/* Copyright (c) 2001-2011, The HSQL Development Group
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the HSQL Development Group nor the names of its
* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL HSQL DEVELOPMENT GROUP, HSQLDB.ORG,
* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.hsqldb.persist;
import java.io.
DataInputStream;
import java.io.
FileNotFoundException;
import java.io.
IOException;
import java.io.
InputStream;
import org.hsqldb.
Database;
import org.hsqldb.lib.
HsqlByteArrayInputStream;
/**
* This class is a random access wrapper around a DataInputStream object and
* enables access to cached tables when a database is included in a jar.
*
* A proof-of-concept prototype was first contributed by winfriedthom@users.
*
* @author Fred Toussi (fredt@users dot sourceforge.net)
* @version 2.3.0
* @since 1.8.0
*/
final class
RAFileInJar implements
RandomAccessInterface {
DataInputStream file;
final
String fileName;
long
fileLength;
boolean
bufferDirty = true;
byte[]
buffer = new byte[4096];
HsqlByteArrayInputStream ba = new
HsqlByteArrayInputStream(
buffer);
long
bufferOffset;
//
long
seekPosition;
long
realPosition;
RAFileInJar(
String name) throws
FileNotFoundException,
IOException {
fileName =
name;
fileLength =
getLength();
resetStream();
}
public long
length() throws
IOException {
return
fileLength;
}
/**
* Some JVM's do not allow seek beyond end of file, so zeros are written
* first in that case. Reported by bohgammer@users in Open Disucssion
* Forum.
*/
public void
seek(long
position) throws
IOException {
seekPosition =
position;
}
public long
getFilePointer() throws
IOException {
return
seekPosition;
}
private void
readIntoBuffer() throws
IOException {
long
filePos =
seekPosition;
bufferDirty = false;
long
subOffset =
filePos %
buffer.length;
long
readLength =
fileLength - (
filePos -
subOffset);
if (
readLength <= 0) {
throw new
IOException("read beyond end of file");
}
if (
readLength >
buffer.length) {
readLength =
buffer.length;
}
fileSeek(
filePos -
subOffset);
file.
readFully(
buffer, 0, (int)
readLength);
bufferOffset =
filePos -
subOffset;
realPosition =
bufferOffset +
readLength;
}
public int
read() throws
IOException {
if (
seekPosition >=
fileLength) {
return -1;
}
if (
bufferDirty ||
seekPosition <
bufferOffset
||
seekPosition >=
bufferOffset +
buffer.length) {
readIntoBuffer();
}
ba.
reset();
ba.
skip(
seekPosition -
bufferOffset);
int
val =
ba.
read();
seekPosition++;
return
val;
}
public long
readLong() throws
IOException {
long
hi =
readInt();
long
lo =
readInt();
return (
hi << 32) + (
lo & 0xffffffffL);
}
public int
readInt() throws
IOException {
if (
bufferDirty ||
seekPosition <
bufferOffset
||
seekPosition >=
bufferOffset +
buffer.length) {
readIntoBuffer();
}
ba.
reset();
ba.
skip(
seekPosition -
bufferOffset);
int
val =
ba.
readInt();
seekPosition += 4;
return
val;
}
public void
read(byte[]
b, int
offset, int
length) throws
IOException {
if (
bufferDirty ||
seekPosition <
bufferOffset
||
seekPosition >=
bufferOffset +
buffer.length) {
readIntoBuffer();
}
ba.
reset();
ba.
skip(
seekPosition -
bufferOffset);
int
bytesRead =
ba.
read(
b,
offset,
length);
seekPosition +=
bytesRead;
if (
bytesRead <
length) {
if (
seekPosition !=
realPosition) {
fileSeek(
seekPosition);
}
file.
readFully(
b,
offset +
bytesRead,
length -
bytesRead);
seekPosition += (
length -
bytesRead);
realPosition =
seekPosition;
}
}
public void
write(byte[]
b, int
off, int
len) throws
IOException {}
public void
writeInt(int
i) throws
IOException {}
public void
writeLong(long
i) throws
IOException {}
public void
close() throws
IOException {
file.
close();
}
public boolean
isReadOnly() {
return true;
}
private long
getLength() throws
IOException {
int
count = 0;
resetStream();
while (true) {
if (
file.
read() < 0) {
break;
}
count++;
}
return
count;
}
private void
resetStream() throws
IOException {
if (
file != null) {
file.
close();
}
InputStream fis = null;
try {
fis =
getClass().
getResourceAsStream(
fileName);
if (
fis == null) {
ClassLoader cl =
Thread.
currentThread().
getContextClassLoader();
if (
cl != null) {
fis =
cl.
getResourceAsStream(
fileName);
}
}
} catch (
Throwable t) {
//
} finally {
if (
fis == null) {
throw new
FileNotFoundException(
fileName);
}
}
file = new
DataInputStream(
fis);
}
private void
fileSeek(long
position) throws
IOException {
long
skipPosition =
realPosition;
if (
position <
skipPosition) {
resetStream();
skipPosition = 0;
}
while (
position >
skipPosition) {
skipPosition +=
file.
skip(
position -
skipPosition);
}
}
public boolean
ensureLength(long
newLong) {
return true;
}
public boolean
setLength(long
newLength) {
return false;
}
public
Database getDatabase() {
return null;
}
public void
synch() {}
}