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Unified Diff: third_party/protobuf/java/src/main/java/com/google/protobuf/Utf8.java

Issue 1842653006: Update //third_party/protobuf to version 3. (Closed) Base URL: https://chromium.googlesource.com/chromium/src.git@master
Patch Set: merge Created 4 years, 8 months ago
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Index: third_party/protobuf/java/src/main/java/com/google/protobuf/Utf8.java
diff --git a/third_party/protobuf/java/src/main/java/com/google/protobuf/Utf8.java b/third_party/protobuf/java/src/main/java/com/google/protobuf/Utf8.java
new file mode 100644
index 0000000000000000000000000000000000000000..48c7e9e62db4c2aafb61ffb5a92548e71d5ccc41
--- /dev/null
+++ b/third_party/protobuf/java/src/main/java/com/google/protobuf/Utf8.java
@@ -0,0 +1,481 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc. All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+// * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+// * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+// * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+/**
+ * A set of low-level, high-performance static utility methods related
+ * to the UTF-8 character encoding. This class has no dependencies
+ * outside of the core JDK libraries.
+ *
+ * <p>There are several variants of UTF-8. The one implemented by
+ * this class is the restricted definition of UTF-8 introduced in
+ * Unicode 3.1, which mandates the rejection of "overlong" byte
+ * sequences as well as rejection of 3-byte surrogate codepoint byte
+ * sequences. Note that the UTF-8 decoder included in Oracle's JDK
+ * has been modified to also reject "overlong" byte sequences, but (as
+ * of 2011) still accepts 3-byte surrogate codepoint byte sequences.
+ *
+ * <p>The byte sequences considered valid by this class are exactly
+ * those that can be roundtrip converted to Strings and back to bytes
+ * using the UTF-8 charset, without loss: <pre> {@code
+ * Arrays.equals(bytes, new String(bytes, Internal.UTF_8).getBytes(Internal.UTF_8))
+ * }</pre>
+ *
+ * <p>See the Unicode Standard,</br>
+ * Table 3-6. <em>UTF-8 Bit Distribution</em>,</br>
+ * Table 3-7. <em>Well Formed UTF-8 Byte Sequences</em>.
+ *
+ * <p>This class supports decoding of partial byte sequences, so that the
+ * bytes in a complete UTF-8 byte sequences can be stored in multiple
+ * segments. Methods typically return {@link #MALFORMED} if the partial
+ * byte sequence is definitely not well-formed, {@link #COMPLETE} if it is
+ * well-formed in the absence of additional input, or if the byte sequence
+ * apparently terminated in the middle of a character, an opaque integer
+ * "state" value containing enough information to decode the character when
+ * passed to a subsequent invocation of a partial decoding method.
+ *
+ * @author martinrb@google.com (Martin Buchholz)
+ */
+final class Utf8 {
+ private Utf8() {}
+
+ /**
+ * Maximum number of bytes per Java UTF-16 char in UTF-8.
+ * @see java.nio.charset.CharsetEncoder#maxBytesPerChar()
+ */
+ static final int MAX_BYTES_PER_CHAR = 3;
+
+ /**
+ * State value indicating that the byte sequence is well-formed and
+ * complete (no further bytes are needed to complete a character).
+ */
+ public static final int COMPLETE = 0;
+
+ /**
+ * State value indicating that the byte sequence is definitely not
+ * well-formed.
+ */
+ public static final int MALFORMED = -1;
+
+ // Other state values include the partial bytes of the incomplete
+ // character to be decoded in the simplest way: we pack the bytes
+ // into the state int in little-endian order. For example:
+ //
+ // int state = byte1 ^ (byte2 << 8) ^ (byte3 << 16);
+ //
+ // Such a state is unpacked thus (note the ~ operation for byte2 to
+ // undo byte1's sign-extension bits):
+ //
+ // int byte1 = (byte) state;
+ // int byte2 = (byte) ~(state >> 8);
+ // int byte3 = (byte) (state >> 16);
+ //
+ // We cannot store a zero byte in the state because it would be
+ // indistinguishable from the absence of a byte. But we don't need
+ // to, because partial bytes must always be negative. When building
+ // a state, we ensure that byte1 is negative and subsequent bytes
+ // are valid trailing bytes.
