chaschev.io.ByteBufferUtils Maven / Gradle / Ivy
/*
* 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 chaschev.io;
import chaschev.util.Exceptions;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.io.InputStream;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.CharacterCodingException;
import java.nio.charset.Charset;
import java.nio.charset.CharsetDecoder;
import java.nio.charset.CoderResult;
import java.util.Arrays;
import static com.google.common.base.Charsets.UTF_8;
/**
* Utility methods to make ByteBuffers less painful
* The following should illustrate the different ways byte buffers can be used
*
* public void testArrayOffet()
* {
*
* byte[] b = "test_slice_array".getBytes();
* ByteBuffer bb = ByteBuffer.allocate(1024);
*
* assert bb.position() == 0;
* assert bb.limit() == 1024;
* assert bb.capacity() == 1024;
*
* bb.put(b);
*
* assert bb.position() == b.length;
* assert bb.remaining() == bb.limit() - bb.position();
*
* ByteBuffer bb2 = bb.slice();
*
* assert bb2.position() == 0;
*
* //slice should begin at other buffers current position
* assert bb2.arrayOffset() == bb.position();
*
* //to match the position in the underlying array one needs to
* //track arrayOffset
* assert bb2.limit()+bb2.arrayOffset() == bb.limit();
*
*
* assert bb2.remaining() == bb.remaining();
*
* }
*
* }
*/
public class ByteBufferUtils {
public static final byte[] EMPTY_BYTE_ARRAY = new byte[0];
public static final ByteBuffer EMPTY_BYTE_BUFFER = ByteBuffer.wrap(EMPTY_BYTE_ARRAY);
public static int compareUnsigned(ByteBuffer o1, ByteBuffer o2) {
assert o1 != null;
assert o2 != null;
int minLength = Math.min(o1.remaining(), o2.remaining());
for (int x = 0, i = o1.position(), j = o2.position(); x < minLength; x++, i++, j++) {
if (o1.get(i) == o2.get(j))
continue;
// compare non-equal bytes as unsigned
return (o1.get(i) & 0xFF) < (o2.get(j) & 0xFF) ? -1 : 1;
}
return (o1.remaining() == o2.remaining()) ? 0 : ((o1.remaining() < o2.remaining()) ? -1 : 1);
}
public static int compare(byte[] o1, ByteBuffer o2) {
return compareUnsigned(ByteBuffer.wrap(o1), o2);
}
public static int compare(ByteBuffer o1, byte[] o2) {
return compareUnsigned(o1, ByteBuffer.wrap(o2));
}
/**
* Decode a String representation.
* This method assumes that the encoding charset is UTF_8.
*
* @param buffer a byte buffer holding the string representation
* @return the decoded string
*/
public static String string(ByteBuffer buffer) throws CharacterCodingException {
return string(buffer, UTF_8);
}
/**
* Decode a String representation.
* This method assumes that the encoding charset is UTF_8.
*
* @param buffer a byte buffer holding the string representation
* @param position the starting position in {@code buffer} to start decoding from
* @param length the number of bytes from {@code buffer} to use
* @return the decoded string
*/
public static String string(ByteBuffer buffer, int position, int length) throws CharacterCodingException {
return string(buffer, position, length, UTF_8);
}
/**
* Decode a String representation.
*
* @param buffer a byte buffer holding the string representation
* @param position the starting position in {@code buffer} to start decoding from
* @param length the number of bytes from {@code buffer} to use
* @param charset the String encoding charset
* @return the decoded string
*/
public static String string(ByteBuffer buffer, int position, int length, Charset charset) throws CharacterCodingException {
ByteBuffer copy = buffer.duplicate();
copy.position(position);
copy.limit(copy.position() + length);
return string(copy, charset);
}
public static void putString(ByteBuffer buffer, String s, Charset charset) {
final byte[] bytes = s.getBytes(charset);
putBytes(buffer, bytes);
}
public static void putBytes(ByteBuffer buffer, byte[] bytes) {
buffer.putInt(bytes.length);
buffer.put(bytes);
}
public static byte[] getBytes(ByteBuffer buffer) {
byte[] bytes = new byte[buffer.getInt()];
buffer.get(bytes);
return bytes;
}
public static String getString(ByteBuffer buffer, Charset charset) {
return new String(getBytes(buffer), charset);
}
/**
* Decode a String representation.
