@Override
public String toString() {
synchronized (TransactionLog.this) {
return "LogReader{"
+ "file="
+ tlogFile
+ ", position="
+ fis.position()
+ ", end="
+ fos.size()
+ "}";
}
}
/**
* Returns the next object from the log, or null if none available.
*
* @return The log record, or null if EOF
* @throws IOException If there is a low-level I/O error.
*/
public Object next() throws IOException, InterruptedException {
long pos = fis.position();
synchronized (TransactionLog.this) {
if (trace) {
log.trace("Reading log record. pos=" + pos + " currentSize=" + fos.size());
}
if (pos >= fos.size()) {
return null;
}
fos.flushBuffer();
}
if (pos == 0) {
readHeader(fis);
// shouldn't currently happen - header and first record are currently written at the same
// time
synchronized (TransactionLog.this) {
if (fis.position() >= fos.size()) {
return null;
}
pos = fis.position();
}
}
Object o = codec.readVal(fis);
// skip over record size
int size = fis.readInt();
assert size == fis.position() - pos - 4;
return o;
}
// returns best effort current position
// for info purposes
public long currentPos() {
return fis.position();
}