+
+ /**
+ * Returns {@code true} if the given byte array is a well-formed
+ * UTF-8 byte sequence.
+ *
+ * <p>This is a convenience method, equivalent to a call to {@code
+ * isValidUtf8(bytes, 0, bytes.length)}.
+ */
+ public static boolean isValidUtf8(byte[] bytes) {
+ return isValidUtf8(bytes, 0, bytes.length);
+ }
+
+ /**
+ * Returns {@code true} if the given byte array slice is a
+ * well-formed UTF-8 byte sequence. The range of bytes to be
+ * checked extends from index {@code index}, inclusive, to {@code
+ * limit}, exclusive.
+ *
+ * <p>This is a convenience method, equivalent to {@code
+ * partialIsValidUtf8(bytes, index, limit) == Utf8.COMPLETE}.
+ */
+ public static boolean isValidUtf8(byte[] bytes, int index, int limit) {
+ return partialIsValidUtf8(bytes, index, limit) == COMPLETE;
+ }
+
+ /**
+ * Tells whether the given byte array slice is a well-formed,
+ * malformed, or incomplete UTF-8 byte sequence. The range of bytes
+ * to be checked extends from index {@code index}, inclusive, to
+ * {@code limit}, exclusive.
+ *
+ * @param state either {@link Utf8#COMPLETE} (if this is the initial decoding
+ * operation) or the value returned from a call to a partial decoding method
+ * for the previous bytes
+ *
+ * @return {@link #MALFORMED} if the partial byte sequence is
+ * definitely not well-formed, {@link #COMPLETE} if it is well-formed
+ * (no additional input needed), or if the byte sequence is
+ * "incomplete", i.e. apparently terminated in the middle of a character,
+ * an opaque integer "state" value containing enough information to
+ * decode the character when passed to a subsequent invocation of a
+ * partial decoding method.
+ */
+ public static int partialIsValidUtf8(
+ int state, byte[] bytes, int index, int limit) {
+ if (state != COMPLETE) {
+ // The previous decoding operation was incomplete (or malformed).
+ // We look for a well-formed sequence consisting of bytes from
+ // the previous decoding operation (stored in state) together
+ // with bytes from the array slice.
+ //
+ // We expect such "straddler characters" to be rare.
+
+ if (index >= limit) { // No bytes? No progress.
+ return state;
+ }
+ int byte1 = (byte) state;
+ // byte1 is never ASCII.
+ if (byte1 < (byte) 0xE0) {
+ // two-byte form
+
+ // Simultaneously checks for illegal trailing-byte in
+ // leading position and overlong 2-byte form.
+ if (byte1 < (byte) 0xC2 ||
+ // byte2 trailing-byte test
+ bytes[index++] > (byte) 0xBF) {
+ return MALFORMED;
+ }
+ } else if (byte1 < (byte) 0xF0) {
+ // three-byte form
+
+ // Get byte2 from saved state or array
+ int byte2 = (byte) ~(state >> 8);
+ if (byte2 == 0) {
+ byte2 = bytes[index++];
+ if (index >= limit) {
+ return incompleteStateFor(byte1, byte2);
+ }
+ }
+ if (byte2 > (byte) 0xBF ||
+ // overlong? 5 most significant bits must not all be zero
+ (byte1 == (byte) 0xE0 && byte2 < (byte) 0xA0) ||
+ // illegal surrogate codepoint?
