/*
* 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.Serializable;
import java.io.UnsupportedEncodingException;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.Charset;
/*
* 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 )
*
* 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.
*/
// TODO: This class could either extend ByteBuffer, or better a ByteBuffer inside
// this way it could provide the search/etc on ByteBuffer, as a helper.
/**
* This class is used to represent a chunk of bytes, and
* utilities to manipulate byte[].
*
* The buffer can be modified and used for both input and output.
*
* 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.
*
* Various search and append method are defined - similar with String and StringBuffer, but
* operating on bytes.
*
* 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.
*
*
* @author dac@sun.com
* @author James Todd [gonzo@sun.com]
* @author Costin Manolache
* @author Remy Maucherat
*/
public final class ByteChunk implements Cloneable, Serializable {
/** Input interface, used when the buffer is emptiy
*
* Same as java.nio.channel.ReadableByteChannel
*/
public static interface ByteInputChannel {
/**
* Read new bytes ( usually the internal conversion buffer ).
* The implementation is allowed to ignore the parameters,
* and mutate the chunk if it wishes to implement its own buffering.
*/
public int realReadBytes(byte cbuf[], int off, int len)
throws IOException;
}
/** Same as java.nio.channel.WrittableByteChannel.
*/
public static interface ByteOutputChannel {
/**
* Send the bytes ( usually the internal conversion buffer ).
* Expect 8k output if the buffer is full.
*/
public void realWriteBytes(byte cbuf[], int off, int len)
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;
static {
Charset c = null;
try {
c = B2CConverter.getCharset("ISO-8859-1");
} catch (UnsupportedEncodingException e) {
// Should never happen since all JVMs must support ISO-8859-1
}
DEFAULT_CHARSET = c;
}
// byte[]
private byte[] buff;
private int start=0;
private int end;
private Charset charset;
private boolean isSet=false; // XXX
// How much can it grow, when data is added
private int limit=-1;
private ByteInputChannel in = null;
private ByteOutputChannel out = null;
private boolean optimizedWrite=true;
/**
* Creates a new, uninitialized ByteChunk object.
*/
public ByteChunk() {
}
public ByteChunk( int initial ) {
allocate( initial, -1 );
}
//--------------------
public ByteChunk getClone() {
try {
return (ByteChunk)this.clone();
} catch( Exception ex) {
return null;
}
}
public boolean isNull() {
return ! isSet; // buff==null;
}
/**
* Resets the message buff to an uninitialized state.
*/
public void recycle() {
// buff = null;
charset=null;
start=0;
end=0;
isSet=false;
}
public void reset() {
buff=null;
}
// -------------------- Setup --------------------
public void allocate( int initial, int limit ) {
if( buff==null || buff.length < initial ) {
buff=new byte[initial];
}
this.limit=limit;
start=0;
end=0;
isSet=true;
}
/**
* Sets the message bytes 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;
}
public void setOptimizedWrite(boolean optimizedWrite) {
this.optimizedWrite = optimizedWrite;
}
public void setCharset(Charset charset) {
this.charset = charset;
}
public Charset getCharset() {
if (charset == null) {
charset = DEFAULT_CHARSET;
}
return charset;
}
/**
* Returns the message bytes.
*/
public byte[] getBytes() {
return getBuffer();
}
/**
* Returns the message bytes.
*/
public byte[] getBuffer() {
return buff;
}
/**
* Returns the start offset of the bytes.
* For output this is the end of the buffer.
*/
public int getStart() {
return start;
}
public int getOffset() {
return start;
}
public void setOffset(int off) {
if (end < off ) end=off;
start=off;
}
/**
* Returns the length of the bytes.
* XXX need to clean this up
*/
public int getLength() {
return end-start;
}
/** Maximum amount of data in this buffer.
*
* If -1 or not set, the buffer will grow undefinitely.
* Can be smaller than the current buffer size ( which will not shrink ).
* When the limit is reached, the buffer will be flushed ( if out is set )
* or throw exception.
*/
public void setLimit(int limit) {
this.limit=limit;
}
public int getLimit() {
return limit;
}
/**
* When the buffer is empty, read the data from 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.
*/
public void setByteOutputChannel(ByteOutputChannel out) {
this.out=out;
}
public int getEnd() {
return end;
}
public void setEnd( int i ) {
end=i;
}
// -------------------- Adding data to the buffer --------------------
/** Append a char, by casting it to byte. This IS NOT intended for unicode.
