/**
* Test that we can read from a stream created by FileJournalManager. Create a single edits
* directory, failing it on the final roll. Then try loading from the point of the 3rd roll.
* Verify that we read the correct number of transactions from this point.
*/
@Test
public void testReadFromStream() throws IOException {
File f = new File(TestEditLog.TEST_DIR + "/filejournaltest1");
// abort after 10th roll
NNStorage storage =
setupEdits(Collections.<URI>singletonList(f.toURI()), 10, new AbortSpec(10, 0));
StorageDirectory sd = storage.dirIterator(NameNodeDirType.EDITS).next();
FileJournalManager jm = new FileJournalManager(sd);
long expectedTotalTxnCount = TXNS_PER_ROLL * 10 + TXNS_PER_FAIL;
assertEquals(expectedTotalTxnCount, jm.getNumberOfTransactions(1));
long skippedTxns = (3 * TXNS_PER_ROLL); // skip first 3 files
long startingTxId = skippedTxns + 1;
long numTransactionsToLoad = jm.getNumberOfTransactions(startingTxId);
long numLoaded = 0;
while (numLoaded < numTransactionsToLoad) {
EditLogInputStream editIn = jm.getInputStream(startingTxId);
FSEditLogLoader.EditLogValidation val = FSEditLogLoader.validateEditLog(editIn);
long count = val.getNumTransactions();
editIn.close();
startingTxId += count;
numLoaded += count;
}
assertEquals(expectedTotalTxnCount - skippedTxns, numLoaded);
}
static FSEditLogLoader.EditLogValidation validateEditLog(File file) throws IOException {
EditLogFileInputStream in;
try {
in = new EditLogFileInputStream(file);
in.getVersion(); // causes us to read the header
} catch (LogHeaderCorruptException e) {
// If the header is malformed or the wrong value, this indicates a corruption
LOG.warn("Log file " + file + " has no valid header", e);
return new FSEditLogLoader.EditLogValidation(0, HdfsConstants.INVALID_TXID, true);
}
try {
return FSEditLogLoader.validateEditLog(in);
} finally {
IOUtils.closeStream(in);
}
}