org.apache.drill.exec.util.Text 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 org.apache.drill.exec.util;
import java.io.DataInput;
import java.io.IOException;
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.CharsetEncoder;
import java.nio.charset.CodingErrorAction;
import java.nio.charset.MalformedInputException;
import java.text.CharacterIterator;
import java.text.StringCharacterIterator;
import java.util.Arrays;
import com.fasterxml.jackson.core.JsonGenerationException;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.databind.SerializerProvider;
import com.fasterxml.jackson.databind.annotation.JsonSerialize;
import com.fasterxml.jackson.databind.ser.std.StdSerializer;
/**
* A simplified byte wrapper similar to Hadoop's Text class without all the dependencies. Lifted from Hadoop 2.7.1
*/
@JsonSerialize(using = Text.TextSerializer.class)
public class Text {
private static ThreadLocal ENCODER_FACTORY =
new ThreadLocal() {
@Override
protected CharsetEncoder initialValue() {
return Charset.forName("UTF-8").newEncoder().
onMalformedInput(CodingErrorAction.REPORT).
onUnmappableCharacter(CodingErrorAction.REPORT);
}
};
private static ThreadLocal DECODER_FACTORY =
new ThreadLocal() {
@Override
protected CharsetDecoder initialValue() {
return Charset.forName("UTF-8").newDecoder().
onMalformedInput(CodingErrorAction.REPORT).
onUnmappableCharacter(CodingErrorAction.REPORT);
}
};
private static final byte[] EMPTY_BYTES = new byte[0];
private byte[] bytes;
private int length;
public Text() {
bytes = EMPTY_BYTES;
}
/**
* Construct from a string.
*/
public Text(String string) {
set(string);
}
/** Construct from another text. */
public Text(Text utf8) {
set(utf8);
}
/**
* Construct from a byte array.
*/
public Text(byte[] utf8) {
set(utf8);
}
/**
* Get a copy of the bytes that is exactly the length of the data. See {@link #getBytes()} for faster access to the
* underlying array.
*/
public byte[] copyBytes() {
byte[] result = new byte[length];
System.arraycopy(bytes, 0, result, 0, length);
return result;
}
/**
* Returns the raw bytes; however, only data up to {@link #getLength()} is valid. Please use {@link #copyBytes()} if
* you need the returned array to be precisely the length of the data.
*/
public byte[] getBytes() {
return bytes;
}
/** Returns the number of bytes in the byte array */
public int getLength() {
return length;
}
/**
* Returns the Unicode Scalar Value (32-bit integer value) for the character at position. Note that this
* method avoids using the converter or doing String instantiation
*
* @return the Unicode scalar value at position or -1 if the position is invalid or points to a trailing byte
*/
public int charAt(int position) {
if (position > this.length)
{
return -1; // too long
}
if (position < 0)
{
return -1; // duh.
}
ByteBuffer bb = (ByteBuffer) ByteBuffer.wrap(bytes).position(position);
return bytesToCodePoint(bb.slice());
}
public int find(String what) {
return find(what, 0);
}
/**
* Finds any occurence of what in the backing buffer, starting as position start. The
* starting position is measured in bytes and the return value is in terms of byte position in the buffer. The backing
* buffer is not converted to a string for this operation.
*
* @return byte position of the first occurence of the search string in the UTF-8 buffer or -1 if not found
*/
public int find(String what, int start) {
try {
ByteBuffer src = ByteBuffer.wrap(this.bytes, 0, this.length);
ByteBuffer tgt = encode(what);
byte b = tgt.get();
src.position(start);
while (src.hasRemaining()) {
if (b == src.get()) { // matching first byte
src.mark(); // save position in loop
tgt.mark(); // save position in target
boolean found = true;
int pos = src.position() - 1;
while (tgt.hasRemaining()) {
if (!src.hasRemaining()) { // src expired first
tgt.reset();
src.reset();
found = false;
break;
}
if (!(tgt.get() == src.get())) {
tgt.reset();
src.reset();
found = false;
break; // no match
}
}
if (found) {
return pos;
}
}
}
return -1; // not found
} catch (CharacterCodingException e) {
// can't get here
e.printStackTrace();
return -1;
}
}
/**
* Set to contain the contents of a string.