+ (byte1 == (byte) 0xED && byte2 >= (byte) 0xA0) ||
+ // byte3 trailing-byte test
+ bytes[index++] > (byte) 0xBF) {
+ return MALFORMED;
+ }
+ } else {
+ // four-byte form
+
+ // Get byte2 and byte3 from saved state or array
+ int byte2 = (byte) ~(state >> 8);
+ int byte3 = 0;
+ if (byte2 == 0) {
+ byte2 = bytes[index++];
+ if (index >= limit) {
+ return incompleteStateFor(byte1, byte2);
+ }
+ } else {
+ byte3 = (byte) (state >> 16);
+ }
+ if (byte3 == 0) {
+ byte3 = bytes[index++];
+ if (index >= limit) {
+ return incompleteStateFor(byte1, byte2, byte3);
+ }
+ }
+
+ // If we were called with state == MALFORMED, then byte1 is 0xFF,
+ // which never occurs in well-formed UTF-8, and so we will return
+ // MALFORMED again below.
+
+ if (byte2 > (byte) 0xBF ||
+ // Check that 1 <= plane <= 16. Tricky optimized form of:
+ // if (byte1 > (byte) 0xF4 ||
+ // byte1 == (byte) 0xF0 && byte2 < (byte) 0x90 ||
+ // byte1 == (byte) 0xF4 && byte2 > (byte) 0x8F)
+ (((byte1 << 28) + (byte2 - (byte) 0x90)) >> 30) != 0 ||
+ // byte3 trailing-byte test
+ byte3 > (byte) 0xBF ||
+ // byte4 trailing-byte test
+ bytes[index++] > (byte) 0xBF) {
+ return MALFORMED;
+ }
+ }
+ }
+
+ return partialIsValidUtf8(bytes, index, limit);
+ }
+
+ /**
+ * Tells whether the given byte array slice is a well-formed,
+ * malformed, or incomplete UTF-8 byte sequence. The range of bytes
+ * to be checked extends from index {@code index}, inclusive, to
+ * {@code limit}, exclusive.
+ *
+ * <p>This is a convenience method, equivalent to a call to {@code
+ * partialIsValidUtf8(Utf8.COMPLETE, bytes, index, limit)}.
+ *
+ * @return {@link #MALFORMED} if the partial byte sequence is
+ * definitely not well-formed, {@link #COMPLETE} if it is well-formed
+ * (no additional input needed), or if the byte sequence is
+ * "incomplete", i.e. apparently terminated in the middle of a character,
+ * an opaque integer "state" value containing enough information to
+ * decode the character when passed to a subsequent invocation of a
+ * partial decoding method.
+ */
+ public static int partialIsValidUtf8(
+ byte[] bytes, int index, int limit) {
+ // Optimize for 100% ASCII.
+ // Hotspot loves small simple top-level loops like this.
+ while (index < limit && bytes[index] >= 0) {
+ index++;
+ }
+
+ return (index >= limit) ? COMPLETE :
+ partialIsValidUtf8NonAscii(bytes, index, limit);
+ }
+
+ private static int partialIsValidUtf8NonAscii(
+ byte[] bytes, int index, int limit) {
+ for (;;) {
+ int byte1, byte2;
+
+ // Optimize for interior runs of ASCII bytes.
+ do {
+ if (index >= limit) {
+ return COMPLETE;
+ }
+ } while ((byte1 = bytes[index++]) >= 0);
+
+ if (byte1 < (byte) 0xE0) {
+ // two-byte form
+
+ if (index >= limit) {
+ return byte1;
+ }
+
+ // Simultaneously checks for illegal trailing-byte in
+ // leading position and overlong 2-byte form.
