ByteChunk.java
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 org.apache.tomcat.util.buf;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.CharacterCodingException;
import java.nio.charset.Charset;
import java.nio.charset.CodingErrorAction;
import java.nio.charset.StandardCharsets;
/**
* This class is used to represent a chunk of bytes, and utilities to manipulate byte[].
* <p>
* The buffer can be modified and used for both input and output.
* <p>
* There are 2 modes: The chunk can be associated with a sink - ByteInputChannel or ByteOutputChannel, which will be
* used when the buffer is empty (on input) or filled (on output). For output, it can also grow. This operating mode is
* selected by calling setLimit() or allocate(initial, limit) with limit != -1.
* <p>
* Various search and append method are defined - similar with String and StringBuffer, but operating on bytes.
* <p>
* This is important because it allows processing the http headers directly on the received bytes, without converting to
* chars and Strings until the strings are needed. In addition, the charset is determined later, from headers or user
* code.
* <p>
* In a server it is very important to be able to operate on
* the original byte[] without converting everything to chars.
* Some protocols are ASCII only, and some allow different
* non-UNICODE encodings. The encoding is not known beforehand,
* and can even change during the execution of the protocol.
* ( for example a multipart message may have parts with different
* encoding )
* <p>
* For HTTP it is not very clear how the encoding of RequestURI
* and mime values can be determined, but it is a great advantage
* to be able to parse the request without converting to string.
*
* @author dac@sun.com
* @author James Todd [gonzo@sun.com]
* @author Costin Manolache
* @author Remy Maucherat
*/
public final class ByteChunk extends AbstractChunk {
private static final long serialVersionUID = 1L;
/**
* Input interface, used when the buffer is empty. Same as java.nio.channels.ReadableByteChannel
*/
public interface ByteInputChannel {
/**
* Read new bytes.
*
* @return The number of bytes read
*
* @throws IOException If an I/O error occurs during reading
*/
int realReadBytes() throws IOException;
}
/**
* When we need more space we'll either grow the buffer ( up to the limit ) or send it to a channel. Same as
* java.nio.channel.WritableByteChannel.
*/
public interface ByteOutputChannel {
/**
* Send the bytes ( usually the internal conversion buffer ). Expect 8k output if the buffer is full.
*
* @param buf bytes that will be written
* @param off offset in the bytes array
* @param len length that will be written
*
* @throws IOException If an I/O occurs while writing the bytes
*/
void realWriteBytes(byte buf[], int off, int len) throws IOException;
/**
* Send the bytes ( usually the internal conversion buffer ). Expect 8k output if the buffer is full.
*
* @param from bytes that will be written
*
* @throws IOException If an I/O occurs while writing the bytes
*/
void realWriteBytes(ByteBuffer from) throws IOException;
}
// --------------------
/**
* Default encoding used to convert to strings. It should be UTF8, as most standards seem to converge, but the
* servlet API requires 8859_1, and this object is used mostly for servlets.
*/
public static final Charset DEFAULT_CHARSET = StandardCharsets.ISO_8859_1;
private transient Charset charset;
// byte[]
private byte[] buff;
// transient as serialization is primarily for values via, e.g. JMX
private transient ByteInputChannel in = null;
private transient ByteOutputChannel out = null;
/**
* Creates a new, uninitialized ByteChunk object.
*/
public ByteChunk() {
}
public ByteChunk(int initial) {
allocate(initial, -1);
}
private void writeObject(ObjectOutputStream oos) throws IOException {
oos.defaultWriteObject();
oos.writeUTF(getCharset().name());
}
private void readObject(ObjectInputStream ois) throws ClassNotFoundException, IOException {
ois.defaultReadObject();
this.charset = Charset.forName(ois.readUTF());
}
@Override
public Object clone() throws CloneNotSupportedException {
return super.clone();
}
@Override
public void recycle() {
super.recycle();
charset = null;
}
// -------------------- Setup --------------------
public void allocate(int initial, int limit) {
if (buff == null || buff.length < initial) {
buff = new byte[initial];
}
setLimit(limit);
start = 0;
end = 0;
isSet = true;
hasHashCode = false;
}
/**
* Sets the buffer to the specified subarray of bytes.
