Learn Blockchain

This is a very simple single module blockchain implementation in Erlang. It does not have much verification, no consensus and networking, and only one type of transactions - transfers of value between two accounts. Also no negative balance checking.

The implementation is about 150 lines long.

Running

• rebar3 shell - will give you a welcoming Erlang shell
• b:open() will open DETS files ready for use
  • NOTE: any exception in shell will close DETS files, so you might need to reopen them if DETS owner process crashes. DETS flushes every 250 msec.
• b:close() - you get it
• b:add([{transaction, <<"a">>, <<"b">>, 10}]) (from Erlang code with records this becomes b:add([#transaction{from= <<"a">>, to= <<"b">>, amount=10}])) writes a new block with list of transactions you supply. They CAN contradict each other and create negative balances there is no verification for this.
• b:balances() folds over the chain from the very beginning and counts the amounts on accounts.