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// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc.  All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file or at
// https://developers.google.com/open-source/licenses/bsd

package com.google.protobuf;

import static com.google.protobuf.Internal.checkNotNull;
import static com.google.protobuf.TextFormatEscaper.escapeBytes;
import static java.lang.Integer.toHexString;
import static java.lang.System.identityHashCode;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InvalidObjectException;
import java.io.ObjectInputStream;
import java.io.OutputStream;
import java.io.Serializable;
import java.io.UnsupportedEncodingException;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.InvalidMarkException;
import java.nio.charset.Charset;
import java.nio.charset.UnsupportedCharsetException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.Locale;
import java.util.NoSuchElementException;

/**
 * Immutable sequence of bytes. Provides conversions to and from {@code byte[]}, {@link
 * java.lang.String}, {@link ByteBuffer}, {@link InputStream}, {@link OutputStream}. Also provides a
 * conversion to {@link CodedInputStream}.
 *
 * 

Like {@link String}, the contents of a {@link ByteString} can never be observed to change, not * even in the presence of a data race or incorrect API usage in the client code. * *

Substring is supported by sharing the reference to the immutable underlying bytes. * Concatenation is likewise supported without copying (long strings) by building a tree of pieces * in {@link RopeByteString}. * * @author [email protected] Bob Lee * @author [email protected] Kenton Varda * @author [email protected] Carl Haverl * @author [email protected] Martin Buchholz */ @CheckReturnValue public abstract class ByteString implements Iterable, Serializable { private static final long serialVersionUID = 1L; /** * When two strings to be concatenated have a combined length shorter than this, we just copy * their bytes on {@link #concat(ByteString)}. The trade-off is copy size versus the overhead of * creating tree nodes in {@link RopeByteString}. */ static final int CONCATENATE_BY_COPY_SIZE = 128; /** * When copying an InputStream into a ByteString with .readFrom(), the chunks in the underlying * rope start at 256 bytes, but double each iteration up to 8192 bytes. */ static final int MIN_READ_FROM_CHUNK_SIZE = 0x100; // 256b static final int MAX_READ_FROM_CHUNK_SIZE = 0x2000; // 8k /** Empty {@code ByteString}. */ public static final ByteString EMPTY = new LiteralByteString(Internal.EMPTY_BYTE_ARRAY); /** * An interface to efficiently copy {@code byte[]}. * *

