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/**
*
*/
package io.pkts.buffer;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
/**
* @author [email protected]
*/
public final class InputStreamBuffer extends AbstractBuffer {
private static final String CANNOT_WRITE_TO_AN_INPUT_STREAM_BUFFER = "Cannot write to an InputStreamBuffer";
private static final String NOT_IMPLEMENTED_JUST_YET = "Not implemented just yet";
private final InputStream is;
/**
* The default capacity for each individual byte array
*/
private static final int DEFAULT_CAPACITY = 4096;
private final List storage;
/**
* The "local" capacity of each "sub-array".
*/
private final int localCapacity;
/**
*
*/
public InputStreamBuffer(final InputStream is) {
this(InputStreamBuffer.DEFAULT_CAPACITY, is);
}
/**
*
* @param initialCapacity
* the initial size of the internal byte array
* @param is
*/
public InputStreamBuffer(final int initialCapacity, final InputStream is) {
super(0, 0, 0, 0);
assert is != null;
this.is = is;
this.localCapacity = initialCapacity;
this.storage = new ArrayList();
this.storage.add(java.nio.ByteBuffer.allocate(this.localCapacity));
}
/**
* {@inheritDoc}
*/
@Override
public Buffer slice(final int start, final int stop) {
checkIndex(this.lowerBoundary + start);
checkIndex(this.lowerBoundary + stop - 1);
// this has to change now that we can have multiple
// rows of byte buffers
final java.nio.ByteBuffer buf = getWritingRow();
final int upperBoundary = this.lowerBoundary + stop;
final int writerIndex = upperBoundary;
return new ByteBuffer(0, this.lowerBoundary + start, upperBoundary, writerIndex, buf.array());
}
/**
* {@inheritDoc}
*
* @throws IOException
*/
@Override
public byte readByte() throws IndexOutOfBoundsException, IOException {
final int read = internalReadBytes(1);
if (read == -1) {
// not sure this is really the right thing to do
throw new IndexOutOfBoundsException();
}
return getByte(this.readerIndex++);
}
/**
* {@inheritDoc}
*/
@Override
public byte peekByte() throws IndexOutOfBoundsException, IOException {
final int read = internalReadBytes(1);
if (read == -1) {
// not sure this is really the right thing to do
throw new IndexOutOfBoundsException();
}
return getByte(this.readerIndex);
}
/**
* {@inheritDoc}
*
* @throws IOException
*/
@Override
public Buffer readBytes(final int length) throws IndexOutOfBoundsException, IOException {
if (!checkReadableBytesSafe(length)) {
final int availableBytes = getReadableBytes();
final int read = internalReadBytes(length - availableBytes);
if (read == -1) {
// end-of-file
return null;
} else if (read + availableBytes < length) {
// do something else?
throw new IndexOutOfBoundsException("Not enough bytes left in the stream. Wanted " + length
+ " but only read " + read);
}
}
// perhaps we should create a composite buffer instead of this
// copying???
int index = 0;
final byte[] buf = new byte[length];
while (index < length) {
final int spaceLeft = getAvailableLocalReadingSpace();
final int readAtMost = Math.min(length - index, spaceLeft);
final int localIndex = getLocalReaderIndex();
final java.nio.ByteBuffer bb = getReadingRow();
System.arraycopy(bb.array(), localIndex, buf, index, readAtMost);
this.readerIndex += readAtMost;
index += readAtMost;
}
return Buffers.wrap(buf);
}
/**
* Read at most length no of bytes and store it into the
* internal buffer. This method is blocking in case we don't have enough
* bytes to read
*
* @param length
* the amount of bytes we wishes to read
* @return the actual number of bytes read.
* @throws IOException
*/
private int internalReadBytes(final int length) throws IOException {
// check if we already have enough bytes available for reading
// and if so, just return the length the user is asking for
if (checkReadableBytesSafe(length)) {
return length;
}
return readFromStream(length);
}
/**
* Since the writer index (upper boundary) is where we are to write for the
* entire buffer we need to translate this into the local index into the
* array we currently are working with.
*
* @return
*/
private int getLocalWriterIndex() {
return this.writerIndex % this.localCapacity;
}
/**
* Translates the global reader index into the local index within a row
*
* @return
*/
private int getLocalReaderIndex() {
return this.readerIndex % this.localCapacity;
}
/**
* Since the underlying storage for this buffer is essentially a 2-D byte
* array we sometimes need to find out how much capacity is left in a
* particular row.
