| Index: third_party/protobuf/java/src/main/java/com/google/protobuf/Utf8.java
|
| ===================================================================
|
| --- third_party/protobuf/java/src/main/java/com/google/protobuf/Utf8.java (revision 0)
|
| +++ third_party/protobuf/java/src/main/java/com/google/protobuf/Utf8.java (revision 0)
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| @@ -0,0 +1,349 @@
|
| +// Protocol Buffers - Google's data interchange format
|
| +// Copyright 2008 Google Inc. All rights reserved.
|
| +// http://code.google.com/p/protobuf/
|
| +//
|
| +// 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
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| +// 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
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| + * to the UTF-8 character encoding. This class has no dependencies
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| + * outside of the core JDK libraries.
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| + *
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| + * <p>There are several variants of UTF-8. The one implemented by
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| + * this class is the restricted definition of UTF-8 introduced in
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| + * Unicode 3.1, which mandates the rejection of "overlong" byte
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| + * sequences as well as rejection of 3-byte surrogate codepoint byte
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| + * sequences. Note that the UTF-8 decoder included in Oracle's JDK
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| + * has been modified to also reject "overlong" byte sequences, but (as
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| + * 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
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| + * Arrays.equals(bytes, new String(bytes, "UTF-8").getBytes("UTF-8"))
|
| + * }</pre>
|
| + *
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| + * <p>See the Unicode Standard,</br>
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| + * Table 3-6. <em>UTF-8 Bit Distribution</em>,</br>
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| + * Table 3-7. <em>Well Formed UTF-8 Byte Sequences</em>.
|
| + *
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| + * <p>This class supports decoding of partial byte sequences, so that the
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| + * bytes in a complete UTF-8 byte sequences can be stored in multiple
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| + * segments. Methods typically return {@link #MALFORMED} if the partial
|
| + * byte sequence is definitely not well-formed, {@link #COMPLETE} if it is
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| + * well-formed in the absence of additional input, or if the byte sequence
|
| + * apparently terminated in the middle of a character, an opaque integer
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| + * "state" value containing enough information to decode the character when
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| + * passed to a subsequent invocation of a partial decoding method.
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| + *
|
| + * @author martinrb@google.com (Martin Buchholz)
|
| + */
|
| +final class Utf8 {
|
| + private Utf8() {}
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| +
|
| + /**
|
| + * State value indicating that the byte sequence is well-formed and
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| + * complete (no further bytes are needed to complete a character).
|
| + */
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| + public static final int COMPLETE = 0;
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| +
|
| + /**
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| + * State value indicating that the byte sequence is definitely not
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| + * well-formed.
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| + */
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| + public static final int MALFORMED = -1;
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| +
|
| + // Other state values include the partial bytes of the incomplete
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| + // character to be decoded in the simplest way: we pack the bytes
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| + // into the state int in little-endian order. For example:
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| + //
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| + // int state = byte1 ^ (byte2 << 8) ^ (byte3 << 16);
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| + //
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| + // Such a state is unpacked thus (note the ~ operation for byte2 to
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| + // undo byte1's sign-extension bits):
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| + //
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| + // int byte1 = (byte) state;
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| + // int byte2 = (byte) ~(state >> 8);
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| + // int byte3 = (byte) (state >> 16);
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| + //
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| + // We cannot store a zero byte in the state because it would be
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| + // indistinguishable from the absence of a byte. But we don't need
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| + // to, because partial bytes must always be negative. When building
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| + // a state, we ensure that byte1 is negative and subsequent bytes
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| + // are valid trailing bytes.
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| +
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| + /**
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| + * Returns {@code true} if the given byte array is a well-formed
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| + * UTF-8 byte sequence.
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| + *
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| + * <p>This is a convenience method, equivalent to a call to {@code
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| + * isValidUtf8(bytes, 0, bytes.length)}.
|
| + */
|
| + public static boolean isValidUtf8(byte[] bytes) {
|
| + return isValidUtf8(bytes, 0, bytes.length);
|
| + }
|
| +
|
| + /**
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| + * Returns {@code true} if the given byte array slice is a
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| + * well-formed UTF-8 byte sequence. The range of bytes to be
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| + * checked extends from index {@code index}, inclusive, to {@code
|
| + * limit}, exclusive.
