# -*- ruby -*-
# frozen_string_literal: true
require 'pg' unless defined?( PG )
require 'io/wait' unless ::IO.public_instance_methods(false).include?(:wait_readable)
require 'socket'
# The PostgreSQL connection class. The interface for this class is based on
# {libpq}[http://www.postgresql.org/docs/current/libpq.html], the C
# application programmer's interface to PostgreSQL. Some familiarity with libpq
# is recommended, but not necessary.
#
# For example, to send query to the database on the localhost:
#
# require 'pg'
# conn = PG::Connection.open(:dbname => 'test')
# res = conn.exec_params('SELECT $1 AS a, $2 AS b, $3 AS c', [1, 2, nil])
# # Equivalent to:
# # res = conn.exec('SELECT 1 AS a, 2 AS b, NULL AS c')
#
# See the PG::Result class for information on working with the results of a query.
#
# Many methods of this class have three variants kind of:
# 1. #exec - the base method which is an alias to #async_exec .
# This is the method that should be used in general.
# 2. #async_exec - the async aware version of the method, implemented by libpq's async API.
# 3. #sync_exec - the method version that is implemented by blocking function(s) of libpq.
#
# Sync and async version of the method can be switched by Connection.async_api= , however it is not recommended to change the default.
class PG::Connection
# The order the options are passed to the ::connect method.
CONNECT_ARGUMENT_ORDER = %w[host port options tty dbname user password].freeze
private_constant :CONNECT_ARGUMENT_ORDER
### Quote a single +value+ for use in a connection-parameter string.
def self.quote_connstr( value )
return "'" + value.to_s.gsub( /[\\']/ ) {|m| '\\' + m } + "'"
end
# Convert Hash options to connection String
#
# Values are properly quoted and escaped.
def self.connect_hash_to_string( hash )
hash.map { |k,v| "#{k}=#{quote_connstr(v)}" }.join( ' ' )
end
# Shareable program name for Ractor
PROGRAM_NAME = $PROGRAM_NAME.dup.freeze
private_constant :PROGRAM_NAME
# Parse the connection +args+ into a connection-parameter string.
# See PG::Connection.new for valid arguments.
#
# It accepts:
# * an option String kind of "host=name port=5432"
# * an option Hash kind of {host: "name", port: 5432}
# * URI string
# * URI object
# * positional arguments
#
# The method adds the option "fallback_application_name" if it isn't already set.
# It returns a connection string with "key=value" pairs.
def self.parse_connect_args( *args )
hash_arg = args.last.is_a?( Hash ) ? args.pop.transform_keys(&:to_sym) : {}
iopts = {}
if args.length == 1
case args.first.to_s
when /=/, /:\/\//
# Option or URL string style
conn_string = args.first.to_s
iopts = PG::Connection.conninfo_parse(conn_string).each_with_object({}){|h, o| o[h[:keyword].to_sym] = h[:val] if h[:val] }
else
# Positional parameters (only host given)
iopts[CONNECT_ARGUMENT_ORDER.first.to_sym] = args.first
end
else
# Positional parameters with host and more
max = CONNECT_ARGUMENT_ORDER.length
raise ArgumentError,
"Extra positional parameter %d: %p" % [ max + 1, args[max] ] if args.length > max
CONNECT_ARGUMENT_ORDER.zip( args ) do |(k,v)|
iopts[ k.to_sym ] = v if v
end
iopts.delete(:tty) # ignore obsolete tty parameter
end
iopts.merge!( hash_arg )
if !iopts[:fallback_application_name]
iopts[:fallback_application_name] = PROGRAM_NAME.sub( /^(.{30}).{4,}(.{30})$/ ){ $1+"..."+$2 }
end
return connect_hash_to_string(iopts)
end
# Return a String representation of the object suitable for debugging.
def inspect
str = self.to_s
str[-1,0] = if finished?
