Class: DB::Postgres::Native::Connection

Inherits:
FFI::Pointer
  • Object
show all
Defined in:
lib/db/postgres/native/connection.rb

Overview

A native FFI connection to the PostgreSQL client library.

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(address, io, types) ⇒ Connection

Initialize a native connection wrapper.



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# File 'lib/db/postgres/native/connection.rb', line 138

def initialize(address, io, types)
	super(address)
	
	@io = io
	@types = types
end

Instance Attribute Details

#types ⇒ Object (readonly)

Returns the value of attribute types.



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# File 'lib/db/postgres/native/connection.rb', line 146

def types
  @types
end

Class Method Details

.connect(types: DEFAULT_TYPES, **options) ⇒ Object

Establish a connection to the PostgreSQL server.



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# File 'lib/db/postgres/native/connection.rb', line 95

def self.connect(types: DEFAULT_TYPES, **options)
	# Postgres expects "dbname" as the key name:
	if database = options.delete(:database)
		options[:dbname] = database
	end
	
	# Postgres expects "user" as the key name:
	if username = options.delete(:username)
		options[:user] = username
	end
	
	keys = Strings.new(options.keys)
	values = Strings.new(options.values)
	
	pointer = Native.connect_start_params(keys.array, values.array, 1)
	Native.set_nonblocking(pointer, 1)
	
	io = ::IO.new(Native.socket(pointer), "r+", autoclose: false)
	
	while status = Native.connect_poll(pointer)
		break if status == :ok || status == :failed
		
		# one of :wait_readable or :wait_writable
		io.send(status)
	end
	
	if status == :failed
		io.close
		
		error_message = Native.error_message(pointer)
		
		Native.finish(pointer)
		
		raise Error, "Could not connect: #{error_message}"
	end
	
	return self.new(pointer, io, types)
end

Instance Method Details

#close ⇒ Object

Close the connection.



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# File 'lib/db/postgres/native/connection.rb', line 164

def close
	Native.finish(self)
	
	@io.close
end

#discard_results ⇒ Object

Silently discard any results that application didn’t read.



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# File 'lib/db/postgres/native/connection.rb', line 234

def discard_results
	while result = self.get_result
		status = Native.result_status(result)
		Native.clear(result)
		
		case status
		when :copy_in
			self.put_copy_end("Discard results")
		when :copy_out
			self.flush_copy_out
		end
	end
	
	return nil
end

#error_message ⇒ Object

Return the last error message.



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# File 'lib/db/postgres/native/connection.rb', line 154

def error_message
	Native.error_message(self)
end

#escape_identifier(value) ⇒ Object

Escape an identifier for safe inclusion in SQL queries.



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# File 'lib/db/postgres/native/connection.rb', line 188

def escape_identifier(value)
	value = value.to_s
	
	result = Native.escape_identifier(self, value, value.bytesize)
	
	string = result.read_string
	
	Native.free_memory(result)
	
	return string
end

#escape_literal(value) ⇒ Object

Escape a literal string value for safe inclusion in SQL queries.



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# File 'lib/db/postgres/native/connection.rb', line 173

def escape_literal(value)
	value = value.to_s
	
	result = Native.escape_literal(self, value, value.bytesize)
	
	string = result.read_string
	
	Native.free_memory(result)
	
	return string
end

#next_result(types: @types) ⇒ Object

Get the next result set from a multi-result query.



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# File 'lib/db/postgres/native/connection.rb', line 217

def next_result(types: @types)
	if result = self.get_result
		status = Native.result_status(result)
		
		if status == :fatal_error
			message = Native.result_error_message(result)
			
			Native.clear(result)
			
			raise Error, message
		end
		
		return Result.new(self, types, result)
	end
end

#send_query(statement) ⇒ Object

Send a query to the server for execution.



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# File 'lib/db/postgres/native/connection.rb', line 207

def send_query(statement)
	check! Native.send_query(self, statement)
	
	flush
end

#single_row_mode! ⇒ Object

Enable single row mode for streaming large result sets.



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# File 'lib/db/postgres/native/connection.rb', line 201

def single_row_mode!
	Native.set_single_row_mode(self)
end

#socket ⇒ Object

Return the underlying socket used for IO.



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# File 'lib/db/postgres/native/connection.rb', line 159

def socket
	Native.socket(self)
end

#status ⇒ Object

Return the status of the connection.



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# File 'lib/db/postgres/native/connection.rb', line 149

def status
	Native.status(self)
end

#The type mapping configuration.=(typemappingconfiguration. = (value)) ⇒ Object 



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# File 'lib/db/postgres/native/connection.rb', line 146

attr :types