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| + *
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| + * <p>This is a convenience method, equivalent to {@code
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| + * partialIsValidUtf8(bytes, index, limit) == Utf8.COMPLETE}.
|
| + */
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| + public static boolean isValidUtf8(byte[] bytes, int index, int limit) {
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| + return partialIsValidUtf8(bytes, index, limit) == COMPLETE;
|
| + }
|
| +
|
| + /**
|
| + * Tells whether the given byte array slice is a well-formed,
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| + * malformed, or incomplete UTF-8 byte sequence. The range of bytes
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| + * to be checked extends from index {@code index}, inclusive, to
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| + * {@code limit}, exclusive.
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| + *
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| + * @param state either {@link Utf8#COMPLETE} (if this is the initial decoding
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| + * operation) or the value returned from a call to a partial decoding method
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| + * for the previous bytes
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| + *
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| + * @return {@link #MALFORMED} if the partial byte sequence is
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| + * definitely not well-formed, {@link #COMPLETE} if it is well-formed
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| + * (no additional input needed), or if the byte sequence is
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| + * "incomplete", i.e. apparently terminated in the middle of a character,
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| + * an opaque integer "state" value containing enough information to
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| + * decode the character when passed to a subsequent invocation of a
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| + * partial decoding method.
|
| + */
|
| + public static int partialIsValidUtf8(
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| + int state, byte[] bytes, int index, int limit) {
|
| + if (state != COMPLETE) {
|
| + // The previous decoding operation was incomplete (or malformed).
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| + // We look for a well-formed sequence consisting of bytes from
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| + // 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;
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| + // byte1 is never ASCII.
|
| + if (byte1 < (byte) 0xE0) {
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| + // two-byte form
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| +
|
| + // Simultaneously checks for illegal trailing-byte in
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| + // leading position and overlong 2-byte form.
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| + if (byte1 < (byte) 0xC2 ||
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| + // byte2 trailing-byte test
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| + bytes[index++] > (byte) 0xBF) {
|
| + return MALFORMED;
|
| + }
|
| + } else if (byte1 < (byte) 0xF0) {
|
| + // three-byte form
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| +
|
| + // Get byte2 from saved state or array
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| + int byte2 = (byte) ~(state >> 8);
|
| + if (byte2 == 0) {
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| + byte2 = bytes[index++];
|
| + if (index >= limit) {
|
| + return incompleteStateFor(byte1, byte2);
|
| + }
|
| + }
|
| + if (byte2 > (byte) 0xBF ||
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| + // overlong? 5 most significant bits must not all be zero
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| + (byte1 == (byte) 0xE0 && byte2 < (byte) 0xA0) ||
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| + // illegal surrogate codepoint?
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| + (byte1 == (byte) 0xED && byte2 >= (byte) 0xA0) ||
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| + // byte3 trailing-byte test
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| + bytes[index++] > (byte) 0xBF) {
|
| + return MALFORMED;
|
| + }
|
| + } else {
|
| + // four-byte form
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| +
|
| + // Get byte2 and byte3 from saved state or array
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| + 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,
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| + // which never occurs in well-formed UTF-8, and so we will return
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| + // MALFORMED again below.
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| +
|
| + if (byte2 > (byte) 0xBF ||
|
| + // Check that 1 <= plane <= 16. Tricky optimized form of:
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| + // if (byte1 > (byte) 0xF4 ||
|
| + // byte1 == (byte) 0xF0 && byte2 < (byte) 0x90 ||
|
| + // byte1 == (byte) 0xF4 && byte2 > (byte) 0x8F)
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| + (((byte1 << 28) + (byte2 - (byte) 0x90)) >> 30) != 0 ||
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| + // byte3 trailing-byte test
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| + byte3 > (byte) 0xBF ||
|
| + // byte4 trailing-byte test
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| + 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
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| + * partialIsValidUtf8(Utf8.COMPLETE, bytes, index, limit)}.
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| + *
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| + * @return {@link #MALFORMED} if the partial byte sequence is
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| + * definitely not well-formed, {@link #COMPLETE} if it is well-formed
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| + * (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 ||
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| + 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();
|
| + }
|
| + }
|
| +}
|
|
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| Property changes on: third_party/protobuf/java/src/main/java/com/google/protobuf/Utf8.java
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| ___________________________________________________________________
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| Added: svn:eol-style
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| + LF
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