" finished"
else
stats = []
stats << " status=#{ PG.constants.grep(/CONNECTION_/).find{|c| PG.const_get(c) == status} }" if status != CONNECTION_OK
stats << " transaction_status=#{ PG.constants.grep(/PQTRANS_/).find{|c| PG.const_get(c) == transaction_status} }" if transaction_status != PG::PQTRANS_IDLE
stats << " nonblocking=#{ isnonblocking }" if isnonblocking
stats << " pipeline_status=#{ PG.constants.grep(/PQ_PIPELINE_/).find{|c| PG.const_get(c) == pipeline_status} }" if respond_to?(:pipeline_status) && pipeline_status != PG::PQ_PIPELINE_OFF
stats << " client_encoding=#{ get_client_encoding }" if get_client_encoding != "UTF8"
stats << " type_map_for_results=#{ type_map_for_results.to_s }" unless type_map_for_results.is_a?(PG::TypeMapAllStrings)
stats << " type_map_for_queries=#{ type_map_for_queries.to_s }" unless type_map_for_queries.is_a?(PG::TypeMapAllStrings)
stats << " encoder_for_put_copy_data=#{ encoder_for_put_copy_data.to_s }" if encoder_for_put_copy_data
stats << " decoder_for_get_copy_data=#{ decoder_for_get_copy_data.to_s }" if decoder_for_get_copy_data
" host=#{host} port=#{port} user=#{user}#{stats.join}"
end
return str
end
BinarySignature = "PGCOPY\n\377\r\n\0".b
private_constant :BinarySignature
# call-seq:
# conn.copy_data( sql [, coder] ) {|sql_result| ... } -> PG::Result
#
# Execute a copy process for transferring data to or from the server.
#
# This issues the SQL COPY command via #exec. The response to this
# (if there is no error in the command) is a PG::Result object that
# is passed to the block, bearing a status code of PGRES_COPY_OUT or
# PGRES_COPY_IN (depending on the specified copy direction).
# The application should then use #put_copy_data or #get_copy_data
# to receive or transmit data rows and should return from the block
# when finished.
#
# #copy_data returns another PG::Result object when the data transfer
# is complete. An exception is raised if some problem was encountered,
# so it isn't required to make use of any of them.
# At this point further SQL commands can be issued via #exec.
# (It is not possible to execute other SQL commands using the same
# connection while the COPY operation is in progress.)
#
# This method ensures, that the copy process is properly terminated
# in case of client side or server side failures. Therefore, in case
# of blocking mode of operation, #copy_data is preferred to raw calls
# of #put_copy_data, #get_copy_data and #put_copy_end.
#
# _coder_ can be a PG::Coder derivation
# (typically PG::TextEncoder::CopyRow or PG::TextDecoder::CopyRow).
# This enables encoding of data fields given to #put_copy_data
# or decoding of fields received by #get_copy_data.
#
# Example with CSV input format:
# conn.exec "create table my_table (a text,b text,c text,d text)"
# conn.copy_data "COPY my_table FROM STDIN CSV" do
# conn.put_copy_data "some,data,to,copy\n"
# conn.put_copy_data "more,data,to,copy\n"
# end
# This creates +my_table+ and inserts two CSV rows.
#
# The same with text format encoder PG::TextEncoder::CopyRow
# and Array input:
# enco = PG::TextEncoder::CopyRow.new
# conn.copy_data "COPY my_table FROM STDIN", enco do
# conn.put_copy_data ['some', 'data', 'to', 'copy']
# conn.put_copy_data ['more', 'data', 'to', 'copy']
# end
#
# Example with CSV output format:
# conn.copy_data "COPY my_table TO STDOUT CSV" do
# while row=conn.get_copy_data
# p row
# end
# end
# This prints all rows of +my_table+ to stdout:
# "some,data,to,copy\n"
# "more,data,to,copy\n"
#
# The same with text format decoder PG::TextDecoder::CopyRow
# and Array output:
# deco = PG::TextDecoder::CopyRow.new
# conn.copy_data "COPY my_table TO STDOUT", deco do
# while row=conn.get_copy_data
# p row
# end
# end
# This receives all rows of +my_table+ as ruby array:
# ["some", "data", "to", "copy"]
# ["more", "data", "to", "copy"]
def copy_data( sql, coder=nil )
raise PG::NotInBlockingMode.new("copy_data can not be used in nonblocking mode", connection: self) if nonblocking?