*
* @param c
* @throws IOException
*/
public void append( char c )
throws IOException
{
append( (byte)c);
}
public void append( byte b )
throws IOException
{
makeSpace( 1 );
// couldn't make space
if( limit >0 && 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
*/
public void append( byte src[], int off, int len )
throws IOException
{
// will grow, up to limit
makeSpace( len );
// if we don't have limit: makeSpace can grow as it wants
if( limit < 0 ) {
// assert: makeSpace made enough space
System.arraycopy( src, off, buff, end, len );
end+=len;
return;
}
// 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 ( optimizedWrite && len == limit && end == start && out != null ) {
out.realWriteBytes( src, off, len );
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
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;
}
// -------------------- Removing data from the buffer --------------------
public int substract()
throws IOException {
if ((end - start) == 0) {
if (in == null)
return -1;
int n = in.realReadBytes( buff, 0, buff.length );
if (n < 0)
return -1;
}
return (buff[start++] & 0xFF);
}
public int substract(ByteChunk src)
throws IOException {
if ((end - start) == 0) {
if (in == null)
return -1;
int n = in.realReadBytes( buff, 0, buff.length );
if (n < 0)
return -1;
}
int len = getLength();
src.append(buff, start, len);
start = end;
return len;
}
public int substract( byte src[], int off, int len )
throws IOException {
if ((end - start) == 0) {
if (in == null)
return -1;
int n = in.realReadBytes( buff, 0, buff.length );
if (n < 0)
return -1;
}
int n = len;
if (len > getLength()) {
n = getLength();
}
System.arraycopy(buff, start, src, off, n);
start += n;
return n;
}
/** Send the buffer to the sink. Called by append() when the limit is reached.
* You can also call it explicitely to force the data to be written.
*
* @throws IOException
*/
public void flushBuffer()
throws IOException
{
//assert out!=null
if( out==null ) {
throw new IOException( "Buffer overflow, no sink " + limit + " " +
buff.length );
}
out.realWriteBytes( buff, start, end-start );
end=start;
}
/** Make space for len chars. If len is small, allocate
* a reserve space too. Never grow bigger than limit.
*/
private void makeSpace(int count)
{
byte[] tmp = null;
int newSize;
int desiredSize=end + count;
// Can't grow above the limit
if( limit > 0 &&
desiredSize > limit) {
desiredSize=limit;
}
if( buff==null ) {
if( desiredSize < 256 ) desiredSize=256; // take a minimum
buff=new byte[desiredSize];
}
// limit < buf.length ( the buffer is already big )
// or we already have space XXX
if( desiredSize <= buff.length ) {
return;
}
// grow in larger chunks
if( desiredSize < 2 * buff.length ) {
newSize= buff.length * 2;
if( limit >0 &&
newSize > limit ) newSize=limit;
tmp=new byte[newSize];
} else {
newSize= buff.length * 2 + count ;
if( limit > 0 &&
newSize > limit ) newSize=limit;
tmp=new byte[newSize];
}
System.arraycopy(buff, start, tmp, 0, end-start);
buff = tmp;
tmp = null;
end=end-start;
start=0;
}
// -------------------- Conversion and getters --------------------
public String toString() {
if (null == buff) {
return null;
} else if (end-start == 0) {
return "";
}
return StringCache.toString(this);
}
public String toStringInternal() {
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;
cb = charset.decode(ByteBuffer.wrap(buff, start, end-start));
return new String(cb.array(), cb.arrayOffset(), cb.length());
}
public int getInt()
{
return Ascii.parseInt(buff, start,end-start);
}
public long getLong() {
return Ascii.parseLong(buff, start,end-start);
}
// -------------------- equals --------------------
/**
* Compares the message bytes to the specified String object.
* @param s the String to compare
* @return true if the comparison succeeded, false otherwise
*/
public boolean equals(String s) {
// XXX ENCODING - this only works if encoding is UTF8-compat
// ( ok for tomcat, where we compare ascii - header names, etc )!!!
byte[] b = buff;
int blen = end-start;
if (b == null || blen != s.length()) {
return false;
}
int boff = start;
for (int i = 0; i < blen; i++) {
if (b[boff++] != s.charAt(i)) {
return false;
}
}
return true;
}
/**
* Compares the message bytes to the specified String object.
