Examples with Transaction org.cojen.tupl.Transaction used on opensource projects

Example 26 with Transaction

use of org.cojen.tupl.Transaction in project Tupl by cojen.

the class MergeCursor method perform.

/**
 * Performs the given action with an appropriate lock mode.
 */
private LockResult perform(Action action) throws IOException {
    Transaction txn = mTxn;
    if (mView.mCombiner.combineLocks()) {
        if (txn == null) {
            txn = mView.newTransaction(null);
            try {
                txn.lockMode(LockMode.REPEATABLE_READ);
                action.perform(txn);
            } finally {
                txn.reset();
            }
            return LockResult.UNOWNED;
        } else if (txn.lockMode() == LockMode.READ_COMMITTED) {
            LockResult result;
            final LockMode original = txn.lockMode();
            try {
                txn.lockMode(LockMode.REPEATABLE_READ);
                result = action.perform(txn);
                if (result.isAcquired()) {
                    txn.unlock();
                    result = LockResult.UNOWNED;
                }
            } finally {
                txn.lockMode(original);
            }
            return result;
        }
    }
    return action.perform(txn);
}

Example 27 with Transaction

use of org.cojen.tupl.Transaction in project Tupl by cojen.

the class ViewUtils method findNoLock.

public static void findNoLock(Cursor c, byte[] key) throws IOException {
    final boolean auto = c.autoload(false);
    final Transaction txn = c.link(Transaction.BOGUS);
    try {
        c.find(key);
    } finally {
        c.link(txn);
        c.autoload(auto);
    }
}

Example 28 with Transaction

use of org.cojen.tupl.Transaction in project Tupl by cojen.

the class ViewUtils method previousCmp.

/**
 * @param cmp 0 for previousGt, -1 for previousGe
 */
public static LockResult previousCmp(Cursor c, byte[] limitKey, int cmp) throws IOException {
    Utils.keyCheck(limitKey);
    while (true) {
        final boolean auto = c.autoload(false);
        final Transaction txn = c.link(Transaction.BOGUS);
        try {
            c.previous();
        } finally {
            c.link(txn);
            c.autoload(auto);
        }
        if (c.key() != null) {
            if (c.compareKeyTo(limitKey) > cmp) {
                LockResult result = auto ? c.load() : c.lock();
                if (c.value() != null) {
                    return result;
                }
                continue;
            }
            c.reset();
        }
        return LockResult.UNOWNED;
    }
}

Example 29 with Transaction

use of org.cojen.tupl.Transaction in project Tupl by cojen.

the class CursorUpgradableUpdater method step.

@Override
public boolean step() throws IOException {
    tryStep: {
        Cursor c = mCursor;
        try {
            Transaction txn = c.link();
            LockMode original = txn.lockMode();
            txn.lockMode(LockMode.UPGRADABLE_READ);
            try {
                c.next();
            } finally {
                txn.lockMode(original);
            }
        } catch (UnpositionedCursorException e) {
            break tryStep;
        } catch (Throwable e) {
            throw Utils.fail(this, e);
        }
        if (c.key() != null) {
            return true;
        }
    }
    return false;
}

Example 30 with Transaction

use of org.cojen.tupl.Transaction in project Tupl by cojen.

the class UpgradableRowUpdater method toFirst.

@Override
protected LockResult toFirst(Cursor c) throws IOException {
    Transaction txn = c.link();
    LockMode original = txn.lockMode();
    txn.lockMode(LockMode.UPGRADABLE_READ);
    try {
        return super.toFirst(c);
    } finally {
        txn.lockMode(original);
    }
}