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products/Sources/formale Sprachen/Java/Tomcat/java/org/apache/tomcat/util/buf/ (Apache Software Stiftung Version 2.4.65^©) Datei vom 10.10.2023 mit Größe 26 kB

Quelle ByteChunk.java Sprache: 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[].
* 
* 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.
* 
* 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.
*
* @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.
 * 
 * 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.
 * 
 * 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 equals(CharChunk cc) {
 return equals(cc.getChars(), cc.getStart(), cc.getLength());
 }

 /**
 * Compares the message bytes to the specified char array.
 * 
 * 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.
 * 
 * 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.
 * 
 * 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.
 * 
 * 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.
 * 
 * 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);
 }
 }
}

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