/*
* #%L
* Common package for I/O and related utilities
* %%
* Copyright (C) 2005 - 2015 Open Microscopy Environment:
* - Board of Regents of the University of Wisconsin-Madison
* - Glencoe Software, Inc.
* - University of Dundee
* %%
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. 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.
*
* 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 THE COPYRIGHT HOLDERS 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.
* #L%
*/
package loci.common;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.EOFException;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
/**
* Abstract IRandomAccess implementation for reading from InputStreams and
* writing to OutputStreams.
*
* @see IRandomAccess
*
* @author Melissa Linkert melissa at glencoesoftware.com
*/
public abstract class StreamHandle implements IRandomAccess {
// -- Fields --
/** Name of the open stream. */
protected String file;
/** InputStream to be used for reading. */
protected DataInputStream stream;
/** OutputStream to be used for writing. */
protected DataOutputStream outStream;
/** Length of the stream. */
protected long length;
/** Current position within the stream. */
protected long fp;
/** Marked position within the stream. */
protected long mark;
/** Byte ordering of this stream. */
protected ByteOrder order;
// -- Constructor --
/**
* Construct a new StreamHandle.
* The file pointer will be set to 0, and the byte ordering
* will be big-endian.
*/
public StreamHandle() {
fp = 0;
order = ByteOrder.BIG_ENDIAN;
}
// -- IRandomAccess API methods --
/* @see IRandomAccess#close() */
@Override
public void close() throws IOException {
length = fp = mark = 0;
if (stream != null) stream.close();
if (outStream != null) outStream.close();
stream = null;
outStream = null;
file = null;
}
/* @see IRandomAccess#getFilePointer() */
@Override
public long getFilePointer() throws IOException {
return fp;
}
/* @see IRandomAccess#length() */
@Override
public long length() throws IOException {
return length;
}
/* @see IRandomAccess#read(byte[]) */
@Override
public int read(byte[] b) throws IOException {
return read(b, 0, b.length);
}
/* @see IRandomAccess#read(byte[], int, int) */
@Override
public int read(byte[] b, int off, int len) throws IOException {
int n = stream.read(b, off, len);
if (n >= 0) fp += n;
else n = 0;
markManager();
while (n < len && fp < length()) {
int s = stream.read(b, off + n, len - n);
fp += s;
n += s;
}
return n == -1 ? 0 : n;
}
/* @see IRandomAccess#read(ByteBuffer) */
@Override
public int read(ByteBuffer buffer) throws IOException {
return read(buffer, 0, buffer.capacity());
}
/* @see IRandomAccess#read(ByteBuffer, int, int) */
@Override
public int read(ByteBuffer buffer, int off, int len) throws IOException {
if (buffer.hasArray()) {
return read(buffer.array(), off, len);
}
byte[] b = new byte[len];
int n = read(b);
buffer.put(b, off, len);
return n;
}
/* @see IRandomAccess#seek(long) */
@Override
public void seek(long pos) throws IOException {
long diff = pos - fp;
fp = pos;
if (diff < 0) {
resetStream();
diff = fp;
}
int skipped = stream.skipBytes((int) diff);
while (skipped < diff) {
int n = stream.skipBytes((int) (diff - skipped));
if (n == 0) break;
skipped += n;
}
}
/* @see IRandomAccess.write(ByteBuffer) */
@Override
public void write(ByteBuffer buf) throws IOException {
write(buf, 0, buf.capacity());
}
/* @see IRandomAccess.write(ByteBuffer, int, int) */
@Override
public void write(ByteBuffer buf, int off, int len) throws IOException {
buf.position(off);
if (buf.hasArray()) {
write(buf.array(), off, len);
}
else {
byte[] b = new byte[len];
buf.get(b);
write(b);
}
}
/* @see IRandomAccess.getOrder() */
@Override
public ByteOrder getOrder() {
return order;
}
/* @see IRandomAccess.setOrder(ByteOrder) */
@Override
public void setOrder(ByteOrder order) {
this.order = order;
}
// -- DataInput API methods --
/* @see java.io.DataInput#readBoolean() */
@Override
public boolean readBoolean() throws IOException {
fp++;
return stream.readBoolean();
}
/* @see java.io.DataInput#readByte() */
@Override
public byte readByte() throws IOException {
fp++;
return stream.readByte();
}
/* @see java.io.DataInput#readChar() */
@Override
public char readChar() throws IOException {
fp++;
return stream.readChar();
}
/* @see java.io.DataInput#readDouble() */
@Override
public double readDouble() throws IOException {
fp += 8;
double v = stream.readDouble();
return order.equals(ByteOrder.LITTLE_ENDIAN) ? DataTools.swap(v) : v;
}
/* @see java.io.DataInput#readFloat() */
@Override
public float readFloat() throws IOException {
fp += 4;
float v = stream.readFloat();
return order.equals(ByteOrder.LITTLE_ENDIAN) ? DataTools.swap(v) : v;
}
/* @see java.io.DataInput#readFully(byte[]) */
@Override
public void readFully(byte[] b) throws IOException {
stream.readFully(b);
fp += b.length;
}
/* @see java.io.DataInput#readFully(byte[], int, int) */
@Override
public void readFully(byte[] b, int off, int len) throws IOException {
stream.readFully(b, off, len);
fp += len;
}
/* @see java.io.DataInput#readInt() */
@Override
public int readInt() throws IOException {
fp += 4;
int v = stream.readInt();
return order.equals(ByteOrder.LITTLE_ENDIAN) ? DataTools.swap(v) : v;
}
/* @see java.io.DataInput#readLine() */