*
* @param b the ascii bytes
* @param off the start offset of the bytes
* @param len the length of the bytes
*/
public void setBytes(byte[] b, int off, int len) {
buff = b;
start = off;
end = start + len;
isSet = true;
hasHashCode = false;
}
public void setCharset(Charset charset) {
this.charset = charset;
}
public Charset getCharset() {
if (charset == null) {
charset = DEFAULT_CHARSET;
}
return charset;
}
/**
* @return the buffer.
*/
public byte[] getBytes() {
return getBuffer();
}
/**
* @return the buffer.
*/
public byte[] getBuffer() {
return buff;
}
/**
* When the buffer is empty, read the data from the input channel.
*
* @param in The input channel
*/
public void setByteInputChannel(ByteInputChannel in) {
this.in = in;
}
/**
* When the buffer is full, write the data to the output channel. Also used when large amount of data is appended.
* If not set, the buffer will grow to the limit.
*
* @param out The output channel
*/
public void setByteOutputChannel(ByteOutputChannel out) {
this.out = out;
}
// -------------------- Adding data to the buffer --------------------
public void append(byte b) throws IOException {
makeSpace(1);
int limit = getLimitInternal();
// couldn't make space
if (end >= limit) {
flushBuffer();
}
buff[end++] = b;
}
public void append(ByteChunk src) throws IOException {
append(src.getBytes(), src.getStart(), src.getLength());
}
/**
* Add data to the buffer.
*
* @param src Bytes array
* @param off Offset
* @param len Length
*
* @throws IOException Writing overflow data to the output channel failed
*/
public void append(byte src[], int off, int len) throws IOException {
// will grow, up to limit
makeSpace(len);
int limit = getLimitInternal();
// Optimize on a common case.
// If the buffer is empty and the source is going to fill up all the
// space in buffer, may as well write it directly to the output,
// and avoid an extra copy
if (len == limit && end == start && out != null) {
out.realWriteBytes(src, off, len);
return;
}
// if we are below the limit
if (len <= limit - end) {
System.arraycopy(src, off, buff, end, len);
end += len;
return;
}
// Need more space than we can afford, need to flush buffer.
// The buffer is already at (or bigger than) limit.
// We chunk the data into slices fitting in the buffer limit, although
// if the data is written directly if it doesn't fit.
int avail = limit - end;
System.arraycopy(src, off, buff, end, avail);
end += avail;
flushBuffer();
int remain = len - avail;
while (remain > (limit - end)) {
out.realWriteBytes(src, (off + len) - remain, limit - end);
remain = remain - (limit - end);
}
System.arraycopy(src, (off + len) - remain, buff, end, remain);
end += remain;
}
/**
* Add data to the buffer.
*
* @param from the ByteBuffer with the data
*
* @throws IOException Writing overflow data to the output channel failed
*/
public void append(ByteBuffer from) throws IOException {
int len = from.remaining();
// will grow, up to limit
makeSpace(len);
int limit = getLimitInternal();
// Optimize on a common case.
// If the buffer is empty and the source is going to fill up all the
// space in buffer, may as well write it directly to the output,
// and avoid an extra copy
if (len == limit && end == start && out != null) {
out.realWriteBytes(from);
from.position(from.limit());
return;
}
// if we have limit and we're below
if (len <= limit - end) {
// makeSpace will grow the buffer to the limit,
// so we have space
from.get(buff, end, len);
end += len;
return;
}
// need more space than we can afford, need to flush
// buffer
// the buffer is already at ( or bigger than ) limit
// We chunk the data into slices fitting in the buffer limit, although
// if the data is written directly if it doesn't fit
int avail = limit - end;
from.get(buff, end, avail);
end += avail;
flushBuffer();
int fromLimit = from.limit();
int remain = len - avail;
avail = limit - end;
while (remain >= avail) {
from.limit(from.position() + avail);
out.realWriteBytes(from);
from.position(from.limit());
remain = remain - avail;
}
from.limit(fromLimit);
from.get(buff, end, remain);
end += remain;
}
// -------------------- Removing data from the buffer --------------------
public int subtract() throws IOException {
if (checkEof()) {
return -1;
}
return buff[start++] & 0xFF;
}
public byte subtractB() throws IOException {
if (checkEof()) {
return -1;
}
return buff[start++];
}
public int subtract(byte dest[], int off, int len) throws IOException {
if (checkEof()) {
return -1;
}
int n = len;
if (len > getLength()) {
n = getLength();
}
System.arraycopy(buff, start, dest, off, n);
start += n;
return n;
}
/**
* Transfers bytes from the buffer to the specified ByteBuffer. After the operation the position of the ByteBuffer
* will be returned to the one before the operation, the limit will be the position incremented by the number of the
* transferred bytes.
