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/*
* Copyright (c) 2011-2013 The original author or authors
* ------------------------------------------------------
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* and Apache License v2.0 which accompanies this distribution.
*
* The Eclipse Public License is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* The Apache License v2.0 is available at
* http://www.opensource.org/licenses/apache2.0.php
*
* You may elect to redistribute this code under either of these licenses.
*/
package io.jsync.buffer;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.util.CharsetUtil;
import java.nio.ByteBuffer;
import java.nio.charset.Charset;
/**
* A Buffer represents a sequence of zero or more bytes that can be written to or read from, and which expands as
* necessary to accommodate any bytes written to it.
* There are two ways to write data to a Buffer: The first method involves methods that take the form {@code setXXX}.
* These methods write data into the buffer starting at the specified position. The position does not have to be inside data that
* has already been written to the buffer; the buffer will automatically expand to encompass the position plus any data that needs
* to be written. All positions are measured in bytes and start with zero.
* The second method involves methods that take the form {@code appendXXX}; these methods append data
* at the end of the buffer.
* Methods exist to both {@code set} and {@code append} all primitive types, {@link String}, {@link ByteBuffer} and
* other instances of Buffer.
* Data can be read from a buffer by invoking methods which take the form {@code getXXX}. These methods take a parameter
* representing the position in the Buffer from where to read data.
* Once a buffer has been written to a socket or other write stream, the same buffer instance can't be written again to another WriteStream.
* Instances of this class are not thread-safe.
*
* @author Tim Fox
*/
public class Buffer {
private final ByteBuf buffer;
/**
* Create an empty buffer
*/
public Buffer() {
this(0);
}
/**
* Creates a new empty Buffer that is expected to have a size of {@code initialSizeHint} after data has been
* written to it.
* Please note that {@code length} of the Buffer immediately after creation will be zero.
* The {@code initialSizeHint} is merely a hint to the system for how much memory to initially allocate to the buffer to prevent excessive
* automatic re-allocations as data is written to it.
*/
public Buffer(int initialSizeHint) {
buffer = Unpooled.unreleasableBuffer(Unpooled.buffer(initialSizeHint, Integer.MAX_VALUE));
}
/**
* Create a new Buffer that contains the contents of a {@code byte[]}
*/
public Buffer(byte[] bytes) {
buffer = Unpooled.unreleasableBuffer(Unpooled.buffer(bytes.length, Integer.MAX_VALUE)).writeBytes(bytes);
}
/**
* Create a new Buffer that contains the contents of a {@code String str} encoded according to the encoding {@code enc}
*/
public Buffer(String str, String enc) {
this(str.getBytes(Charset.forName(enc)));
}
/**
* Create a new Buffer that contains the contents of {@code String str} encoded with UTF-8 encoding
*/
public Buffer(String str) {
this(str, "UTF-8");
}
/**
* Create a new Buffer from a Netty {@code ByteBuf} instance.
* This method is meant for internal use only.
*/
public Buffer(ByteBuf buffer) {
this.buffer = Unpooled.unreleasableBuffer(buffer);
}
/**
* Returns a {@code String} representation of the Buffer assuming it contains a {@code String} encoding in UTF-8
*/
public String toString() {
return buffer.toString(Charset.forName("UTF-8"));
}
/**
* Returns a {@code String} representation of the Buffer with the encoding specified by {@code enc}
*/
public String toString(String enc) {
return buffer.toString(Charset.forName(enc));
}
/**
* Returns the {@code byte} at position {@code pos} in the Buffer.
*
* @throws IndexOutOfBoundsException if the specified {@code pos} is less than {@code 0} or {@code pos + 1} is greater than the length of the Buffer.
*/
public byte getByte(int pos) {
return buffer.getByte(pos);
}
/**
* Returns the {@code int} at position {@code pos} in the Buffer.
*
* @throws IndexOutOfBoundsException if the specified {@code pos} is less than {@code 0} or {@code pos + 4} is greater than the length of the Buffer.