One of the noticeable costs of copying a byte[] into a new array using {@code * System.arraycopy} is nullification of a new buffer before the copy. It has been shown the * Hotspot VM is capable to intrisicfy {@code Arrays.copyOfRange} operation to avoid this * expensive nullification and provide substantial performance gain. Unfortunately this does not * hold on Android runtimes and could make the copy slightly slower due to additional code in the * {@code Arrays.copyOfRange}. Thus we provide two different implementation for array copier for * Hotspot and Android runtimes. */ private interface ByteArrayCopier { /** Copies the specified range of the specified array into a new array */ byte[] copyFrom(byte[] bytes, int offset, int size); } /** Implementation of {@code ByteArrayCopier} which uses {@link System#arraycopy}. */ private static final class SystemByteArrayCopier implements ByteArrayCopier { @Override public byte[] copyFrom(byte[] bytes, int offset, int size) { byte[] copy = new byte[size]; System.arraycopy(bytes, offset, copy, 0, size); return copy; } } /** Implementation of {@code ByteArrayCopier} which uses {@link Arrays#copyOfRange}. */ private static final class ArraysByteArrayCopier implements ByteArrayCopier { @Override public byte[] copyFrom(byte[] bytes, int offset, int size) { return Arrays.copyOfRange(bytes, offset, offset + size); } } private static final ByteArrayCopier byteArrayCopier; static { byteArrayCopier = Android.isOnAndroidDevice() ? new SystemByteArrayCopier() : new ArraysByteArrayCopier(); } /** * Cached hash value. Intentionally accessed via a data race, which is safe because of the Java * Memory Model's "no out-of-thin-air values" guarantees for ints. A value of 0 implies that the * hash has not been set. */ private int hash = 0; // This constructor is here to prevent subclassing outside of this package, ByteString() {} /** * Gets the byte at the given index. This method should be used only for random access to * individual bytes. To access bytes sequentially, use the {@link ByteIterator} returned by {@link * #iterator()}, and call {@link #substring(int, int)} first if necessary. * * @param index index of byte * @return the value * @throws IndexOutOfBoundsException {@code index < 0 or index >= size} */ public abstract byte byteAt(int index); /** * Gets the byte at the given index, assumes bounds checking has already been performed. * * @param index index of byte * @return the value * @throws IndexOutOfBoundsException {@code index < 0 or index >= size} */ abstract byte internalByteAt(int index); /** * Return a {@link ByteString.ByteIterator} over the bytes in the ByteString. To avoid * auto-boxing, you may get the iterator manually and call {@link ByteIterator#nextByte()}. * * @return the iterator */ @Override public ByteIterator iterator() { return new AbstractByteIterator() { private int position = 0; private final int limit = size(); @Override public boolean hasNext() { return position < limit; } @Override public byte nextByte() { int currentPos = position; if (currentPos >= limit) { throw new NoSuchElementException(); } position = currentPos + 1; return internalByteAt(currentPos); } }; } /** * This interface extends {@code Iterator}, so that we can return an unboxed {@code byte}. */ public interface ByteIterator extends Iterator { /** * An alternative to {@link Iterator#next()} that returns an unboxed primitive {@code byte}. * * @return the next {@code byte} in the iteration * @throws NoSuchElementException if the iteration has no more elements */ byte nextByte(); } abstract static class AbstractByteIterator implements ByteIterator { @Override public final Byte next() { // Boxing calls Byte.valueOf(byte), which does not instantiate. return nextByte(); } @Override public final void remove() { throw new UnsupportedOperationException(); } } /** * Gets the number of bytes. * * @return size in bytes */ public abstract int size(); /** * Returns {@code true} if the size is {@code 0}, {@code false} otherwise. * * @return true if this is zero bytes long */ public final boolean isEmpty() { return size() == 0; } /** Returns an empty {@code ByteString} of size {@code 0}. */ public static final ByteString empty() { return EMPTY; } // ================================================================= // Comparison private static final int UNSIGNED_BYTE_MASK = 0xFF; /** * Returns the value of the given byte as an integer, interpreting the byte as an unsigned value. * That is, returns {@code value + 256} if {@code value} is negative; {@code value} itself * otherwise. * *

Note: This code was copied from {@link com.google.common.primitives.UnsignedBytes#toInt}, as * Guava libraries cannot be used in the {@code com.google.protobuf} package. */ private static int toInt(byte value) { return value & UNSIGNED_BYTE_MASK; } /** Returns the numeric value of the given character in hex, or -1 if invalid. */ private static int hexDigit(char c) { if (c >= '0' && c <= '9') { return c - '0'; } else if (c >= 'A' && c <= 'F') { return c - 'A' + 10; } else if (c >= 'a' && c <= 'f') { return c - 'a' + 10; } else { return -1; } } /** * Returns the numeric value of the given character at index in hexString. * * @throws NumberFormatException if the hexString character is invalid. */ private static int extractHexDigit(String hexString, int index) { int digit = hexDigit(hexString.charAt(index)); if (digit == -1) { throw new NumberFormatException( "Invalid hexString " + hexString + " must only contain [0-9a-fA-F] but contained " + hexString.charAt(index) + " at index " + index); } return digit; } /** * Compares two {@link ByteString}s lexicographically, treating their contents as unsigned byte * values between 0 and 255 (inclusive). * *

