/*
* Copyright 2006-2012 Amazon Technologies, Inc. or its affiliates.
* Amazon, Amazon.com and Carbonado are trademarks or registered trademarks
* of Amazon Technologies, Inc. or its affiliates. All rights reserved.
*
* 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 com.amazon.carbonado.lob;
import java.io.InputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Arrays;
import com.amazon.carbonado.PersistException;
/**
* Implementation of a Blob which is backed by a growable in-memory byte array.
*
* @author Brian S O'Neill
*/
public class ByteArrayBlob extends AbstractBlob {
private final int mInitialCapacity;
private byte[] mData;
private int mLength;
/**
* Construct a ByteArrayBlob with the given initial capacity.
*
* @param capacity initial capacity of internal byte array
*/
public ByteArrayBlob(int capacity) {
if (capacity == 0) {
throw new IllegalArgumentException();
}
mInitialCapacity = capacity;
mData = new byte[capacity];
}
/**
* Construct a ByteArrayBlob initially backed by the given byte array. The
* byte array is not cloned until this ByteArrayBlob grows or shrinks.
*
* @param data initial data backing the Blob
*/
public ByteArrayBlob(byte[] data) {
if (data.length == 0) {
throw new IllegalArgumentException();
}
mLength = mInitialCapacity = data.length;
mData = data;
}
/**
* Construct a ByteArrayBlob initially backed by the given byte array. The
* byte array is not cloned until this ByteArrayBlob grows or shrinks.
*
* @param data initial data backing the Blob
* @param length initial length of data
*/
public ByteArrayBlob(byte[] data, int length) {
if (data.length < length) {
throw new IllegalArgumentException();
}
mInitialCapacity = data.length;
mData = data;
mLength = length;
}
public InputStream openInputStream() {
return new Input(this, 0);
}
public InputStream openInputStream(long pos) {
if (pos < 0) {
throw new IllegalArgumentException("Position is negative: " + pos);
}
return new Input(this, pos);
}
public InputStream openInputStream(long pos, int bufferSize) {
return openInputStream(pos);
}
public synchronized long getLength() {
return mLength;
}
synchronized int read(long pos) {
if (pos < 0) {
throw new IllegalArgumentException("Position is negative: " + pos);
}
if (pos > Integer.MAX_VALUE) {
return -1;
}
int ipos = (int) pos;
if (ipos >= mLength) {
return -1;
}
return mData[ipos];
}
synchronized int read(long pos, byte[] bytes) {
if (pos < 0) {
throw new IllegalArgumentException("Position is negative: " + pos);
}
if (bytes == null) {
throw new IllegalArgumentException("Byte array is null");
}
if (pos > Integer.MAX_VALUE) {
return -1;
}
int ipos = (int) pos;
if (ipos > mLength) { // the use of '>' instead of '>=' is intentional
return -1;
}
int length = bytes.length;
if (ipos + length > mLength) {
length = mLength - ipos;
}
if (length > 0) {
System.arraycopy(mData, ipos, bytes, 0, length);
return length;
} else {
return -1;
}
}
synchronized int read(long pos, byte[] bytes, int offset, int length) {
if (pos < 0) {
throw new IllegalArgumentException("Position is negative: " + pos);
}
if (bytes == null) {
throw new IllegalArgumentException("Byte array is null");
}
if (offset < 0) {
throw new IllegalArgumentException("Offset is negative: " + offset);
}
if (length < 0) {
throw new IllegalArgumentException("Length is negative: " + length);
}
if (pos > Integer.MAX_VALUE) {
return -1;
}
int ipos = (int) pos;
if (ipos > mLength) { // the use of '>' instead of '>=' is intentional
return -1;
}
if (ipos + length > mLength) {
length = mLength - ipos;
}
if (length > 0) {
try {
System.arraycopy(mData, ipos, bytes, offset, length);
} catch (IndexOutOfBoundsException e) {
if (offset >= bytes.length && length > 0) {
throw new IllegalArgumentException("Offset is too large: " + offset);
}
throw e;
}
return length;
} else {
return -1;
}
}
public OutputStream openOutputStream() {
return new Output(this, 0);
}
public OutputStream openOutputStream(long pos) {
if (pos < 0) {
throw new IllegalArgumentException("Position is negative: " + pos);
}
return new Output(this, pos);
}
public OutputStream openOutputStream(long pos, int bufferSize) {
return openOutputStream(pos);
}
public synchronized void setLength(long length) throws PersistException {
if (length < 0) {
throw new IllegalArgumentException("Length is negative: " + length);
}
if (length > Integer.MAX_VALUE) {
throw new PersistException("Length too long: " + length);
}
int ilength = (int) length;
if (ilength < mLength) {
mLength = ilength;
if (mData.length > mInitialCapacity) {
// Free up some space.
