/* 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.types;
import java.io.
IOException;
import java.io.
InputStream;
import org.hsqldb.
SessionInterface;
import org.hsqldb.error.
Error;
import org.hsqldb.error.
ErrorCode;
import org.hsqldb.lib.java.
JavaSystem;
/**
* This class is used as an InputStream to retrieve data from a Blob.
* mark() and reset() are not supported.
*
* @author Fred Toussi (fredt@users dot sourceforge.net)
* @version 2.0.1
* @since 1.9.0
*/
public class
BlobInputStream extends
InputStream {
final
BlobData blob;
final long
availableLength;
long
bufferOffset;
long
currentPosition;
byte[]
buffer;
boolean
isClosed;
int
streamBlockSize;
public final
SessionInterface session;
public
BlobInputStream(
SessionInterface session,
BlobData blob,
long
offset, long
length) {
final long
blobLength =
blob.
length(
session);
this.
session =
session;
this.
blob =
blob;
this.
availableLength =
offset +
Math.
min(
length,
blobLength -
offset);
this.
currentPosition =
offset;
this.
streamBlockSize =
session.
getStreamBlockSize();
}
public int
read() throws
IOException {
checkClosed();
if (
currentPosition >=
availableLength) {
return -1;
}
if (
buffer == null
||
currentPosition >=
bufferOffset +
buffer.length) {
try {
checkClosed();
readIntoBuffer();
} catch (
Exception e) {
throw
JavaSystem.
toIOException(
e);
}
}
int
val =
buffer[(int) (
currentPosition -
bufferOffset)] & 0xff;
currentPosition++;
return
val;
}
public long
skip(long
n) throws
IOException {
checkClosed();
if (
n <= 0) {
return 0;
}
if (
currentPosition +
n >
availableLength) {
n =
availableLength -
currentPosition;
}
currentPosition +=
n;
return
n;
}
public int
available() {
long
avail =
availableLength -
currentPosition;
if (
avail >
Integer.
MAX_VALUE) {
return
Integer.
MAX_VALUE;
}
return (int)
avail;
}
public void
close() throws
IOException {
isClosed = true;
}
private void
checkClosed() throws
IOException {
if (
isClosed ||
blob.
isClosed()) {
throw new
IOException(
Error.
getMessage(
ErrorCode.
X_0F503));
}
}
private void
readIntoBuffer() {
long
readLength =
availableLength -
currentPosition;
if (
readLength <= 0) {
return;
}
if (
readLength >
streamBlockSize) {
readLength =
streamBlockSize;
}
buffer =
blob.
getBytes(
session,
currentPosition, (int)
readLength);
bufferOffset =
currentPosition;
}
static boolean
isInLimits(long
fullLength, long
pos, long
len) {
return
pos >= 0 &&
len >= 0 &&
pos +
len <=
fullLength;
}
}