/*
* 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.
*/
/**
* This file is based on source code from the Hadoop Project (http://hadoop.apache.org/), licensed by the Apache
* Software Foundation (ASF) under the Apache License, Version 2.0. See the NOTICE file distributed with this work for
* additional information regarding copyright ownership.
*/
package org.apache.flink.core.io;
import java.io.DataInput;
import java.io.DataOutput;
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 org.apache.flink.core.memory.DataInputView;
import org.apache.flink.core.memory.DataOutputView;
import org.apache.flink.types.Value;
/**
* This class stores text using standard UTF8 encoding. It provides methods to
* serialize, deserialize, and compare texts at byte level. The type of length
* is integer and is serialized using zero-compressed format.
* <p>
* In addition, it provides methods for string traversal without converting the byte array to a string.
* <p>
* Also includes utilities for serializing/deserialing a string, coding/decoding a string, checking if a byte array
* contains valid UTF8 code, calculating the length of an encoded string.
*/
public class StringRecord implements Value {
private static final long serialVersionUID = 1L;
private static final ThreadLocal<CharsetEncoder> ENCODER_FACTORY = new ThreadLocal<CharsetEncoder>() {
protected CharsetEncoder initialValue() {
return Charset.forName("UTF-8").newEncoder().onMalformedInput(CodingErrorAction.REPORT)
.onUnmappableCharacter(CodingErrorAction.REPORT);
}
};
private static final ThreadLocal<CharsetDecoder> DECODER_FACTORY = new ThreadLocal<CharsetDecoder>() {
protected CharsetDecoder initialValue() {
return Charset.forName("UTF-8").newDecoder().onMalformedInput(CodingErrorAction.REPORT)
.onUnmappableCharacter(CodingErrorAction.REPORT);
}
};
/**
* Cache the hash code for the encapsulated string.
**/
private int hash = 0;
private static final byte[] EMPTY_BYTES = new byte[0];
private byte[] bytes;
private int length;
public StringRecord() {
this.bytes = EMPTY_BYTES;
this.hash = 0;
}
/**
* Construct from a string.
*/
public StringRecord(final String string) {
set(string);
}
/** Construct from another text. */
public StringRecord(final StringRecord utf8) {
set(utf8);
}
/**
* Construct from a byte array.
*/
public StringRecord(final byte[] utf8) {
set(utf8);
}
/**
* Returns the raw bytes; however, only data up to {@link #getLength()} is
* valid.
*/
public byte[] getBytes() {
return bytes;
}
/**
* Returns the Unicode Scalar Value (32-bit integer value) for the character
* at <code>position</code>. 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(final int position) {
if (position > this.length) {
return -1; // too long
}
if (position < 0) {
return -1;
}
final ByteBuffer bb = (ByteBuffer) ByteBuffer.wrap(this.bytes).position(position);
return bytesToCodePoint(bb.slice());
}
public int find(final String what) {
return find(what, 0);
}
/**
* Finds any occurrence of <code>what</code> in the backing buffer, starting
* as position <code>start</code>. 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(final String what, final int start) {
try {
final ByteBuffer src = ByteBuffer.wrap(this.bytes, 0, this.length);
final ByteBuffer tgt = encode(what);
final 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;
final 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(final String string) {
try {
final ByteBuffer bb = encode(string, true);
this.bytes = bb.array();
this.length = bb.limit();
this.hash = 0;
} catch (CharacterCodingException e) {
throw new RuntimeException("Should not have happened " + e.toString());
}
}
/**
* Set to a utf8 byte array
*/
public void set(final byte[] utf8) {
set(utf8, 0, utf8.length);
}
/** copy a text. */
public void set(final StringRecord other) {
set(other.getBytes(), 0, other.getLength());
}
/** Returns the number of bytes in the byte array */
public int getLength() {
return length;
}
/**
* 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(final byte[] utf8, final int start, final int len) {
setCapacity(len, false);
System.arraycopy(utf8, start, bytes, 0, len);
this.length = len;
this.hash = 0;
}
/**
* 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(final byte[] utf8, final int start, final int len) {
setCapacity(length + len, true);
System.arraycopy(utf8, start, bytes, length, len);
this.length += len;
this.hash = 0;
}
/**
* Clear the string to empty.
