Function GetNetworkHashPS

src/rpc/mining.cpp:96–140

* Return average network hashes per second based on the last 'lookup' blocks, * or from the last difficulty change if 'lookup' is -1. * If 'height' is -1, compute the estimate from current chain tip. * If 'height' is a valid block height, compute the estimate at the time when a given block was found. */

 * If 'height' is a valid block height, compute the estimate at the time when a given block was found.
 */
static UniValue GetNetworkHashPS(int lookup, int height, const CChain& active_chain) {
    if (lookup < -1 || lookup == 0) {
        throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid nblocks. Must be a positive number or -1.");
    }

    if (height < -1 || height > active_chain.Height()) {
        throw JSONRPCError(RPC_INVALID_PARAMETER, "Block does not exist at specified height");
    }

    const CBlockIndex* pb = active_chain.Tip();

    if (height >= 0) {
        pb = active_chain[height];
    }

    if (pb == nullptr || !pb->nHeight)
        return 0;

    // If lookup is -1, then use blocks since last difficulty change.
    if (lookup == -1)
        lookup = pb->nHeight % Params().GetConsensus().DifficultyAdjustmentInterval() + 1;

    // If lookup is larger than chain, then set it to chain length.
    if (lookup > pb->nHeight)
        lookup = pb->nHeight;

    const CBlockIndex* pb0 = pb;
    int64_t minTime = pb0->GetBlockTime();
    int64_t maxTime = minTime;
    for (int i = 0; i < lookup; i++) {
        pb0 = pb0->pprev;
        int64_t time = pb0->GetBlockTime();
        minTime = std::min(time, minTime);
        maxTime = std::max(time, maxTime);
    }

    // In case there's a situation where minTime == maxTime, we don't want a divide by zero exception.
    if (minTime == maxTime)
        return 0;

    arith_uint256 workDiff = pb->nChainWork - pb0->nChainWork;
    int64_t timeDiff = maxTime - minTime;

    return workDiff.getdouble() / timeDiff;
}

static RPCMethod getnetworkhashps()
{