*
* @param buffer a byte buffer holding the string representation
* @param charset the String encoding charset
* @return the decoded string
*/
public static String string(ByteBuffer buffer, Charset charset) throws CharacterCodingException {
try {
return charset.newDecoder().decode(buffer.duplicate()).toString();
} catch (CharacterCodingException e) {
throw Exceptions.runtime(e);
}
}
public static String stringUntilError(ByteBuffer buffer, Charset charset) throws CharacterCodingException {
return decodeSkippingErrors(charset.newDecoder(), buffer.duplicate(), 1, false).toString();
}
public static String string(ByteBuffer buffer, int maxErrorCount) throws CharacterCodingException {
return string(buffer, UTF_8, maxErrorCount, false);
}
public static String string(ByteBuffer buffer, Charset charset, int maxErrorCount, boolean throwException) throws CharacterCodingException {
return decodeSkippingErrors(charset.newDecoder(), buffer.duplicate(), maxErrorCount, throwException).toString();
}
/**
* You should almost never use this. Instead, use the write* methods to avoid copies.
*/
public static byte[] getArray(ByteBuffer buffer) {
int length = buffer.remaining();
if (buffer.hasArray()) {
int boff = buffer.arrayOffset() + buffer.position();
if (boff == 0 && length == buffer.array().length)
return buffer.array();
else
return Arrays.copyOfRange(buffer.array(), boff, boff + length);
}
// else, DirectByteBuffer.get() is the fastest route
byte[] bytes = new byte[length];
buffer.duplicate().get(bytes);
return bytes;
}
/**
* ByteBuffer adaptation of org.apache.commons.lang.ArrayUtils.lastIndexOf method
*
* @param buffer the array to traverse for looking for the object, may be null
* @param valueToFind the value to find
* @param startIndex the start index (i.e. BB position) to travers backwards from
* @return the last index (i.e. BB position) of the value within the array
* [between buffer.position() and buffer.limit()]; -1 if not found.
*/
public static int lastIndexOf(ByteBuffer buffer, byte valueToFind, int startIndex) {
assert buffer != null;
if (startIndex < buffer.position()) {
return -1;
} else if (startIndex >= buffer.limit()) {
startIndex = buffer.limit() - 1;
}
for (int i = startIndex; i >= buffer.position(); i--) {
if (valueToFind == buffer.get(i))
return i;
}
return -1;
}
/**
* Encode a String in a ByteBuffer using UTF_8.
*
* @param s the string to encode
* @return the encoded string
*/
public static ByteBuffer bytes(String s) {
return ByteBuffer.wrap(s.getBytes(UTF_8));
}
/**
* Encode a String in a ByteBuffer using the provided charset.
*
* @param s the string to encode
* @param charset the String encoding charset to use
* @return the encoded string
*/
public static ByteBuffer bytes(String s, Charset charset) {
return ByteBuffer.wrap(s.getBytes(charset));
}
/**
* @return a new copy of the data in @param buffer
* USUALLY YOU SHOULD USE ByteBuffer.duplicate() INSTEAD, which creates a new Buffer
* (so you can mutate its position without affecting the original) without copying the underlying array.