res = exec( sql )
case res.result_status
when PGRES_COPY_IN
begin
if res.binary_tuples == 1
# Binary file header (11 byte signature, 32 bit flags and 32 bit extension length)
put_copy_data(BinarySignature + ("\x00" * 8))
end
if coder
old_coder = self.encoder_for_put_copy_data
self.encoder_for_put_copy_data = coder
end
yield res
rescue Exception => err
errmsg = "%s while copy data: %s" % [ err.class.name, err.message ]
begin
put_copy_end( errmsg )
rescue PG::Error
# Ignore error in cleanup to avoid losing original exception
end
discard_results
raise err
else
begin
self.encoder_for_put_copy_data = old_coder if coder
if res.binary_tuples == 1
put_copy_data("\xFF\xFF") # Binary file trailer 16 bit "-1"
end
put_copy_end
rescue PG::Error => err
raise PG::LostCopyState.new("#{err} (probably by executing another SQL query while running a COPY command)", connection: self)
end
get_last_result
ensure
self.encoder_for_put_copy_data = old_coder if coder
end
when PGRES_COPY_OUT
begin
if coder
old_coder = self.decoder_for_get_copy_data
self.decoder_for_get_copy_data = coder
end
yield res
rescue Exception
cancel
discard_results
raise
else
if res.binary_tuples == 1
# there are two end markers in binary mode: file trailer and the final nil
if get_copy_data
discard_results
raise PG::NotAllCopyDataRetrieved.new("Not all binary COPY data retrieved", connection: self)
end
end
res = get_last_result
if !res
discard_results
raise PG::LostCopyState.new("Lost COPY state (probably by executing another SQL query while running a COPY command)", connection: self)
elsif res.result_status != PGRES_COMMAND_OK
discard_results
raise PG::NotAllCopyDataRetrieved.new("Not all COPY data retrieved", connection: self)
end
res
ensure
self.decoder_for_get_copy_data = old_coder if coder
end
else
raise ArgumentError, "SQL command is no COPY statement: #{sql}"
end
end
# Backward-compatibility aliases for stuff that's moved into PG.
class << self
define_method( :isthreadsafe, &PG.method(:isthreadsafe) )
end
#
# call-seq:
# conn.transaction { |conn| ... } -> result of the block
#
# Executes a +BEGIN+ at the start of the block,
# and a +COMMIT+ at the end of the block, or
# +ROLLBACK+ if any exception occurs.
def transaction
rollback = false
exec "BEGIN"
yield(self)
rescue Exception
rollback = true
cancel if transaction_status == PG::PQTRANS_ACTIVE
block
exec "ROLLBACK"
raise
ensure
exec "COMMIT" unless rollback
end
### Returns an array of Hashes with connection defaults. See ::conndefaults
### for details.
def conndefaults
return self.class.conndefaults
end
### Return the Postgres connection defaults structure as a Hash keyed by option
### keyword (as a Symbol).
###
### See also #conndefaults
def self.conndefaults_hash
return self.conndefaults.each_with_object({}) do |info, hash|
hash[ info[:keyword].to_sym ] = info[:val]
end
end
### Returns a Hash with connection defaults. See ::conndefaults_hash
### for details.
def conndefaults_hash
return self.class.conndefaults_hash
end
### Return the Postgres connection info structure as a Hash keyed by option
### keyword (as a Symbol).
###
### See also #conninfo
def conninfo_hash
return self.conninfo.each_with_object({}) do |info, hash|
hash[ info[:keyword].to_sym ] = info[:val]
end
end
# Method 'ssl_attribute' was introduced in PostgreSQL 9.5.
if self.instance_methods.find{|m| m.to_sym == :ssl_attribute }
# call-seq:
# conn.ssl_attributes -> Hash<String,String>
#
# Returns SSL-related information about the connection as key/value pairs
#
# The available attributes varies depending on the SSL library being used,
# and the type of connection.
#
# See also #ssl_attribute
def ssl_attributes
ssl_attribute_names.each.with_object({}) do |n,h|
h[n] = ssl_attribute(n)
end
end
end
# Read all pending socket input to internal memory and raise an exception in case of errors.
#
# This verifies that the connection socket is in a usable state and not aborted in any way.
# No communication is done with the server.
# Only pending data is read from the socket - the method doesn't wait for any outstanding server answers.
#
# Raises a kind of PG::Error if there was an error reading the data or if the socket is in a failure state.
#
# The method doesn't verify that the server is still responding.
# To verify that the communication to the server works, it is recommended to use something like <tt>conn.exec('')</tt> instead.