For example, {@code (byte) -1} is considered to be greater than {@code (byte) 1} because it * is interpreted as an unsigned value, {@code 255}. */ private static final Comparator UNSIGNED_LEXICOGRAPHICAL_COMPARATOR = new Comparator() { @Override public int compare(ByteString former, ByteString latter) { ByteIterator formerBytes = former.iterator(); ByteIterator latterBytes = latter.iterator(); while (formerBytes.hasNext() && latterBytes.hasNext()) { int result = Integer.valueOf(toInt(formerBytes.nextByte())) .compareTo(toInt(latterBytes.nextByte())); if (result != 0) { return result; } } return Integer.valueOf(former.size()).compareTo(Integer.valueOf(latter.size())); } }; /** * Returns a {@link Comparator} which compares {@link ByteString}-s lexicographically as sequences * of unsigned bytes (i.e. values between 0 and 255, inclusive). * *

For example, {@code (byte) -1} is considered to be greater than {@code (byte) 1} because it * is interpreted as an unsigned value, {@code 255}: * *

    *
  • {@code `-1` -> 0b11111111 (two's complement) -> 255} *
  • {@code `1` -> 0b00000001 -> 1} *
*/ public static Comparator unsignedLexicographicalComparator() { return UNSIGNED_LEXICOGRAPHICAL_COMPARATOR; } // ================================================================= // ByteString -> substring /** * Return the substring from {@code beginIndex}, inclusive, to the end of the string. * * @param beginIndex start at this index * @return substring sharing underlying data * @throws IndexOutOfBoundsException if {@code beginIndex < 0} or {@code beginIndex > size()}. */ public final ByteString substring(int beginIndex) { return substring(beginIndex, size()); } /** * Return the substring from {@code beginIndex}, inclusive, to {@code endIndex}, exclusive. * * @param beginIndex start at this index * @param endIndex the last character is the one before this index * @return substring sharing underlying data * @throws IndexOutOfBoundsException if {@code beginIndex < 0}, {@code endIndex > size()}, or * {@code beginIndex > endIndex}. */ public abstract ByteString substring(int beginIndex, int endIndex); /** * Tests if this bytestring starts with the specified prefix. Similar to {@link * String#startsWith(String)} * * @param prefix the prefix. * @return true if the byte sequence represented by the argument is a prefix of the * byte sequence represented by this string; false otherwise. */ public final boolean startsWith(ByteString prefix) { return size() >= prefix.size() && substring(0, prefix.size()).equals(prefix); } /** * Tests if this bytestring ends with the specified suffix. Similar to {@link * String#endsWith(String)} * * @param suffix the suffix. * @return true if the byte sequence represented by the argument is a suffix of the * byte sequence represented by this string; false otherwise. */ public final boolean endsWith(ByteString suffix) { return size() >= suffix.size() && substring(size() - suffix.size()).equals(suffix); } // ================================================================= // String -> ByteString /** * Returns a {@code ByteString} from a hexadecimal String. * * @param hexString String of hexadecimal digits to create {@code ByteString} from. * @throws NumberFormatException if the hexString does not contain a parsable hex String. */ public static ByteString fromHex(@CompileTimeConstant String hexString) { if (hexString.length() % 2 != 0) { throw new NumberFormatException( "Invalid hexString " + hexString + " of length " + hexString.length() + " must be even."); } byte[] bytes = new byte[hexString.length() / 2]; for (int i = 0; i < bytes.length; i++) { int d1 = extractHexDigit(hexString, 2 * i); int d2 = extractHexDigit(hexString, 2 * i + 1); bytes[i] = (byte) (d1 << 4 | d2); } return new LiteralByteString(bytes); } // ================================================================= // byte[] -> ByteString /** * Copies the given bytes into a {@code ByteString}. * * @param bytes source array * @param offset offset