*/
public static ByteBuffer clone(ByteBuffer buffer) {
assert buffer != null;
if (buffer.remaining() == 0)
return EMPTY_BYTE_BUFFER;
ByteBuffer clone = ByteBuffer.allocate(buffer.remaining());
if (buffer.hasArray()) {
System.arraycopy(buffer.array(), buffer.arrayOffset() + buffer.position(), clone.array(), 0, buffer.remaining());
} else {
clone.put(buffer.duplicate());
clone.flip();
}
return clone;
}
public static void arrayCopy(ByteBuffer buffer, int position, byte[] bytes, int offset, int length) {
if (buffer.hasArray())
System.arraycopy(buffer.array(), buffer.arrayOffset() + position, bytes, offset, length);
else
((ByteBuffer) buffer.duplicate().position(position)).get(bytes, offset, length);
}
/**
* Transfer bytes from one ByteBuffer to another.
* This function acts as System.arrayCopy() but for ByteBuffers.
*
* @param src the source ByteBuffer
* @param srcPos starting position in the source ByteBuffer
* @param dst the destination ByteBuffer
* @param dstPos starting position in the destination ByteBuffer
* @param length the number of bytes to copy
*/
public static void arrayCopy(ByteBuffer src, int srcPos, ByteBuffer dst, int dstPos, int length) {
if (src.hasArray() && dst.hasArray()) {
System.arraycopy(src.array(),
src.arrayOffset() + srcPos,
dst.array(),
dst.arrayOffset() + dstPos,
length);
} else {
if (src.limit() - srcPos < length || dst.limit() - dstPos < length)
throw new IndexOutOfBoundsException();
for (int i = 0; i < length; i++)
// TODO: ByteBuffer.put is polymorphic, and might be slow here
dst.put(dstPos++, src.get(srcPos++));
}
}
public static void writeWithLength(ByteBuffer bytes, DataOutput out) throws IOException {
out.writeInt(bytes.remaining());
write(bytes, out); // writing data bytes to output source
}
public static void write(ByteBuffer buffer, DataOutput out) throws IOException {
if (buffer.hasArray()) {
out.write(buffer.array(), buffer.arrayOffset() + buffer.position(), buffer.remaining());
} else {
for (int i = buffer.position(); i < buffer.limit(); i++) {
out.writeByte(buffer.get(i));
}
}
}
public static void writeWithShortLength(ByteBuffer buffer, DataOutput out) {
int length = buffer.remaining();
assert 0 <= length && length <= FBUtilities.MAX_UNSIGNED_SHORT : length;
try {
out.writeByte((length >> 8) & 0xFF);
out.writeByte(length & 0xFF);
write(buffer, out); // writing data bytes to output source
} catch (IOException e) {
throw new RuntimeException(e);
}
}
public static ByteBuffer readWithLength(DataInput in) throws IOException {
int length = in.readInt();
if (length < 0) {
throw new IOException("Corrupt (negative) value length encountered");
}
return ByteBufferUtils.read(in, length);
}
/* @return An unsigned short in an integer. */
private static int readShortLength(DataInput in) throws IOException {
int length = (in.readByte() & 0xFF) << 8;
return length | (in.readByte() & 0xFF);
}
/**
* @param in data input
* @return An unsigned short in an integer.
* @throws java.io.IOException if an I/O error occurs.
*/
public static ByteBuffer readWithShortLength(DataInput in) throws IOException {
return ByteBufferUtils.read(in, readShortLength(in));
}
private static ByteBuffer read(DataInput in, int length) throws IOException {
byte[] buff = new byte[length];
in.readFully(buff);
return ByteBuffer.wrap(buff);
}
/**
* Convert a byte buffer to an integer.
* Does not change the byte buffer position.
