DVM

DVM (Denaro Virtual Machine) is a layer built on top of Denaro Blockchain, which uses transactions messages to communicate with the VM.

Data is stored in PostgreSQL like denaro.

This is a very early stage and anything can change at anytime

installation

It will install DVM and clone denaro in DVM folder. You can't use DVM with docker

git clone https://github.com/denaro-coin/denaro
git clone https://github.com/denaro-coin/dvm
cd dvm
ln -s ../denaro/denaro/ denaro
psql -d denaro -f schema.sql

usage

There are 2 parts of DVM, the "daemon" and the "server".

daemon

The daemon scans the blockchain and processes valid DVM transactions, thus updating DVM state

python3 daemon.py

server

The server is an API which servers DVM data in a readable way, enabling users and apps to read the DVM

uvicorn server:app --port 3007

DVM Smart Contracts development

Smart contracts in DVM are written in Python (and this is a unique feature in crypto).

@Contract.deploy
class Token(Contract):    
    def constructor(self, sender: str, name: str, ticker: str):
        self.minter = sender
        self.name = name
        self.ticker = ticker
        self.balances = {}

    def mint(self, sender: str, address: str, amount: Decimal):
        assert sender == self.minter, 'Unauthorized'
        assert amount > 0
        balance = self.balance(address)
        self.balances.update({address: balance + amount})

    def transfer(self, sender: str, receiver: str, amount: Decimal):
        assert amount > 0, 'amount cannot be zero or lower'
        sender_balance = self.balance(sender)
        assert sender_balance >= amount, f'Sender ({sender}) does not have enough coins (has {sender_balance} while required {amount})'
        receiver_balance = self.balance(receiver)
        self.balances.update({sender: sender_balance - amount, receiver: receiver_balance + amount})

    def balance(self, address: str):
        return self.balances.get(address) or 0

You can interact with the DVM with cli wallet.

deployment

python3 create_contract.py contract_source.py "('argument 1', 'argument 2')"

It will return a hex string that should be used as transaction message

denaro send -to DsmArTjpJNuEBuHB2x4f14cDifdduTtu2CR1BMs1P5RcF -d 50 -m 'HEXSTRING'

calling

python3 call_contract.py contract_hash method "('argument 1', 'argument 2')"
python3 call_contract.py e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855 mint "('address', Decimal('1234'))"

It will return a hex string that should be used as transaction message

denaro send -to DsmArTjpJNuEBuHB2x4f14cDifdduTtu2CR1BMs1P5RcF -d 50 -m 'HEXSTRING'