*/
public void set(String string) {
try {
ByteBuffer bb = encode(string, true);
bytes = bb.array();
length = bb.limit();
} catch (CharacterCodingException e) {
throw new RuntimeException("Should not have happened ", e);
}
}
/**
* Set to a utf8 byte array
*/
public void set(byte[] utf8) {
set(utf8, 0, utf8.length);
}
/** copy a text. */
public void set(Text other) {
set(other.getBytes(), 0, other.getLength());
}
/**
* Set the Text to range of bytes
*
* @param utf8
* the data to copy from
* @param start
* the first position of the new string
* @param len
* the number of bytes of the new string
*/
public void set(byte[] utf8, int start, int len) {
setCapacity(len, false);
System.arraycopy(utf8, start, bytes, 0, len);
this.length = len;
}
/**
* Append a range of bytes to the end of the given text
*
* @param utf8
* the data to copy from
* @param start
* the first position to append from utf8
* @param len
* the number of bytes to append
*/
public void append(byte[] utf8, int start, int len) {
setCapacity(length + len, true);
System.arraycopy(utf8, start, bytes, length, len);
length += len;
}
/**
* Clear the string to empty.
*
* Note: For performance reasons, this call does not clear the underlying byte array that is retrievable via
* {@link #getBytes()}. In order to free the byte-array memory, call {@link #set(byte[])} with an empty byte array
* (For example, new byte[0]).
*/
public void clear() {
length = 0;
}
/*
* Sets the capacity of this Text object to at least len bytes. If the current buffer is longer,
* then the capacity and existing content of the buffer are unchanged. If len is larger than the current
* capacity, the Text object's capacity is increased to match.
*
* @param len the number of bytes we need
*
* @param keepData should the old data be kept
*/
private void setCapacity(int len, boolean keepData) {
if (bytes == null || bytes.length < len) {
if (bytes != null && keepData) {
bytes = Arrays.copyOf(bytes, Math.max(len, length << 1));
} else {
bytes = new byte[len];
}
}
}
/**
* Convert text back to string
*
* @see java.lang.Object#toString()
*/
@Override
public String toString() {
try {
return decode(bytes, 0, length);
} catch (CharacterCodingException e) {
throw new RuntimeException("Should not have happened ", e);
}
}
/**
* Read a Text object whose length is already known. This allows creating Text from a stream which uses a different
* serialization format.
*/
public void readWithKnownLength(DataInput in, int len) throws IOException {
setCapacity(len, false);
in.readFully(bytes, 0, len);
length = len;
}
/** Returns true iff o is a Text with the same contents. */
@Override
public boolean equals(Object o) {
if (!(o instanceof Text)) {
return false;
}
final Text that = (Text) o;
if (this.getLength() != that.getLength()) {
return false;
}
byte[] thisBytes = Arrays.copyOf(this.getBytes(), getLength());
byte[] thatBytes = Arrays.copyOf(that.getBytes(), getLength());
return Arrays.equals(thisBytes, thatBytes);
}
@Override
public int hashCode() {
return super.hashCode();
}
// / STATIC UTILITIES FROM HERE DOWN
/**
* Converts the provided byte array to a String using the UTF-8 encoding. If the input is malformed, replace by a
* default value.
*/
public static String decode(byte[] utf8) throws CharacterCodingException {
return decode(ByteBuffer.wrap(utf8), true);
}
public static String decode(byte[] utf8, int start, int length)
throws CharacterCodingException {
return decode(ByteBuffer.wrap(utf8, start, length), true);
}
/**
* Converts the provided byte array to a String using the UTF-8 encoding. If replace is true, then
* malformed input is replaced with the substitution character, which is U+FFFD. Otherwise the method throws a
* MalformedInputException.