def check_socket
while socket_io.wait_readable(0)
consume_input
end
nil
end
# call-seq:
# conn.get_result() -> PG::Result
# conn.get_result() {|pg_result| block }
#
# Blocks waiting for the next result from a call to
# #send_query (or another asynchronous command), and returns
# it. Returns +nil+ if no more results are available.
#
# Note: call this function repeatedly until it returns +nil+, or else
# you will not be able to issue further commands.
#
# If the optional code block is given, it will be passed <i>result</i> as an argument,
# and the PG::Result object will automatically be cleared when the block terminates.
# In this instance, <code>conn.exec</code> returns the value of the block.
def get_result
block
sync_get_result
end
alias async_get_result get_result
# call-seq:
# conn.get_copy_data( [ nonblock = false [, decoder = nil ]] ) -> Object
#
# Return one row of data, +nil+
# if the copy is done, or +false+ if the call would
# block (only possible if _nonblock_ is true).
#
# If _decoder_ is not set or +nil+, data is returned as binary string.
#
# If _decoder_ is set to a PG::Coder derivation, the return type depends on this decoder.
# PG::TextDecoder::CopyRow decodes the received data fields from one row of PostgreSQL's
# COPY text format to an Array of Strings.
# Optionally the decoder can type cast the single fields to various Ruby types in one step,
# if PG::TextDecoder::CopyRow#type_map is set accordingly.
#
# See also #copy_data.
#
def get_copy_data(async=false, decoder=nil)
if async
return sync_get_copy_data(async, decoder)
else
while (res=sync_get_copy_data(true, decoder)) == false
socket_io.wait_readable
consume_input
end
return res
end
end
alias async_get_copy_data get_copy_data
# In async_api=true mode (default) all send calls run nonblocking.
# The difference is that setnonblocking(true) disables automatic handling of would-block cases.
# In async_api=false mode all send calls run directly on libpq.
# Blocking vs. nonblocking state can be changed in libpq.
# call-seq:
# conn.setnonblocking(Boolean) -> nil
#
# Sets the nonblocking status of the connection.
# In the blocking state, calls to #send_query
# will block until the message is sent to the server,
# but will not wait for the query results.
# In the nonblocking state, calls to #send_query
# will return an error if the socket is not ready for
# writing.
# Note: This function does not affect #exec, because
# that function doesn't return until the server has
# processed the query and returned the results.
#
# Returns +nil+.
def setnonblocking(enabled)
singleton_class.async_send_api = !enabled
self.flush_data = !enabled
sync_setnonblocking(true)
end
alias async_setnonblocking setnonblocking
# sync/async isnonblocking methods are switched by async_setnonblocking()
# call-seq:
# conn.isnonblocking() -> Boolean
#
# Returns the blocking status of the database connection.
# Returns +true+ if the connection is set to nonblocking mode and +false+ if blocking.
def isnonblocking
false
end
alias async_isnonblocking isnonblocking
alias nonblocking? isnonblocking
# call-seq:
# conn.put_copy_data( buffer [, encoder] ) -> Boolean
#
# Transmits _buffer_ as copy data to the server.
# Returns true if the data was sent, false if it was
# not sent (false is only possible if the connection
# is in nonblocking mode, and this command would block).
#
# _encoder_ can be a PG::Coder derivation (typically PG::TextEncoder::CopyRow).
# This encodes the data fields given as _buffer_ from an Array of Strings to
# PostgreSQL's COPY text format inclusive proper escaping. Optionally
# the encoder can type cast the fields from various Ruby types in one step,
# if PG::TextEncoder::CopyRow#type_map is set accordingly.
#
# Raises an exception if an error occurs.
#
# See also #copy_data.
#
def put_copy_data(buffer, encoder=nil)
# sync_put_copy_data does a non-blocking attept to flush data.
until res=sync_put_copy_data(buffer, encoder)
