/*
* Copyright 2012 Future Systems
*
* 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
*
* http://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 org.krakenapps.logdb.sort;
import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.ByteBuffer;
import java.util.NoSuchElementException;
import org.krakenapps.codec.EncodingRule;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
class FileRunIterator implements CloseableIterator {
private final Logger logger = LoggerFactory.getLogger(FileRunIterator.class);
private static final int READ_BUFFER_SIZE = 1024 * 128;
private File f;
private InputStream bis;
private Item next;
private byte[] buf = new byte[640 * 1024];
private byte[] intbuf = new byte[4];
private long totalRead;
public FileRunIterator(File f) throws IOException {
this.f = f;
bis = new BufferedInputStream(new FileInputStream(f), READ_BUFFER_SIZE);
}
@Override
public boolean hasNext() {
if (next == null) {
try {
int readBytes = IoHelper.ensureRead(bis, intbuf, 4);
totalRead += readBytes;
if (readBytes == 4) {
int len = IoHelper.decodeInt(intbuf);
readBytes = IoHelper.ensureRead(bis, buf, len);
totalRead += readBytes;
if (readBytes == len)
next = (Item) EncodingRule.decode(ByteBuffer.wrap(buf, 0, len), SortCodec.instance);
}
} catch (IOException e) {
try {
close();
} catch (IOException e1) {
logger.error("kraken logdb: cannot close file", e1);
}
}
}
return next != null;
}
@Override
public Item next() {
if (!hasNext())
throw new NoSuchElementException();
Item ret = next;
next = null;
return ret;
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
@Override
public void close() throws IOException {
bis.close();
f.delete();
}
}