect
else
spec[:id] = column.type.inspect
spec.merge!(prepare_column_options(column).delete_if { |key, _| [:name, :type, :null].include?(key) })
end
spec
end
# Adds +:array+ option to the default set provided by the
# AbstractAdapter
def prepare_column_options(column) # :nodoc:
spec = super
spec[:array] = 'true' if column.array?
spec[:default] = "\"#{column.default_function}\"" if column.default_function
spec
end
# Adds +:array+ as a valid migration key
def migration_keys
super + [:array]
end
# Returns +true+, since this connection adapter supports prepared statement
# caching.
def supports_statement_cache?
true
end
def supports_index_sort_order?
true
end
def supports_partial_index?
true
end
def supports_transaction_isolation?
true
end
def supports_foreign_keys?
true
end
def supports_views?
true
end
def index_algorithms
{ concurrently: 'CONCURRENTLY' }
end
class StatementPool < ConnectionAdapters::StatementPool
def initialize(connection, max)
super
@counter = 0
@cache = Hash.new { |h,pid| h[pid] = {} }
end
def each(&block); cache.each(&block); end
def key?(key); cache.key?(key); end
def [](key); cache[key]; end
def length; cache.length; end
def next_key
"a#{@counter + 1}"
end
def []=(sql, key)
while @max <= cache.size
dealloc(cache.shift.last)
end
@counter += 1
cache[sql] = key
end
def clear
cache.each_value do |stmt_key|
dealloc stmt_key
end
cache.clear
end
def delete(sql_key)
dealloc cache[sql_key]
cache.delete sql_key
end
private
def cache
@cache[Process.pid]
end
def dealloc(key)
@connection.query "DEALLOCATE #{key}" if connection_active?
end
def connection_active?
@connection.status == PGconn::CONNECTION_OK
rescue PGError
false
end
end
# Initializes and connects a PostgreSQL adapter.
def initialize(connection, logger, connection_parameters, config)
super(connection, logger)
@visitor = Arel::Visitors::PostgreSQL.new self
if self.class.type_cast_config_to_boolean(config.fetch(:prepared_statements) { true })
@prepared_statements = true
else
@prepared_statements = false
end
@connection_parameters, @config = connection_parameters, config
# @local_tz is initialized as nil to avoid warnings when connect tries to use it
@local_tz = nil
@table_alias_length = nil
connect
add_pg_decoders
@statements = StatementPool.new @connection,
self.class.type_cast_config_to_integer(config.fetch(:statement_limit) { 1000 })
if postgresql_version < 80200
raise "Your version of PostgreSQL (#{postgresql_version}) is too old, please upgrade!"
end
@type_map = Type::HashLookupTypeMap.new
initialize_type_map(type_map)
@local_tz = execute('SHOW TIME ZONE', 'SCHEMA').first["TimeZone"]
@use_insert_returning = @config.key?(:insert_returning) ? self.class.type_cast_config_to_boolean(@config[:insert_returning]) : true
end
# Clears the prepared statements cache.
def clear_cache!
@statements.clear
end
def truncate(table_name, name = nil)
exec_query "TRUNCATE TABLE #{quote_table_name(table_name)}", name, []
end
# Is this connection alive and ready for queries?
def active?
@connection.query 'SELECT 1'
true
rescue PGError
false
end
# Close then reopen the connection.
def reconnect!
super
@connection.reset
configure_connection
end
def reset!
clear_cache!
reset_transaction
unless @connection.transaction_status == ::PG::PQTRANS_IDLE
@connection.query 'ROLLBACK'
end
@connection.query 'DISCARD ALL'
configure_connection
end
# Disconnects from the database if already connected. Otherwise, this
# method does nothing.
def disconnect!
super
@connection.close rescue nil
end
def native_database_types #:nodoc:
NATIVE_DATABASE_TYPES
end
# Returns true, since this connection adapter supports migrations.
def supports_migrations?