*
* @param to the ByteBuffer into which bytes are to be written.
*
* @return an integer specifying the actual number of bytes read, or -1 if the end of the stream is reached
*
* @throws IOException if an input or output exception has occurred
*/
public int subtract(ByteBuffer to) throws IOException {
if (checkEof()) {
return -1;
}
int n = Math.min(to.remaining(), getLength());
to.put(buff, start, n);
to.limit(to.position());
to.position(to.position() - n);
start += n;
return n;
}
private boolean checkEof() throws IOException {
if ((end - start) == 0) {
if (in == null) {
return true;
}
int n = in.realReadBytes();
if (n < 0) {
return true;
}
}
return false;
}
/**
* Send the buffer to the sink. Called by append() when the limit is reached. You can also call it explicitly to
* force the data to be written.
*
* @throws IOException Writing overflow data to the output channel failed
*/
public void flushBuffer() throws IOException {
// assert out!=null
if (out == null) {
throw new BufferOverflowException(
sm.getString("chunk.overflow", Integer.valueOf(getLimit()), Integer.valueOf(buff.length)));
}
out.realWriteBytes(buff, start, end - start);
end = start;
}
/**
* Make space for len bytes. If len is small, allocate a reserve space too. Never grow bigger than the limit or
* {@link AbstractChunk#ARRAY_MAX_SIZE}.
*
* @param count The size
*/
public void makeSpace(int count) {
byte[] tmp = null;
int limit = getLimitInternal();
long newSize;
long desiredSize = end + count;
// Can't grow above the limit
if (desiredSize > limit) {
desiredSize = limit;
}
if (buff == null) {
if (desiredSize < 256) {
desiredSize = 256; // take a minimum
}
buff = new byte[(int) desiredSize];
}
// limit < buf.length (the buffer is already big)
// or we already have space
if (desiredSize <= buff.length) {
return;
}
// grow in larger chunks
if (desiredSize < 2L * buff.length) {
newSize = buff.length * 2L;
} else {
newSize = buff.length * 2L + count;
}
if (newSize > limit) {
newSize = limit;
}
tmp = new byte[(int) newSize];
// Compacts buffer
System.arraycopy(buff, start, tmp, 0, end - start);
buff = tmp;
tmp = null;
end = end - start;
start = 0;
}
// -------------------- Conversion and getters --------------------
@Override
public String toString() {
try {
return toString(CodingErrorAction.REPLACE, CodingErrorAction.REPLACE);
} catch (CharacterCodingException e) {
// Unreachable code. Use of REPLACE above means the exception will never be thrown.
throw new IllegalStateException(e);
}
}
public String toString(CodingErrorAction malformedInputAction, CodingErrorAction unmappableCharacterAction)
throws CharacterCodingException {
if (isNull()) {
return null;
} else if (end - start == 0) {
return "";
}
return StringCache.toString(this, malformedInputAction, unmappableCharacterAction);
}
/**
* Converts the current content of the byte buffer to a String using the configured character set.
*
* @return The result of converting the bytes to a String
*
* @deprecated Unused. This method will be removed in Tomcat 11 onwards.
*/
@Deprecated
public String toStringInternal() {
try {
return toStringInternal(CodingErrorAction.REPLACE, CodingErrorAction.REPLACE);
} catch (CharacterCodingException e) {
// Unreachable code. Use of REPLACE above means the exception will never be thrown.
throw new IllegalStateException(e);
}
}
/**
* Converts the current content of the byte buffer to a String using the configured character set.
