private void fetchStoreAndValidateParentOutputs(ArrayList<Transaction> transactions)
throws WapiException {
Map<Sha256Hash, TransactionEx> parentTransactions = new HashMap<Sha256Hash, TransactionEx>();
Map<OutPoint, TransactionOutputEx> parentOutputs = new HashMap<OutPoint, TransactionOutputEx>();
// Find list of parent outputs to fetch
Collection<Sha256Hash> toFetch = new HashSet<Sha256Hash>();
for (Transaction t : transactions) {
for (TransactionInput in : t.inputs) {
if (in.outPoint.hash.equals(OutPoint.COINBASE_OUTPOINT.hash)) {
// Coinbase input, so no parent
continue;
}
TransactionOutputEx parentOutput = _backing.getParentTransactionOutput(in.outPoint);
if (parentOutput != null) {
// We already have the parent output, no need to fetch the entire
// parent transaction
parentOutputs.put(parentOutput.outPoint, parentOutput);
continue;
}
TransactionEx parentTransaction = _backing.getTransaction(in.outPoint.hash);
if (parentTransaction != null) {
// We had the parent transaction in our own transactions, no need to
// fetch it remotely
parentTransactions.put(parentTransaction.txid, parentTransaction);
} else {
// Need to fetch it
toFetch.add(in.outPoint.hash);
}
}
}
// Fetch missing parent transactions
if (toFetch.size() > 0) {
GetTransactionsResponse result =
_wapi.getTransactions(new GetTransactionsRequest(Wapi.VERSION, toFetch)).getResult();
for (TransactionEx tx : result.transactions) {
// Verify transaction hash. This is important as we don't want to
// have a transaction output associated with an outpoint that
// doesn't match.
// This is the end users protection against a rogue server that lies
// about the value of an output and makes you pay a large fee.
Sha256Hash hash = HashUtils.doubleSha256(tx.binary).reverse();
if (hash.equals(tx.txid)) {
parentTransactions.put(tx.txid, tx);
} else {
_logger.logError(
"Failed to validate transaction hash from server. Expected: "
+ tx.txid
+ " Calculated: "
+ hash);
throw new RuntimeException(
"Failed to validate transaction hash from server. Expected: "
+ tx.txid
+ " Calculated: "
+ hash);
}
}
}
// We should now have all parent transactions or parent outputs. There is
// a slight probability that one of them was not found due to double
// spends and/or malleability and network latency etc.
// Now figure out which parent outputs we need to persist
List<TransactionOutputEx> toPersist = new LinkedList<TransactionOutputEx>();
for (Transaction t : transactions) {
for (TransactionInput in : t.inputs) {
if (in.outPoint.hash.equals(OutPoint.COINBASE_OUTPOINT.hash)) {
// coinbase input, so no parent
continue;
}
TransactionOutputEx parentOutput = parentOutputs.get(in.outPoint);
if (parentOutput != null) {
// We had it all along
continue;
}
TransactionEx parentTex = parentTransactions.get(in.outPoint.hash);
if (parentTex != null) {
// Parent output not found, maybe we already have it
parentOutput = TransactionEx.getTransactionOutput(parentTex, in.outPoint.index);
toPersist.add(parentOutput);
continue;
}
_logger.logError("Parent transaction not found: " + in.outPoint.hash);
}
}
// Persist
for (TransactionOutputEx output : toPersist) {
_backing.putParentTransactionOutput(output);
}
}
protected boolean synchronizeUnspentOutputs(Collection<Address> addresses) {
// Get the current unspent outputs as dictated by the block chain
QueryUnspentOutputsResponse UnspentOutputResponse;
try {
UnspentOutputResponse =
_wapi
.queryUnspentOutputs(new QueryUnspentOutputsRequest(Wapi.VERSION, addresses))
.getResult();
} catch (WapiException e) {
_logger.logError("Server connection failed with error code: " + e.errorCode, e);
postEvent(Event.SERVER_CONNECTION_ERROR);
return false;
}
Collection<TransactionOutputEx> remoteUnspent = UnspentOutputResponse.unspent;
// Store the current block height
setBlockChainHeight(UnspentOutputResponse.height);
// Make a map for fast lookup
Map<OutPoint, TransactionOutputEx> remoteMap = toMap(remoteUnspent);
// Get the current unspent outputs as it is believed to be locally
Collection<TransactionOutputEx> localUnspent = _backing.getAllUnspentOutputs();
// Make a map for fast lookup
Map<OutPoint, TransactionOutputEx> localMap = toMap(localUnspent);
// Find remotely removed unspent outputs
for (TransactionOutputEx l : localUnspent) {
TransactionOutputEx r = remoteMap.get(l.outPoint);
if (r == null) {
// An output has gone. Maybe it was spent in another wallet, or
// never confirmed due to missing fees, double spend, or mutated.
// Either way, we delete it locally
_backing.deleteUnspentOutput(l.outPoint);
}
}
// Find remotely added unspent outputs
Set<Sha256Hash> transactionsToAddOrUpdate = new HashSet<Sha256Hash>();
List<TransactionOutputEx> unspentOutputsToAddOrUpdate = new LinkedList<TransactionOutputEx>();
for (TransactionOutputEx r : remoteUnspent) {
TransactionOutputEx l = localMap.get(r.outPoint);
if (l == null || l.height != r.height) {
// New remote output or new height (Maybe it confirmed or we
// might even have had a reorg). Either way we just update it
unspentOutputsToAddOrUpdate.add(r);
transactionsToAddOrUpdate.add(r.outPoint.hash);
// Note: We are not adding the unspent output to the DB just yet. We
// first want to verify the full set of funding transactions of the
// transaction that this unspent output belongs to
}
}
// Fetch updated or added transactions
if (transactionsToAddOrUpdate.size() > 0) {
GetTransactionsResponse response;
try {
response =
_wapi
.getTransactions(
new GetTransactionsRequest(Wapi.VERSION, transactionsToAddOrUpdate))
.getResult();
} catch (WapiException e) {
_logger.logError("Server connection failed with error code: " + e.errorCode, e);
postEvent(Event.SERVER_CONNECTION_ERROR);
return false;
}
try {
handleNewExternalTransactions(response.transactions);
} catch (WapiException e) {
_logger.logError("Server connection failed with error code: " + e.errorCode, e);
postEvent(Event.SERVER_CONNECTION_ERROR);
return false;
}
// Finally update out list of unspent outputs with added or updated
// outputs
for (TransactionOutputEx output : unspentOutputsToAddOrUpdate) {
_backing.putUnspentOutput(output);
}
}
return true;
}