lbry-sdk/lbrynet/dht/constants.py

#!/usr/bin/env python
#
# This library is free software, distributed under the terms of
# the GNU Lesser General Public License Version 3, or any later version.
# See the COPYING file included in this archive
#
# The docstrings in this module contain epytext markup; API documentation
# may be created by processing this file with epydoc: http://epydoc.sf.net

""" This module defines the charaterizing constants of the Kademlia network

C{checkRefreshInterval} and C{udpDatagramMaxSize} are implementation-specific
constants, and do not affect general Kademlia operation.
"""

######### KADEMLIA CONSTANTS ###########

#: Small number Representing the degree of parallelism in network calls
alpha = 3

#: Maximum number of contacts stored in a bucket; this should be an even number
k = 8

#: Maximum number of contacts stored in the replacement cache
replacementCacheSize = 8

#: Timeout for network operations (in seconds)
rpcTimeout = 8

# number of rpc attempts to make before a timeout results in the node being removed as a contact
rpcAttempts = 5

# Delay between iterations of iterative node lookups (for loose parallelism)  (in seconds)
iterativeLookupDelay = rpcTimeout / 2

#: If a k-bucket has not been used for this amount of time, refresh it (in seconds)
refreshTimeout = 3600  # 1 hour
#: The interval at which nodes replicate (republish/refresh) data they are holding
replicateInterval = refreshTimeout
# The time it takes for data to expire in the network; the original publisher of the data
# will also republish the data at this time if it is still valid
dataExpireTimeout = 86400  # 24 hours

tokenSecretChangeInterval = 300  # 5 minutes

######## IMPLEMENTATION-SPECIFIC CONSTANTS ###########

#: The interval for the node to check whether any buckets need refreshing
checkRefreshInterval = refreshTimeout / 5

#: Max size of a single UDP datagram, in bytes. If a message is larger than this, it will
#: be spread across several UDP packets.
udpDatagramMaxSize = 8192  # 8 KB

key_bits = 384

rpc_id_length = 20

protocolVersion = 1