HADOOP-9103. UTF8 class does not properly decode Unicode characters outside the basic multilingual plane. Contributed by Todd Lipcon.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1417649 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Todd Lipcon 2012-12-05 21:13:46 +00:00
parent d6c50b4a67
commit bd239a8d97
3 changed files with 107 additions and 3 deletions

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@ -460,6 +460,9 @@ Release 2.0.3-alpha - Unreleased
HADOOP-8958. ViewFs:Non absolute mount name failures when running
multiple tests on Windows. (Chris Nauroth via suresh)
HADOOP-9103. UTF8 class does not properly decode Unicode characters
outside the basic multilingual plane. (todd)
Release 2.0.2-alpha - 2012-09-07
INCOMPATIBLE CHANGES

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@ -22,6 +22,7 @@
import java.io.DataInput;
import java.io.DataOutput;
import org.apache.hadoop.util.StringUtils;
import org.apache.commons.logging.*;
import org.apache.hadoop.classification.InterfaceAudience;
@ -31,6 +32,9 @@
*
* <p>Also includes utilities for efficiently reading and writing UTF-8.
*
* Note that this decodes UTF-8 but actually encodes CESU-8, a variant of
* UTF-8: see http://en.wikipedia.org/wiki/CESU-8
*
* @deprecated replaced by Text
*/
@Deprecated
@ -209,6 +213,19 @@ public static byte[] getBytes(String string) {
return result;
}
/**
* Convert a UTF-8 encoded byte array back into a string.
*
* @throws IOException if the byte array is invalid UTF8
*/
public static String fromBytes(byte[] bytes) throws IOException {
DataInputBuffer dbuf = new DataInputBuffer();
dbuf.reset(bytes, 0, bytes.length);
StringBuilder buf = new StringBuilder(bytes.length);
readChars(dbuf, buf, bytes.length);
return buf.toString();
}
/** Read a UTF-8 encoded string.
*
* @see DataInput#readUTF()
@ -230,18 +247,48 @@ private static void readChars(DataInput in, StringBuilder buffer, int nBytes)
while (i < nBytes) {
byte b = bytes[i++];
if ((b & 0x80) == 0) {
// 0b0xxxxxxx: 1-byte sequence
buffer.append((char)(b & 0x7F));
} else if ((b & 0xE0) != 0xE0) {
} else if ((b & 0xE0) == 0xC0) {
// 0b110xxxxx: 2-byte sequence
buffer.append((char)(((b & 0x1F) << 6)
| (bytes[i++] & 0x3F)));
} else {
} else if ((b & 0xF0) == 0xE0) {
// 0b1110xxxx: 3-byte sequence
buffer.append((char)(((b & 0x0F) << 12)
| ((bytes[i++] & 0x3F) << 6)
| (bytes[i++] & 0x3F)));
} else if ((b & 0xF8) == 0xF0) {
// 0b11110xxx: 4-byte sequence
int codepoint =
((b & 0x07) << 18)
| ((bytes[i++] & 0x3F) << 12)
| ((bytes[i++] & 0x3F) << 6)
| ((bytes[i++] & 0x3F));
buffer.append(highSurrogate(codepoint))
.append(lowSurrogate(codepoint));
} else {
// The UTF8 standard describes 5-byte and 6-byte sequences, but
// these are no longer allowed as of 2003 (see RFC 3629)
// Only show the next 6 bytes max in the error code - in case the
// buffer is large, this will prevent an exceedingly large message.
int endForError = Math.min(i + 5, nBytes);
throw new IOException("Invalid UTF8 at " +
StringUtils.byteToHexString(bytes, i - 1, endForError));
}
}
}
private static char highSurrogate(int codePoint) {
return (char) ((codePoint >>> 10)
+ (Character.MIN_HIGH_SURROGATE - (Character.MIN_SUPPLEMENTARY_CODE_POINT >>> 10)));
}
private static char lowSurrogate(int codePoint) {
return (char) ((codePoint & 0x3ff) + Character.MIN_LOW_SURROGATE);
}
/** Write a UTF-8 encoded string.
*
* @see DataOutput#writeUTF(String)

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@ -19,8 +19,12 @@
package org.apache.hadoop.io;
import junit.framework.TestCase;
import java.io.IOException;
import java.util.Random;
import org.apache.hadoop.test.GenericTestUtils;
import org.apache.hadoop.util.StringUtils;
/** Unit tests for UTF8. */
@SuppressWarnings("deprecation")
public class TestUTF8 extends TestCase {
@ -93,4 +97,54 @@ public void testNullEncoding() throws Exception {
assertEquals(s, new String(dob.getData(), 2, dob.getLength()-2, "UTF-8"));
}
/**
* Test encoding and decoding of UTF8 outside the basic multilingual plane.
*
* This is a regression test for HADOOP-9103.
*/
public void testNonBasicMultilingualPlane() throws Exception {
// Test using the "CAT FACE" character (U+1F431)
// See http://www.fileformat.info/info/unicode/char/1f431/index.htm
String catFace = "\uD83D\uDC31";
// This encodes to 4 bytes in UTF-8:
byte[] encoded = catFace.getBytes("UTF-8");
assertEquals(4, encoded.length);
assertEquals("f09f90b1", StringUtils.byteToHexString(encoded));
// Decode back to String using our own decoder
String roundTrip = UTF8.fromBytes(encoded);
assertEquals(catFace, roundTrip);
}
/**
* Test that decoding invalid UTF8 throws an appropriate error message.
*/
public void testInvalidUTF8() throws Exception {
byte[] invalid = new byte[] {
0x01, 0x02, (byte)0xff, (byte)0xff, 0x01, 0x02, 0x03, 0x04, 0x05 };
try {
UTF8.fromBytes(invalid);
fail("did not throw an exception");
} catch (IOException ioe) {
GenericTestUtils.assertExceptionContains(
"Invalid UTF8 at ffff01020304", ioe);
}
}
/**
* Test for a 5-byte UTF8 sequence, which is now considered illegal.
*/
public void test5ByteUtf8Sequence() throws Exception {
byte[] invalid = new byte[] {
0x01, 0x02, (byte)0xf8, (byte)0x88, (byte)0x80,
(byte)0x80, (byte)0x80, 0x04, 0x05 };
try {
UTF8.fromBytes(invalid);
fail("did not throw an exception");
} catch (IOException ioe) {
GenericTestUtils.assertExceptionContains(
"Invalid UTF8 at f88880808004", ioe);
}
}
}