diff options
Diffstat (limited to 'activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb')
| -rw-r--r-- | activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb | 882 |
1 files changed, 882 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb new file mode 100644 index 0000000000..381d5ab29b --- /dev/null +++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb @@ -0,0 +1,882 @@ +# frozen_string_literal: true + +# Make sure we're using pg high enough for type casts and Ruby 2.2+ compatibility +gem "pg", ">= 0.18", "< 2.0" +require "pg" + +# Use async_exec instead of exec_params on pg versions before 1.1 +class ::PG::Connection # :nodoc: + unless self.public_method_defined?(:async_exec_params) + remove_method :exec_params + alias exec_params async_exec + end +end + +require "active_record/connection_adapters/abstract_adapter" +require "active_record/connection_adapters/statement_pool" +require "active_record/connection_adapters/postgresql/column" +require "active_record/connection_adapters/postgresql/database_statements" +require "active_record/connection_adapters/postgresql/explain_pretty_printer" +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_creation" +require "active_record/connection_adapters/postgresql/schema_definitions" +require "active_record/connection_adapters/postgresql/schema_dumper" +require "active_record/connection_adapters/postgresql/schema_statements" +require "active_record/connection_adapters/postgresql/type_metadata" +require "active_record/connection_adapters/postgresql/utils" + +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 + + 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 PG::Connection.connect. + valid_conn_param_keys = PG::Connection.conndefaults_hash.keys + [:requiressl] + conn_params.slice!(*valid_conn_param_keys) + + conn = PG.connect(conn_params) + ConnectionAdapters::PostgreSQLAdapter.new(conn, logger, conn_params, config) + rescue ::PG::Error => error + if error.message.include?("does not exist") + raise ActiveRecord::NoDatabaseError + else + raise + end + 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 + # https://www.postgresql.org/docs/current/static/libpq-connect.html for the + # list of parameters. + # + # In addition, default connection parameters of libpq can be set per environment variables. + # See https://www.postgresql.org/docs/current/static/libpq-envars.html . + class PostgreSQLAdapter < AbstractAdapter + ADAPTER_NAME = "PostgreSQL" + + ## + # :singleton-method: + # PostgreSQL allows the creation of "unlogged" tables, which do not record + # data in the PostgreSQL Write-Ahead Log. This can make the tables faster, + # but significantly increases the risk of data loss if the database + # crashes. As a result, this should not be used in production + # environments. If you would like all created tables to be unlogged in + # the test environment you can add the following line to your test.rb + # file: + # + # ActiveRecord::ConnectionAdapters::PostgreSQLAdapter.create_unlogged_tables = true + class_attribute :create_unlogged_tables, default: false + + NATIVE_DATABASE_TYPES = { + primary_key: "bigserial primary key", + string: { name: "character varying" }, + text: { name: "text" }, + integer: { name: "integer", limit: 4 }, + 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" }, + 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" }, + line: { name: "line" }, + lseg: { name: "lseg" }, + box: { name: "box" }, + path: { name: "path" }, + polygon: { name: "polygon" }, + circle: { name: "circle" }, + bit: { name: "bit" }, + bit_varying: { name: "bit varying" }, + money: { name: "money" }, + interval: { name: "interval" }, + oid: { name: "oid" }, + } + + OID = PostgreSQL::OID #:nodoc: + + include PostgreSQL::Quoting + include PostgreSQL::ReferentialIntegrity + include PostgreSQL::SchemaStatements + include PostgreSQL::DatabaseStatements + + def supports_bulk_alter? + true + end + + def supports_index_sort_order? + true + end + + def supports_partial_index? + true + end + + def supports_expression_index? + true + end + + def supports_transaction_isolation? + true + end + + def supports_foreign_keys? + true + end + + def supports_validate_constraints? + true + end + + def supports_views? + true + end + + def supports_datetime_with_precision? + true + end + + def supports_json? + true + end + + def supports_comments? + true + end + + def supports_savepoints? + true + end + + def index_algorithms + { concurrently: "CONCURRENTLY" } + end + + class StatementPool < ConnectionAdapters::StatementPool # :nodoc: + def initialize(connection, max) + super(max) + @connection = connection + @counter = 0 + end + + def next_key + "a#{@counter + 1}" + end + + def []=(sql, key) + super.tap { @counter += 1 } + end + + private + def dealloc(key) + @connection.query "DEALLOCATE #{key}" if connection_active? + rescue PG::Error + end + + def connection_active? + @connection.status == PG::CONNECTION_OK + rescue PG::Error + false + end + end + + # Initializes and connects a PostgreSQL adapter. + def initialize(connection, logger, connection_parameters, config) + super(connection, logger, config) + + @connection_parameters = connection_parameters + + # @local_tz is initialized as nil to avoid warnings when connect tries to use it + @local_tz = nil + @max_identifier_length = nil + + configure_connection + add_pg_encoders + @statements = StatementPool.new @connection, + self.class.type_cast_config_to_integer(config[:statement_limit]) + + add_pg_decoders + + @type_map = Type::HashLookupTypeMap.new + initialize_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! + @lock.synchronize do + @statements.clear + end + 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? + @lock.synchronize do + @connection.query "SELECT 1" + end + true + rescue PG::Error + false + end + + # Close then reopen the connection. + def reconnect! + @lock.synchronize do + super + @connection.reset + configure_connection + end + end + + def reset! + @lock.synchronize do + clear_cache! + reset_transaction + unless @connection.transaction_status == ::PG::PQTRANS_IDLE + @connection.query "ROLLBACK" + end + @connection.query "DISCARD ALL" + configure_connection + end + end + + # Disconnects from the database if already connected. Otherwise, this + # method does nothing. + def disconnect! + @lock.synchronize do + super + @connection.close rescue nil + end + end + + def discard! # :nodoc: + @connection.socket_io.reopen(IO::NULL) rescue nil + @connection = nil + end + + def native_database_types #:nodoc: + NATIVE_DATABASE_TYPES + end + + def set_standard_conforming_strings + execute("SET standard_conforming_strings = on", "SCHEMA") + end + + def supports_ddl_transactions? + true + end + + def supports_advisory_locks? + true + end + + def supports_explain? + true + end + + def supports_extensions? + true + end + + def supports_ranges? + true + end + deprecate :supports_ranges? + + def supports_materialized_views? + true + end + + def supports_foreign_tables? + true + end + + def supports_pgcrypto_uuid? + postgresql_version >= 90400 + end + + def supports_lazy_transactions? + true + end + + def get_advisory_lock(lock_id) # :nodoc: + unless lock_id.is_a?(Integer) && lock_id.bit_length <= 63 + raise(ArgumentError, "PostgreSQL requires advisory lock ids to be a signed 64 bit integer") + end + query_value("SELECT pg_try_advisory_lock(#{lock_id})") + end + + def release_advisory_lock(lock_id) # :nodoc: + unless lock_id.is_a?