mData = new byte[mInitialCapacity];
}
} else if (ilength > mLength) {
if (ilength <= mData.length) {
Arrays.fill(mData, mLength, ilength, (byte) 0);
mLength = ilength;
} else {
int newLength = mData.length * 2;
if (newLength < ilength) {
newLength = ilength;
}
byte[] newData = new byte[newLength];
System.arraycopy(mData, 0, newData, 0, mLength);
}
mLength = ilength;
}
}
synchronized void write(long pos, int b) throws IOException {
if (pos < 0) {
throw new IllegalArgumentException("Position is negative: " + pos);
}
if (pos > Integer.MAX_VALUE) {
throw new IOException("Position too high: " + pos);
}
int ipos = (int) pos;
ensureLengthForWrite(ipos + 1);
mData[ipos] = (byte) b;
}
synchronized void write(long pos, byte[] bytes) throws IOException {
if (pos < 0) {
throw new IllegalArgumentException("Position is negative: " + pos);
}
if (bytes == null) {
throw new IllegalArgumentException("Byte array is null");
}
if (pos > Integer.MAX_VALUE) {
throw new IOException("Position too high: " + pos);
}
if (pos + bytes.length > Integer.MAX_VALUE) {
throw new IOException("Position plus length too high: " + (pos + bytes.length));
}
int ipos = (int) pos;
ensureLengthForWrite(ipos + bytes.length);
System.arraycopy(bytes, 0, mData, ipos, bytes.length);
}
synchronized void write(long pos, byte[] bytes, int offset, int length) throws IOException {
if (pos < 0) {
throw new IllegalArgumentException("Position is negative: " + pos);
}
if (bytes == null) {
throw new IllegalArgumentException("Byte array is null");
}
if (offset < 0) {
throw new IllegalArgumentException("Offset is negative: " + offset);
}
if (length < 0) {
throw new IllegalArgumentException("Length is negative: " + length);
}
if (pos > Integer.MAX_VALUE) {
throw new IOException("Position too high: " + pos);
}
if (pos + length > Integer.MAX_VALUE) {
throw new IOException("Position plus length too high: " + (pos + length));
}
int ipos = (int) pos;
ensureLengthForWrite(ipos + length);
System.arraycopy(bytes, offset, mData, ipos, length);
}
// Caller must be synchronized
private void ensureLengthForWrite(int ilength) {
if (ilength > mLength) {
if (ilength <= mData.length) {
mLength = ilength;
} else {
int newLength = mData.length * 2;
if (newLength < ilength) {
newLength = ilength;
}
byte[] newData = new byte[newLength];
System.arraycopy(mData, 0, newData, 0, mLength);
mData = newData;
}
mLength = ilength;
}
}
/**
* Always returns null.
*/
public Object getLocator() {
return null;
}
private static class Input extends InputStream {
private final ByteArrayBlob mBlob;
private long mPos;
private long mMarkPos;
Input(ByteArrayBlob blob, long pos) {
mBlob = blob;
mPos = pos;
mMarkPos = pos;
}
@Override
public int read() {
int b = mBlob.read(mPos);
if (b >= 0) {
mPos++;
}
return b;
}
@Override
public int read(byte[] bytes) {
int length = mBlob.read(mPos, bytes);
if (length > 0) {
mPos += length;
}
return length;
}
@Override
public int read(byte[] bytes, int offset, int length) {
length = mBlob.read(mPos, bytes, offset, length);
if (length > 0) {
mPos += length;
}
return length;
}
@Override
public long skip(long n) {
if (n <= 0) {
return 0;
}
long newPos = mPos + n;
if (newPos < 0) {
newPos = Long.MAX_VALUE;
}
long length = mBlob.getLength();
if (newPos > length) {
newPos = length;
}
n = newPos - mPos;
mPos = newPos;
return n;
}
@Override
public int available() {
long avail = mBlob.getLength() - mPos;
if (avail > Integer.MAX_VALUE) {
return Integer.MAX_VALUE;
}
return (int) avail;
}
@Override
public void mark(int readlimit) {
mMarkPos = mPos;
}
@Override
public void reset() {
mPos = mMarkPos;
}
@Override
public boolean markSupported() {
return true;
}
}
private static class Output extends OutputStream {
private final ByteArrayBlob mBlob;
private long mPos;
Output(ByteArrayBlob blob, long pos) {
mBlob = blob;
mPos = pos;
}
@Override
public void write(int b) throws IOException {
mBlob.write(mPos, b);
mPos++;
}
@Override
public void write(byte[] b) throws IOException {
mBlob.write(mPos, b);
mPos += b.length;
}
@Override
public void write(byte[] b, int offset, int length) throws IOException {
mBlob.write(mPos, b, offset, length);
mPos += length;
}
}
}