# -*- ruby -*-
# frozen_string_literal: true
require 'pg' unless defined?( PG )
require 'uri'
require 'io/wait'
require 'socket'
# The PostgreSQL connection class. The interface for this class is based on
# {libpq}[http://www.postgresql.org/docs/9.2/interactive/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.
#
class PG::Connection
# The order the options are passed to the ::connect method.
CONNECT_ARGUMENT_ORDER = %w[host port options tty dbname user password]
### 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
# Decode a connection string to Hash options
#
# Value are properly unquoted and unescaped.
def self.connect_string_to_hash( str )
options = {}
key = nil
value = String.new
str.scan(/\G\s*(?>([^\s\\\']+)\s*=\s*|([^\s\\\']+)|'((?:[^\'\\]|\\.)*)'|(\\.?)|(\S))(\s|\z)?/m) do
|k, word, sq, esc, garbage, sep|
raise ArgumentError, "unterminated quoted string in connection info string: #{str.inspect}" if garbage
if k
key = k
else
value << (word || (sq || esc).gsub(/\\(.)/, '\\1'))
end
if sep
raise ArgumentError, "missing = after #{value.inspect}" unless key
options[key.to_sym] = value
key = nil
value = String.new
end
end
options
end
# URI defined in RFC3986
# This regexp is modified to allow host to specify multiple comma separated components captured as <hostports> and to disallow comma in hostnames.
# Taken from: https://github.com/ruby/ruby/blob/be04006c7d2f9aeb7e9d8d09d945b3a9c7850202/lib/uri/rfc3986_parser.rb#L6
HOST_AND_PORT = /(?<hostport>(?<host>(?<IP-literal>\[(?:(?<IPv6address>(?:\h{1,4}:){6}(?<ls32>\h{1,4}:\h{1,4}|(?<IPv4address>(?<dec-octet>[1-9]\d|1\d{2}|2[0-4]\d|25[0-5]|\d)\.\g<dec-octet>\.\g<dec-octet>\.\g<dec-octet>))|::(?:\h{1,4}:){5}\g<ls32>|\h{1,4}?::(?:\h{1,4}:){4}\g<ls32>|(?:(?:\h{1,4}:)?\h{1,4})?::(?:\h{1,4}:){3}\g<ls32>|(?:(?:\h{1,4}:){,2}\h{1,4})?::(?:\h{1,4}:){2}\g<ls32>|(?:(?:\h{1,4}:){,3}\h{1,4})?::\h{1,4}:\g<ls32>|(?:(?:\h{1,4}:){,4}\h{1,4})?::\g<ls32>|(?:(?:\h{1,4}:){,5}\h{1,4})?::\h{1,4}|(?:(?:\h{1,4}:){,6}\h{1,4})?::)|(?<IPvFuture>v\h+\.[!$&-.0-;=A-Z_a-z~]+))\])|\g<IPv4address>|(?<reg-name>(?:%\h\h|[-\.!$&-+0-9;=A-Z_a-z~])+))?(?::(?<port>\d*))?)/
POSTGRESQL_URI = /\A(?<URI>(?<scheme>[A-Za-z][+\-.0-9A-Za-z]*):(?<hier-part>\/\/(?<authority>(?:(?<userinfo>(?:%\h\h|[!$&-.0-;=A-Z_a-z~])*)@)?(?<hostports>#{HOST_AND_PORT}(?:,\g<hostport>)*))(?<path-abempty>(?:\/(?<segment>(?:%\h\h|[!$&-.0-;=@-Z_a-z~])*))*)|(?<path-absolute>\/(?:(?<segment-nz>(?:%\h\h|[!$&-.0-;=@-Z_a-z~])+)(?:\/\g<segment>)*)?)|(?<path-rootless>\g<segment-nz>(?:\/\g<segment>)*)|(?<path-empty>))(?:\?(?<query>[^#]*))?(?:\#(?<fragment>(?:%\h\h|[!$&-.0-;=@-Z_a-z~\/?])*))?)\z/
# 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 "hostaddr" and "fallback_application_name" if they aren't already set.
# The URI and the options string is passed through and "hostaddr" as well as "fallback_application_name"
# are added to the end.
def self::parse_connect_args( *args )
hash_arg = args.last.is_a?( Hash ) ? args.pop.transform_keys(&:to_sym) : {}
option_string = ""
iopts = {}
if args.length == 1
case args.first
when URI, POSTGRESQL_URI
uri = args.first.to_s
uri_match = POSTGRESQL_URI.match(uri)
if uri_match['query']
iopts = URI.decode_www_form(uri_match['query']).to_h.transform_keys(&:to_sym)
end
# extract "host1,host2" from "host1:5432,host2:5432"
iopts[:host] = uri_match['hostports'].split(',', -1).map do |hostport|
hostmatch = HOST_AND_PORT.match(hostport)
hostmatch['IPv6address'] || hostmatch['IPv4address'] || hostmatch['reg-name']&.gsub(/%(\h\h)/){ $1.hex.chr }
end.join(',')
oopts = {}
when /=/
# Option string style
option_string = args.first.to_s
iopts = connect_string_to_hash(option_string)
oopts = {}
else
# Positional parameters (only host given)
iopts[CONNECT_ARGUMENT_ORDER.first.to_sym] = args.first
oopts = iopts.dup
end
else
# Positional parameters
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
oopts = iopts.dup
end
iopts.merge!( hash_arg )
oopts.merge!( hash_arg )
# Resolve DNS in Ruby to avoid blocking state while connecting, when it ...
if (host=iopts[:host]) && !iopts[:hostaddr]
hostaddrs = host.split(",", -1).map do |mhost|
if !mhost.empty? && !mhost.start_with?("/") && # isn't UnixSocket
# isn't a path on Windows
(RUBY_PLATFORM !~ /mingw|mswin/ || mhost !~ /\A\w:[\/\\]/)
if Fiber.respond_to?(:scheduler) &&
Fiber.scheduler &&
RUBY_VERSION < '3.1.'