(Integer) && lock_id.bit_length <= 63 + raise(ArgumentError, "PostgreSQL requires advisory lock ids to be a signed 64 bit integer") + end + query_value("SELECT pg_advisory_unlock(#{lock_id})") + 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) + 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 + + def extensions + exec_query("SELECT extname FROM pg_extension", "SCHEMA").cast_values + end + + # Returns the configured supported identifier length supported by PostgreSQL + def max_identifier_length + @max_identifier_length ||= query_value("SHOW max_identifier_length", "SCHEMA").to_i + end + alias table_alias_length max_identifier_length + alias index_name_length max_identifier_length + + # Set the authorized user for this session + def session_auth=(user) + clear_cache! + execute("SET SESSION AUTHORIZATION #{user}") + end + + def use_insert_returning? + @use_insert_returning + 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", + } + + # Returns the version of the connected PostgreSQL server. + def postgresql_version + @connection.server_version + end + + def default_index_type?(index) # :nodoc: + index.using == :btree || super + end + + private + def check_version + if postgresql_version < 90300 + raise "Your version of PostgreSQL (#{postgresql_version}) is too old. Active Record supports PostgreSQL >= 9.3." + end + end + + # See https://www.postgresql.org/docs/current/static/errcodes-appendix.html + VALUE_LIMIT_VIOLATION = "22001" + NUMERIC_VALUE_OUT_OF_RANGE = "22003" + NOT_NULL_VIOLATION = "23502" + FOREIGN_KEY_VIOLATION = "23503" + UNIQUE_VIOLATION = "23505" + SERIALIZATION_FAILURE = "40001" + DEADLOCK_DETECTED = "40P01" + LOCK_NOT_AVAILABLE = "55P03" + QUERY_CANCELED = "57014" + + def translate_exception(exception, message:, sql:, binds:) + return exception unless exception.respond_to?(:result) + + case exception.result.try(:error_field, PG::PG_DIAG_SQLSTATE) + when UNIQUE_VIOLATION + RecordNotUnique.new(message, sql: sql, binds: binds) + when FOREIGN_KEY_VIOLATION + InvalidForeignKey.new(message, sql: sql, binds: binds) + when VALUE_LIMIT_VIOLATION + ValueTooLong.new(message, sql: sql, binds: binds) + when NUMERIC_VALUE_OUT_OF_RANGE + RangeError.new(message, sql: sql, binds: binds) + when NOT_NULL_VIOLATION + NotNullViolation.new(message, sql: sql, binds: binds) + when SERIALIZATION_FAILURE + SerializationFailure.new(message, sql: sql, binds: binds) + when DEADLOCK_DETECTED + Deadlocked.new(message, sql: sql, binds: binds) + when LOCK_NOT_AVAILABLE + LockWaitTimeout.new(message, sql: sql, binds: binds) + when QUERY_CANCELED + QueryCanceled.new(message, sql: sql, binds: binds) + else + super + end + end + + def get_oid_type(oid, fmod, column_name, sql_type = "") + if !type_map.key?(oid) + load_additional_types([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.default_value.tap do |cast_type| + type_map.register_type(oid, cast_type) + end + } + end + + def initialize_type_map(m = type_map) + m.register_type "int2", Type::Integer.new(limit: 2) + m.register_type "int4", Type::Integer.new(limit: 4) + m.register_type "int8", Type::Integer.new(limit: 8) + m.register_type "oid", OID::Oid.new + 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", OID::Date.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", Type::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) + m.register_type "line", OID::SpecializedString.new(:line) + m.register_type "lseg", OID::SpecializedString.new(:lseg) + m.register_type "box", OID::SpecializedString.new(:box) + m.register_type "path", OID::SpecializedString.new(:path) + m.register_type "polygon", OID::SpecializedString.new(:polygon) + m.register_type "circle", OID::SpecializedString.new(:circle) + + m.register_type "interval" do |_, _, sql_type| + precision = extract_precision(sql_type) + OID::SpecializedString.new(:interval, precision: precision) + end + + register_class_with_precision m, "time", Type::Time + register_class_with_precision m, "timestamp", OID::DateTime + + 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 + end + + # Extracts the value from a PostgreSQL column default definition. + def extract_value_from_default(default) + case default + # Quoted types + when /\A[\(B]?'(.*)'.*::"?([\w. ]+)"?(?:\[\])?\z/m + # The default 'now'::date is CURRENT_DATE + if $1 == "now" && $2 == "date" + nil + else + $1.gsub("''", "'") + end + # 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) + default if has_default_function?