private SnapshotImpl getSnapshot(ReadOptions options) {
SnapshotImpl snapshot;
if (options.snapshot() != null) {
snapshot = (SnapshotImpl) options.snapshot();
} else {
snapshot = new SnapshotImpl(versions.getCurrent(), versions.getLastSequence());
snapshot.close(); // To avoid holding the snapshot active..
}
return snapshot;
}
@Override
public byte[] get(byte[] key, ReadOptions options) throws DBException {
checkBackgroundException();
LookupKey lookupKey;
mutex.lock();
try {
SnapshotImpl snapshot = getSnapshot(options);
lookupKey = new LookupKey(Slices.wrappedBuffer(key), snapshot.getLastSequence());
// First look in the memtable, then in the immutable memtable (if any).
LookupResult lookupResult = memTable.get(lookupKey);
if (lookupResult != null) {
Slice value = lookupResult.getValue();
if (value == null) {
return null;
}
return value.getBytes();
}
if (immutableMemTable != null) {
lookupResult = immutableMemTable.get(lookupKey);
if (lookupResult != null) {
Slice value = lookupResult.getValue();
if (value == null) {
return null;
}
return value.getBytes();
}
}
} finally {
mutex.unlock();
}
// Not in memTables; try live files in level order
LookupResult lookupResult = versions.get(lookupKey);
// schedule compaction if necessary
mutex.lock();
try {
if (versions.needsCompaction()) {
maybeScheduleCompaction();
}
} finally {
mutex.unlock();
}
if (lookupResult != null) {
Slice value = lookupResult.getValue();
if (value != null) {
return value.getBytes();
}
}
return null;
}
private ISnapshot parse(
File file, String prefix, Map<String, String> args, IProgressListener listener)
throws SnapshotException {
List<Parser> parsers = ParserRegistry.matchParser(file.getName());
if (parsers.isEmpty()) parsers.addAll(ParserRegistry.allParsers()); // try all...
List<IOException> errors = new ArrayList<IOException>();
for (Parser parser : parsers) {
IIndexBuilder indexBuilder = parser.getIndexBuilder();
if (indexBuilder == null) continue;
try {
indexBuilder.init(file, prefix);
XSnapshotInfo snapshotInfo = new XSnapshotInfo();
snapshotInfo.setPath(file.getAbsolutePath());
snapshotInfo.setPrefix(prefix);
snapshotInfo.setProperty("$heapFormat", parser.getId()); // $NON-NLS-1$
if (Boolean.parseBoolean(args.get("keep_unreachable_objects"))) // $NON-NLS-1$
{
snapshotInfo.setProperty(
"keep_unreachable_objects", GCRootInfo.Type.UNREACHABLE); // $NON-NLS-1$
}
PreliminaryIndexImpl idx = new PreliminaryIndexImpl(snapshotInfo);
indexBuilder.fill(idx, listener);
SnapshotImplBuilder builder = new SnapshotImplBuilder(idx.getSnapshotInfo());
int[] purgedMapping = GarbageCleaner.clean(idx, builder, args, listener);
indexBuilder.clean(purgedMapping, listener);
SnapshotImpl snapshot = builder.create(parser);
snapshot.calculateDominatorTree(listener);
return snapshot;
} catch (IOException ioe) {
errors.add(ioe);
indexBuilder.cancel();
} catch (Exception e) {
indexBuilder.cancel();
throw SnapshotException.rethrow(e);
}
}
throw new SnapshotException(
MessageUtil.format(Messages.SnapshotFactoryImpl_Error_NoParserRegistered, file.getName()));
}