*/
public int getInt(int pos) {
return buffer.getInt(pos);
}
/**
* Returns the {@code long} at position {@code pos} in the Buffer.
*
* @throws IndexOutOfBoundsException if the specified {@code pos} is less than {@code 0} or {@code pos + 8} is greater than the length of the Buffer.
*/
public long getLong(int pos) {
return buffer.getLong(pos);
}
/**
* Returns the {@code double} at position {@code pos} in the Buffer.
*
* @throws IndexOutOfBoundsException if the specified {@code pos} is less than {@code 0} or {@code pos + 8} is greater than the length of the Buffer.
*/
public double getDouble(int pos) {
return buffer.getDouble(pos);
}
/**
* Returns the {@code float} at position {@code pos} in the Buffer.
*
* @throws IndexOutOfBoundsException if the specified {@code pos} is less than {@code 0} or {@code pos + 4} is greater than the length of the Buffer.
*/
public float getFloat(int pos) {
return buffer.getFloat(pos);
}
/**
* Returns the {@code short} at position {@code pos} in the Buffer.
*
* @throws IndexOutOfBoundsException if the specified {@code pos} is less than {@code 0} or {@code pos + 2} is greater than the length of the Buffer.
*/
public short getShort(int pos) {
return buffer.getShort(pos);
}
/**
* Returns a copy of the entire Buffer as a {@code byte[]}
*/
public byte[] getBytes() {
byte[] arr = new byte[buffer.writerIndex()];
buffer.getBytes(0, arr);
return arr;
}
/**
* Returns a copy of a sub-sequence the Buffer as a {@code byte[]} starting at position {@code start}
* and ending at position {@code end - 1}
*/
public byte[] getBytes(int start, int end) {
byte[] arr = new byte[end - start];
buffer.getBytes(start, arr, 0, end - start);
return arr;
}
/**
* Returns a copy of a sub-sequence the Buffer as a {@link Buffer} starting at position {@code start}
* and ending at position {@code end - 1}
*/
public Buffer getBuffer(int start, int end) {
return new Buffer(getBytes(start, end));
}
/**
* Returns a copy of a sub-sequence the Buffer as a {@code String} starting at position {@code start}
* and ending at position {@code end - 1} interpreted as a String in the specified encoding
*/
public String getString(int start, int end, String enc) {
byte[] bytes = getBytes(start, end);
Charset cs = Charset.forName(enc);
return new String(bytes, cs);
}
/**
* Returns a copy of a sub-sequence the Buffer as a {@code String} starting at position {@code start}
* and ending at position {@code end - 1} interpreted as a String in UTF-8 encoding
*/
public String getString(int start, int end) {
byte[] bytes = getBytes(start, end);
Charset cs = Charset.forName("UTF-8");
return new String(bytes, cs);
}
/**
* Appends the specified {@code Buffer} to the end of this Buffer. The buffer will expand as necessary to accommodate
* any bytes written.
* Returns a reference to {@code this} so multiple operations can be appended together.
*/
public Buffer appendBuffer(Buffer buff) {
ByteBuf cb = buff.getByteBuf();
buffer.writeBytes(buff.getByteBuf());
cb.readerIndex(0); // Need to reset readerindex since Netty write modifies readerIndex of source!
return this;
}
/**
* Appends the specified {@code Buffer} starting at the {@code offset} using {@code len} to the end of this Buffer. The buffer will expand as necessary to accommodate
* any bytes written.
* Returns a reference to {@code this} so multiple operations can be appended together.
*/
public Buffer appendBuffer(Buffer buff, int offset, int len) {
buffer.writeBytes(buff.getByteBuf(), offset, len);
return this;
}
/**
* Appends the specified {@code byte[]} to the end of the Buffer. The buffer will expand as necessary to accommodate any bytes written.
* Returns a reference to {@code this} so multiple operations can be appended together.
*/
public Buffer appendBytes(byte[] bytes) {
buffer.writeBytes(bytes);
return this;
}
/**
* Appends the specified number of bytes from {@code byte[]} to the end of the Buffer, starting at the given offset.
