Exemplo n.º 1
0
  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);
    }
  }
Exemplo n.º 2
0
 public static TransactionEx fromUnconfirmedTransaction(byte[] rawTransaction) {
   int now = (int) (System.currentTimeMillis() / 1000);
   Sha256Hash hash = HashUtils.doubleSha256(rawTransaction).reverse();
   return new TransactionEx(hash, -1, now, rawTransaction);
 }