jetbrains.exodus.log.LogAwareFixedLengthByteIterable Maven / Gradle / Ivy
/**
* Copyright 2010 - 2022 JetBrains s.r.o.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package jetbrains.exodus.log;
import jetbrains.exodus.ByteIterable;
import jetbrains.exodus.ByteIterator;
import jetbrains.exodus.FixedLengthByteIterable;
import org.jetbrains.annotations.NotNull;
class LogAwareFixedLengthByteIterable extends FixedLengthByteIterable {
LogAwareFixedLengthByteIterable(@NotNull final ByteIterableWithAddress source, final int offset, final int length) {
super(source, offset, length);
}
@Override
public int compareTo(final @NotNull ByteIterable right) {
return getSource().compareTo(offset, length, right);
}
@Override
public ByteIterableWithAddress getSource() {
return (ByteIterableWithAddress) super.getSource();
}
@Override
protected ByteIterator getIterator() {
if (length == 0) {
return ByteIterable.EMPTY_ITERATOR;
}
final ByteIterator bi = source.iterator();
bi.skip(offset);
return new LogAwareFixedLengthByteIterator(bi, length);
}
private static class LogAwareFixedLengthByteIterator extends ByteIterator implements BlockByteIterator {
private final ByteIterator si;
private int bytesToRead;
LogAwareFixedLengthByteIterator(@NotNull final ByteIterator si, final int length) {
this.si = si;
bytesToRead = length;
}
@Override
public boolean hasNext() {
return bytesToRead > 0 && si.hasNext();
}
@Override
public byte next() {
bytesToRead--;
return si.next();
}
@Override
public long skip(long bytes) {
long result = si.skip(Math.min(bytes, bytesToRead));
bytesToRead -= (int) result;
return result;
}
@Override
public int nextBytes(byte[] array, int off, int len) {
final int bytesToRead = Math.min(len, this.bytesToRead);
if (si instanceof BlockByteIterator) {
final int result = ((BlockByteIterator) si).nextBytes(array, off, bytesToRead);
this.bytesToRead -= result;
return result;
}
for (int i = 0; i < bytesToRead; ++i) {
array[off + i] = next();
}
return bytesToRead;
}
}
}