def parameterStatus(name, value):
"""
Constructs a new ParameterStatus message holding the given name and value.
"""
m = BackendMessage()
l = pack_int32(len(name) + len(value) + 2 + 4)
m.consume('S%s%s\x00%s\x00' % (l, name, value))
return m
def startup(user):
"""
Constructs a new Startup message.
"""
m = FrontendMessage()
payload = ('\x00\x03\x00\x00' 'user\x00%s\x00' % user)
m.consume(pack_int32(len(payload) + 4) + payload)
return m
def parameterStatus(name, value):
"""
Constructs a new ParameterStatus message holding the given name and value.
"""
m = BackendMessage()
l = pack_int32(len(name) + len(value) + 2 + 4)
m.consume('S%s%s\x00%s\x00' % (l, name, value))
return m
def startup(user):
"""
Constructs a new Startup message.
"""
m = FrontendMessage()
payload = ('\x00\x03\x00\x00'
'user\x00%s\x00' % user)
m.consume(pack_int32(len(payload)+4) + payload)
return m
def errorResponse(*fields):
"""
Creates an ErrorResponse message. Fields should be a list of 2-tuples
consisting of a single-byte field type and a string.
"""
m = BackendMessage()
# convert fields to strings
fields = [(b, str(f)) for b, f in fields]
# four bytes for the length, one byte plus string length plus \0 for
# each field, one terminating \0.
length = pack_int32(4 + sum([1 + 1 + len(f) for _, f in fields]) + 1)
m.consume('E' + length)
for b, f in fields:
m.consume(b + f + '\x00')
m.consume('\x00')
return m
def errorResponse(*fields):
"""
Creates an ErrorResponse message. Fields should be a list of 2-tuples
consisting of a single-byte field type and a string.
"""
m = BackendMessage()
# convert fields to strings
fields = [(b, str(f)) for b, f in fields]
# four bytes for the length, one byte plus string length plus \0 for
# each field, one terminating \0.
length = pack_int32(4 + sum([1+1+len(f) for _, f in fields]) + 1)
m.consume('E' + length)
for b, f in fields:
m.consume(b+f+'\x00')
m.consume('\x00')
return m
def _int_message(t, intval, cls):
m = cls()
m.consume('%s%s%s' % (t, eight_packed, pack_int32(intval)))
return m
def _string_message(s, t, cls):
m = cls()
m.consume('%s%s%s\x00' % (t, pack_int32(len(s) + 5), s))
return m
"""
This module is responsible for parsing and serializing messages for the postgres
frontend/backend protocol.
The Message class handles parsing messages, and the exported functions can be
used to construct new messages.
See here:
http://developer.postgresql.org/pgdocs/postgres/protocol-message-formats.html
"""
from fifobuffer import FIFOBuffer
from data import pack_int32
# constant values
eight_packed = pack_int32(8)
five_packed = pack_int32(5)
class Message(object):
"""
Base class that for frontend or backend messages. Data is parsed
via the consume() method, and the message can be persisted for the wire
using the serialize() method.
Instances of this class will have a variable set of properties, as
determined by the self.type field. Messages that are not yet completely
parsed will also have an inconsistent set of properties.
"""
def __init__(self):
def _int_message(t, intval, cls):
m = cls()
m.consume('%s%s%s' % (t, eight_packed, pack_int32(intval)))
return m
def _string_message(s, t, cls):
m = cls()
m.consume('%s%s%s\x00' % (t, pack_int32(len(s)+5), s))
return m
This module is responsible for parsing and serializing messages for the postgres
frontend/backend protocol.
The Message class handles parsing messages, and the exported functions can be
used to construct new messages.
See here:
http://developer.postgresql.org/pgdocs/postgres/protocol-message-formats.html
"""
from fifobuffer import FIFOBuffer
from data import pack_int32
# constant values
eight_packed = pack_int32(8)
five_packed = pack_int32(5)
class Message(object):
"""
Base class that for frontend or backend messages. Data is parsed
via the consume() method, and the message can be persisted for the wire
using the serialize() method.
Instances of this class will have a variable set of properties, as
determined by the self.type field. Messages that are not yet completely
parsed will also have an inconsistent set of properties.
"""
