Method ChargeFees

src/darksend.cpp:658–756

Charge clients a fee if they're abusive Why bother? Darksend uses collateral to ensure abuse to the process is kept to a minimum. The submission and signing stages in darksend are completely separate. In the cases where a client submits a transaction then refused to sign, there must be a cost. Otherwise they would be able to do this over and over again and bring the mixing to a hault. How does t

// until the transaction is either complete or fails.
//
void CDarkSendPool::ChargeFees() {
    if (fMasterNode) {
        //we don't need to charge collateral for every offence.
        int offences = 0;
        int r = rand() % 100;
        if (r > 33) return;

        if (state == POOL_STATUS_ACCEPTING_ENTRIES) {
            for (const CTransaction& txCollateral : vecSessionCollateral) {
                bool found = false;
                for (const CDarkSendEntry& v : entries) {
                    if (v.collateral == txCollateral) {
                        found = true;
                    }
                }

                // This queue entry didn't send us the promised transaction
                if (!found) {
                    LogPrintf("CDarkSendPool::ChargeFees -- found uncooperative node (didn't send transaction). Found offence.\n");
                    offences++;
                }
            }
        }

        if (state == POOL_STATUS_SIGNING) {
            // who didn't sign?
            for (const CDarkSendEntry v : entries) {
                for (const CDarkSendEntryVin s : v.sev) {
                    if (!s.isSigSet) {
                        LogPrintf("CDarkSendPool::ChargeFees -- found uncooperative node (didn't sign). Found offence\n");
                        offences++;
                    }
                }
            }
        }

        r = rand() % 100;
        int target = 0;

        //mostly offending?
        if (offences >= POOL_MAX_TRANSACTIONS - 1 && r > 33) return;

        //everyone is an offender? That's not right
        if (offences >= POOL_MAX_TRANSACTIONS) return;

        //charge one of the offenders randomly
        if (offences > 1) target = 50;

        //pick random client to charge
        r = rand() % 100;

        if (state == POOL_STATUS_ACCEPTING_ENTRIES) {
            for (const CTransaction& txCollateral : vecSessionCollateral) {
                bool found = false;
                for (const CDarkSendEntry& v : entries) {
                    if (v.collateral == txCollateral) {
                        found = true;
                    }