true
end
# Does PostgreSQL support finding primary key on non-Active Record tables?
def supports_primary_key? #:nodoc:
true
end
# Enable standard-conforming strings if available.
def set_standard_conforming_strings
old, self.client_min_messages = client_min_messages, 'panic'
execute('SET standard_conforming_strings = on', 'SCHEMA') rescue nil
ensure
self.client_min_messages = old
end
def supports_ddl_transactions?
true
end
def supports_explain?
true
end
# Returns true if pg > 9.1
def supports_extensions?
postgresql_version >= 90100
end
# Range datatypes weren't introduced until PostgreSQL 9.2
def supports_ranges?
postgresql_version >= 90200
end
def supports_materialized_views?
postgresql_version >= 90300
end
def enable_extension(name)
exec_query("CREATE EXTENSION IF NOT EXISTS \"#{name}\"").tap {
reload_type_map
}
end
def disable_extension(name)
exec_query("DROP EXTENSION IF EXISTS \"#{name}\" CASCADE").tap {
reload_type_map
}
end
def extension_enabled?(name)
if supports_extensions?
res = exec_query "SELECT EXISTS(SELECT * FROM pg_available_extensions WHERE name = '#{name}' AND installed_version IS NOT NULL) as enabled",
'SCHEMA'
res.cast_values.first
end
end
def extensions
if supports_extensions?
exec_query("SELECT extname from pg_extension", "SCHEMA").cast_values
else
super
end
end
# Returns the configured supported identifier length supported by PostgreSQL
def table_alias_length
@table_alias_length ||= query('SHOW max_identifier_length', 'SCHEMA')[0][0].to_i
end
# Set the authorized user for this session
def session_auth=(user)
clear_cache!
exec_query "SET SESSION AUTHORIZATION #{user}"
end
def use_insert_returning?
@use_insert_returning
end
def valid_type?(type)
!native_database_types[type].nil?
end
def update_table_definition(table_name, base) #:nodoc:
PostgreSQL::Table.new(table_name, base)
end
def lookup_cast_type(sql_type) # :nodoc:
oid = execute("SELECT #{quote(sql_type)}::regtype::oid", "SCHEMA").first['oid'].to_i
super(oid)
end
def column_name_for_operation(operation, node) # :nodoc:
OPERATION_ALIASES.fetch(operation) { operation.downcase }
end
OPERATION_ALIASES = { # :nodoc:
"maximum" => "max",
"minimum" => "min",
"average" => "avg",
}
protected
# Returns the version of the connected PostgreSQL server.
def postgresql_version
@connection.server_version
end
# See http://www.postgresql.org/docs/9.1/static/errcodes-appendix.html
FOREIGN_KEY_VIOLATION = "23503"
UNIQUE_VIOLATION = "23505"
def translate_exception(exception, message)
return exception unless exception.respond_to?(:result)
case exception.result.try(:error_field, PGresult::PG_DIAG_SQLSTATE)
when UNIQUE_VIOLATION
RecordNotUnique.new(message, exception)
when FOREIGN_KEY_VIOLATION
InvalidForeignKey.new(message, exception)
else
super
end
end
private
def get_oid_type(oid, fmod, column_name, sql_type = '') # :nodoc:
if !type_map.key?(oid)
load_additional_types(type_map, [oid])
end
type_map.fetch(oid, fmod, sql_type) {
warn "unknown OID #{oid}: failed to recognize type of '#{column_name}'. It will be treated as String."
