public static void load(
final Iterator<ProcedureWALFile> logs,
final ProcedureStoreTracker tracker,
final Loader loader)
throws IOException {
ProcedureWALFormatReader reader = new ProcedureWALFormatReader(tracker);
tracker.setKeepDeletes(true);
try {
while (logs.hasNext()) {
ProcedureWALFile log = logs.next();
log.open();
try {
reader.read(log, loader);
} finally {
log.close();
}
}
reader.finalize(loader);
// The tracker is now updated with all the procedures read from the logs
tracker.setPartialFlag(false);
tracker.resetUpdates();
} finally {
tracker.setKeepDeletes(false);
}
}
public void readTracker(ProcedureStoreTracker tracker) throws IOException {
ProcedureWALTrailer trailer = readTrailer();
try {
stream.seek(trailer.getTrackerPos());
tracker.readFrom(stream);
} finally {
stream.seek(startPos);
}
}
/*
* +-----------------+
* | END OF WAL DATA | <---+
* +-----------------+ |
* | | |
* | Tracker | |
* | | |
* +-----------------+ |
* | version | |
* +-----------------+ |
* | TRAILER_MAGIC | |
* +-----------------+ |
* | offset |-----+
* +-----------------+
*/
public static long writeTrailer(FSDataOutputStream stream, ProcedureStoreTracker tracker)
throws IOException {
long offset = stream.getPos();
// Write EOF Entry
ProcedureWALEntry.newBuilder()
.setType(ProcedureWALEntry.Type.PROCEDURE_WAL_EOF)
.build()
.writeDelimitedTo(stream);
// Write Tracker
tracker.writeTo(stream);
stream.write(TRAILER_VERSION);
StreamUtils.writeLong(stream, TRAILER_MAGIC);
StreamUtils.writeLong(stream, offset);
return stream.getPos() - offset;
}