*
* @param malformedInputAction Action to take if the input is malformed
* @param unmappableCharacterAction Action to take if a byte sequence can't be mapped to a character
*
* @return The result of converting the bytes to a String
*
* @throws CharacterCodingException If an error occurs during the conversion
*/
public String toStringInternal(CodingErrorAction malformedInputAction, CodingErrorAction unmappableCharacterAction)
throws CharacterCodingException {
if (charset == null) {
charset = DEFAULT_CHARSET;
}
// new String(byte[], int, int, Charset) takes a defensive copy of the
// entire byte array. This is expensive if only a small subset of the
// bytes will be used. The code below is from Apache Harmony.
CharBuffer cb;
if (malformedInputAction == CodingErrorAction.REPLACE && unmappableCharacterAction == CodingErrorAction.REPLACE) {
cb = charset.decode(ByteBuffer.wrap(buff, start, end - start));
} else {
cb = charset.newDecoder().onMalformedInput(malformedInputAction)
.onUnmappableCharacter(unmappableCharacterAction).decode(ByteBuffer.wrap(buff, start, end - start));
}
return new String(cb.array(), cb.arrayOffset(), cb.length());
}
public long getLong() {
return Ascii.parseLong(buff, start, end - start);
}
// -------------------- equals --------------------
@Override
public boolean equals(Object obj) {
if (obj instanceof ByteChunk) {
return equals((ByteChunk) obj);
}
return false;
}
/**
* Compares the message bytes to the specified String object.
* <p>
* NOTE: This only works for characters in the range 0-127.
*
* @param s the String to compare
*
* @return <code>true</code> if the comparison succeeded, <code>false</code> otherwise
*/
public boolean equals(String s) {
byte[] b = buff;
int len = end - start;
if (b == null || len != s.length()) {
return false;
}
int off = start;
for (int i = 0; i < len; i++) {
if (b[off++] != s.charAt(i)) {
return false;
}
}
return true;
}
/**
* Compares the message bytes to the specified String object.
* <p>
* NOTE: This only works for characters in the range 0-127.
*
* @param s the String to compare
*
* @return <code>true</code> if the comparison succeeded, <code>false</code> otherwise
*/
public boolean equalsIgnoreCase(String s) {
byte[] b = buff;
int len = end - start;
if (b == null || len != s.length()) {
return false;
}
int off = start;
for (int i = 0; i < len; i++) {
if (Ascii.toLower(b[off++]) != Ascii.toLower(s.charAt(i))) {
return false;
}
}
return true;
}
public boolean equals(ByteChunk bb) {
return equals(bb.getBytes(), bb.getStart(), bb.getLength());
}
public boolean equals(byte b2[], int off2, int len2) {
byte b1[] = buff;
if (b1 == null && b2 == null) {
return true;
}
int len = end - start;
if (len != len2 || b1 == null || b2 == null) {
return false;
}
int off1 = start;
while (len-- > 0) {
if (b1[off1++] != b2[off2++]) {
return false;
}
}
return true;
}
public boolean equalsIgnoreCase(byte b2[], int off2, int len2) {
byte b1[] = buff;
if (b1 == null && b2 == null) {
return true;
}
int len = end - start;
if (len != len2 || b1 == null || b2 == null) {
return false;
}
int off1 = start;
while (len-- > 0) {
if (Ascii.toLower(b1[off1++]) != Ascii.toLower(b2[off2++])) {
return false;
}
}
return true;
}
public boolean equals(CharChunk cc) {
return equals(cc.getChars(), cc.getStart(), cc.getLength());
}
/**
* Compares the message bytes to the specified char array.
* <p>
* NOTE: This only works for characters in the range 0-127.