@Override
public String readLine() throws IOException {
throw new IOException("Unimplemented");
}
/* @see java.io.DataInput#readLong() */
@Override
public long readLong() throws IOException {
fp += 8;
long v = stream.readLong();
return order.equals(ByteOrder.LITTLE_ENDIAN) ? DataTools.swap(v) : v;
}
/* @see java.io.DataInput#readShort() */
@Override
public short readShort() throws IOException {
fp += 2;
short v = stream.readShort();
return order.equals(ByteOrder.LITTLE_ENDIAN) ? DataTools.swap(v) : v;
}
/* @see java.io.DataInput#readUnsignedByte() */
@Override
public int readUnsignedByte() throws IOException {
fp++;
return stream.readUnsignedByte();
}
/* @see java.io.DataInput#readUnsignedShort() */
@Override
public int readUnsignedShort() throws IOException {
return readShort() & 0xffff;
}
/* @see java.io.DataInput#readUTF() */
@Override
public String readUTF() throws IOException {
String s = stream.readUTF();
fp += s.length();
return s;
}
/* @see java.io.DataInput#skipBytes(int) */
@Override
public int skipBytes(int n) throws IOException {
int skipped = 0;
try {
for (int i=0; i<n; i++) {
if (readUnsignedByte() != -1) skipped++;
markManager();
}
}
catch (EOFException e) { }
return skipped;
}
// -- DataOutput API methods --
/* @see java.io.DataOutput#write(byte[]) */
@Override
public void write(byte[] b) throws IOException {
if (outStream == null) {
throw new HandleException("This stream is read-only.");
}
outStream.write(b);
}
/* @see java.io.DataOutput#write(byte[], int, int) */
@Override
public void write(byte[] b, int off, int len) throws IOException {
if (outStream == null) {
throw new HandleException("This stream is read-only.");
}
outStream.write(b, off, len);
}
/* @see java.io.DataOutput#write(int) */
@Override
public void write(int b) throws IOException {
if (outStream == null) {
throw new HandleException("This stream is read-only.");
}
if (order.equals(ByteOrder.LITTLE_ENDIAN)) b = DataTools.swap(b);
outStream.write(b);
}
/* @see java.io.DataOutput#writeBoolean(boolean) */
@Override
public void writeBoolean(boolean v) throws IOException {
if (outStream == null) {
throw new HandleException("This stream is read-only.");
}
outStream.writeBoolean(v);
}
/* @see java.io.DataOutput#writeByte(int) */
@Override
public void writeByte(int v) throws IOException {
if (outStream == null) {
throw new HandleException("This stream is read-only.");
}
if (order.equals(ByteOrder.LITTLE_ENDIAN)) v = DataTools.swap(v);
outStream.writeByte(v);
}
/* @see java.io.DataOutput#writeBytes(String) */
@Override
public void writeBytes(String s) throws IOException {
if (outStream == null) {
throw new HandleException("This stream is read-only.");
}
outStream.writeBytes(s);
}
/* @see java.io.DataOutput#writeChar(int) */
@Override
public void writeChar(int v) throws IOException {
if (outStream == null) {
throw new HandleException("This stream is read-only.");
}
if (order.equals(ByteOrder.LITTLE_ENDIAN)) v = DataTools.swap(v);
outStream.writeChar(v);
}
/* @see java.io.DataOutput#writeChars(String) */
@Override
public void writeChars(String s) throws IOException {
if (outStream == null) {
throw new HandleException("This stream is read-only.");
}
outStream.writeChars(s);
}
/* @see java.io.DataOutput#writeDouble(double) */
@Override
public void writeDouble(double v) throws IOException {
if (outStream == null) {
throw new HandleException("This stream is read-only.");
}
if (order.equals(ByteOrder.LITTLE_ENDIAN)) v = DataTools.swap(v);
outStream.writeDouble(v);
}
/* @see java.io.DataOutput#writeFloat(float) */
@Override
public void writeFloat(float v) throws IOException {
if (outStream == null) {
throw new HandleException("This stream is read-only.");
}
if (order.equals(ByteOrder.LITTLE_ENDIAN)) v = DataTools.swap(v);
outStream.writeFloat(v);
}
/* @see java.io.DataOutput#writeInt(int) */
@Override
public void writeInt(int v) throws IOException {
if (outStream == null) {
throw new HandleException("This stream is read-only.");
}
if (order.equals(ByteOrder.LITTLE_ENDIAN)) v = DataTools.swap(v);
outStream.writeInt(v);
}
/* @see java.io.DataOutput#writeLong(long) */
@Override
public void writeLong(long v) throws IOException {
if (outStream == null) {
throw new HandleException("This stream is read-only.");
}
if (order.equals(ByteOrder.LITTLE_ENDIAN)) v = DataTools.swap(v);
outStream.writeLong(v);
}
/* @see java.io.DataOutput#writeShort(int) */
@Override
public void writeShort(int v) throws IOException {
if (outStream == null) {
throw new HandleException("This stream is read-only.");
}
if (order.equals(ByteOrder.LITTLE_ENDIAN)) v = DataTools.swap(v);
outStream.writeShort(v);
}
/* @see java.io.DataOutput#writeUTF(String) */
@Override
public void writeUTF(String str) throws IOException {
if (outStream == null) {
throw new HandleException("This stream is read-only.");
}
outStream.writeUTF(str);
}
// -- Helper methods --
/**
* Close and reopen the stream; the stream pointer and mark should be
* reset to 0. This method is called if we need to seek backwards within
* the stream.
*/
protected abstract void resetStream() throws IOException;
/** Reset the marked position, if necessary. */
private void markManager() {
if (fp >= mark + RandomAccessInputStream.MAX_OVERHEAD - 1) {
mark = fp;
stream.mark(RandomAccessInputStream.MAX_OVERHEAD);
}
}
}