Class: OnChain

Inherits:
Object
  • Object
show all
Defined in:
lib/onchain/block_chain.rb,
lib/onchain/sweeper.rb,
lib/onchain/payments.rb

Overview

We support a number of blockchain API providers, if one goes down we automatically switch over to another.

Each provider has to support the following methods

get_balance(address) get_all_balances([]) send_tx(tx_hex) get_transactions(address)

Defined Under Namespace

Classes: BlockChain

Constant Summary collapse

FEE = 
50000

Class Method Summary collapse

Class Method Details

.create_payment_tx(redemption_script, payments) ⇒ Object

With a bunch of HD wallet paths, build a transaction That pays all the coins to a certain address



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# File 'lib/onchain/payments.rb', line 22

def create_payment_tx(redemption_script, payments)
  
  begin
    
    fund_address = get_address_from_redemption_script(redemption_script)
    
    tx = Bitcoin::Protocol::Tx.new
  
    total_amount = FEE  
  
    payments.each do |payment|
      if payment[1].is_a?(String)
        payment[1] = payment[1].to_i
      end
      total_amount = total_amount + payment[1]
    end
  
    total_in_fund = OnChain::BlockChain.get_balance_satoshi(fund_address)
    
    # Do we have enough in the fund.
    if(total_amount > total_in_fund)
      return 'Balance is not enough to cover payment'
    end
    
    # OK, let's get some inputs
    amount_so_far = 0
    unspent = OnChain::BlockChain.get_unspent_outs(fund_address)
    unspent.each do |spent|

      txin = Bitcoin::Protocol::TxIn.new

      txin.prev_out = spent[0].scan(/../).map { |x| x.hex }.pack('c*').reverse
      txin.prev_out_index = spent[1]
      txin.script = hex_to_script(redemption_script).to_payload
  
      tx.add_in(txin)
      
      amount_so_far = amount_so_far + spent[3].to_i
      if amount_so_far >= total_amount
        next
      end
    end
    change = amount_so_far - total_amount
    
    payments.each do |payment|
      
      txout = Bitcoin::Protocol::TxOut.new(payment[1], 
        Bitcoin::Script.to_address_script(payment[0]))
  
      tx.add_out(txout)
    end
    
    # Send the chnage back.
    if total_in_fund > total_amount
      
      txout = Bitcoin::Protocol::TxOut.new(total_in_fund - total_amount, 
        Bitcoin::Script.to_address_script(fund_address))
  
      tx.add_out(txout)
    end
    
    return tx
    
  rescue Exception => e
    return 'Unable to parse payment :: ' + e.to_s
  end
end

.get_address_from_redemption_script(redemption_script) ⇒ Object 



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# File 'lib/onchain/payments.rb', line 6

def get_address_from_redemption_script(redemption_script)
  
  sbin = redemption_script.scan(/../).map { |x| x.hex }.pack('c*')
  hex = sbin.unpack("H*")[0]
  fund_address = Bitcoin.hash160_to_p2sh_address(Bitcoin.hash160(hex))
  
  return fund_address
end

.hex_to_script(hex) ⇒ Object 



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# File 'lib/onchain/payments.rb', line 15

def hex_to_script(hex)
  sbin = hex.scan(/../).map { |x| x.hex }.pack('c*')
  return Bitcoin::Script.new(sbin)
end

.sweep(paths, mpk, destination_address) ⇒ Object

With a bunch of HD wallet paths, build a transaction That pays all the coins to a certain address



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# File 'lib/onchain/sweeper.rb', line 7

def sweep(paths, mpk, destination_address)
  
  master = MoneyTree::Node.from_serialized_address(mpk)
  
  tx = Bitcoin::Protocol::Tx.new
  
  amount = 0
  
  paths.each do |path|
  
    address = master.node_for_path(path).to_address
  
    unspent = OnChain::BlockChain.get_unspent_outs(address)
  
    unspent.each do |spent|
      txin = Bitcoin::Protocol::TxIn.new

      txin.prev_out = spent[0]
      txin.prev_out_index = spent[1]
      amount += spent[3].to_i
    
      tx.add_in(txin)
    end
  end

  txout = Bitcoin::Protocol::TxOut.new(amount, Bitcoin::Script.from_string(
    "OP_DUP OP_HASH160 #{destination_address} " + 
    "OP_EQUALVERIFY OP_CHECKSIG").to_payload)
  
  tx.add_out(txout)
end