*
* @param bytes byte buffer to convert to integer
* @return int representation of the byte buffer
*/
public static int toInt(ByteBuffer bytes) {
return bytes.getInt(bytes.position());
}
public static long toLong(ByteBuffer bytes) {
return bytes.getLong(bytes.position());
}
public static float toFloat(ByteBuffer bytes) {
return bytes.getFloat(bytes.position());
}
public static double toDouble(ByteBuffer bytes) {
return bytes.getDouble(bytes.position());
}
public static ByteBuffer bytes(int i) {
return ByteBuffer.allocate(4).putInt(0, i);
}
public static ByteBuffer bytes(long n) {
return ByteBuffer.allocate(8).putLong(0, n);
}
public static ByteBuffer bytes(float f) {
return ByteBuffer.allocate(4).putFloat(0, f);
}
public static ByteBuffer bytes(double d) {
return ByteBuffer.allocate(8).putDouble(0, d);
}
public static InputStream inputStream(ByteBuffer bytes) {
final ByteBuffer copy = bytes.duplicate();
return new InputStream() {
public int read() throws IOException {
if (!copy.hasRemaining())
return -1;
return copy.get() & 0xFF;
}
@Override
public int read(byte[] bytes, int off, int len) throws IOException {
if (!copy.hasRemaining())
return -1;
len = Math.min(len, copy.remaining());
copy.get(bytes, off, len);
return len;
}
@Override
public int available() throws IOException {
return copy.remaining();
}
};
}
public static String bytesToHex(ByteBuffer bytes) {
final int offset = bytes.position();
final int size = bytes.remaining();
final char[] c = new char[size * 2];
for (int i = 0; i < size; i++) {
final int bint = bytes.get(i + offset);
c[i * 2] = FBUtilities.byteToChar[(bint & 0xf0) >> 4];
c[1 + i * 2] = FBUtilities.byteToChar[bint & 0x0f];
}
return FBUtilities.wrapCharArray(c);
}
public static ByteBuffer hexToBytes(String str) {
return ByteBuffer.wrap(FBUtilities.hexToBytes(str));
}
/**
* Compare two ByteBuffer at specified offsets for length.
* Compares the non equal bytes as unsigned.
*
* @param bytes1 First byte buffer to compare.
* @param offset1 Position to start the comparison at in the first array.
* @param bytes2 Second byte buffer to compare.
* @param offset2 Position to start the comparison at in the second array.
* @param length How many bytes to compare?
* @return -1 if byte1 is less than byte2, 1 if byte2 is less than byte1 or 0 if equal.
*/
public static int compareSubArrays(ByteBuffer bytes1, int offset1, ByteBuffer bytes2, int offset2, int length) {
if (null == bytes1) {
if (null == bytes2) return 0;
else return -1;
}
if (null == bytes2) return 1;
assert bytes1.limit() >= offset1 + length : "The first byte array isn't long enough for the specified offset and length.";
assert bytes2.limit() >= offset2 + length : "The second byte array isn't long enough for the specified offset and length.";
for (int i = 0; i < length; i++) {
byte byte1 = bytes1.get(offset1 + i);
byte byte2 = bytes2.get(offset2 + i);
if (byte1 == byte2)
continue;
// compare non-equal bytes as unsigned
return (byte1 & 0xFF) < (byte2 & 0xFF) ? -1 : 1;
}
return 0;
}
public String convertToString(ByteBuffer buffer, Charset charset) throws CharacterCodingException {
return charset.newDecoder().decode(buffer).toString();
}
public static CharBuffer decodeSkippingErrors(
CharsetDecoder decoder, ByteBuffer in, int maxErrorCount, boolean throwException)
throws CharacterCodingException {
int n = (int) (in.remaining() * decoder.averageCharsPerByte());
CharBuffer out = CharBuffer.allocate(n);
if ((n == 0) && (in.remaining() == 0))
return out;
decoder.reset();
int errorCount = 0;
for (; ; ) {
CoderResult cr = in.hasRemaining() ?
decoder.decode(in, out, true) : CoderResult.UNDERFLOW;
if (cr.isUnderflow())
cr = decoder.flush(out);
if (cr.isUnderflow())
break;
if (cr.isOverflow()) {
n = 2 * n + 1; // Ensure progress; n might be 0!
CharBuffer o = CharBuffer.allocate(n);
out.flip();
o.put(out);
out = o;
continue;
}
errorCount++;
if (errorCount == maxErrorCount) {
if(throwException){
throw new CharacterCodingException();
}
break;
}
//skip an error
in.get();
// break;
}
out.flip();
return out;
}
}
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