# Use a second thread to avoid blocking of the scheduler.
# `IPSocket.getaddress` isn't fiber aware before ruby-3.1.
Thread.new{ IPSocket.getaddress(mhost) rescue '' }.value
else
IPSocket.getaddress(mhost) rescue ''
end
end
end
oopts[:hostaddr] = hostaddrs.join(",") if hostaddrs.any?
end
if !iopts[:fallback_application_name]
oopts[:fallback_application_name] = $0.sub( /^(.{30}).{4,}(.{30})$/ ){ $1+"..."+$2 }
end
if uri
uri += uri_match['query'] ? "&" : "?"
uri += URI.encode_www_form( oopts )
return uri
else
option_string += ' ' unless option_string.empty? && oopts.empty?
return option_string + connect_hash_to_string(oopts)
end
end
# 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 )
res = exec( sql )
case res.result_status
when PGRES_COPY_IN
begin
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 ]
put_copy_end( errmsg )
get_result
raise
else
put_copy_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 => err
cancel
while get_copy_data
end
while get_result
end
raise
else
res = get_last_result
if !res || res.result_status != PGRES_COMMAND_OK
while get_copy_data
end
while get_result
end
raise PG::NotAllCopyDataRetrieved, "Not all COPY data retrieved"
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
exec "BEGIN"
res = yield(self)
rescue Exception
cancel if transaction_status != PG::PQTRANS_IDLE
block
exec "ROLLBACK"
raise
else
exec "COMMIT"
res
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
alias sync_get_result get_result
def async_get_result(*args)
block
sync_get_result
end
alias sync_get_copy_data get_copy_data
def async_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
# In async_api=false mode all send calls run directly on libpq.
# Blocking vs. nonblocking state can be changed in libpq.
alias sync_setnonblocking setnonblocking
# In async_api=true mode (default) all send calls run nonblocking.
# The difference is that setnonblocking(true) disables automatic handling of would-block cases.
def async_setnonblocking(enabled)
singleton_class.async_send_api = !enabled
self.flush_data = !enabled
sync_setnonblocking(true)
end
# sync/async isnonblocking methods are switched by async_setnonblocking()
alias sync_isnonblocking isnonblocking
def async_isnonblocking
false
end
alias sync_put_copy_data put_copy_data
def async_put_copy_data(buffer, encoder=nil)
until sync_put_copy_data(buffer, encoder)
flush
end
flush
end
alias sync_put_copy_end put_copy_end
def async_put_copy_end(*args)
until sync_put_copy_end(*args)
flush
end
flush
end
if method_defined? :encrypt_password
alias sync_encrypt_password encrypt_password
def async_encrypt_password( password, username, algorithm=nil )
algorithm ||= exec("SHOW password_encryption").getvalue(0,0)
sync_encrypt_password(password, username, algorithm)
end
end
alias sync_reset reset
def async_reset
reset_start
async_connect_or_reset(:reset_poll)
end
alias sync_cancel cancel
def async_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
private def async_connect_or_reset(poll_meth)
# Now grab a reference to the underlying socket so we know when the connection is established
socket = socket_io
# Track the progress of the connection, waiting for the socket to become readable/writable before polling it
poll_status = PG::PGRES_POLLING_WRITING
until poll_status == PG::PGRES_POLLING_OK ||
poll_status == PG::PGRES_POLLING_FAILED
# If the socket needs to read, wait 'til it becomes readable to poll again
case poll_status
when PG::PGRES_POLLING_READING
socket.wait_readable
# ...and the same for when the socket needs to write
when PG::PGRES_POLLING_WRITING
socket.wait_writable
end
# Check to see if it's finished or failed yet
poll_status = send( poll_meth )
end
raise(PG::ConnectionBad, error_message) unless status == PG::CONNECTION_OK
# 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
self
end
class << self
alias sync_connect new
def async_connect(*args, **kwargs)
conn = PG::Connection.connect_start(*args, **kwargs ) 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)
end
alias sync_ping ping
def async_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
REDIRECT_CLASS_METHODS = {
:new => [:async_connect, :sync_connect],
:ping => [:async_ping, :sync_ping],
}
# These methods are affected by PQsetnonblocking
REDIRECT_SEND_METHODS = {
: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],
}
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],
}
if PG::Connection.instance_methods.include? :async_encrypt_password
REDIRECT_METHODS.merge!({
:encrypt_password => [:async_encrypt_password, :sync_encrypt_password],
})
end
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
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
# pg-1.1.0+ defaults to libpq's async API for query related blocking methods
self.async_api = true
end # class PG::Connection