Type::Value.new.tap do |cast_type|
type_map.register_type(oid, cast_type)
end
}
end
def initialize_type_map(m) # :nodoc:
register_class_with_limit m, 'int2', Type::Integer
register_class_with_limit m, 'int4', Type::Integer
register_class_with_limit m, 'int8', Type::Integer
m.alias_type 'oid', 'int2'
m.register_type 'float4', Type::Float.new
m.alias_type 'float8', 'float4'
m.register_type 'text', Type::Text.new
register_class_with_limit m, 'varchar', Type::String
m.alias_type 'char', 'varchar'
m.alias_type 'name', 'varchar'
m.alias_type 'bpchar', 'varchar'
m.register_type 'bool', Type::Boolean.new
register_class_with_limit m, 'bit', OID::Bit
register_class_with_limit m, 'varbit', OID::BitVarying
m.alias_type 'timestamptz', 'timestamp'
m.register_type 'date', Type::Date.new
m.register_type 'time', Type::Time.new
m.register_type 'money', OID::Money.new
m.register_type 'bytea', OID::Bytea.new
m.register_type 'point', OID::Point.new
m.register_type 'hstore', OID::Hstore.new
m.register_type 'json', OID::Json.new
m.register_type 'jsonb', OID::Jsonb.new
m.register_type 'cidr', OID::Cidr.new
m.register_type 'inet', OID::Inet.new
m.register_type 'uuid', OID::Uuid.new
m.register_type 'xml', OID::Xml.new
m.register_type 'tsvector', OID::SpecializedString.new(:tsvector)
m.register_type 'macaddr', OID::SpecializedString.new(:macaddr)
m.register_type 'citext', OID::SpecializedString.new(:citext)
m.register_type 'ltree', OID::SpecializedString.new(:ltree)
# FIXME: why are we keeping these types as strings?
m.alias_type 'interval', 'varchar'
m.alias_type 'path', 'varchar'
m.alias_type 'line', 'varchar'
m.alias_type 'polygon', 'varchar'
m.alias_type 'circle', 'varchar'
m.alias_type 'lseg', 'varchar'
m.alias_type 'box', 'varchar'
m.register_type 'timestamp' do |_, _, sql_type|
precision = extract_precision(sql_type)
OID::DateTime.new(precision: precision)
end
m.register_type 'numeric' do |_, fmod, sql_type|
precision = extract_precision(sql_type)
scale = extract_scale(sql_type)
# The type for the numeric depends on the width of the field,
# so we'll do something special here.
#
# When dealing with decimal columns:
#
# places after decimal = fmod - 4 & 0xffff
# places before decimal = (fmod - 4) >> 16 & 0xffff
if fmod && (fmod - 4 & 0xffff).zero?
# FIXME: Remove this class, and the second argument to
# lookups on PG
Type::DecimalWithoutScale.new(precision: precision)
else
OID::Decimal.new(precision: precision, scale: scale)
end
end
load_additional_types(m)
end
def extract_limit(sql_type) # :nodoc:
case sql_type
when /^bigint/i, /^int8/i
8
when /^smallint/i
2
else
super
end
end
# Extracts the value from a PostgreSQL column default definition.
def extract_value_from_default(default) # :nodoc:
case default
# Quoted types
when /\A[\(B]?'(.*)'::/m
$1.gsub(/''/, "'")
# Boolean types
when 'true', 'false'
default
# Numeric types
when /\A\(?(-?\d+(\.\d*)?)\)?(::bigint)?\z/
$1
# Object identifier types
when /\A-?\d+\z/
$1
else
# Anything else is blank, some user type, or some function
# and we can't know the value of that, so return nil.
nil
end
end
def extract_default_function(default_value, default) # :nodoc:
default if has_default_function?(default_value, default)
end
def has_default_function?(default_value, default) # :nodoc:
!default_value && (%r{\w+\(.*\)} === default)
end
def load_additional_types(type_map, oids = nil) # :nodoc:
if supports_ranges?