(default_value, default) + end + + def has_default_function?(default_value, default) + !default_value && %r{\w+\(.*\)|\(.*\)::\w+|CURRENT_DATE|CURRENT_TIMESTAMP}.match?(default) + end + + def load_additional_types(oids = nil) + initializer = OID::TypeMapInitializer.new(type_map) + + 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 + + if oids + query += "WHERE t.oid::integer IN (%s)" % oids.join(", ") + else + query += initializer.query_conditions_for_initial_load + end + + execute_and_clear(query, "SCHEMA", []) do |records| + initializer.run(records) + end + end + + FEATURE_NOT_SUPPORTED = "0A000" #:nodoc: + + def execute_and_clear(sql, name, binds, prepare: false) + if preventing_writes? && write_query?(sql) + raise ActiveRecord::ReadOnlyError, "Write query attempted while in readonly mode: #{sql}" + end + + if without_prepared_statement?(binds) + result = exec_no_cache(sql, name, []) + elsif !prepare + result = exec_no_cache(sql, name, binds) + else + result = exec_cache(sql, name, binds) + end + ret = yield result + result.clear + ret + end + + def exec_no_cache(sql, name, binds) + materialize_transactions + + type_casted_binds = type_casted_binds(binds) + log(sql, name, binds, type_casted_binds) do + ActiveSupport::Dependencies.interlock.permit_concurrent_loads do + @connection.exec_params(sql, type_casted_binds) + end + end + end + + def exec_cache(sql, name, binds) + materialize_transactions + + stmt_key = prepare_statement(sql, binds) + type_casted_binds = type_casted_binds(binds) + + log(sql, name, binds, type_casted_binds, stmt_key) do + ActiveSupport::Dependencies.interlock.permit_concurrent_loads do + @connection.exec_prepared(stmt_key, type_casted_binds) + end + end + rescue ActiveRecord::StatementInvalid => e + raise unless is_cached_plan_failure?(e) + + # Nothing we can do if we are in a transaction because all commands + # will raise InFailedSQLTransaction + if in_transaction? + raise ActiveRecord::PreparedStatementCacheExpired.new(e.cause.message) + else + @lock.synchronize do + # outside of transactions we can simply flush this query and retry + @statements.delete sql_key(sql) + end + retry + end + end + + # Annoyingly, the code for prepared statements whose return value may + # have changed is FEATURE_NOT_SUPPORTED. + # + # This covers various different error types so we need to do additional + # work to classify the exception definitively as a + # ActiveRecord::PreparedStatementCacheExpired + # + # Check here for more details: + # https://git.postgresql.org/gitweb/?p=postgresql.git;a=blob;f=src/backend/utils/cache/plancache.c#l573 + CACHED_PLAN_HEURISTIC = "cached plan must not change result type" + def is_cached_plan_failure?(e) + pgerror = e.cause + code = pgerror.result.result_error_field(PG::PG_DIAG_SQLSTATE) + code == FEATURE_NOT_SUPPORTED && pgerror.message.include?(CACHED_PLAN_HEURISTIC) + rescue + false + end + + def in_transaction? + open_transactions > 0 + 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, binds) + @lock.synchronize do + 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, binds) + end + # Clear the queue + @connection.get_last_result + @statements[sql_key] = nextkey + end + @statements[sql_key] + end + end + + # Connects to a PostgreSQL server and sets up the adapter depending on the + # connected server's characteristics. + def connect + @connection = PG.connect(@connection_parameters) + configure_connection + 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 so we don't have to do the E'...' dance. + set_standard_conforming_strings + + variables = @config.fetch(:variables, {}).stringify_keys + + # If using Active Record's time zone support configure the connection to return + # TIMESTAMP WITH ZONE types in UTC. + unless variables["timezone"] + if ActiveRecord::Base.default_timezone == :utc + variables["timezone"] = "UTC" + elsif @local_tz + variables["timezone"] = @local_tz + end + end + + # SET statements from :variables config hash + # https://www.postgresql.org/docs/current/static/sql-set.html + 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 list of a table's column names, data types, and default values. + # + # The underlying query is roughly: + # SELECT column.name, column.type, default.value, column.comment + # 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) + query(<<~SQL, "SCHEMA") + SELECT a.attname, format_type(a.atttypid, a.atttypmod), + pg_get_expr(d.adbin, d.adrelid), a.attnotnull, a.atttypid, a.atttypmod, + c.collname, col_description(a.attrelid, a.attnum) AS comment + FROM pg_attribute a + LEFT JOIN pg_attrdef d ON a.attrelid = d.adrelid AND a.attnum = d.adnum + LEFT JOIN pg_type t ON a.atttypid = t.oid + LEFT JOIN pg_collation c ON a.attcollation = c.oid AND a.attcollation <> t.typcollation + WHERE a.attrelid = #{quote(quote_table_name(table_name))}::regclass + AND a.attnum > 0 AND NOT a.attisdropped + ORDER BY a.attnum + SQL + end + + def extract_table_ref_from_insert_sql(sql) + sql[/into\s("[A-Za-z0-9_."\[\]\s]+"|[A-Za-z0-9_."\[\]]+)\s*/im] + $1.strip if $1 + end + + def arel_visitor + Arel::Visitors::PostgreSQL.new(self) + end + + def can_perform_case_insensitive_comparison_for?(column) + @case_insensitive_cache ||= {} + @case_insensitive_cache[column.sql_type] ||= begin + sql = <<~SQL + SELECT exists( + SELECT * FROM pg_proc + WHERE proname = 'lower' + AND proargtypes = ARRAY[#{quote column.sql_type}::regtype]::oidvector + ) OR exists( + SELECT * FROM pg_proc + INNER JOIN pg_cast + ON ARRAY[casttarget]::oidvector = proargtypes + WHERE proname = 'lower' + AND castsource = #{quote column.sql_type}::regtype + ) + SQL + execute_and_clear(sql, "SCHEMA", []) do |result| + result.getvalue(0, 0) + end + end + end + + def add_pg_encoders + map = PG::TypeMapByClass.new + map[Integer] = PG::TextEncoder::Integer.new + map[TrueClass] = PG::TextEncoder::Boolean.new + map[FalseClass] = PG::TextEncoder::Boolean.new + @connection.type_map_for_queries = map + 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, + } + known_coder_types = coders_by_name.keys.map { |n| quote(n) } + query = <<~SQL % known_coder_types.join(", ") + SELECT t.oid, t.typname + FROM pg_type as t + WHERE t.typname IN (%s) + SQL + coders = execute_and_clear(query, "SCHEMA", []) do |result| + result + .map { |row| construct_coder(row, coders_by_name[row["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"].to_i, name: row["typname"]) + end + + ActiveRecord::Type.add_modifier({ array: true }, OID::Array, adapter: :postgresql) + ActiveRecord::Type.add_modifier({ range: true }, OID::Range, adapter: :postgresql) + ActiveRecord::Type.register(:bit, OID::Bit, adapter: :postgresql) + ActiveRecord::Type.register(:bit_varying, OID::BitVarying, adapter: :postgresql) + ActiveRecord::Type.register(:binary, OID::Bytea, adapter: :postgresql) + ActiveRecord::Type.register(:cidr, OID::Cidr, adapter: :postgresql) + ActiveRecord::Type.register(:date, OID::Date, adapter: :postgresql) + ActiveRecord::Type.register(:datetime, OID::DateTime, adapter: :postgresql) + ActiveRecord::Type.register(:decimal, OID::Decimal, adapter: :postgresql) + ActiveRecord::Type.register(:enum, OID::Enum, adapter: :postgresql) + ActiveRecord::Type.register(:hstore, OID::Hstore, adapter: :postgresql) + ActiveRecord::Type.register(:inet, OID::Inet, adapter: :postgresql) + ActiveRecord::Type.register(:jsonb, OID::Jsonb, adapter: :postgresql) + ActiveRecord::Type.register(:money, OID::Money, adapter: :postgresql) + ActiveRecord::Type.register(:point, OID::Point, adapter: :postgresql) + ActiveRecord::Type.register(:legacy_point, OID::LegacyPoint, adapter: :postgresql) + ActiveRecord::Type.register(:uuid, OID::Uuid, adapter: :postgresql) + ActiveRecord::Type.register(:vector, OID::Vector, adapter: :postgresql) + ActiveRecord::Type.register(:xml, OID::Xml, adapter: :postgresql) + end + end +end |