*/
public void clear() {
this.length = 0;
this.hash = 0;
}
/*
* Sets the capacity of this Text object to <em>at least</em>
* <code>len</code> bytes. If the current buffer is longer, then the
* capacity and existing content of the buffer are unchanged. If
* <code>len</code> 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(final int len, final boolean keepData) {
if (this.bytes == null || this.bytes.length < len) {
final byte[] newBytes = new byte[len];
if (this.bytes != null && keepData) {
System.arraycopy(this.bytes, 0, newBytes, 0, this.length);
}
this.bytes = newBytes;
}
}
/**
* Convert text back to string
*
* @see java.lang.Object#toString()
*/
public String toString() {
try {
return decode(bytes, 0, length);
} catch (CharacterCodingException e) {
throw new RuntimeException("Should not have happened " + e.toString());
}
}
/**
* deserialize
* @param in
*/
public void read(final DataInputView in) throws IOException {
final int newLength = in.readInt();
setCapacity(newLength, false);
in.readFully(this.bytes, 0, newLength);
this.length = newLength;
this.hash = 0;
}
/** Skips over one Text in the input. */
public static void skip(final DataInput in) throws IOException {
final int length = in.readInt();
skipFully(in, length);
}
public static void skipFully(final DataInput in, final int len) throws IOException {
int total = 0;
int cur = 0;
while ((total < len) && ((cur = in.skipBytes(len - total)) > 0)) {
total += cur;
}
if (total < len) {
throw new IOException("Not able to skip " + len + " bytes, possibly " + "due to end of input.");
}
}
@Override
public void write(final DataOutputView out) throws IOException {
out.writeInt(this.length);
out.write(this.bytes, 0, this.length);
}
@Override
public boolean equals(final Object obj) {
if (!(obj instanceof StringRecord)) {
return false;
}
final StringRecord sr = (StringRecord) obj;
if (this.length != sr.getLength()) {
return false;
}
if (this.bytes.length == this.length && sr.bytes.length == sr.length) {
return Arrays.equals(this.bytes, sr.bytes);
} else {
for (int i = 0; i < this.length; ++i) {
if (this.bytes[i] != sr.bytes[i]) {
return false;
}
}
}
return true;
}
@Override
public int hashCode() {
int h = this.hash;
if (h == 0 && this.length > 0) {
int off = 0;
byte[] val = this.bytes;
int len = this.length;
for (int i = 0; i < len; i++) {
h = 31 * h + val[off++];
}
this.hash = h;
}
return h;
}
// / 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(final byte[] utf8) throws CharacterCodingException {
return decode(ByteBuffer.wrap(utf8), true);
}
public static String decode(final byte[] utf8, final int start, final 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 <code>replace</code> 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(final byte[] utf8, final int start, final int length, final boolean replace)
throws CharacterCodingException {
return decode(ByteBuffer.wrap(utf8, start, length), replace);
}
private static String decode(final ByteBuffer utf8, final boolean replace) throws CharacterCodingException {
final CharsetDecoder decoder = DECODER_FACTORY.get();
if (replace) {
decoder.onMalformedInput(java.nio.charset.CodingErrorAction.REPLACE);
decoder.onUnmappableCharacter(CodingErrorAction.REPLACE);
}
final 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(final String string) throws CharacterCodingException {
return encode(string, true);
}
/**
* Converts the provided String to bytes using the UTF-8 encoding. If <code>replace</code> 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(final String string, final boolean replace) throws CharacterCodingException {
final 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;
}
/**
* Read a UTF8 encoded string from in
*/
public static String readString(final DataInput in) throws IOException {
if (in.readBoolean()) {
final int length = in.readInt();
if (length < 0) {
throw new IOException("length of StringRecord is " + length);
}
final byte[] bytes = new byte[length];
in.readFully(bytes, 0, length);
return decode(bytes);
}
return null;
}
/**
* Write a UTF8 encoded string to out
*/
public static int writeString(final DataOutput out, final String s) throws IOException {
int length = 0;
if (s == null) {
out.writeBoolean(false);
} else {
out.writeBoolean(true);
final ByteBuffer bytes = encode(s);
length = bytes.limit();
out.writeInt(length);
out.write(bytes.array(), 0, length);
}
return length;
}
// //// 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(final 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(final byte[] utf8, final int start, final int len) throws MalformedInputException {
int count = start;
int leadByte = 0;
int length = 0;
int state = LEAD_BYTE;
while (count < start + len) {
final int aByte = ((int) 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 <em>follow</em> 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(final ByteBuffer bytes) {
bytes.mark();
final byte b = bytes.get();
bytes.reset();
final 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);
default:
break;
}
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(final String string) {
final 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;
}
}