query = <<-SQL
SELECT t.oid, t.typname, t.typelem, t.typdelim, t.typinput, r.rngsubtype, t.typtype, t.typbasetype
FROM pg_type as t
LEFT JOIN pg_range as r ON oid = rngtypid
SQL
else
query = <<-SQL
SELECT t.oid, t.typname, t.typelem, t.typdelim, t.typinput, t.typtype, t.typbasetype
FROM pg_type as t
SQL
end
if oids
query += "WHERE t.oid::integer IN (%s)" % oids.join(", ")
end
initializer = OID::TypeMapInitializer.new(type_map)
records = execute(query, 'SCHEMA')
initializer.run(records)
end
FEATURE_NOT_SUPPORTED = "0A000" #:nodoc:
def execute_and_clear(sql, name, binds)
result = without_prepared_statement?(binds) ? exec_no_cache(sql, name, binds) :
exec_cache(sql, name, binds)
ret = yield result
result.clear
ret
end
def exec_no_cache(sql, name, binds)
log(sql, name, binds) { @connection.async_exec(sql, []) }
end
def exec_cache(sql, name, binds)
stmt_key = prepare_statement(sql)
type_casted_binds = binds.map { |attr| type_cast(attr.value_for_database) }
log(sql, name, binds, stmt_key) do
@connection.exec_prepared(stmt_key, type_casted_binds)
end
rescue ActiveRecord::StatementInvalid => e
pgerror = e.original_exception
# Get the PG code for the failure. Annoyingly, the code for
# prepared statements whose return value may have changed is
# FEATURE_NOT_SUPPORTED. Check here for more details:
# http://git.postgresql.org/gitweb/?p=postgresql.git;a=blob;f=src/backend/utils/cache/plancache.c#l573
begin
code = pgerror.result.result_error_field(PGresult::PG_DIAG_SQLSTATE)
rescue
raise e
end
if FEATURE_NOT_SUPPORTED == code
@statements.delete sql_key(sql)
retry
else
raise e
end
end
# Returns the statement identifier for the client side cache
# of statements
def sql_key(sql)
"#{schema_search_path}-#{sql}"
end
# Prepare the statement if it hasn't been prepared, return
# the statement key.
def prepare_statement(sql)
sql_key = sql_key(sql)
unless @statements.key? sql_key
nextkey = @statements.next_key
begin
@connection.prepare nextkey, sql
rescue => e
raise translate_exception_class(e, sql)
end
# Clear the queue
@connection.get_last_result
@statements[sql_key] = nextkey
end
@statements[sql_key]
end
# Connects to a PostgreSQL server and sets up the adapter depending on the
# connected server's characteristics.
def connect
@connection = PGconn.connect(@connection_parameters)
# Money type has a fixed precision of 10 in PostgreSQL 8.2 and below, and as of
# PostgreSQL 8.3 it has a fixed precision of 19. PostgreSQLColumn.extract_precision
# should know about this but can't detect it there, so deal with it here.
OID::Money.precision = (postgresql_version >= 80300) ? 19 : 10
configure_connection
rescue ::PG::Error => error
if error.message.include?("does not exist")
raise ActiveRecord::NoDatabaseError.new(error.message, error)
else
raise
end
end
# Configures the encoding, verbosity, schema search path, and time zone of the connection.
# This is called by #connect and should not be called manually.
def configure_connection
if @config[:encoding]
@connection.set_client_encoding(@config[:encoding])
end
self.client_min_messages = @config[:min_messages] || 'warning'
self.schema_search_path = @config[:schema_search_path] || @config[:schema_order]
# Use standard-conforming strings if available so we don't have to do the E'...' dance.
set_standard_conforming_strings
# If using Active Record's time zone support configure the connection to return
# TIMESTAMP WITH ZONE types in UTC.
# (SET TIME ZONE does not use an equals sign like other SET variables)
if ActiveRecord::Base.default_timezone == :utc
execute("SET time zone 'UTC'", 'SCHEMA')
elsif @local_tz
execute("SET time zone '#{@local_tz}'", 'SCHEMA')
end
# SET statements from :variables config hash
# http://www.postgresql.org/docs/8.3/static/sql-set.html
variables = @config[:variables] || {}
variables.map do |k, v|
if v == ':default' || v == :default
# Sets the value to the global or compile default
execute("SET SESSION #{k} TO DEFAULT", 'SCHEMA')
elsif !v.nil?
