/**
* deleting a container affects the containers in RAM and all the BLOB files the deleted
* containers are merged and returned as result of the method
*
* @throws IOException
*/
@Override
public ReferenceContainer<ReferenceType> remove(final byte[] termHash) throws IOException {
removeDelayed();
ReferenceContainer<ReferenceType> c1 = null;
try {
c1 = this.array.get(termHash);
} catch (final SpaceExceededException e2) {
ConcurrentLog.logException(e2);
}
if (c1 != null) {
this.array.delete(termHash);
}
final ReferenceContainer<ReferenceType> c0 = this.ram.remove(termHash);
if (c1 == null) return c0;
if (c0 == null) return c1;
try {
return c1.merge(c0);
} catch (final SpaceExceededException e) {
// try to free some ram
try {
return c1.merge(c0);
} catch (final SpaceExceededException e1) {
// go silently over the problem
return (c1.size() > c0.size()) ? c1 : c0;
}
}
}
/**
* count number of references for a given term this method may cause strong IO load if called too
* frequently.
*/
@Override
public int count(final byte[] termHash) {
final Integer cachedCount = this.countCache.get(termHash);
if (cachedCount != null) return cachedCount.intValue();
int countFile = 0;
// read fresh values from file
try {
countFile = this.array.count(termHash);
} catch (final Throwable e) {
ConcurrentLog.logException(e);
}
assert countFile >= 0;
// count from container in ram
final ReferenceContainer<ReferenceType> countRam = this.ram.get(termHash, null);
assert countRam == null || countRam.size() >= 0;
int c = countRam == null ? countFile : countFile + countRam.size();
// exclude entries from delayed remove
synchronized (this.removeDelayedURLs) {
final HandleSet s = this.removeDelayedURLs.get(termHash);
if (s != null) c -= s.size();
if (c < 0) c = 0;
}
// put count result into cache
if (MemoryControl.shortStatus()) this.countCache.clear();
this.countCache.insert(termHash, c);
return c;
}
/**
* all containers in the BLOBs and the RAM are merged and returned. Please be aware that the
* returned values may be top-level cloned ReferenceContainers or direct links to containers If
* the containers are modified after they are returned, they MAY alter the stored index.
*
* @throws IOException
* @return a container with merged ReferenceContainer from RAM and the file array or null if there
* is no data to be returned
*/
@Override
public ReferenceContainer<ReferenceType> get(final byte[] termHash, final HandleSet urlselection)
throws IOException {
final ReferenceContainer<ReferenceType> c0 = this.ram.get(termHash, null);
ReferenceContainer<ReferenceType> c1 = null;
try {
c1 = this.array.get(termHash);
} catch (final SpaceExceededException e2) {
ConcurrentLog.logException(e2);
}
ReferenceContainer<ReferenceType> result = null;
if (c0 != null && c1 != null) {
try {
result = c1.merge(c0);
} catch (final SpaceExceededException e) {
// try to free some ram
try {
result = c1.merge(c0);
} catch (final SpaceExceededException e1) {
// go silently over the problem
result = (c1.size() > c0.size()) ? c1 : c0;
}
}
} else if (c0 != null) {
result = c0;
} else if (c1 != null) {
result = c1;
}
if (result == null) return null;
// remove the failed urls
synchronized (this.removeDelayedURLs) {
final HandleSet s = this.removeDelayedURLs.get(termHash);
if (s != null) result.removeEntries(s);
}
return result;
}