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Continuously rate-limit free transactions.

Changed algorithm to use continuous exponential function instead of discrete 10-minute window.
Changed -limitfreerelay to be kilobytes-per-minute instead of boolean.
0.8
Gavin Andresen 14 years ago
parent
commit
5de8b54c51
  1. 25
      main.cpp

25
main.cpp

@ -738,19 +738,22 @@ bool CTransaction::AcceptToMemoryPool(CTxDB& txdb, bool fCheckInputs, bool* pfMi @@ -738,19 +738,22 @@ bool CTransaction::AcceptToMemoryPool(CTxDB& txdb, bool fCheckInputs, bool* pfMi
if (nFees < GetMinFee(1000))
return error("AcceptToMemoryPool() : not enough fees");
// Limit free transactions per 10 minutes
if (nFees < CENT && GetBoolArg("-limitfreerelay"))
// Continuously rate-limit free transactions
if (nFees < CENT)
{
static int64 nNextReset;
static int64 nFreeCount;
if (GetTime() > nNextReset)
{
nNextReset = GetTime() + 10 * 60;
nFreeCount = 0;
}
if (nFreeCount > 150000 && !IsFromMe())
static double dFreeCount;
static int64 nLastTime;
int64 nNow = GetTime();
// Use an exponentially decaying ~10-minute window:
dFreeCount *= pow(1.0 - 1.0/600.0, (double)(nNow - nLastTime));
nLastTime = nNow;
// -limitfreerelay unit is thousand-bytes-per-minute
// At default rate it would take over a month to fill 1GB
if (dFreeCount > GetArg("-limitfreerelay", 15)*10*1000 && !IsFromMe())
return error("AcceptToMemoryPool() : free transaction rejected by rate limiter");
nFreeCount += nSize;
if (fDebug)
printf("Rate limit dFreeCount: %g => %g\n", dFreeCount, dFreeCount+nSize);
dFreeCount += nSize;
}
}

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