*
* @return
*/
private int getAvailableLocalWritingSpace() {
return this.localCapacity - getLocalWriterIndex();
}
/**
* Find out how many bytes are left to read in the current row
*
* @return
*/
private int getAvailableLocalReadingSpace() {
return this.localCapacity - getLocalReaderIndex();
}
/**
* Get which "row" we currently are working with for writing
*
* @return
*/
private java.nio.ByteBuffer getWritingRow() {
final int row = this.writerIndex / this.localCapacity;
if (row >= this.storage.size()) {
final java.nio.ByteBuffer buf = java.nio.ByteBuffer.allocate(this.localCapacity);
this.storage.add(buf);
return buf;
}
return this.storage.get(row);
}
/**
* Get which "row" we currently are working with for reading
*
* @return
*/
private java.nio.ByteBuffer getReadingRow() {
final int row = this.readerIndex / this.localCapacity;
return this.storage.get(row);
}
/**
* Method for reading bytes off the stream and store it in the local
* "storage"
*
* @param length
* the length we wish to read
* @return the actual amount of bytes we read
* @throws IOException
* in case anything goes wrong while reading
*/
private int readFromStream(final int length) throws IOException {
int total = 0;
int actual = 0;
while (total < length && actual != -1) {
final int localIndex = getLocalWriterIndex();
final int spaceLeft = getAvailableLocalWritingSpace();
final int readAtMost = Math.min(length - total, spaceLeft);
final java.nio.ByteBuffer bb = getWritingRow();
actual = this.is.read(bb.array(), localIndex, readAtMost);
if (actual > 0) {
this.upperBoundary += actual;
this.writerIndex = this.upperBoundary;
total += actual;
}
}
return total;
}
/**
* {@inheritDoc}
*/
@Override
public int getReadableBytes() {
return super.getReadableBytes();
// return this.upperBoundary - this.readerIndex;
}
/**
* {@inheritDoc}
*
* @throws IOException
* @throws IndexOutOfBoundsException
*/
@Override
public boolean hasReadableBytes() {
if (!checkReadableBytesSafe(1)) {
try {
// if we don't have any bytes available for reading
// then try and read a bunch at the same time. However,
// we are satisfied if we can only read one byte
return internalReadBytes(100) >= 1;
} catch (final IOException e) {
return false;
}
}
return true;
}
/**
* {@inheritDoc}
*/
@Override
public boolean isEmpty() {
// TODO Auto-generated method stub
return false;
}
/**
* {@inheritDoc}
*/
@Override
public byte[] getArray() {
// TODO Auto-generated method stub
return null;
}
/**
* {@inheritDoc}
*/
@Override
public byte getByte(final int index) throws IndexOutOfBoundsException, IOException {
checkIndex(this.lowerBoundary + index);
final java.nio.ByteBuffer bb = getWritingRow();
// this has to be localized as well
return bb.get(this.lowerBoundary + index);
}
/**
* Convenience method for checking if we can get the byte at the specified
* index. If we can't, then we will try and read the missing bytes off of
* the underlying {@link InputStream}. If that fails, e.g. we don't ready
* enough bytes off of the stream, then we will eventually throw an
* {@link IndexOutOfBoundsException}
*
* @param index
* the actual index to check. I.e., this is the actual index in
* our byte array, irrespective of what the lowerBoundary is set
* to.