in source array * @param size number of bytes to copy * @return new {@code ByteString} * @throws IndexOutOfBoundsException if {@code offset} or {@code size} are out of bounds */ public static ByteString copyFrom(byte[] bytes, int offset, int size) { checkRange(offset, offset + size, bytes.length); return new LiteralByteString(byteArrayCopier.copyFrom(bytes, offset, size)); } /** * Copies the given bytes into a {@code ByteString}. * * @param bytes to copy * @return new {@code ByteString} */ public static ByteString copyFrom(byte[] bytes) { return copyFrom(bytes, 0, bytes.length); } /** * Wraps the given bytes into a {@code ByteString}. Intended for internal usage within the * library. */ static ByteString wrap(ByteBuffer buffer) { if (buffer.hasArray()) { final int offset = buffer.arrayOffset(); return ByteString.wrap(buffer.array(), offset + buffer.position(), buffer.remaining()); } else { return new NioByteString(buffer); } } // For use in tests static ByteString nioByteString(ByteBuffer buffer) { return new NioByteString(buffer); } /** * Wraps the given bytes into a {@code ByteString}. Intended for internal usage within the library * to force a classload of ByteString before LiteralByteString. */ static ByteString wrap(byte[] bytes) { // TODO: Return EMPTY when bytes are empty to reduce allocations? return new LiteralByteString(bytes); } /** * Wraps the given bytes into a {@code ByteString}. Intended for internal usage within the library * to force a classload of ByteString before BoundedByteString and LiteralByteString. */ static ByteString wrap(byte[] bytes, int offset, int length) { return new BoundedByteString(bytes, offset, length); } /** * Copies the next {@code size} bytes from a {@code java.nio.ByteBuffer} into a {@code * ByteString}. * * @param bytes source buffer * @param size number of bytes to copy * @return new {@code ByteString} * @throws IndexOutOfBoundsException if {@code size > bytes.remaining()} */ public static ByteString copyFrom(ByteBuffer bytes, int size) { checkRange(0, size, bytes.remaining()); byte[] copy = new byte[size]; bytes.get(copy); return new LiteralByteString(copy); } /** * Copies the remaining bytes from a {@code java.nio.ByteBuffer} into a {@code ByteString}. * * @param bytes sourceBuffer * @return new {@code ByteString} */ public static ByteString copyFrom(ByteBuffer bytes) { return copyFrom(bytes, bytes.remaining()); } /** * Encodes {@code text} into a sequence of bytes using the named charset and returns the result as * a {@code ByteString}. * * @param text source string * @param charsetName encoding to use * @return new {@code ByteString} * @throws UnsupportedEncodingException if the encoding isn't found */ public static ByteString copyFrom(String text, String charsetName) throws UnsupportedEncodingException { return new LiteralByteString(text.getBytes(charsetName)); } /** * Encodes {@code text} into a sequence of bytes using the named charset and returns the result as * a {@code ByteString}. * * @param text source string * @param charset encode using this charset * @return new {@code ByteString} */ public static ByteString copyFrom(String text, Charset charset) { return new LiteralByteString(text.getBytes(charset)); } /** * Encodes {@code text} into a sequence of UTF-8 bytes and returns the result as a {@code * ByteString}. * * @param text source string * @return new {@code ByteString} */ public static ByteString copyFromUtf8(String text) { return new LiteralByteString(text.getBytes(Internal.UTF_8)); } // ================================================================= // InputStream -> ByteString /** * Completely reads the given stream's bytes into a {@code ByteString}, blocking if necessary * until all bytes are read through to the end of the stream. * *

Performance notes: The returned {@code ByteString} is an immutable tree of byte * arrays ("chunks") of the stream data. The first chunk is small, with subsequent chunks each * being double the size, up to 8K. * *