+ if (byte1 < (byte) 0xC2 ||
+ bytes[index++] > (byte) 0xBF) {
+ return MALFORMED;
+ }
+ } else if (byte1 < (byte) 0xF0) {
+ // three-byte form
+
+ if (index >= limit - 1) { // incomplete sequence
+ return incompleteStateFor(bytes, index, limit);
+ }
+ if ((byte2 = bytes[index++]) > (byte) 0xBF ||
+ // overlong? 5 most significant bits must not all be zero
+ (byte1 == (byte) 0xE0 && byte2 < (byte) 0xA0) ||
+ // check for illegal surrogate codepoints
+ (byte1 == (byte) 0xED && byte2 >= (byte) 0xA0) ||
+ // byte3 trailing-byte test
+ bytes[index++] > (byte) 0xBF) {
+ return MALFORMED;
+ }
+ } else {
+ // four-byte form
+
+ if (index >= limit - 2) { // incomplete sequence
+ return incompleteStateFor(bytes, index, limit);
+ }
+ if ((byte2 = bytes[index++]) > (byte) 0xBF ||
+ // Check that 1 <= plane <= 16. Tricky optimized form of:
+ // if (byte1 > (byte) 0xF4 ||
+ // byte1 == (byte) 0xF0 && byte2 < (byte) 0x90 ||
+ // byte1 == (byte) 0xF4 && byte2 > (byte) 0x8F)
+ (((byte1 << 28) + (byte2 - (byte) 0x90)) >> 30) != 0 ||
+ // byte3 trailing-byte test
+ bytes[index++] > (byte) 0xBF ||
+ // byte4 trailing-byte test
+ bytes[index++] > (byte) 0xBF) {
+ return MALFORMED;
+ }
+ }
+ }
+ }
+
+ private static int incompleteStateFor(int byte1) {
+ return (byte1 > (byte) 0xF4) ?
+ MALFORMED : byte1;
+ }
+
+ private static int incompleteStateFor(int byte1, int byte2) {
+ return (byte1 > (byte) 0xF4 ||
+ byte2 > (byte) 0xBF) ?
+ MALFORMED : byte1 ^ (byte2 << 8);
+ }
+
+ private static int incompleteStateFor(int byte1, int byte2, int byte3) {
+ return (byte1 > (byte) 0xF4 ||
+ byte2 > (byte) 0xBF ||
+ byte3 > (byte) 0xBF) ?
+ MALFORMED : byte1 ^ (byte2 << 8) ^ (byte3 << 16);
+ }
+
+ private static int incompleteStateFor(byte[] bytes, int index, int limit) {
+ int byte1 = bytes[index - 1];
+ switch (limit - index) {
+ case 0: return incompleteStateFor(byte1);
+ case 1: return incompleteStateFor(byte1, bytes[index]);
+ case 2: return incompleteStateFor(byte1, bytes[index], bytes[index + 1]);
+ default: throw new AssertionError();
+ }
+ }
+
+
+ // These UTF-8 handling methods are copied from Guava's Utf8 class with a modification to throw
+ // a protocol buffer local exception. This exception is then caught in CodedOutputStream so it can
+ // fallback to more lenient behavior.
+
+ static class UnpairedSurrogateException extends IllegalArgumentException {
+
+ private UnpairedSurrogateException(int index, int length) {
+ super("Unpaired surrogate at index " + index + " of " + length);
+ }
+ }
+
+ /**
+ * Returns the number of bytes in the UTF-8-encoded form of {@code sequence}. For a string,
+ * this method is equivalent to {@code string.getBytes(UTF_8).length}, but is more efficient in
+ * both time and space.
+ *
+ * @throws IllegalArgumentException if {@code sequence} contains ill-formed UTF-16 (unpaired
+ * surrogates)
+ */
+ static int encodedLength(CharSequence sequence) {
+ // Warning to maintainers: this implementation is highly optimized.
+ int utf16Length = sequence.length();
+ int utf8Length = utf16Length;
+ int i = 0;
+
+ // This loop optimizes for pure ASCII.
+ while (i < utf16Length && sequence.charAt(i) < 0x80) {
+ i++;
+ }
+
+ // This loop optimizes for chars less than 0x800.
+ for (; i < utf16Length; i++) {
+ char c = sequence.charAt(i);
+ if (c < 0x800) {
+ utf8Length += ((0x7f - c) >>> 31); // branch free!
