/*
* Copyright 2004-2011 H2 Group. Multiple-Licensed under the H2 License,
* Version 1.0, and under the Eclipse Public License, Version 1.0
* (http://h2database.com/html/license.html).
* Initial Developer: H2 Group
*/
package org.h2.dev.fs;
import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
import java.util.zip.ZipInputStream;
import org.h2.store.fs.FileObject;
import org.h2.util.IOUtils;
/**
* The file is read from a stream. When reading from start to end, the same
* input stream is re-used, however when reading from end to start, a new input
* stream is opened for each request.
*/
public class FileObjectZip2 implements FileObject {
private static final byte[] SKIP_BUFFER = new byte[1024];
private final String fullName;
private final String name;
private final long length;
private long pos;
private InputStream in;
private long inPos;
private boolean skipUsingRead;
FileObjectZip2(String fullName, String name, ZipInputStream in, long length) {
this.fullName = fullName;
this.name = name;
this.length = length;
this.in = in;
}
public void close() {
try {
in.close();
} catch (IOException e) {
// ignore
}
}
public long getFilePointer() {
return pos;
}
public long length() {
return length;
}
public void readFully(byte[] b, int off, int len) throws IOException {
if (inPos > pos) {
if (in != null) {
in.close();
}
in = null;
}
if (in == null) {
in = IOUtils.openFileInputStream(fullName);
inPos = 0;
}
if (inPos < pos) {
long skip = pos - inPos;
if (!skipUsingRead) {
try {
IOUtils.skipFully(in, skip);
} catch (NullPointerException e) {
// workaround for Android
skipUsingRead = true;
}
}
if (skipUsingRead) {
while (skip > 0) {
int s = (int) Math.min(SKIP_BUFFER.length, skip);
s = in.read(SKIP_BUFFER, 0, s);
skip -= s;
}
}
inPos = pos;
}
int l = IOUtils.readFully(in, b, off, len);
if (l != len) {
throw new EOFException();
}
pos += len;
inPos += len;
}
public void seek(long newPos) {
this.pos = newPos;
}
public void setFileLength(long newLength) throws IOException {
throw new IOException("File is read-only");
}
public void sync() {
// nothing to do
}
public void write(byte[] b, int off, int len) throws IOException {
throw new IOException("File is read-only");
}
public String getName() {
return name;
}
public boolean tryLock() {
return false;
}
public void releaseLock() {
// ignore
}
}