* The buffer will expand as necessary to accommodate any bytes written.
* Returns a reference to {@code this} so multiple operations can be appended together.
*/
public Buffer appendBytes(byte[] bytes, int offset, int len) {
buffer.writeBytes(bytes, offset, len);
return this;
}
/**
* Appends the specified {@code byte} to the end of the Buffer. The buffer will expand as necessary to accommodate any bytes written.
* Returns a reference to {@code this} so multiple operations can be appended together.
*/
public Buffer appendByte(byte b) {
buffer.writeByte(b);
return this;
}
/**
* Appends the specified {@code int} to the end of the Buffer. The buffer will expand as necessary to accommodate any bytes written.
* Returns a reference to {@code this} so multiple operations can be appended together.
*/
public Buffer appendInt(int i) {
buffer.writeInt(i);
return this;
}
/**
* Appends the specified {@code long} to the end of the Buffer. The buffer will expand as necessary to accommodate any bytes written.
* Returns a reference to {@code this} so multiple operations can be appended together.
*/
public Buffer appendLong(long l) {
buffer.writeLong(l);
return this;
}
/**
* Appends the specified {@code short} to the end of the Buffer.The buffer will expand as necessary to accommodate any bytes written.
* Returns a reference to {@code this} so multiple operations can be appended together.
*/
public Buffer appendShort(short s) {
buffer.writeShort(s);
return this;
}
/**
* Appends the specified {@code float} to the end of the Buffer. The buffer will expand as necessary to accommodate any bytes written.
* Returns a reference to {@code this} so multiple operations can be appended together.
*/
public Buffer appendFloat(float f) {
buffer.writeFloat(f);
return this;
}
/**
* Appends the specified {@code double} to the end of the Buffer. The buffer will expand as necessary to accommodate any bytes written.
* Returns a reference to {@code this} so multiple operations can be appended together.
*/
public Buffer appendDouble(double d) {
buffer.writeDouble(d);
return this;
}
/**
* Appends the specified {@code String} to the end of the Buffer with the encoding as specified by {@code enc}.
* The buffer will expand as necessary to accommodate any bytes written.
* Returns a reference to {@code this} so multiple operations can be appended together.
*/
public Buffer appendString(String str, String enc) {
return append(str, Charset.forName(enc));
}
/**
* Appends the specified {@code String str} to the end of the Buffer with UTF-8 encoding.
* The buffer will expand as necessary to accommodate any bytes written.
* Returns a reference to {@code this} so multiple operations can be appended together
*/
public Buffer appendString(String str) {
return append(str, CharsetUtil.UTF_8);
}
/**
* Sets the {@code byte} at position {@code pos} in the Buffer to the value {@code b}.
* The buffer will expand as necessary to accommodate any value written.
*/
public Buffer setByte(int pos, byte b) {
ensureWritable(pos, 1);
buffer.setByte(pos, b);
return this;
}
/**
* Sets the {@code int} at position {@code pos} in the Buffer to the value {@code i}.
* The buffer will expand as necessary to accommodate any value written.
*/
public Buffer setInt(int pos, int i) {
ensureWritable(pos, 4);
buffer.setInt(pos, i);
return this;
}
/**
* Sets the {@code long} at position {@code pos} in the Buffer to the value {@code l}.
* The buffer will expand as necessary to accommodate any value written.
*/
public Buffer setLong(int pos, long l) {
ensureWritable(pos, 8);
buffer.setLong(pos, l);
return this;
}
/**
* Sets the {@code double} at position {@code pos} in the Buffer to the value {@code d}.
* The buffer will expand as necessary to accommodate any value written.
*/
public Buffer setDouble(int pos, double d) {
ensureWritable(pos, 8);
buffer.setDouble(pos, d);
return this;
}
/**
* Sets the {@code float} at position {@code pos} in the Buffer to the value {@code f}.
* The buffer will expand as necessary to accommodate any value written.
*/
public Buffer setFloat(int pos, float f) {
ensureWritable(pos, 4);
buffer.setFloat(pos, f);
return this;
}
/**
* Sets the {@code short} at position {@code pos} in the Buffer to the value {@code s}.