# It didn't flush immediately and allocation of more buffering memory failed.
# Wait for all data sent by doing a blocking flush.
res = flush
end
# And do a blocking flush every 100 calls.
# This is to avoid memory bloat, when sending the data is slower than calls to put_copy_data happen.
if (@calls_to_put_copy_data += 1) > 100
@calls_to_put_copy_data = 0
res = flush
end
res
end
alias async_put_copy_data put_copy_data
# call-seq:
# conn.put_copy_end( [ error_message ] ) -> Boolean
#
# Sends end-of-data indication to the server.
#
# _error_message_ is an optional parameter, and if set,
# forces the COPY command to fail with the string
# _error_message_.
#
# Returns true if the end-of-data was sent, #false* if it was
# not sent (*false* is only possible if the connection
# is in nonblocking mode, and this command would block).
def put_copy_end(*args)
until sync_put_copy_end(*args)
flush
end
@calls_to_put_copy_data = 0
flush
end
alias async_put_copy_end put_copy_end
if method_defined? :sync_encrypt_password
# call-seq:
# conn.encrypt_password( password, username, algorithm=nil ) -> String
#
# This function is intended to be used by client applications that wish to send commands like <tt>ALTER USER joe PASSWORD 'pwd'</tt>.
# It is good practice not to send the original cleartext password in such a command, because it might be exposed in command logs, activity displays, and so on.
# Instead, use this function to convert the password to encrypted form before it is sent.
#
# The +password+ and +username+ arguments are the cleartext password, and the SQL name of the user it is for.
# +algorithm+ specifies the encryption algorithm to use to encrypt the password.
# Currently supported algorithms are +md5+ and +scram-sha-256+ (+on+ and +off+ are also accepted as aliases for +md5+, for compatibility with older server versions).
# Note that support for +scram-sha-256+ was introduced in PostgreSQL version 10, and will not work correctly with older server versions.
# If algorithm is omitted or +nil+, this function will query the server for the current value of the +password_encryption+ setting.
# That can block, and will fail if the current transaction is aborted, or if the connection is busy executing another query.
# If you wish to use the default algorithm for the server but want to avoid blocking, query +password_encryption+ yourself before calling #encrypt_password, and pass that value as the algorithm.
#
# Return value is the encrypted password.
# The caller can assume the string doesn't contain any special characters that would require escaping.
#
# Available since PostgreSQL-10.
# See also corresponding {libpq function}[https://www.postgresql.org/docs/current/libpq-misc.html#LIBPQ-PQENCRYPTPASSWORDCONN].
def encrypt_password( password, username, algorithm=nil )
algorithm ||= exec("SHOW password_encryption").getvalue(0,0)
sync_encrypt_password(password, username, algorithm)
end
alias async_encrypt_password encrypt_password
end
# call-seq:
# conn.reset()
#
# Resets the backend connection. This method closes the
# backend connection and tries to re-connect.
def reset
reset_start
async_connect_or_reset(:reset_poll)
self
end
alias async_reset reset
# call-seq:
# conn.cancel() -> String
#
# Requests cancellation of the command currently being
# processed.
#
# Returns +nil+ on success, or a string containing the
# error message if a failure occurs.
def cancel
be_pid = backend_pid
be_key = backend_key
cancel_request = [0x10, 1234, 5678, be_pid, be_key].pack("NnnNN")
if Fiber.respond_to?(:scheduler) && Fiber.scheduler && RUBY_PLATFORM =~ /mingw|mswin/
# Ruby's nonblocking IO is not really supported on Windows.
# We work around by using threads and explicit calls to wait_readable/wait_writable.
cl = Thread.new(socket_io.remote_address) { |ra| ra.connect }.value
begin
cl.write_nonblock(cancel_request)
rescue IO::WaitReadable, Errno::EINTR
cl.wait_writable
retry
end
begin
cl.read_nonblock(1)
rescue IO::WaitReadable, Errno::EINTR
cl.wait_readable
retry
rescue EOFError
end
elsif RUBY_ENGINE == 'truffleruby'
begin
cl = socket_io.remote_address.connect
rescue NotImplementedError
# Workaround for truffleruby < 21.3.0
cl2 = Socket.for_fd(socket_io.fileno)
cl2.autoclose = false
adr = cl2.remote_address
if adr.ip?