execute("SET SESSION #{k} TO #{quote(v)}", 'SCHEMA')
end
end
end
# Returns the current ID of a table's sequence.
def last_insert_id(sequence_name) #:nodoc:
Integer(last_insert_id_value(sequence_name))
end
def last_insert_id_value(sequence_name)
last_insert_id_result(sequence_name).rows.first.first
end
def last_insert_id_result(sequence_name) #:nodoc:
exec_query("SELECT currval('#{sequence_name}')", 'SQL')
end
# Returns the list of a table's column names, data types, and default values.
#
# The underlying query is roughly:
# SELECT column.name, column.type, default.value
# FROM column LEFT JOIN default
# ON column.table_id = default.table_id
# AND column.num = default.column_num
# WHERE column.table_id = get_table_id('table_name')
# AND column.num > 0
# AND NOT column.is_dropped
# ORDER BY column.num
#
# If the table name is not prefixed with a schema, the database will
# take the first match from the schema search path.
#
# Query implementation notes:
# - format_type includes the column size constraint, e.g. varchar(50)
# - ::regclass is a function that gives the id for a table name
def column_definitions(table_name) # :nodoc:
exec_query(<<-end_sql, 'SCHEMA').rows
SELECT a.attname, format_type(a.atttypid, a.atttypmod),
pg_get_expr(d.adbin, d.adrelid), a.attnotnull, a.atttypid, a.atttypmod
FROM pg_attribute a LEFT JOIN pg_attrdef d
ON a.attrelid = d.adrelid AND a.attnum = d.adnum
WHERE a.attrelid = '#{quote_table_name(table_name)}'::regclass
AND a.attnum > 0 AND NOT a.attisdropped
ORDER BY a.attnum
end_sql
end
def extract_table_ref_from_insert_sql(sql) # :nodoc:
sql[/into\s+([^\(]*).*values\s*\(/im]
$1.strip if $1
end
def create_table_definition(name, temporary = false, options = nil, as = nil) # :nodoc:
PostgreSQL::TableDefinition.new native_database_types, name, temporary, options, as
end
def can_perform_case_insensitive_comparison_for?(column)
@case_insensitive_cache ||= {}
@case_insensitive_cache[column.sql_type] ||= begin
sql = <<-end_sql
SELECT exists(
SELECT * FROM pg_proc
INNER JOIN pg_cast
ON casttarget::text::oidvector = proargtypes
WHERE proname = 'lower'
AND castsource = '#{column.sql_type}'::regtype::oid
)
end_sql
execute_and_clear(sql, "SCHEMA", []) do |result|
result.getvalue(0, 0) == 't'
end
end
end
def add_pg_decoders
coders_by_name = {
'int2' => PG::TextDecoder::Integer,
'int4' => PG::TextDecoder::Integer,
'int8' => PG::TextDecoder::Integer,
'oid' => PG::TextDecoder::Integer,
'float4' => PG::TextDecoder::Float,
'float8' => PG::TextDecoder::Float,
'bool' => PG::TextDecoder::Boolean,
}
query = <<-SQL
SELECT t.oid, t.typname, t.typelem, t.typdelim, t.typinput, t.typtype, t.typbasetype
FROM pg_type as t
SQL
coders = execute_and_clear(query, "SCHEMA", []) do |result|
result
.map { |row| construct_coder(row, coders_by_name['typname']) }
.compact
end
map = PG::TypeMapByOid.new
coders.each { |coder| map.add_coder(coder) }
@connection.type_map_for_results = map
end
def construct_coder(row, coder_class)
return unless coder_class
coder_class.new(oid: row['oid'], name: row['typname'])
end
end
end
end