6c8b023298
The wrapper code is adapted from the swarm/services/chequebook package
with the following mostly cosmetic changes:
* The code now uses the new Go API interfaces to query balances. Some
minor functional changes were required to make this work.
* The package no longer depends on swarm/services/swap/swap. References
to swap.Promise are replaced by interface{}, the base type of Promise.
This is temporary.
* The contract wrapper has been regenerated with latest abigen
and solc v0.3.6.
* There is a new generator that creates the 'deployed code' variable.
* Documentation comments now follow the recommended godoc style.
* [CHEQUEBOOK] log prefixes are gone.
* LGPL license headers have been added to all files.
44 lines
1.8 KiB
Solidity
44 lines
1.8 KiB
Solidity
import "mortal";
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/// @title Chequebook for Ethereum micropayments
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/// @author Daniel A. Nagy <daniel@ethdev.com>
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contract chequebook is mortal {
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// Cumulative paid amount in wei to each beneficiary
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mapping (address => uint256) public sent;
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/// @notice Overdraft event
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event Overdraft(address deadbeat);
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/// @notice Cash cheque
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///
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/// @param beneficiary beneficiary address
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/// @param amount cumulative amount in wei
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/// @param sig_v signature parameter v
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/// @param sig_r signature parameter r
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/// @param sig_s signature parameter s
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/// The digital signature is calculated on the concatenated triplet of contract address, beneficiary address and cumulative amount
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function cash(address beneficiary, uint256 amount,
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uint8 sig_v, bytes32 sig_r, bytes32 sig_s) {
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// Check if the cheque is old.
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// Only cheques that are more recent than the last cashed one are considered.
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if(amount <= sent[beneficiary]) return;
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// Check the digital signature of the cheque.
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bytes32 hash = sha3(address(this), beneficiary, amount);
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if(owner != ecrecover(hash, sig_v, sig_r, sig_s)) return;
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// Attempt sending the difference between the cumulative amount on the cheque
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// and the cumulative amount on the last cashed cheque to beneficiary.
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if (amount - sent[beneficiary] >= this.balance) {
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if (beneficiary.send(amount - sent[beneficiary])) {
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// Upon success, update the cumulative amount.
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sent[beneficiary] = amount;
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}
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} else {
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// Upon failure, punish owner for writing a bounced cheque.
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// owner.sendToDebtorsPrison();
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Overdraft(owner);
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// Compensate beneficiary.
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suicide(beneficiary);
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}
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}
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}
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