*
* @param c2 the array to compare to
* @param off2 offset
* @param len2 length
* @return <code>true</code> if the comparison succeeded, <code>false</code> otherwise
*/
public boolean equals(char c2[], int off2, int len2) {
byte b1[] = buff;
if (c2 == null && b1 == null) {
return true;
}
if (b1 == null || c2 == null || end - start != len2) {
return false;
}
int off1 = start;
int len = end - start;
while (len-- > 0) {
if ((char) b1[off1++] != c2[off2++]) {
return false;
}
}
return true;
}
/**
* Returns true if the buffer starts with the specified string when tested in a case sensitive manner.
* <p>
* NOTE: This only works for characters in the range 0-127.
*
* @param s the string
* @param pos The position
*
* @return <code>true</code> if the start matches
*/
public boolean startsWith(String s, int pos) {
byte[] b = buff;
int len = s.length();
if (b == null || len + pos > end - start) {
return false;
}
int off = start + pos;
for (int i = 0; i < len; i++) {
if (b[off++] != s.charAt(i)) {
return false;
}
}
return true;
}
/**
* Returns true if the buffer starts with the specified string when tested in a case insensitive manner.
* <p>
* NOTE: This only works for characters in the range 0-127.
*
* @param s the string
* @param pos The position
*
* @return <code>true</code> if the start matches
*/
public boolean startsWithIgnoreCase(String s, int pos) {
byte[] b = buff;
int len = s.length();
if (b == null || len + pos > end - start) {
return false;
}
int off = start + pos;
for (int i = 0; i < len; i++) {
if (Ascii.toLower(b[off++]) != Ascii.toLower(s.charAt(i))) {
return false;
}
}
return true;
}
@Override
protected int getBufferElement(int index) {
return buff[index];
}
/**
* Returns the first instance of the given character in this ByteChunk starting at the specified byte. If the
* character is not found, -1 is returned.
* <p>
* NOTE: This only works for characters in the range 0-127.
*
* @param c The character
* @param starting The start position
*
* @return The position of the first instance of the character or -1 if the character is not found.
*/
public int indexOf(char c, int starting) {
int ret = indexOf(buff, start + starting, end, c);
return (ret >= start) ? ret - start : -1;
}
/**
* Returns the first instance of the given character in the given byte array between the specified start and end.
* <p>
* NOTE: This only works for characters in the range 0-127.
*
* @param bytes The array to search
* @param start The point to start searching from in the array
* @param end The point to stop searching in the array
* @param s The character to search for
*
* @return The position of the first instance of the character or -1 if the character is not found.
*/
public static int indexOf(byte bytes[], int start, int end, char s) {
int offset = start;
while (offset < end) {
byte b = bytes[offset];
if (b == s) {
return offset;
}
offset++;
}
return -1;
}
/**
* Returns the first instance of the given byte in the byte array between the specified start and end.
*
* @param bytes The byte array to search
* @param start The point to start searching from in the byte array
* @param end The point to stop searching in the byte array
* @param b The byte to search for
*
* @return The position of the first instance of the byte or -1 if the byte is not found.
*/
public static int findByte(byte bytes[], int start, int end, byte b) {
int offset = start;
while (offset < end) {
if (bytes[offset] == b) {
return offset;
}
offset++;
}
return -1;
}
/**
* Returns the first instance of any of the given bytes in the byte array between the specified start and end.
*
* @param bytes The byte array to search
* @param start The point to start searching from in the byte array
* @param end The point to stop searching in the byte array
* @param b The array of bytes to search for
*
* @return The position of the first instance of the byte or -1 if the byte is not found.
*/
public static int findBytes(byte bytes[], int start, int end, byte b[]) {
int offset = start;
while (offset < end) {
for (byte value : b) {
if (bytes[offset] == value) {
return offset;
}
}
offset++;
}
return -1;
}
/**
* Convert specified String to a byte array. This ONLY WORKS for ascii, UTF chars will be truncated.
*
* @param value to convert to byte array
*
* @return the byte array value
*/
public static byte[] convertToBytes(String value) {
byte[] result = new byte[value.length()];
for (int i = 0; i < value.length(); i++) {
result[i] = (byte) value.charAt(i);
}
return result;
}
public static class BufferOverflowException extends IOException {
private static final long serialVersionUID = 1L;
public BufferOverflowException(String message) {
super(message);
}
}
}