* @throws IndexOutOfBoundsException
* @throws IOException
*/
@Override
protected void checkIndex(final int index) throws IndexOutOfBoundsException {
final int missingBytes = index + 1 - (this.lowerBoundary + capacity());
if (missingBytes <= 0) {
// we got all the bytes needed
return;
}
try {
final int read = readFromStream(missingBytes);
if (read == -1 || read < missingBytes) {
throw new IndexOutOfBoundsException();
}
} catch (final IOException e) {
throw new IndexOutOfBoundsException();
}
}
/**
* {@inheritDoc}
*/
@Override
public long readUnsignedInt() throws IndexOutOfBoundsException {
// TODO Auto-generated method stub
return 0;
}
/**
* {@inheritDoc}
*/
@Override
public int readInt() throws IndexOutOfBoundsException {
// TODO Auto-generated method stub
return 0;
}
/**
* {@inheritDoc}
*/
@Override
public int getInt(final int index) throws IndexOutOfBoundsException {
// TODO Auto-generated method stub
return 0;
}
/**
* {@inheritDoc}
*/
@Override
public short getShort(final int index) throws IndexOutOfBoundsException {
// TODO Auto-generated method stub
return 0;
}
/**
* {@inheritDoc}
*/
@Override
public int readUnsignedShort() throws IndexOutOfBoundsException {
// TODO Auto-generated method stub
return 0;
}
/**
* {@inheritDoc}
*/
@Override
public int getUnsignedShort(final int index) throws IndexOutOfBoundsException {
// TODO Auto-generated method stub
return 0;
}
/**
* {@inheritDoc}
*/
@Override
public short readShort() throws IndexOutOfBoundsException {
// TODO Auto-generated method stub
return 0;
}
/**
* {@inheritDoc}
*/
@Override
public short getUnsignedByte(final int index) throws IndexOutOfBoundsException {
// TODO Auto-generated method stub
return 0;
}
/**
* {@inheritDoc}
*/
@Override
public String dumpAsHex() {
// TODO Auto-generated method stub
return null;
}
/**
* {@inheritDoc}
*/
@Override
public void setByte(final int index, final byte value) throws IndexOutOfBoundsException {
// TODO Auto-generated method stub
}
@Override
public void setUnsignedByte(final int index, final short value) throws IndexOutOfBoundsException {
// TODO Auto-generated method stub
}
@Override
public void setUnsignedShort(final int index, final int value) throws IndexOutOfBoundsException {
// TODO Auto-generated method stub
}
@Override
public Buffer clone() {
return null;
}
/**
* {@inheritDoc}
*/
@Override
public boolean equals(final Object other) {
if (other == null) {
return false;
}
if (this == other) {
return true;
}
try {
final Buffer b = (Buffer) other;
// should we care about how far we may have read into
// the two buffers? For now we will...
// Also, we may want to implement our own array compare
// since now the two arrays will be copied, which is kind
// of stupid but for now that is ok. Will worry about potential
// bottlenecks later. Issue has been added to the tracker to keep
// track of this...
return Arrays.equals(getArray(), b.getArray());
} catch (final ClassCastException e) {
return false;
}
}
@Override
public boolean equalsIgnoreCase(final Object other) {
throw new RuntimeException("Sorry, InputStreamBuffer.equalsIgnoreCase isn't implemented yet");
}
/**
* {@inheritDoc}
*/
@Override
public int hashCode() {
// TODO: actually go over the array instead of copying like this
return Arrays.hashCode(getArray());
}
@Override
public String toString() {
// perhaps not the most efficient way? but it works
// so for now we'll leave it as this until proven
// slow
final Buffer b = this.slice();
return b.toString();
}
@Override
public int getWritableBytes() {
return 0;
}
@Override
public boolean hasWritableBytes() {
return false;
}
@Override
public void write(byte[] bytes) throws IndexOutOfBoundsException, WriteNotSupportedException {
throw new WriteNotSupportedException("Cannot write to an InputStreamBuffer");
}
public void getBytes() {
}
@Override
public void getBytes(final Buffer dst) {
throw new RuntimeException(NOT_IMPLEMENTED_JUST_YET);
}
@Override
public void getBytes(final byte[] dst) throws IndexOutOfBoundsException {
throw new RuntimeException(NOT_IMPLEMENTED_JUST_YET);
}
@Override
public void getBytes(final int index, final Buffer dst) throws IndexOutOfBoundsException {
throw new RuntimeException(NOT_IMPLEMENTED_JUST_YET);
}
@Override
public void setInt(final int index, final int value) throws IndexOutOfBoundsException {
throw new RuntimeException(NOT_IMPLEMENTED_JUST_YET);
}
@Override
public void write(final int value) throws IndexOutOfBoundsException, WriteNotSupportedException {
throw new WriteNotSupportedException(CANNOT_WRITE_TO_AN_INPUT_STREAM_BUFFER);
}
@Override
public void write(final long value) throws IndexOutOfBoundsException, WriteNotSupportedException {
throw new WriteNotSupportedException(CANNOT_WRITE_TO_AN_INPUT_STREAM_BUFFER);
}
@Override
public void writeAsString(final int value) throws IndexOutOfBoundsException, WriteNotSupportedException {
throw new WriteNotSupportedException(CANNOT_WRITE_TO_AN_INPUT_STREAM_BUFFER);
}
@Override
public void writeAsString(final long value) throws IndexOutOfBoundsException, WriteNotSupportedException {
throw new WriteNotSupportedException(CANNOT_WRITE_TO_AN_INPUT_STREAM_BUFFER);
}
@Override
public void setUnsignedInt(final int index, final long value) throws IndexOutOfBoundsException {
// TODO Auto-generated method stub
}
}
