From ea1cd5b47f473eed60b3ed95853b053e9f686d69 Mon Sep 17 00:00:00 2001 From: Gavin Andresen Date: Wed, 18 Sep 2013 11:48:41 +1000 Subject: [PATCH 1/2] Remove CENT-output free transaction rule when relaying Remove the (relay/mempool) rule that all outputs of free transactions must be greater than 0.01 XBT. Dust spam is now taken care of by making dusty outputs non-standard. --- src/main.cpp | 6 ++++-- src/wallet.cpp | 7 ++++--- 2 files changed, 8 insertions(+), 5 deletions(-) diff --git a/src/main.cpp b/src/main.cpp index 4b2c32e34..e2e2d3b84 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -760,8 +760,10 @@ int64 GetMinFee(const CTransaction& tx, bool fAllowFree, enum GetMinFee_mode mod nMinFee = 0; } - // To limit dust spam, require base fee if any output is less than 0.01 - if (nMinFee < nBaseFee) + // This code can be removed after enough miners have upgraded to version 0.9. + // Until then, be safe when sending and require a fee if any output + // is less than CENT: + if (nMinFee < nBaseFee && mode == GMF_SEND) { BOOST_FOREACH(const CTxOut& txout, tx.vout) if (txout.nValue < CENT) diff --git a/src/wallet.cpp b/src/wallet.cpp index 54ede12a5..daa5ba06f 100644 --- a/src/wallet.cpp +++ b/src/wallet.cpp @@ -1232,9 +1232,10 @@ bool CWallet::CreateTransaction(const vector >& vecSend, } int64 nChange = nValueIn - nValue - nFeeRet; - // if sub-cent change is required, the fee must be raised to at least nMinTxFee - // or until nChange becomes zero - // NOTE: this depends on the exact behaviour of GetMinFee + // The following if statement should be removed once enough miners + // have upgraded to the 0.9 GetMinFee() rules. Until then, this avoids + // creating free transactions that have change outputs less than + // CENT bitcoins. if (nFeeRet < CTransaction::nMinTxFee && nChange > 0 && nChange < CENT) { int64 nMoveToFee = min(nChange, CTransaction::nMinTxFee - nFeeRet); From 16b3ff66e0137b68de0d08ad88ce9798bce2d68d Mon Sep 17 00:00:00 2001 From: Gavin Andresen Date: Wed, 18 Sep 2013 12:04:29 +1000 Subject: [PATCH 2/2] Lower maximum size for free transaction creation Changes the maximum size of a free transaction that will be created from 10,000 bytes to 1,000 bytes. The idea behind this change is to make the free transaction area available to a greater number of people; with the default 27K-per-block, just three very-large very-high-priority transactions could fill the space. --- src/main.cpp | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/main.cpp b/src/main.cpp index e2e2d3b84..648bde771 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -753,10 +753,11 @@ int64 GetMinFee(const CTransaction& tx, bool fAllowFree, enum GetMinFee_mode mod { // There is a free transaction area in blocks created by most miners, // * If we are relaying we allow transactions up to DEFAULT_BLOCK_PRIORITY_SIZE - 1000 - // to be considered to fall into this category - // * If we are creating a transaction we allow transactions up to DEFAULT_BLOCK_PRIORITY_SIZE - 17000 - // (= 10000) to be considered safe and assume they can likely make it into this section - if (nBytes < (mode == GMF_SEND ? (DEFAULT_BLOCK_PRIORITY_SIZE - 17000) : (DEFAULT_BLOCK_PRIORITY_SIZE - 1000))) + // to be considered to fall into this category. We don't want to encourage sending + // multiple transactions instead of one big transaction to avoid fees. + // * If we are creating a transaction we allow transactions up to 1,000 bytes + // to be considered safe and assume they can likely make it into this section. + if (nBytes < (mode == GMF_SEND ? 1000 : (DEFAULT_BLOCK_PRIORITY_SIZE - 1000))) nMinFee = 0; }