82 lines
2.4 KiB
Java
82 lines
2.4 KiB
Java
package it.cavallium.dbengine.database.disk;
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import static it.cavallium.dbengine.database.disk.LLLocalDictionary.getRocksIterator;
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import it.cavallium.dbengine.database.LLRange;
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import it.unimi.dsi.fastutil.objects.ObjectArrayList;
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import java.util.Arrays;
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import java.util.List;
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import org.rocksdb.ColumnFamilyHandle;
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import org.rocksdb.ReadOptions;
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import org.rocksdb.RocksDB;
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import org.rocksdb.RocksMutableObject;
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import reactor.core.publisher.Flux;
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public abstract class LLLocalGroupedReactiveRocksIterator<T> {
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private static final byte[] EMPTY = new byte[0];
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private final RocksDB db;
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private final ColumnFamilyHandle cfh;
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private final int prefixLength;
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private final LLRange range;
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private final ReadOptions readOptions;
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private final boolean canFillCache;
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private final boolean readValues;
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public LLLocalGroupedReactiveRocksIterator(RocksDB db,
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ColumnFamilyHandle cfh,
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int prefixLength,
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LLRange range,
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ReadOptions readOptions,
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boolean canFillCache,
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boolean readValues) {
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this.db = db;
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this.cfh = cfh;
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this.prefixLength = prefixLength;
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this.range = range;
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this.readOptions = readOptions;
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this.canFillCache = canFillCache;
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this.readValues = readValues;
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}
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public Flux<List<T>> flux() {
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return Flux
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.generate(() -> {
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var readOptions = new ReadOptions(this.readOptions);
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readOptions.setFillCache(canFillCache && range.hasMin() && range.hasMax());
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return getRocksIterator(readOptions, range, db, cfh);
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}, (tuple, sink) -> {
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var rocksIterator = tuple.getT1();
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ObjectArrayList<T> values = new ObjectArrayList<>();
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byte[] firstGroupKey = null;
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while (rocksIterator.isValid()) {
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byte[] key = rocksIterator.key();
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if (firstGroupKey == null) {
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firstGroupKey = key;
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} else if (!Arrays.equals(firstGroupKey, 0, prefixLength, key, 0, prefixLength)) {
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break;
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}
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byte[] value = readValues ? rocksIterator.value() : EMPTY;
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rocksIterator.next();
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values.add(getEntry(key, value));
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}
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if (!values.isEmpty()) {
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sink.next(values);
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} else {
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sink.complete();
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}
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return tuple;
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}, tuple -> {
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var rocksIterator = tuple.getT1();
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rocksIterator.close();
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tuple.getT2().ifPresent(RocksMutableObject::close);
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tuple.getT3().ifPresent(RocksMutableObject::close);
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});
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}
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public abstract T getEntry(byte[] key, byte[] value);
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}
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