*/
public static String decode(byte[] utf8, int start, int length, boolean replace)
throws CharacterCodingException {
return decode(ByteBuffer.wrap(utf8, start, length), replace);
}
private static String decode(ByteBuffer utf8, boolean replace)
throws CharacterCodingException {
CharsetDecoder decoder = DECODER_FACTORY.get();
if (replace) {
decoder.onMalformedInput(
java.nio.charset.CodingErrorAction.REPLACE);
decoder.onUnmappableCharacter(CodingErrorAction.REPLACE);
}
String str = decoder.decode(utf8).toString();
// set decoder back to its default value: REPORT
if (replace) {
decoder.onMalformedInput(CodingErrorAction.REPORT);
decoder.onUnmappableCharacter(CodingErrorAction.REPORT);
}
return str;
}
/**
* Converts the provided String to bytes using the UTF-8 encoding. If the input is malformed, invalid chars are
* replaced by a default value.
*
* @return ByteBuffer: bytes stores at ByteBuffer.array() and length is ByteBuffer.limit()
*/
public static ByteBuffer encode(String string)
throws CharacterCodingException {
return encode(string, true);
}
/**
* Converts the provided String to bytes using the UTF-8 encoding. If replace is true, then malformed
* input is replaced with the substitution character, which is U+FFFD. Otherwise the method throws a
* MalformedInputException.
*
* @return ByteBuffer: bytes stores at ByteBuffer.array() and length is ByteBuffer.limit()
*/
public static ByteBuffer encode(String string, boolean replace)
throws CharacterCodingException {
CharsetEncoder encoder = ENCODER_FACTORY.get();
if (replace) {
encoder.onMalformedInput(CodingErrorAction.REPLACE);
encoder.onUnmappableCharacter(CodingErrorAction.REPLACE);
}
ByteBuffer bytes =
encoder.encode(CharBuffer.wrap(string.toCharArray()));
if (replace) {
encoder.onMalformedInput(CodingErrorAction.REPORT);
encoder.onUnmappableCharacter(CodingErrorAction.REPORT);
}
return bytes;
}
static final public int DEFAULT_MAX_LEN = 1024 * 1024;
// //// states for validateUTF8
private static final int LEAD_BYTE = 0;
private static final int TRAIL_BYTE_1 = 1;
private static final int TRAIL_BYTE = 2;
/**
* Check if a byte array contains valid utf-8
*
* @param utf8
* byte array
* @throws MalformedInputException
* if the byte array contains invalid utf-8
*/
public static void validateUTF8(byte[] utf8) throws MalformedInputException {
validateUTF8(utf8, 0, utf8.length);
}
/**
* Check to see if a byte array is valid utf-8
*
* @param utf8
* the array of bytes
* @param start
* the offset of the first byte in the array
* @param len
* the length of the byte sequence
* @throws MalformedInputException
* if the byte array contains invalid bytes
*/
public static void validateUTF8(byte[] utf8, int start, int len)
throws MalformedInputException {
int count = start;
int leadByte = 0;
int length = 0;
int state = LEAD_BYTE;
while (count < start + len) {
int aByte = utf8[count] & 0xFF;
switch (state) {
case LEAD_BYTE:
leadByte = aByte;
length = bytesFromUTF8[aByte];
switch (length) {
case 0: // check for ASCII
if (leadByte > 0x7F) {
throw new MalformedInputException(count);
}
break;
case 1:
if (leadByte < 0xC2 || leadByte > 0xDF) {
throw new MalformedInputException(count);
}
state = TRAIL_BYTE_1;
break;
case 2:
if (leadByte < 0xE0 || leadByte > 0xEF) {
throw new MalformedInputException(count);
}
state = TRAIL_BYTE_1;
break;
case 3:
if (leadByte < 0xF0 || leadByte > 0xF4) {
throw new MalformedInputException(count);
}
state = TRAIL_BYTE_1;
break;
default:
// too long! Longest valid UTF-8 is 4 bytes (lead + three)
// or if < 0 we got a trail byte in the lead byte position
throw new MalformedInputException(count);
} // switch (length)
break;
case TRAIL_BYTE_1:
if (leadByte == 0xF0 && aByte < 0x90) {
throw new MalformedInputException(count);
}
if (leadByte == 0xF4 && aByte > 0x8F) {
throw new MalformedInputException(count);
}
if (leadByte == 0xE0 && aByte < 0xA0) {
throw new MalformedInputException(count);
}
if (leadByte == 0xED && aByte > 0x9F) {
throw new MalformedInputException(count);
}
// falls through to regular trail-byte test!!
