/**
* Rotate the head log file to a read-only log file, and open a new empty head log file to write
* in.
*
* <p>All cursors opened on this log are temporarily disabled (closing underlying resources) and
* then re-open with their previous state.
*/
private void rotateHeadLogFile() throws ChangelogException {
// Temporarily disable cursors opened on head, saving their state
final List<Pair<AbortableLogCursor<K, V>, CursorState<K, V>>> cursorsOnHead =
disableOpenedCursorsOnHead();
final LogFile<K, V> headLogFile = getHeadLogFile();
final File readOnlyLogFile = new File(logPath, generateReadOnlyFileName(headLogFile));
headLogFile.close();
renameHeadLogFileTo(readOnlyLogFile);
openHeadLogFile();
openReadOnlyLogFile(readOnlyLogFile);
// Re-enable cursors previously opened on head, with the saved state
updateOpenedCursorsOnHeadAfterRotation(cursorsOnHead);
// Notify even if time-based rotation is not enabled, as it could be enabled at any time
replicationEnv.notifyLogFileRotation(this);
lastRotationTime = timeService.now();
}
private boolean mustRotate(LogFile<K, V> headLogFile) {
if (lastAppendedKey == null) {
// never rotate an empty file
return false;
}
if (headLogFile.getSizeInBytes() > sizeLimitPerLogFileInBytes) {
// rotate because file size exceeded threshold
logger.trace(
"Rotate log %s due to size: %s", logPath.getPath(), headLogFile.getSizeInBytes());
return true;
}
if (rotationIntervalInMillis > 0) {
// rotate if time limit is reached
final long timeElapsed = timeService.since(lastRotationTime);
boolean shouldRotate = timeElapsed > rotationIntervalInMillis;
if (shouldRotate) {
logger.trace(
"Rotate log %s due to time: time elapsed %s, rotation interval: %s",
logPath.getPath(), timeElapsed, rotationIntervalInMillis);
}
return shouldRotate;
}
return false;
}