Each byte read from the input stream will be copied twice to ensure that the resulting * ByteString is truly immutable. * * @param streamToDrain The source stream, which is read completely but not closed. * @return A new {@code ByteString} which is made up of chunks of various sizes, depending on the * behavior of the underlying stream. * @throws IOException if there is a problem reading the underlying stream * @throws IllegalArgumentException if the stream supplies more than Integer.MAX_VALUE bytes */ public static ByteString readFrom(InputStream streamToDrain) throws IOException { return readFrom(streamToDrain, MIN_READ_FROM_CHUNK_SIZE, MAX_READ_FROM_CHUNK_SIZE); } /** * Completely reads the given stream's bytes into a {@code ByteString}, blocking if necessary * until all bytes are read through to the end of the stream. * *

Performance notes: The returned {@code ByteString} is an immutable tree of byte * arrays ("chunks") of the stream data. The chunkSize parameter sets the size of these byte * arrays. * *

Each byte read from the input stream will be copied twice to ensure that the resulting * ByteString is truly immutable. * * @param streamToDrain The source stream, which is read completely but not closed. * @param chunkSize The size of the chunks in which to read the stream. * @return A new {@code ByteString} which is made up of chunks of the given size. * @throws IOException if there is a problem reading the underlying stream * @throws IllegalArgumentException if the stream supplies more than Integer.MAX_VALUE bytes */ public static ByteString readFrom(InputStream streamToDrain, int chunkSize) throws IOException { return readFrom(streamToDrain, chunkSize, chunkSize); } /** * Helper method that takes the chunk size range as a parameter. * * @param streamToDrain the source stream, which is read completely but not closed * @param minChunkSize the minimum size of the chunks in which to read the stream * @param maxChunkSize the maximum size of the chunks in which to read the stream * @return a new {@code ByteString} which is made up of chunks within the given size range * @throws IOException if there is a problem reading the underlying stream * @throws IllegalArgumentException if the stream supplies more than Integer.MAX_VALUE bytes */ public static ByteString readFrom(InputStream streamToDrain, int minChunkSize, int maxChunkSize) throws IOException { Collection results = new ArrayList(); // copy the inbound bytes into a list of chunks; the chunk size // grows exponentially to support both short and long streams. int chunkSize = minChunkSize; while (true) { ByteString chunk = readChunk(streamToDrain, chunkSize); if (chunk == null) { break; } results.add(chunk); chunkSize = Math.min(chunkSize * 2, maxChunkSize); } return ByteString.copyFrom(results); } /** * Blocks until a chunk of the given size can be made from the stream, or EOF is reached. Calls * read() repeatedly in case the given stream implementation doesn't completely fill the given * buffer in one read() call. * * @return A chunk of the desired size, or else a chunk as large as was available when end of * stream was reached. Returns null if the given stream had no more data in it. */ private static ByteString readChunk(InputStream in, final int chunkSize) throws IOException { final byte[] buf = new byte[chunkSize]; int bytesRead = 0; while (bytesRead < chunkSize) { final int count = in.read(buf, bytesRead, chunkSize - bytesRead); if (count == -1) { break; } bytesRead += count; } if (bytesRead == 0) { return null; } // Always make a copy since InputStream could steal a reference to buf. return ByteString.copyFrom(buf, 0, bytesRead); } // ================================================================= // Multiple ByteStrings -> One ByteString /** * Concatenate the given {@code ByteString} to this one. Short concatenations, of total size * smaller than {@link ByteString#CONCATENATE_BY_COPY_SIZE}, are produced by copying the * underlying bytes (as per Rope.java, * BAP95 . In general, the concatenate involves no copying. * * @param other string to concatenate * @return a new {@code ByteString} instance * @throws IllegalArgumentException if the combined size of the two byte strings exceeds * Integer.MAX_VALUE */ public final ByteString concat(ByteString other) { if (Integer.MAX_VALUE - size() < other.size()) { throw new IllegalArgumentException( "ByteString would be too long: " + size() + "+" + other.size()); } return RopeByteString.concatenate(this, other); } /** * Concatenates all byte strings in the iterable and returns the result. This is designed to run * in O(list size), not O(total bytes). * *