cl = TCPSocket.new(adr.ip_address, adr.ip_port)
cl.autoclose = false
else
cl = UNIXSocket.new(adr.unix_path)
cl.autoclose = false
end
end
cl.write(cancel_request)
cl.read(1)
else
cl = socket_io.remote_address.connect
# Send CANCEL_REQUEST_CODE and parameters
cl.write(cancel_request)
# Wait for the postmaster to close the connection, which indicates that it's processed the request.
cl.read(1)
end
cl.close
nil
rescue SystemCallError => err
err.to_s
end
alias async_cancel cancel
private def async_connect_or_reset(poll_meth)
# Track the progress of the connection, waiting for the socket to become readable/writable before polling it
if (timeo = conninfo_hash[:connect_timeout].to_i) && timeo > 0
# Lowest timeout is 2 seconds - like in libpq
timeo = [timeo, 2].max
host_count = conninfo_hash[:host].to_s.count(",") + 1
stop_time = timeo * host_count + Process.clock_gettime(Process::CLOCK_MONOTONIC)
end
poll_status = PG::PGRES_POLLING_WRITING
until poll_status == PG::PGRES_POLLING_OK ||
poll_status == PG::PGRES_POLLING_FAILED
# Set single timeout to parameter "connect_timeout" but
# don't exceed total connection time of number-of-hosts * connect_timeout.
timeout = [timeo, stop_time - Process.clock_gettime(Process::CLOCK_MONOTONIC)].min if stop_time
event = if !timeout || timeout >= 0
# If the socket needs to read, wait 'til it becomes readable to poll again
case poll_status
when PG::PGRES_POLLING_READING
if defined?(IO::READABLE) # ruby-3.0+
socket_io.wait(IO::READABLE | IO::PRIORITY, timeout)
else
IO.select([socket_io], nil, [socket_io], timeout)
end
# ...and the same for when the socket needs to write
when PG::PGRES_POLLING_WRITING
if defined?(IO::WRITABLE) # ruby-3.0+
# Use wait instead of wait_readable, since connection errors are delivered as
# exceptional/priority events on Windows.
socket_io.wait(IO::WRITABLE | IO::PRIORITY, timeout)
else
# io#wait on ruby-2.x doesn't wait for priority, so fallback to IO.select
IO.select(nil, [socket_io], [socket_io], timeout)
end
end
end
# connection to server at "localhost" (127.0.0.1), port 5433 failed: timeout expired (PG::ConnectionBad)
# connection to server on socket "/var/run/postgresql/.s.PGSQL.5433" failed: No such file or directory
unless event
if self.class.send(:host_is_named_pipe?, host)
connhost = "on socket \"#{host}\""
elsif respond_to?(:hostaddr)
connhost = "at \"#{host}\" (#{hostaddr}), port #{port}"
else
connhost = "at \"#{host}\", port #{port}"
end
raise PG::ConnectionBad.new("connection to server #{connhost} failed: timeout expired", connection: self)
end
# Check to see if it's finished or failed yet
poll_status = send( poll_meth )
end
unless status == PG::CONNECTION_OK
msg = error_message
finish
raise PG::ConnectionBad.new(msg, connection: self)
end
# Set connection to nonblocking to handle all blocking states in ruby.
# That way a fiber scheduler is able to handle IO requests.
sync_setnonblocking(true)
self.flush_data = true
set_default_encoding
end
class << self
# call-seq:
# PG::Connection.new -> conn
# PG::Connection.new(connection_hash) -> conn
# PG::Connection.new(connection_string) -> conn
# PG::Connection.new(host, port, options, tty, dbname, user, password) -> conn
#
# Create a connection to the specified server.
#
# +connection_hash+ must be a ruby Hash with connection parameters.
# See the {list of valid parameters}[https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-PARAMKEYWORDS] in the PostgreSQL documentation.
#
# There are two accepted formats for +connection_string+: plain <code>keyword = value</code> strings and URIs.
# See the documentation of {connection strings}[https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNSTRING].
#
# The positional parameter form has the same functionality except that the missing parameters will always take on default values. The parameters are:
# [+host+]
# server hostname
# [+port+]
# server port number
# [+options+]
# backend options
# [+tty+]
# (ignored in all versions of PostgreSQL)
# [+dbname+]
# connecting database name
# [+user+]
# login user name
# [+password+]
# login password
#
# Examples:
#
# # Connect using all defaults
# PG::Connection.new
#
# # As a Hash
# PG::Connection.new( dbname: 'test', port: 5432 )
#
# # As a String
# PG::Connection.new( "dbname=test port=5432" )
#
# # As an Array
# PG::Connection.new( nil, 5432, nil, nil, 'test', nil, nil )
#
# # As an URI
# PG::Connection.new( "postgresql://user:pass@pgsql.example.com:5432/testdb?sslmode=require" )
#
# If the Ruby default internal encoding is set (i.e., <code>Encoding.default_internal != nil</code>), the
# connection will have its +client_encoding+ set accordingly.
#
# Raises a PG::Error if the connection fails.
def new(*args)
conn = connect_to_hosts(*args)
if block_given?