+ } else {
+ utf8Length += encodedLengthGeneral(sequence, i);
+ break;
+ }
+ }
+
+ if (utf8Length < utf16Length) {
+ // Necessary and sufficient condition for overflow because of maximum 3x expansion
+ throw new IllegalArgumentException("UTF-8 length does not fit in int: "
+ + (utf8Length + (1L << 32)));
+ }
+ return utf8Length;
+ }
+
+ private static int encodedLengthGeneral(CharSequence sequence, int start) {
+ int utf16Length = sequence.length();
+ int utf8Length = 0;
+ for (int i = start; i < utf16Length; i++) {
+ char c = sequence.charAt(i);
+ if (c < 0x800) {
+ utf8Length += (0x7f - c) >>> 31; // branch free!
+ } else {
+ utf8Length += 2;
+ // jdk7+: if (Character.isSurrogate(c)) {
+ if (Character.MIN_SURROGATE <= c && c <= Character.MAX_SURROGATE) {
+ // Check that we have a well-formed surrogate pair.
+ int cp = Character.codePointAt(sequence, i);
+ if (cp < Character.MIN_SUPPLEMENTARY_CODE_POINT) {
+ throw new UnpairedSurrogateException(i, utf16Length);
+ }
+ i++;
+ }
+ }
+ }
+ return utf8Length;
+ }
+
+ static int encode(CharSequence sequence, byte[] bytes, int offset, int length) {
+ int utf16Length = sequence.length();
+ int j = offset;
+ int i = 0;
+ int limit = offset + length;
+ // Designed to take advantage of
+ // https://wikis.oracle.com/display/HotSpotInternals/RangeCheckElimination
+ for (char c; i < utf16Length && i + j < limit && (c = sequence.charAt(i)) < 0x80; i++) {
+ bytes[j + i] = (byte) c;
+ }
+ if (i == utf16Length) {
+ return j + utf16Length;
+ }
+ j += i;
+ for (char c; i < utf16Length; i++) {
+ c = sequence.charAt(i);
+ if (c < 0x80 && j < limit) {
+ bytes[j++] = (byte) c;
+ } else if (c < 0x800 && j <= limit - 2) { // 11 bits, two UTF-8 bytes
+ bytes[j++] = (byte) ((0xF << 6) | (c >>> 6));
+ bytes[j++] = (byte) (0x80 | (0x3F & c));
+ } else if ((c < Character.MIN_SURROGATE || Character.MAX_SURROGATE < c) && j <= limit - 3) {
+ // Maximum single-char code point is 0xFFFF, 16 bits, three UTF-8 bytes
+ bytes[j++] = (byte) ((0xF << 5) | (c >>> 12));
+ bytes[j++] = (byte) (0x80 | (0x3F & (c >>> 6)));
+ bytes[j++] = (byte) (0x80 | (0x3F & c));
+ } else if (j <= limit - 4) {
+ // Minimum code point represented by a surrogate pair is 0x10000, 17 bits, four UTF-8 bytes
+ final char low;
+ if (i + 1 == sequence.length()
+ || !Character.isSurrogatePair(c, (low = sequence.charAt(++i)))) {
+ throw new UnpairedSurrogateException((i - 1), utf16Length);
+ }
+ int codePoint = Character.toCodePoint(c, low);
+ bytes[j++] = (byte) ((0xF << 4) | (codePoint >>> 18));
+ bytes[j++] = (byte) (0x80 | (0x3F & (codePoint >>> 12)));
+ bytes[j++] = (byte) (0x80 | (0x3F & (codePoint >>> 6)));
+ bytes[j++] = (byte) (0x80 | (0x3F & codePoint));
+ } else {
+ // If we are surrogates and we're not a surrogate pair, always throw an
+ // IllegalArgumentException instead of an ArrayOutOfBoundsException.
+ if ((Character.MIN_SURROGATE <= c && c <= Character.MAX_SURROGATE)
+ && (i + 1 == sequence.length()
+ || !Character.isSurrogatePair(c, sequence.charAt(i + 1)))) {
+ throw new UnpairedSurrogateException(i, utf16Length);
+ }
+ throw new ArrayIndexOutOfBoundsException("Failed writing " + c + " at index " + j);
+ }
+ }
+ return j;
+ }
+ // End Guava UTF-8 methods.
+}

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