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Update bloom filter if coins were sent
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Fixes bitcoinj#2070 (comment)
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@oscarguindzberg
oscarguindzberg committed Dec 16, 2020
1 parent 902679f commit 1a786a2
Showing 1 changed file with 48 additions and 33 deletions.
81 changes: 48 additions & 33 deletions core/src/main/java/org/bitcoinj/core/PeerGroup.java
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Original file line number Diff line number Diff line change
Expand Up @@ -33,6 +33,7 @@
import org.bitcoinj.wallet.listeners.KeyChainEventListener;
import org.bitcoinj.wallet.listeners.ScriptsChangeEventListener;
import org.bitcoinj.wallet.listeners.WalletCoinsReceivedEventListener;
import org.bitcoinj.wallet.listeners.WalletCoinsSentEventListener;
import org.slf4j.*;

import javax.annotation.*;
Expand Down Expand Up @@ -188,42 +189,54 @@ public static void setIgnoreHttpSeeds(boolean ignoreHttpSeeds) {
private final WalletCoinsReceivedEventListener walletCoinsReceivedEventListener = new WalletCoinsReceivedEventListener() {
@Override
public void onCoinsReceived(Wallet wallet, Transaction tx, Coin prevBalance, Coin newBalance) {
// We received a relevant transaction. We MAY need to recalculate and resend the Bloom filter, but only
// if we have received a transaction that includes a relevant P2PK or P2WPKH output.
//
// The reason is that P2PK and P2WPKH outputs, when spent, will not repeat any data we can predict in their
// inputs. So a remote peer will update the Bloom filter for us when such an output is seen matching the
// existing filter, so that it includes the tx hash in which the P2PK/P2WPKH output was observed. Thus
// the spending transaction will always match (due to the outpoint structure).
//
// Unfortunately, whilst this is required for correct sync of the chain in blocks, there are two edge cases.
//
// (1) If a wallet receives a relevant, confirmed P2PK/P2WPKH output that was not broadcast across the network,
// for example in a coinbase transaction, then the node that's serving us the chain will update its filter
// but the rest will not. If another transaction then spends it, the other nodes won't match/relay it.
//
// (2) If we receive a P2PK/P2WPKH output broadcast across the network, all currently connected nodes will see
// it and update their filter themselves, but any newly connected nodes will receive the last filter we
// calculated, which would not include this transaction.
//
// For this reason we check if the transaction contained any relevant P2PKs or P2WPKHs and force a recalc
// and possibly retransmit if so. The recalculation process will end up including the tx hash into the
// filter. In case (1), we need to retransmit the filter to the connected peers. In case (2), we don't
// and shouldn't, we should just recalculate and cache the new filter for next time.
for (TransactionOutput output : tx.getOutputs()) {
Script scriptPubKey = output.getScriptPubKey();
if (ScriptPattern.isP2PK(scriptPubKey) || ScriptPattern.isP2WPKH(scriptPubKey)) {
if (output.isMine(wallet)) {
if (tx.getConfidence().getConfidenceType() == TransactionConfidence.ConfidenceType.BUILDING)
recalculateFastCatchupAndFilter(FilterRecalculateMode.SEND_IF_CHANGED);
else
recalculateFastCatchupAndFilter(FilterRecalculateMode.DONT_SEND);
return;
}
onCoinsReceivedOrSent(wallet, tx);
}
};

private final WalletCoinsSentEventListener walletCoinsSentEventListener = new WalletCoinsSentEventListener() {
@Override
public void onCoinsSent(Wallet wallet, Transaction tx, Coin prevBalance, Coin newBalance) {
onCoinsReceivedOrSent(wallet, tx);
}
};


private void onCoinsReceivedOrSent(Wallet wallet, Transaction tx) {
// We received a relevant transaction. We MAY need to recalculate and resend the Bloom filter, but only
// if we have received a transaction that includes a relevant P2PK or P2WPKH output.
//
// The reason is that P2PK and P2WPKH outputs, when spent, will not repeat any data we can predict in their
// inputs. So a remote peer will update the Bloom filter for us when such an output is seen matching the
// existing filter, so that it includes the tx hash in which the P2PK/P2WPKH output was observed. Thus
// the spending transaction will always match (due to the outpoint structure).
//
// Unfortunately, whilst this is required for correct sync of the chain in blocks, there are two edge cases.
//
// (1) If a wallet receives a relevant, confirmed P2PK/P2WPKH output that was not broadcast across the network,
// for example in a coinbase transaction, then the node that's serving us the chain will update its filter
// but the rest will not. If another transaction then spends it, the other nodes won't match/relay it.
//
// (2) If we receive a P2PK/P2WPKH output broadcast across the network, all currently connected nodes will see
// it and update their filter themselves, but any newly connected nodes will receive the last filter we
// calculated, which would not include this transaction.
//
// For this reason we check if the transaction contained any relevant P2PKs or P2WPKHs and force a recalc
// and possibly retransmit if so. The recalculation process will end up including the tx hash into the
// filter. In case (1), we need to retransmit the filter to the connected peers. In case (2), we don't
// and shouldn't, we should just recalculate and cache the new filter for next time.
for (TransactionOutput output : tx.getOutputs()) {
Script scriptPubKey = output.getScriptPubKey();
if (ScriptPattern.isP2PK(scriptPubKey) || ScriptPattern.isP2WPKH(scriptPubKey)) {
if (output.isMine(wallet)) {
if (tx.getConfidence().getConfidenceType() == TransactionConfidence.ConfidenceType.BUILDING)
recalculateFastCatchupAndFilter(FilterRecalculateMode.SEND_IF_CHANGED);
else
recalculateFastCatchupAndFilter(FilterRecalculateMode.DONT_SEND);
return;
}
}
}
};
}

// Exponential backoff for peers starts at 1 second and maxes at 10 minutes.
private final ExponentialBackoff.Params peerBackoffParams = new ExponentialBackoff.Params(1000, 1.5f, 10 * 60 * 1000);
Expand Down Expand Up @@ -1204,6 +1217,7 @@ public void addWallet(Wallet wallet) {
wallets.add(wallet);
wallet.setTransactionBroadcaster(this);
wallet.addCoinsReceivedEventListener(Threading.SAME_THREAD, walletCoinsReceivedEventListener);
wallet.addCoinsSentEventListener(Threading.SAME_THREAD, walletCoinsSentEventListener);
wallet.addKeyChainEventListener(Threading.SAME_THREAD, walletKeyEventListener);
wallet.addScriptChangeEventListener(Threading.SAME_THREAD, walletScriptEventListener);
addPeerFilterProvider(wallet);
Expand Down Expand Up @@ -1276,6 +1290,7 @@ public void removeWallet(Wallet wallet) {
wallets.remove(checkNotNull(wallet));
peerFilterProviders.remove(wallet);
wallet.removeCoinsReceivedEventListener(walletCoinsReceivedEventListener);
wallet.removeCoinsSentEventListener(walletCoinsSentEventListener);
wallet.removeKeyChainEventListener(walletKeyEventListener);
wallet.removeScriptChangeEventListener(walletScriptEventListener);
wallet.setTransactionBroadcaster(null);
Expand Down

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