begin
return yield conn
ensure
conn.finish
end
end
conn
end
alias async_connect new
alias connect new
alias open new
alias setdb new
alias setdblogin new
private def connect_to_hosts(*args)
option_string = parse_connect_args(*args)
iopts = PG::Connection.conninfo_parse(option_string).each_with_object({}){|h, o| o[h[:keyword].to_sym] = h[:val] if h[:val] }
iopts = PG::Connection.conndefaults.each_with_object({}){|h, o| o[h[:keyword].to_sym] = h[:val] if h[:val] }.merge(iopts)
if iopts[:hostaddr]
# hostaddr is provided -> no need to resolve hostnames
elsif iopts[:host] && !iopts[:host].empty? && PG.library_version >= 100000
# Resolve DNS in Ruby to avoid blocking state while connecting.
# Multiple comma-separated values are generated, if the hostname resolves to both IPv4 and IPv6 addresses.
# This requires PostgreSQL-10+, so no DNS resolving is done on earlier versions.
ihosts = iopts[:host].split(",", -1)
iports = iopts[:port].split(",", -1)
iports = [nil] if iports.size == 0
iports = iports * ihosts.size if iports.size == 1
raise PG::ConnectionBad, "could not match #{iports.size} port numbers to #{ihosts.size} hosts" if iports.size != ihosts.size
dests = ihosts.each_with_index.flat_map do |mhost, idx|
unless host_is_named_pipe?(mhost)
if Fiber.respond_to?(:scheduler) &&
Fiber.scheduler &&
RUBY_VERSION < '3.1.'
# Use a second thread to avoid blocking of the scheduler.
# `TCPSocket.gethostbyname` isn't fiber aware before ruby-3.1.
hostaddrs = Thread.new{ Addrinfo.getaddrinfo(mhost, nil, nil, :STREAM).map(&:ip_address) rescue [''] }.value
else
hostaddrs = Addrinfo.getaddrinfo(mhost, nil, nil, :STREAM).map(&:ip_address) rescue ['']
end
else
# No hostname to resolve (UnixSocket)
hostaddrs = [nil]
end
hostaddrs.map { |hostaddr| [hostaddr, mhost, iports[idx]] }
end
iopts.merge!(
hostaddr: dests.map{|d| d[0] }.join(","),
host: dests.map{|d| d[1] }.join(","),
port: dests.map{|d| d[2] }.join(","))
else
# No host given
end
conn = self.connect_start(iopts) or
raise(PG::Error, "Unable to create a new connection")
raise PG::ConnectionBad, conn.error_message if conn.status == PG::CONNECTION_BAD
conn.send(:async_connect_or_reset, :connect_poll)
conn
end
private def host_is_named_pipe?(host_string)
host_string.empty? || host_string.start_with?("/") || # it's UnixSocket?
host_string.start_with?("@") || # it's UnixSocket in the abstract namespace?
# it's a path on Windows?
(RUBY_PLATFORM =~ /mingw|mswin/ && host_string =~ /\A([\/\\]|\w:[\/\\])/)
end
# call-seq:
# PG::Connection.ping(connection_hash) -> Integer
# PG::Connection.ping(connection_string) -> Integer
# PG::Connection.ping(host, port, options, tty, dbname, login, password) -> Integer
#
# PQpingParams reports the status of the server.
#
# It accepts connection parameters identical to those of PQ::Connection.new .
# It is not necessary to supply correct user name, password, or database name values to obtain the server status; however, if incorrect values are provided, the server will log a failed connection attempt.
