void GetAddressBalances(unsigned int cutoffTime, BalanceMap& mapBalance)
{
    CBlockIndex* pblk0 = pindexGenesisBlock, *pblk1 = pindexBest;
    if (!pblk0) throw runtime_error("No genesis block.");
    if (!pblk1) throw runtime_error("No best block chain.");

    if (cutoffTime>pblk1->nTime)
        throw runtime_error("Cutoff date later than most recent block.");

    BalanceMap mapRunningBalance = mapBalance;
    CTxDB txdb("r");
    int nBlks = 0;
    int nBlockSpan = 0;
    while (pblk0 != pblk1)
    {
        if (pblk0->nTime >= cutoffTime)
        {
            if (nBlockSpan == 0) {
                nBlockSpan = pblk1->nHeight - pblk0->nHeight + 1;
            }
            for (BalanceMap::iterator it = mapRunningBalance.begin(); it != mapRunningBalance.end(); it++) {
                mapBalance[it->first] += it->second / nBlockSpan;
            }
        }

        CBlock block;
        block.ReadFromDisk(pblk0, true);

        BOOST_FOREACH(const CTransaction& tx, block.vtx)
        {
            ScanTransactionInputs(txdb, tx, mapRunningBalance);
            ScanTransactionOutputs(tx, mapRunningBalance);
        }

        pblk0 = pblk0->pnext;
        nBlks++;
    }
}