The returned {@code ByteString} is not necessarily a unique object. If the list is empty, * the returned object is the singleton empty {@code ByteString}. If the list has only one * element, that {@code ByteString} will be returned without copying. * * @param byteStrings strings to be concatenated * @return new {@code ByteString} * @throws IllegalArgumentException if the combined size of the byte strings exceeds * Integer.MAX_VALUE */ public static ByteString copyFrom(Iterable byteStrings) { // Determine the size; final int size; if (!(byteStrings instanceof Collection)) { int tempSize = 0; for (Iterator iter = byteStrings.iterator(); iter.hasNext(); iter.next(), ++tempSize) {} size = tempSize; } else { size = ((Collection) byteStrings).size(); } if (size == 0) { return EMPTY; } return balancedConcat(byteStrings.iterator(), size); } // Internal function used by copyFrom(Iterable). // Create a balanced concatenation of the next "length" elements from the // iterable. private static ByteString balancedConcat(Iterator iterator, int length) { if (length < 1) { throw new IllegalArgumentException(String.format("length (%s) must be >= 1", length)); } ByteString result; if (length == 1) { result = iterator.next(); } else { int halfLength = length >>> 1; ByteString left = balancedConcat(iterator, halfLength); ByteString right = balancedConcat(iterator, length - halfLength); result = left.concat(right); } return result; } // ================================================================= // ByteString -> byte[] /** * Copies bytes into a buffer at the given offset. * *

To copy a subset of bytes, you call this method on the return value of {@link * #substring(int, int)}. Example: {@code byteString.substring(start, end).copyTo(target, offset)} * * @param target buffer to copy into * @param offset in the target buffer * @throws IndexOutOfBoundsException if the offset is negative or too large */ public void copyTo(byte[] target, int offset) { copyTo(target, 0, offset, size()); } /** * Copies bytes into a buffer. * * @param target buffer to copy into * @param sourceOffset offset within these bytes * @param targetOffset offset within the target buffer * @param numberToCopy number of bytes to copy * @throws IndexOutOfBoundsException if an offset or size is negative or too large * @deprecated Instead, call {@code byteString.substring(sourceOffset, sourceOffset + * numberToCopy).copyTo(target, targetOffset)} */ @Deprecated public final void copyTo(byte[] target, int sourceOffset, int targetOffset, int numberToCopy) { checkRange(sourceOffset, sourceOffset + numberToCopy, size()); checkRange(targetOffset, targetOffset + numberToCopy, target.length); if (numberToCopy > 0) { copyToInternal(target, sourceOffset, targetOffset, numberToCopy); } } /** * Internal (package private) implementation of {@link #copyTo(byte[],int,int,int)}. It assumes * that all error checking has already been performed and that {@code numberToCopy > 0}. */ protected abstract void copyToInternal( byte[] target, int sourceOffset, int targetOffset, int numberToCopy); /** * Copies bytes into a ByteBuffer. * *

To copy a subset of bytes, you call this method on the return value of {@link * #substring(int, int)}. Example: {@code byteString.substring(start, end).copyTo(target)} * * @param target ByteBuffer to copy into. * @throws java.nio.ReadOnlyBufferException if the {@code target} is read-only * @throws java.nio.BufferOverflowException if the {@code target}'s remaining() space is not large * enough to hold the data. */ public abstract void copyTo(ByteBuffer target); /** * Copies bytes to a {@code byte[]}. * * @return copied bytes */ public final byte[] toByteArray() { final int size = size(); if (size == 0) { return Internal.EMPTY_BYTE_ARRAY; } byte[] result = new byte[size]; copyToInternal(result, 0, 0, size); return result; } /** * Writes a copy of the contents of this byte string to the specified output stream argument. * * @param out the output stream to which to write the data. * @throws IOException if an I/O error occurs. */ public abstract void writeTo(OutputStream out) throws IOException; /** * Writes a specified part of this byte string to an output stream. * * @param out the output stream to which to write the data. * @param sourceOffset offset within these bytes * @param numberToWrite number of bytes to write * @throws IOException if an I/O error occurs. * @throws IndexOutOfBoundsException if an offset or size is negative or too large */ final void writeTo(OutputStream out, int sourceOffset, int numberToWrite) throws IOException { checkRange(sourceOffset, sourceOffset + numberToWrite, size()); if (numberToWrite > 0) { writeToInternal(out, sourceOffset, numberToWrite); } } /** * Internal version of {@link #writeTo(OutputStream,int,int)} that assumes all error checking has * already been done. */ abstract void writeToInternal(OutputStream out, int sourceOffset, int numberToWrite) throws IOException; /** * Writes this {@link ByteString} to the provided {@link ByteOutput}. Calling this method may * result in multiple operations on the target {@link ByteOutput}. * *

