Refactor generation of packet headers

Added global variable Header - a compiled Struct to pack/unpack headers so as to avoid repeatedly compiling the same format string
Add a new method CreatePacket to simply and efficiently construct a packet that is ready to be sent
Modify assembleVersionMessage to use CreatePacket
This commit is contained in:
bmng-dev 2014-05-22 12:30:51 +00:00
parent 9b40838f25
commit 947f7655ab
1 changed files with 19 additions and 5 deletions

View File

@ -21,6 +21,7 @@ import stat
import threading
import time
from os import path, environ
from struct import Struct
# Project imports.
from addresses import *
@ -104,6 +105,23 @@ frozen = getattr(sys,'frozen', None)
# security.
trustedPeer = None
#Compiled struct for packing/unpacking headers
#New code should use CreatePacket instead of Header.pack
Header = Struct('!L12sL4s')
#Create a packet
def CreatePacket(command, payload=''):
payload_length = len(payload)
if payload_length == 0:
checksum = '\xCF\x83\xE1\x35'
else:
checksum = hashlib.sha512(payload).digest()[0:4]
b = bytearray(Header.size + payload_length)
Header.pack_into(b, 0, 0xE9BEB4D9, command, payload_length, checksum)
b[Header.size:] = payload
return bytes(b)
def isInSqlInventory(hash):
queryreturn = sqlQuery('''select hash from inventory where hash=?''', hash)
return queryreturn != []
@ -141,11 +159,7 @@ def assembleVersionMessage(remoteHost, remotePort, myStreamNumber):
1) # The number of streams about which I care. PyBitmessage currently only supports 1 per connection.
payload += encodeVarint(myStreamNumber)
datatosend = '\xe9\xbe\xb4\xd9' # magic bits, slighly different from Bitcoin's magic bits.
datatosend = datatosend + 'version\x00\x00\x00\x00\x00' # version command
datatosend = datatosend + pack('>L', len(payload)) # payload length
datatosend = datatosend + hashlib.sha512(payload).digest()[0:4]
return datatosend + payload
return CreatePacket('version', payload)
def lookupAppdataFolder():
APPNAME = "PyBitmessage"