logFile = testDir.listFiles()[0];
long validLength = getNonTrailerLength(logFile);
// Make sure that uncorrupted log has the expected length and number
// of transactions.
EditLogValidation validation = EditLogFileInputStream.validateEditLog(logFile);
assertEquals(NUM_TXNS + 2, validation.getNumTransactions());
assertEquals(validLength, validation.getValidLength());
// Back up the uncorrupted log
File logFileBak = new File(testDir, logFile.getName() + ".bak");
Files.copy(logFile, logFileBak);
// Corrupt the log file in various ways for each txn
for (Map.Entry<Long, Long> entry : offsetToTxId.entrySet()) {
long txOffset = entry.getKey();
long txid = entry.getValue();
// Restore backup, truncate the file exactly before the txn
Files.copy(logFileBak, logFile);
truncateFile(logFile, txOffset);
validation = EditLogFileInputStream.validateEditLog(logFile);
assertEquals("Failed when truncating to length " + txOffset,
txid - 1, validation.getNumTransactions());
assertEquals(txOffset, validation.getValidLength());
// Restore backup, truncate the file with one byte in the txn,
// also isn't valid
Files.copy(logFileBak, logFile);
truncateFile(logFile, txOffset + 1);
validation = EditLogFileInputStream.validateEditLog(logFile);
assertEquals("Failed when truncating to length " + (txOffset + 1),
txid - 1, validation.getNumTransactions());
assertEquals(txOffset, validation.getValidLength());
// Restore backup, corrupt the txn opcode
Files.copy(logFileBak, logFile);
corruptByteInFile(logFile, txOffset);
validation = EditLogFileInputStream.validateEditLog(logFile);
assertEquals("Failed when corrupting txn opcode at " + txOffset,
txid - 1, validation.getNumTransactions());
assertEquals(txOffset, validation.getValidLength());
// Restore backup, corrupt a byte a few bytes into the txn
Files.copy(logFileBak, logFile);
corruptByteInFile(logFile, txOffset+5);
validation = EditLogFileInputStream.validateEditLog(logFile);
assertEquals("Failed when corrupting txn data at " + (txOffset+5),
txid - 1, validation.getNumTransactions());
assertEquals(txOffset, validation.getValidLength());
}
// Corrupt the log at every offset to make sure that validation itself
// never throws an exception, and that the calculated lengths are monotonically
// increasing
long prevNumValid = 0;
for (long offset = 0; offset < validLength; offset++) {
Files.copy(logFileBak, logFile);
corruptByteInFile(logFile, offset);
EditLogValidation val = EditLogFileInputStream.validateEditLog(logFile);
assertTrue(String.format("%d should have been >= %d",
val.getNumTransactions(), prevNumValid),
val.getNumTransactions() >= prevNumValid);
prevNumValid = val.getNumTransactions();
}
}