This method may expose internal backing buffers of the {@link ByteString} to the {@link * ByteOutput} in order to avoid additional copying overhead. It would be possible for a malicious * {@link ByteOutput} to corrupt the {@link ByteString}. Use with caution! * * @param byteOutput the output target to receive the bytes * @throws IOException if an I/O error occurs * @see UnsafeByteOperations#unsafeWriteTo(ByteString, ByteOutput) */ abstract void writeTo(ByteOutput byteOutput) throws IOException; /** * This method behaves exactly the same as {@link #writeTo(ByteOutput)} unless the {@link * ByteString} is a rope. For ropes, the leaf nodes are written in reverse order to the {@code * byteOutput}. * * @param byteOutput the output target to receive the bytes * @throws IOException if an I/O error occurs * @see UnsafeByteOperations#unsafeWriteToReverse(ByteString, ByteOutput) */ abstract void writeToReverse(ByteOutput byteOutput) throws IOException; /** * Constructs a read-only {@code java.nio.ByteBuffer} whose content is equal to the contents of * this byte string. The result uses the same backing array as the byte string, if possible. * * @return wrapped bytes */ public abstract ByteBuffer asReadOnlyByteBuffer(); /** * Constructs a list of read-only {@code java.nio.ByteBuffer} objects such that the concatenation * of their contents is equal to the contents of this byte string. The result uses the same * backing arrays as the byte string. * *

By returning a list, implementations of this method may be able to avoid copying even when * there are multiple backing arrays. * * @return a list of wrapped bytes */ public abstract List asReadOnlyByteBufferList(); /** * Constructs a new {@code String} by decoding the bytes using the specified charset. * * @param charsetName encode using this charset * @return new string * @throws UnsupportedEncodingException if charset isn't recognized */ public final String toString(String charsetName) throws UnsupportedEncodingException { try { return toString(Charset.forName(charsetName)); } catch (UnsupportedCharsetException e) { UnsupportedEncodingException exception = new UnsupportedEncodingException(charsetName); exception.initCause(e); throw exception; } } /** * Constructs a new {@code String} by decoding the bytes using the specified charset. Returns the * same empty String if empty. * * @param charset encode using this charset * @return new string */ public final String toString(Charset charset) { return size() == 0 ? "" : toStringInternal(charset); } /** * Constructs a new {@code String} by decoding the bytes using the specified charset. * * @param charset encode using this charset * @return new string */ protected abstract String toStringInternal(Charset charset); // ================================================================= // UTF-8 decoding /** * Constructs a new {@code String} by decoding the bytes as UTF-8. * * @return new string using UTF-8 encoding */ public final String toStringUtf8() { return toString(Internal.UTF_8); } /** * Tells whether this {@code ByteString} represents a well-formed UTF-8 byte sequence, such that * the original bytes can be converted to a String object and then round tripped back to bytes * without loss. * *

More precisely, returns {@code true} whenever: * *

{@code
   * Arrays.equals(byteString.toByteArray(),
   *     new String(byteString.toByteArray(), "UTF-8").getBytes("UTF-8"))
   * }
* *