* @param s the String to compare
* @return true if the comparison succeeded, false otherwise
*/
public boolean equalsIgnoreCase(String s) {
byte[] b = buff;
int blen = end-start;
if (b == null || blen != s.length()) {
return false;
}
int boff = start;
for (int i = 0; i < blen; i++) {
if (Ascii.toLower(b[boff++]) != 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 ( len2 != len || b1==null || b2==null )
return false;
int off1 = start;
while ( len-- > 0) {
if (b1[off1++] != b2[off2++]) {
return false;
}
}
return true;
}
public boolean equals( CharChunk cc ) {
return equals( cc.getChars(), cc.getStart(), cc.getLength());
}
public boolean equals( char c2[], int off2, int len2) {
// XXX works only for enc compatible with ASCII/UTF !!!
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 message bytes starts with the specified string.
* @param s the string
*/
public boolean startsWith(String s) {
// Works only if enc==UTF
byte[] b = buff;
int blen = s.length();
if (b == null || blen > end-start) {
return false;
}
int boff = start;
for (int i = 0; i < blen; i++) {
if (b[boff++] != s.charAt(i)) {
return false;
}
}
return true;
}
/* Returns true if the message bytes start with the specified byte array */
public boolean startsWith(byte[] b2) {
byte[] b1 = buff;
if (b1 == null && b2 == null) {
return true;
}
int len = end - start;
if (b1 == null || b2 == null || b2.length > len) {
return false;
}
for (int i = start, j = 0; i < end && j < b2.length; ) {
if (b1[i++] != b2[j++])
return false;
}
return true;
}
/**
* Returns true if the message bytes starts with the specified string.
* @param s the string
* @param pos The position
*/
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;
}
public int indexOf( String src, int srcOff, int srcLen, int myOff ) {
char first=src.charAt( srcOff );
// Look for first char
int srcEnd = srcOff + srcLen;
mainLoop:
for( int i=myOff+start; i <= (end - srcLen); i++ ) {
if( buff[i] != first ) continue;
// found first char, now look for a match
int myPos=i+1;
for( int srcPos=srcOff + 1; srcPos< srcEnd; ) {
if( buff[myPos++] != src.charAt( srcPos++ ))
continue mainLoop;
}
return i-start; // found it
}
return -1;
}
// -------------------- Hash code --------------------
// normal hash.
public int hash() {
return hashBytes( buff, start, end-start);
}
// hash ignoring case
public int hashIgnoreCase() {
return hashBytesIC( buff, start, end-start );
}
private static int hashBytes( byte buff[], int start, int bytesLen ) {
int max=start+bytesLen;
byte bb[]=buff;
int code=0;
for (int i = start; i < max ; i++) {
code = code * 37 + bb[i];
}
return code;
}
private static int hashBytesIC( byte bytes[], int start,
int bytesLen )
{
int max=start+bytesLen;
byte bb[]=bytes;
int code=0;
for (int i = start; i < max ; i++) {
code = code * 37 + Ascii.toLower(bb[i]);
}
return code;
}
/**
* Returns true if the message bytes starts with the specified string.
* @param c the character
* @param starting The start position
*/
public int indexOf(char c, int starting) {
int ret = indexOf( buff, start+starting, end, c);
return (ret >= start) ? ret - start : -1;
}
public static int indexOf( byte bytes[], int off, int end, char qq )
{
// Works only for UTF
while( off < end ) {
byte b=bytes[off];
if( b==qq )
return off;
off++;
}
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 blen = b.length;
int offset = start;
while (offset < end) {
for (int i = 0; i < blen; i++)
if (bytes[offset] == b[i]) {
return offset;
}
offset++;
}
return -1;
}
/** Find a character, no side effects.
* @return index of char if found, -1 if not
*/
public static int findChar( byte buf[], int start, int end, char c ) {
byte b=(byte)c;
int offset = start;
while (offset < end) {
if (buf[offset] == b) {
return offset;
}
offset++;
}
return -1;
}
/** Find a character, no side effects.
* @return index of char if found, -1 if not
*/
public static int findChars( byte buf[], int start, int end, byte c[] ) {
int clen=c.length;
int offset = start;
while (offset < end) {
for( int i=0; i<clen; i++ )
if (buf[offset] == c[i]) {
return offset;
}
offset++;
}
return -1;
}
/** Find the first character != c
* @return index of char if found, -1 if not
*/
public static int findNotChars( byte buf[], int start, int end, byte c[] )
{
int clen=c.length;
int offset = start;
boolean found;
while (offset < end) {
found=true;
for( int i=0; i<clen; i++ ) {
if (buf[offset] == c[i]) {
found=false;
break;
}
}
if( found ) { // buf[offset] != c[0..len]
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 final 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;
}
}