def CheckDataReceived(self):
"""Tries to extract a Message from the data buffer and process it."""
currentLength = len(self.buffer_in)
if currentLength < 24:
return
# Extract the message header from the buffer, and return if not enough
# buffer to fully deserialize the message object.
try:
# Construct message
mstart = self.buffer_in[:24]
ms = StreamManager.GetStream(mstart)
reader = BinaryReader(ms)
m = Message()
# Extract message metadata
m.Magic = reader.ReadUInt32()
m.Command = reader.ReadFixedString(12).decode('utf-8')
m.Length = reader.ReadUInt32()
m.Checksum = reader.ReadUInt32()
# Return if not enough buffer to fully deserialize object.
messageExpectedLength = 24 + m.Length
# percentcomplete = int(100 * (currentLength / messageExpectedLength))
# self.Log("Receiving %s data: %s percent complete" % (m.Command, percentcomplete))
if currentLength < messageExpectedLength:
return
except Exception as e:
self.Log('Error: Could not read initial bytes %s ' % e)
return
finally:
StreamManager.ReleaseStream(ms)
del reader
# The message header was successfully extracted, and we have enough enough buffer
# to extract the full payload
try:
# Extract message bytes from buffer and truncate buffer
mdata = self.buffer_in[:messageExpectedLength]
self.buffer_in = self.buffer_in[messageExpectedLength:]
# Deserialize message with payload
stream = StreamManager.GetStream(mdata)
reader = BinaryReader(stream)
message = Message()
message.Deserialize(reader)
# Propagate new message
self.MessageReceived(message)
except Exception as e:
self.Log('Error: Could not extract message: %s ' % e)
return
finally:
StreamManager.ReleaseStream(stream)
# Finally, after a message has been fully deserialized and propagated,
# check if another message can be extracted with the current buffer:
if len(self.buffer_in) >= 24:
self.CheckDataReceived()
def CheckDataReceived(self):
"""Tries to extract a Message from the data buffer and process it."""
currentLength = len(self.buffer_in)
if currentLength < 24:
return False
# Extract the message header from the buffer, and return if not enough
# buffer to fully deserialize the message object.
try:
# Construct message
mstart = self.buffer_in[:24]
ms = StreamManager.GetStream(mstart)
reader = BinaryReader(ms)
m = Message()
# Extract message metadata
m.Magic = reader.ReadUInt32()
m.Command = reader.ReadFixedString(12).decode('utf-8')
m.Length = reader.ReadUInt32()
m.Checksum = reader.ReadUInt32()
# Return if not enough buffer to fully deserialize object.
messageExpectedLength = 24 + m.Length
if currentLength < messageExpectedLength:
return False
except Exception as e:
logger.debug(
f"{self.prefix} Error: could not read message header from stream {e}"
)
# self.Log('Error: Could not read initial bytes %s ' % e)
return False
finally:
StreamManager.ReleaseStream(ms)
del reader
# The message header was successfully extracted, and we have enough enough buffer
# to extract the full payload
try:
# Extract message bytes from buffer and truncate buffer
mdata = self.buffer_in[:messageExpectedLength]
self.buffer_in = self.buffer_in[messageExpectedLength:]
# Deserialize message with payload
stream = StreamManager.GetStream(mdata)
reader = BinaryReader(stream)
message = Message()
message.Deserialize(reader)
if self.incoming_client and self.expect_verack_next:
if message.Command != 'verack':
self.Disconnect("Expected 'verack' got {}".format(
message.Command))
# Propagate new message
self.MessageReceived(message)
except Exception as e:
logger.debug(f"{self.prefix} Could not extract message {e}")
# self.Log('Error: Could not extract message: %s ' % e)
return False
finally:
StreamManager.ReleaseStream(stream)
return True
