payment sender interface.md

• createDeposit(amount map[common.Address]uint64) depositID
  • sends a transaction to create a new deposit with the given target allowances
• subscribeDepositEvents(ch chan struct {id depositID, state int})
  • sends an event to the given channel every time a deposit goes into pending, active or expired state
• estimatedExpiry(id depositID) time.Duration
  • returns the estimated remaining time while cheques can still be written using this deposit
• allowancesLeft(id depositID) map[common.Address]uint64
• lastCheque(id depositID, to common.Address) (totalSpent, allowanceLeft uint64)
• writeCheque(id depositID, to common.Address, amount uint64) (totalSpent, allowanceLeft uint64, proofOfPayment []byte)
  • creates a cheque if the deposit is in active state and there is enough allowance left (otherwise proofOfPayment should be nil)
  • allowances are nominated in currency units, the payment channel module converts it to probability based on the total deposit amount
  • proofOfPayment is a serialized format of the cheque. It should contain the following info:
    • address of the deposit contract
    • deposit ID
    • highest winning random number (incremental)
    • Merkle proof of the server being assigned to a random number range that contains the current highest winning number