* The buffer will expand as necessary to accommodate any value written.
*/
public Buffer setShort(int pos, short s) {
ensureWritable(pos, 2);
buffer.setShort(pos, s);
return this;
}
/**
* Sets the bytes at position {@code pos} in the Buffer to the bytes represented by the {@code Buffer b}.
* The buffer will expand as necessary to accommodate any value written.
*/
public Buffer setBuffer(int pos, Buffer b) {
ensureWritable(pos, b.length());
buffer.setBytes(pos, b.getByteBuf());
return this;
}
/**
* Sets the bytes at position {@code pos} in the Buffer to the bytes represented by the {@code Buffer b} on the given {@code offset} and {@code len}.
* The buffer will expand as necessary to accommodate any value written.
*/
public Buffer setBuffer(int pos, Buffer b, int offset, int len) {
ensureWritable(pos, len);
buffer.setBytes(pos, b.getByteBuf(), offset, len);
return this;
}
/**
* Sets the bytes at position {@code pos} in the Buffer to the bytes represented by the {@code ByteBuffer b}.
* The buffer will expand as necessary to accommodate any value written.
*/
public Buffer setBytes(int pos, ByteBuffer b) {
ensureWritable(pos, b.limit());
buffer.setBytes(pos, b);
return this;
}
/**
* Sets the bytes at position {@code pos} in the Buffer to the bytes represented by the {@code byte[] b}.
* The buffer will expand as necessary to accommodate any value written.
*/
public Buffer setBytes(int pos, byte[] b) {
ensureWritable(pos, b.length);
buffer.setBytes(pos, b);
return this;
}
/**
* Sets the given number of bytes at position {@code pos} in the Buffer to the bytes represented by the {@code byte[] b}.
* The buffer will expand as necessary to accommodate any value written.
*/
public Buffer setBytes(int pos, byte[] b, int offset, int len) {
ensureWritable(pos, len);
buffer.setBytes(pos, b, offset, len);
return this;
}
/**
* Sets the bytes at position {@code pos} in the Buffer to the value of {@code str} encoded in UTF-8.
* The buffer will expand as necessary to accommodate any value written.
*/
public Buffer setString(int pos, String str) {
return setBytes(pos, str, CharsetUtil.UTF_8);
}
/**
* Sets the bytes at position {@code pos} in the Buffer to the value of {@code str} encoded in encoding {@code enc}.
* The buffer will expand as necessary to accommodate any value written.
*/
public Buffer setString(int pos, String str, String enc) {
return setBytes(pos, str, Charset.forName(enc));
}
/**
* Returns the length of the buffer, measured in bytes.
* All positions are indexed from zero.
*/
public int length() {
return buffer.writerIndex();
}
/**
* Returns a copy of the entire Buffer.
*/
public Buffer copy() {
return new Buffer(buffer.copy());
}
/**
* Returns the Buffer as a Netty {@code ByteBuf}.
* This method is meant for internal use only.
*/
public ByteBuf getByteBuf() {
// Return a duplicate so the Buffer can be written multiple times.
// See #648
return buffer.duplicate();
}
private Buffer append(String str, Charset charset) {
byte[] bytes = str.getBytes(charset);
buffer.writeBytes(bytes);
return this;
}
private Buffer setBytes(int pos, String str, Charset charset) {
byte[] bytes = str.getBytes(charset);
ensureWritable(pos, bytes.length);
buffer.setBytes(pos, bytes);
return this;
}
private void ensureWritable(int pos, int len) {
int ni = pos + len;
int cap = buffer.capacity();
int over = ni - cap;
if (over > 0) {
buffer.writerIndex(cap);
buffer.ensureWritable(over);
}
//We have to make sure that the writerindex is always positioned on the last bit of data set in the buffer
if (ni > buffer.writerIndex()) {
buffer.writerIndex(ni);
}
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
Buffer buffer1 = (Buffer) o;
return buffer.equals(buffer1.buffer);
}
}