case TRAIL_BYTE:
if (aByte < 0x80 || aByte > 0xBF) {
throw new MalformedInputException(count);
}
if (--length == 0) {
state = LEAD_BYTE;
} else {
state = TRAIL_BYTE;
}
break;
default:
break;
} // switch (state)
count++;
}
}
/**
* Magic numbers for UTF-8. These are the number of bytes that follow a given lead byte. Trailing bytes have
* the value -1. The values 4 and 5 are presented in this table, even though valid UTF-8 cannot include the five and
* six byte sequences.
*/
static final int[] bytesFromUTF8 =
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0,
// trail bytes
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3,
3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5 };
/**
* Returns the next code point at the current position in the buffer. The buffer's position will be incremented. Any
* mark set on this buffer will be changed by this method!
*/
public static int bytesToCodePoint(ByteBuffer bytes) {
bytes.mark();
byte b = bytes.get();
bytes.reset();
int extraBytesToRead = bytesFromUTF8[(b & 0xFF)];
if (extraBytesToRead < 0)
{
return -1; // trailing byte!
}
int ch = 0;
switch (extraBytesToRead) {
case 5:
ch += (bytes.get() & 0xFF);
ch <<= 6; /* remember, illegal UTF-8 */
case 4:
ch += (bytes.get() & 0xFF);
ch <<= 6; /* remember, illegal UTF-8 */
case 3:
ch += (bytes.get() & 0xFF);
ch <<= 6;
case 2:
ch += (bytes.get() & 0xFF);
ch <<= 6;
case 1:
ch += (bytes.get() & 0xFF);
ch <<= 6;
case 0:
ch += (bytes.get() & 0xFF);
}
ch -= offsetsFromUTF8[extraBytesToRead];
return ch;
}
static final int offsetsFromUTF8[] =
{ 0x00000000, 0x00003080,
0x000E2080, 0x03C82080, 0xFA082080, 0x82082080 };
/**
* For the given string, returns the number of UTF-8 bytes required to encode the string.
*
* @param string
* text to encode
* @return number of UTF-8 bytes required to encode
*/
public static int utf8Length(String string) {
CharacterIterator iter = new StringCharacterIterator(string);
char ch = iter.first();
int size = 0;
while (ch != CharacterIterator.DONE) {
if ((ch >= 0xD800) && (ch < 0xDC00)) {
// surrogate pair?
char trail = iter.next();
if ((trail > 0xDBFF) && (trail < 0xE000)) {
// valid pair
size += 4;
} else {
// invalid pair
size += 3;
iter.previous(); // rewind one
}
} else if (ch < 0x80) {
size++;
} else if (ch < 0x800) {
size += 2;
} else {
// ch < 0x10000, that is, the largest char value
size += 3;
}
ch = iter.next();
}
return size;
}
public static class TextSerializer extends StdSerializer {
public TextSerializer() {
super(Text.class);
}
@Override
public void serialize(Text text, JsonGenerator jsonGenerator, SerializerProvider serializerProvider)
throws IOException, JsonGenerationException {
jsonGenerator.writeString(text.toString());
}
}
}
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