Examples with Transaction org.bitcoinj.core.Transaction used on opensource projects

Example 56 with Transaction

use of org.bitcoinj.core.Transaction in project catena-java by alinush.

the class TxUtils method findDoubleSpendsAgainst.

/**
 * Checks if any of the transactions in txs spend the same outputs as the transactions in candidates.
 *
 * The ordering of the transactions in the collection associated with the output is the following.
 * (1) first, the tx from 'txs'
 * (2) second, any double spends from 'candidates'
 *
 * @param txs
 * @param candidates
 * @return
 */
public static Map<TransactionOutPoint, List<Transaction>> findDoubleSpendsAgainst(Iterator<Transaction> txsIt, Map<Sha256Hash, Transaction> candidates) {
    // Maps an outpoint to a list of transactions that spend it (ideally, that list should be of size one)
    ArrayListMultimap<TransactionOutPoint, Transaction> outpoints = ArrayListMultimap.create();
    while (txsIt.hasNext()) {
        Transaction tx = txsIt.next();
        // Coinbase TXs cannot double spend
        if (tx.isCoinBase())
            continue;
        // Compile a set of outpoints that are spent by tx.
        for (TransactionInput input : tx.getInputs()) {
            outpoints.put(input.getOutpoint(), tx);
        }
    }
    // Now for each candidate transaction, see if it spends any outpoints as this tx.
    for (Transaction tx : candidates.values()) {
        for (TransactionInput input : tx.getInputs()) {
            TransactionOutPoint outpoint = input.getOutpoint();
            // double spends amongst txs in candidates, which might not be desired by callers.
            if (outpoints.containsKey(outpoint)) {
                // It does, it's a double spend against the candidates, which makes it relevant.
                outpoints.put(outpoint, tx);
            }
        }
    }
    // Now clear <outp, list(tx)> pairs where the sizeof(list) == 1 (i.e., no double spend)
    Map<TransactionOutPoint, List<Transaction>> doubleSpends = Multimaps.asMap(outpoints);
    Iterator<List<Transaction>> it = doubleSpends.values().iterator();
    while (it.hasNext()) {
        int numSpends = it.next().size();
        if (numSpends < 2) {
            it.remove();
        }
    }
    return doubleSpends;
}

Example 57 with Transaction

use of org.bitcoinj.core.Transaction in project catena-java by alinush.

the class TxUtils method findDoubleSpendsAmongst.

public static Map<TransactionOutPoint, List<Transaction>> findDoubleSpendsAmongst(Collection<Transaction> candidates) {
    ArrayListMultimap<TransactionOutPoint, Transaction> map = ArrayListMultimap.create();
    // "spends" <o, tx> pair to the map.
    for (Transaction tx : candidates) {
        for (TransactionInput input : tx.getInputs()) {
            TransactionOutPoint outpoint = input.getOutpoint();
            map.put(outpoint, tx);
        }
    }
    // Now clear <o, list(tx)> pairs where the sizeof(list) == 1 (i.e., no double spend)
    Map<TransactionOutPoint, List<Transaction>> doubleSpends = Multimaps.asMap(map);
    Iterator<List<Transaction>> it = doubleSpends.values().iterator();
    while (it.hasNext()) {
        int numSpends = it.next().size();
        if (numSpends < 2) {
            it.remove();
        }
    }
    return doubleSpends;
}

Example 58 with Transaction

use of org.bitcoinj.core.Transaction in project catena-java by alinush.

the class CatenaServer method appendStatement.

/**
 * Appends a statement to the Catena chain. This function first commits
 * the statement on disk, then schedules it for publication on the
 * blockchain.
 *
 * @param statement
 * @throws InsufficientMoneyException
 *
 * @return
 */
public Transaction appendStatement(byte[] statement) throws InsufficientMoneyException {
    Transaction tx = wallet.appendStatement(statement);
    // Broadcast Catena transaction
    // 
    // WARNING: Sending the TX this way by calling sendCatenaTxOfflline
    // (it used to be Wallet::sendCoinsOffline but we subclassed Wallet) and then
    // peerGroup().broadcastTransaction() might not work in future version of
    // bitcoinj
    final SendResult result = new SendResult();
    result.tx = tx;
    result.broadcast = peerGroup().broadcastTransaction(tx);
    result.broadcastComplete = result.broadcast.future();
    log.trace("Catena server TX (" + tx.getHash() + ") for '" + statement + "' after sending: " + tx);
    return tx;
}

Example 59 with Transaction

use of org.bitcoinj.core.Transaction in project catena-java by alinush.

the class CatenaApp method listStatements.

protected static void listStatements(boolean isFwd, int numPrint) {
    int numStmts = wallet.getNumStatements();
    Iterator<CatenaStatement> it = wallet.statementIterator(isFwd);
    int c = isFwd ? 1 : numStmts;
    for (int i = 0; i < numPrint; i++) {
        if (it.hasNext()) {
            CatenaStatement s = it.next();
            Transaction prevTx = CatenaUtils.getPrevCatenaTx(wallet, s.getTxHash());
            System.out.printf("Statement #%d: %s (tx %s, prev %s)\n", c, s.getAsString(), s.getTxHash(), prevTx.getHash());
            c = isFwd ? c + 1 : c - 1;
        }
    }
}

Example 60 with Transaction

use of org.bitcoinj.core.Transaction in project catena-java by alinush.

the class CatenaUtils method getNextCatenaTx.

public static Transaction getNextCatenaTx(Wallet wallet, Sha256Hash currHash) {
    checkNotNull(currHash);
    Transaction currTxn = wallet.getTransaction(currHash);
    checkNotNull(currTxn);
    return getNextCatenaTx(wallet, currTxn);
}