#
# See PG::Connection.new for a description of the parameters.
#
# Returns one of:
# [+PQPING_OK+]
# server is accepting connections
# [+PQPING_REJECT+]
# server is alive but rejecting connections
# [+PQPING_NO_RESPONSE+]
# could not establish connection
# [+PQPING_NO_ATTEMPT+]
# connection not attempted (bad params)
#
# See also check_socket for a way to check the connection without doing any server communication.
def ping(*args)
if Fiber.respond_to?(:scheduler) && Fiber.scheduler
# Run PQping in a second thread to avoid blocking of the scheduler.
# Unfortunately there's no nonblocking way to run ping.
Thread.new { sync_ping(*args) }.value
else
sync_ping(*args)
end
end
alias async_ping ping
REDIRECT_CLASS_METHODS = PG.make_shareable({
:new => [:async_connect, :sync_connect],
:connect => [:async_connect, :sync_connect],
:open => [:async_connect, :sync_connect],
:setdb => [:async_connect, :sync_connect],
:setdblogin => [:async_connect, :sync_connect],
:ping => [:async_ping, :sync_ping],
})
private_constant :REDIRECT_CLASS_METHODS
# These methods are affected by PQsetnonblocking
REDIRECT_SEND_METHODS = PG.make_shareable({
:isnonblocking => [:async_isnonblocking, :sync_isnonblocking],
:nonblocking? => [:async_isnonblocking, :sync_isnonblocking],
:put_copy_data => [:async_put_copy_data, :sync_put_copy_data],
:put_copy_end => [:async_put_copy_end, :sync_put_copy_end],
:flush => [:async_flush, :sync_flush],
})
private_constant :REDIRECT_SEND_METHODS
REDIRECT_METHODS = {
:exec => [:async_exec, :sync_exec],
:query => [:async_exec, :sync_exec],
:exec_params => [:async_exec_params, :sync_exec_params],
:prepare => [:async_prepare, :sync_prepare],
:exec_prepared => [:async_exec_prepared, :sync_exec_prepared],
:describe_portal => [:async_describe_portal, :sync_describe_portal],
:describe_prepared => [:async_describe_prepared, :sync_describe_prepared],
:setnonblocking => [:async_setnonblocking, :sync_setnonblocking],
:get_result => [:async_get_result, :sync_get_result],
:get_last_result => [:async_get_last_result, :sync_get_last_result],
:get_copy_data => [:async_get_copy_data, :sync_get_copy_data],
:reset => [:async_reset, :sync_reset],
:set_client_encoding => [:async_set_client_encoding, :sync_set_client_encoding],
:client_encoding= => [:async_set_client_encoding, :sync_set_client_encoding],
:cancel => [:async_cancel, :sync_cancel],
}
private_constant :REDIRECT_METHODS
if PG::Connection.instance_methods.include? :async_encrypt_password
REDIRECT_METHODS.merge!({
:encrypt_password => [:async_encrypt_password, :sync_encrypt_password],
})
end
PG.make_shareable(REDIRECT_METHODS)
def async_send_api=(enable)
REDIRECT_SEND_METHODS.each do |ali, (async, sync)|
undef_method(ali) if method_defined?(ali)
alias_method( ali, enable ? async : sync )
end
end
# Switch between sync and async libpq API.
#
# PG::Connection.async_api = true
# this is the default.
# It sets an alias from #exec to #async_exec, #reset to #async_reset and so on.
#
# PG::Connection.async_api = false
# sets an alias from #exec to #sync_exec, #reset to #sync_reset and so on.
#
# pg-1.1.0+ defaults to libpq's async API for query related blocking methods.
# pg-1.3.0+ defaults to libpq's async API for all possibly blocking methods.
#
# _PLEASE_ _NOTE_: This method is not part of the public API and is for debug and development use only.
# Do not use this method in production code.
# Any issues with the default setting of <tt>async_api=true</tt> should be reported to the maintainers instead.
#
def async_api=(enable)
self.async_send_api = enable
REDIRECT_METHODS.each do |ali, (async, sync)|
remove_method(ali) if method_defined?(ali)
alias_method( ali, enable ? async : sync )
end
REDIRECT_CLASS_METHODS.each do |ali, (async, sync)|
singleton_class.remove_method(ali) if method_defined?(ali)
singleton_class.alias_method(ali, enable ? async : sync )
end
end
end
self.async_api = true
end # class PG::Connection