BlockEval/fullNode.py at master · deepakgouda/BlockEval · GitHub

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"""
Implementation of custom full node resource
"""
import simpy
import numpy as np
from block import Block
from broadcast import broadcast
from utils import getBlockDelay, getTransmissionDelay
from transactionPool import TransactionPool


class FullNode:
    """docstring for FullNode"""

    def __init__(
        self, identifier, env, neighbourList, pipes, nodes, location, data, params
    ):
        self.identifier = identifier
        self.env = env
        self.neighbourList = neighbourList
        self.pipes = pipes
        self.nodes = nodes
        self.location = location
        self.data = data
        self.params = params
        self.transactionPool = TransactionPool(
            env, identifier, neighbourList, nodes, params
        )
        self.blockchain = []
        self.currentBlockID = 0
        self.env.process(self.receiveBlock())

    def validator(self):
        """Validate transactions"""
        if bool(self.params["verbose"]):
            print("miner", self.pipes)

    def getBlockchain(self, destination):
        self.env.timeout(getTransmissionDelay(self.location, destination) * 2)
        return self.blockchain

    def receiveBlock(self):
        """Receive newly mined block from neighbour"""
        while True:
            b = yield self.pipes[self.identifier].get()
            if len(self.blockchain) > 0:
                currID = int(self.blockchain[-1].identifier[1:])
            else:
                currID = -1
            currIDs = [x.identifier for x in self.blockchain]
            if int(b.identifier[1:]) == currID + 1 and b.identifier not in currIDs:
                """Remove already mined transactions from private pool"""
                for transaction in b.transactionList:
                    if self.transactionPool.transactionQueue.isPresent(transaction):
                        self.transactionPool.transactionQueue.remove(transaction)
                        self.transactionPool.prevTransactions.append(transaction)
                """Append block to own chain"""
                self.blockchain.append(b)
                if bool(self.params["verbose"]):
                    print(
                        "%7.4f" % self.env.now
                        + " : "
                        + "%s" % self.identifier
                        + " added Block %s" % b.identifier
                        + " to the chain"
                    )
                    self.displayChain()
                """Mark the receive time of the block"""
                self.data["blockProp"][b.hash][1] = self.env.now
            else:
                """If an invalid block is received, check neighbours and update
				the chain if a longer chain is found"""
                self.updateBlockchain()

    def updateBlockchain(self):
        """Update blockchain by requesting blocks from peers"""
        maxChain = self.blockchain.copy()
        neighbourID = ""
        flag = False
        numStaleBlocks = 0

        for neighbour in self.neighbourList:
            neighbourChain = self.nodes[neighbour].getBlockchain(self.location)
            if len(maxChain) < len(neighbourChain):
                maxChain = neighbourChain.copy()
                neighbourID = neighbour
                flag = True
        numStaleBlocks = len(maxChain) - len(self.blockchain)
        self.data["numStaleBlocks"] += numStaleBlocks
        self.blockchain = maxChain.copy()
        if flag:
            self.currentBlockID = int(self.blockchain[-1].identifier[1:]) + 1
        if bool(self.params["verbose"]):
            if neighbourID:
                print(
                    "%7.4f" % self.env.now
                    + " : "
                    + "%s" % self.identifier
                    + " updated to chain of %s and reverted %d blocks"
                    % (neighbourID, numStaleBlocks)
                )

    def displayChain(self):
        chain = [b.identifier for b in self.blockchain]
        print(
            "%7.4f" % self.env.now
            + " : %s" % self.identifier
            + " has current chain: %s" % chain
        )

    def displayLastBlock(self):
        if self.blockchain:
            block = self.blockchain[-1]
            transactions = block.transactionList
        print(
            "%7.4f" % self.env.now
            + " : %s" % self.identifier
            + " has last block: %s" % transactions
        )