protected Map handleItem()

in src/main/java/com/amazonaws/services/dynamodbv2/transactions/ReadCommittedIsolationHandlerImpl.java [133:178]
36 lines of code
9 McCabe index (conditional complexity)

    protected Map<String, AttributeValue> handleItem(
            final Map<String, AttributeValue> item,
            final String tableName,
            final int numRetries) {
        GetItemRequest request = null; // only create if necessary
        for (int i = 0; i <= numRetries; i++) {
            final Map<String, AttributeValue> currentItem;
            if (i == 0) {
                currentItem = item;
            } else {
                if (request == null) {
                    request = createGetItemRequest(tableName, item);
                }
                currentItem = txManager.getClient().getItem(request).getItem();
            }

            // 1. Return the item if it isn't locked (or if it's locked, but not applied yet)
            try {
                return checkItemCommitted(currentItem);
            } catch (TransactionException e1) {
                try {
                    // 2. Load the locking transaction
                    Transaction lockingTx = loadTransaction(e1.getTxId());

                    /*
                     * 3. See if the locking transaction has been committed. If so, return the item. This is valid because you cannot
                     * write to an item multiple times in the same transaction. Otherwise it would expose intermediate state.
                     */
                    if (TransactionItem.State.COMMITTED.equals(lockingTx.getTxItem().getState())) {
                        return currentItem;
                    }

                    // 4. Try to get a previously committed version of the item
                    if (request == null) {
                        request = createGetItemRequest(tableName, item);
                    }
                    return getOldCommittedItem(lockingTx, tableName, request.getKey());
                } catch (UnknownCompletedTransactionException e2) {
                    LOG.debug("Could not find item image. Transaction must have already completed.", e2);
                } catch (TransactionNotFoundException e2) {
                    LOG.debug("Unable to find locking transaction. Transaction must have already completed.", e2);
                }
            }
        }
        throw new TransactionException(null, "Ran out of attempts to get a committed image of the item");
    }