/**
* Test correct detection and resolution of a write-write conflict. An index is registered with an
* {@link IConflictResolver} and the journal is committed. Two transactions (tx1, tx2) are then
* started. Both transactions write a value under the same key. tx1 prepares and commits. tx2
* attempts to prepare, and the test verifies that the conflict resolver is invoked, that it may
* resolve the conflict causing validation to succeed and that the value determined by conflict
* resolution is made persistent when tx2 commits.
*/
public void test_writeWriteConflict_conflictIsResolved() {
final Journal journal = new Journal(getProperties());
try {
final String name = "abc";
final byte[] k1 = new byte[] {1};
final byte[] v1a = new byte[] {1};
final byte[] v1b = new byte[] {2};
final byte[] v1c = new byte[] {3};
{
/*
* register an index with a conflict resolver and commit the
* journal.
*/
final IndexMetadata metadata = new IndexMetadata(name, UUID.randomUUID());
metadata.setIsolatable(true);
metadata.setConflictResolver(new SingleValueConflictResolver(k1, v1c));
journal.registerIndex(name, BTree.create(journal, metadata));
journal.commit();
}
/*
* Create two transactions.
*/
final long tx1 = journal.newTx(ITx.UNISOLATED);
final long tx2 = journal.newTx(ITx.UNISOLATED);
/*
* Write a value under the same key on the same index in both
* transactions.
*/
journal.getIndex(name, tx1).insert(k1, v1a);
journal.getIndex(name, tx2).insert(k1, v1b);
journal.commit(tx1);
/*
* verify that the value from tx1 is found under the key on the
* unisolated index.
*/
assertEquals(v1a, (byte[]) journal.getIndex(name).lookup(k1));
journal.commit(tx2);
/*
* verify that the resolved value is found under the key on the
* unisolated index.
*/
assertEquals(v1c, (byte[]) journal.getIndex(name).lookup(k1));
} finally {
journal.destroy();
}
}
/**
* Test correct detection of a write-write conflict. An index is registered and the journal is
* committed. Two transactions (tx1, tx2) are then started. Both transactions write a value under
* the same key. tx1 prepares and commits. tx2 attempts to prepare, and the test verifies that a
* {@link ValidationError} is reported.
*/
public void test_writeWriteConflict_correctDetection() {
final Journal journal = new Journal(getProperties());
try {
String name = "abc";
final byte[] k1 = new byte[] {1};
final byte[] v1a = new byte[] {1};
final byte[] v1b = new byte[] {2};
{
/*
* register an index and commit the journal.
*/
IndexMetadata metadata = new IndexMetadata(name, UUID.randomUUID());
metadata.setIsolatable(true);
// Note: No conflict resolver.
journal.registerIndex(name, BTree.create(journal, metadata));
journal.commit();
}
/*
* Create two transactions.
*/
final long tx1 = journal.newTx(ITx.UNISOLATED);
final long tx2 = journal.newTx(ITx.UNISOLATED);
/*
* Write a value under the same key on the same index in both
* transactions.
*/
journal.getIndex(name, tx1).insert(k1, v1a);
journal.getIndex(name, tx2).insert(k1, v1b);
journal.commit(tx1);
/*
* verify that the value from tx1 is found under the key on the
* unisolated index.
*/
assertEquals(v1a, (byte[]) journal.getIndex(name).lookup(k1));
// final ITx tmp = journal.getTx(tx2);
try {
journal.commit(tx2);
fail("Expecting: " + ValidationError.class);
} catch (ValidationError ex) {
if (log.isInfoEnabled()) log.info("Ignoring expected exception: " + ex);
// assertTrue(tmp.isAborted());
}
} finally {
journal.destroy();
}
}