/*
* Copyright 2014 NAVER Corp.
*
* 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.navercorp.pinpoint.thrift.io;
import java.io.IOException;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.nio.charset.Charset;
import java.util.Arrays;
/**
* @author emeroad
*/
public class UnsafeByteArrayOutputStream extends ResettableByteArrayOutputStream {
private static final String UTF8 = "UTF8";
private static final Charset UTF8_CHARSET = Charset.forName(UTF8);
private final boolean autoExpand;
/**
* Creates a new byte array output stream. The buffer capacity is
* initially 32 bytes, though its size increases if necessary.
*/
public UnsafeByteArrayOutputStream() {
this(32);
}
/**
* Creates a new byte array output stream, with a buffer capacity of
* the specified size, in bytes.
*
* @param size the initial size.
* @throws IllegalArgumentException if size is negative.
*/
public UnsafeByteArrayOutputStream(int size) {
this(size, true);
}
public UnsafeByteArrayOutputStream(int size, boolean autoExpand) {
super(size);
this.autoExpand = autoExpand;
}
/**
* Writes the specified byte to this byte array output stream.
*
* @param b the byte to be written.
*/
public void write(int b) {
int newcount = count + 1;
if (isOverflow(newcount)) {
if (autoExpand) {
buf = Arrays.copyOf(buf, Math.max(buf.length << 1, newcount));
} else {
throw new BufferOverflowException("Buffer size cannot exceed " + buf.length + ". (now:" + count + ", input-size:1");
}
}
buf[count] = (byte) b;
count = newcount;
}
/**
* Writes <code>len</code> bytes from the specified byte array
* starting at offset <code>off</code> to this byte array output stream.
*
* @param b the data.
* @param off the start offset in the data.
* @param len the number of bytes to write.
*/
public void write(byte b[], int off, int len) {
if ((off < 0) || (off > b.length) || (len < 0) ||
((off + len) > b.length) || ((off + len) < 0)) {
throw new IndexOutOfBoundsException();
} else if (len == 0) {
return;
}
int newcount = count + len;
if (isOverflow(newcount)) {
if (autoExpand) {
buf = Arrays.copyOf(buf, Math.max(buf.length << 1, newcount));
} else {
throw new BufferOverflowException("Buffer size cannot exceed " + buf.length + ". (now:" + count + ", input-size:" + len);
}
}
System.arraycopy(b, off, buf, count, len);
count = newcount;
}
/**
* Writes the complete contents of this byte array output stream to
* the specified output stream argument, as if by calling the output
* stream's write method using <code>out.write(buf, 0, count)</code>.
*
* @param out the output stream to which to write the data.
* @throws java.io.IOException if an I/O error occurs.
*/
public void writeTo(OutputStream out) throws IOException {
out.write(buf, 0, count);
}
/**
* Resets the <code>count</code> field of this byte array output
* stream to zero, so that all currently accumulated output in the
* output stream is discarded. The output stream can be used again,
* reusing the already allocated buffer space.
*
* @see java.io.ByteArrayInputStream#count
*/
public void reset() {
count = 0;
}
/**
* Creates a newly allocated byte array. Its size is the current
* size of this output stream and the valid contents of the buffer
* have been copied into it.
*
* @return the current contents of this output stream, as a byte array.
* @see java.io.ByteArrayOutputStream#size()
*/
public byte toByteArray()[] {
return buf;
}
/**
* Returns the current size of the buffer.
*
* @return the value of the <code>count</code> field, which is the number
* of valid bytes in this output stream.
* @see java.io.ByteArrayOutputStream#count
*/
public int size() {
return count;
}
/**
* Converts the buffer's contents into a string decoding bytes using the
* platform's default character set. The length of the new <tt>String</tt>
* is a function of the character set, and hence may not be equal to the
* size of the buffer.
* <p/>
* <p> This method always replaces malformed-input and unmappable-character
* sequences with the default replacement string for the platform's
* default character set. The {@linkplain java.nio.charset.CharsetDecoder}
* class should be used when more control over the decoding process is
* required.
*
* @return String decoded from the buffer's contents.
* @since JDK1.1
*/
public String toString() {
try {
return toString(UTF8);
} catch (UnsupportedEncodingException ex) {
return new String(buf, 0, count, UTF8_CHARSET);
}
}
/**
* Converts the buffer's contents into a string by decoding the bytes using
* the specified {@link java.nio.charset.Charset charsetName}. The length of
* the new <tt>String</tt> is a function of the charset, and hence may not be
* equal to the length of the byte array.
* <p/>
* <p> This method always replaces malformed-input and unmappable-character
* sequences with this charset's default replacement string. The {@link
* java.nio.charset.CharsetDecoder} class should be used when more control
* over the decoding process is required.
*
* @param charsetName the name of a supported
* {@linkplain java.nio.charset.Charset </code>charset<code>}
* @return String decoded from the buffer's contents.
* @throws java.io.UnsupportedEncodingException
* If the named charset is not supported
* @since JDK1.1
*/
public String toString(String charsetName)
throws UnsupportedEncodingException {
return new String(buf, 0, count, charsetName);
}
/**
* Closing a <tt>ByteArrayOutputStream</tt> has no effect. The methods in
* this class can be called after the stream has been closed without
* generating an <tt>IOException</tt>.
* <p/>
*/
public void close() throws IOException {
}
private boolean isOverflow(int minCapacity) {
if (minCapacity - buf.length > 0) {
return true;
}
return false;
}
}