This method returns {@code false} for "overlong" byte sequences, as well as for 3-byte * sequences that would map to a surrogate character, in accordance with the restricted definition * of UTF-8 introduced in Unicode 3.1. 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 character byte sequences. * *

See the Unicode Standard,
* Table 3-6. UTF-8 Bit Distribution,
* Table 3-7. Well Formed UTF-8 Byte Sequences. * * @return whether the bytes in this {@code ByteString} are a well-formed UTF-8 byte sequence */ public abstract boolean isValidUtf8(); /** * Tells whether the given byte sequence is a well-formed, malformed, or incomplete UTF-8 byte * sequence. This method accepts and returns a partial state result, allowing the bytes for a * complete UTF-8 byte sequence to be composed from multiple {@code ByteString} segments. * * @param state either {@code 0} (if this is the initial decoding operation) or the value returned * from a call to a partial decoding method for the previous bytes * @param offset offset of the first byte to check * @param length number of bytes to check * @return {@code -1} if the partial byte sequence is definitely malformed, {@code 0} 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. */ protected abstract int partialIsValidUtf8(int state, int offset, int length); // ================================================================= // equals() and hashCode() @Override public abstract boolean equals(Object o); /** Base class for leaf {@link ByteString}s (i.e. non-ropes). */ abstract static class LeafByteString extends ByteString { private static final long serialVersionUID = 1L; @Override protected final int getTreeDepth() { return 0; } @Override protected final boolean isBalanced() { return true; } @Override void writeToReverse(ByteOutput byteOutput) throws IOException { writeTo(byteOutput); } /** * Check equality of the substring of given length of this object starting at zero with another * {@code ByteString} substring starting at offset. * * @param other what to compare a substring in * @param offset offset into other * @param length number of bytes to compare * @return true for equality of substrings, else false. */ abstract boolean equalsRange(ByteString other, int offset, int length); private LeafByteString() {} } /** * Compute the hashCode using the traditional algorithm from {@link ByteString}. * * @return hashCode value */ @Override public final int hashCode() { int h = hash; if (h == 0) { int size = size(); h = partialHash(size, 0, size); if (h == 0) { h = 1; } hash = h; } return h; } // ================================================================= // Input stream /** * Creates an {@code InputStream} which can be used to read the bytes. * *

The {@link InputStream} returned by this method is guaranteed to be completely non-blocking. * The method {@link InputStream#available()} returns the number of bytes remaining in the stream. * The methods {@link InputStream#read(byte[])}, {@link InputStream#read(byte[],int,int)} and * {@link InputStream#skip(long)} will read/skip as many bytes as are available. The method {@link * InputStream#markSupported()} returns {@code true}. * *

The methods in the returned {@link InputStream} might not be thread safe. * * @return an input stream that returns the bytes of this byte string. */ public abstract InputStream newInput(); /** * Creates a {@link CodedInputStream} which can be used to read the bytes. Using this is often * more efficient than creating a {@link CodedInputStream} that wraps the result of {@link * #newInput()}. * * @return stream based on wrapped data */ public abstract CodedInputStream newCodedInput(); // ================================================================= // Output stream /** * Creates a new {@link Output} with the given initial capacity. Call {@link * Output#toByteString()} to create the {@code ByteString} instance. * *

A {@link ByteString.Output} offers the same functionality as a {@link * ByteArrayOutputStream}, except that it returns a {@link ByteString} rather than a {@code byte} * array. * * @param initialCapacity estimate of number of bytes to be written * @return {@code OutputStream} for building a {@code ByteString} */ public static Output newOutput(int initialCapacity) { return new Output(initialCapacity); } /** * Creates a new {@link Output}. Call {@link Output#toByteString()} to create the {@code * ByteString} instance. * *

A {@link ByteString.Output} offers the same functionality as a {@link * ByteArrayOutputStream}, except that it returns a {@link ByteString} rather than a {@code byte * array}. * * @return {@code OutputStream} for building a {@code ByteString} */ public static Output newOutput() { return new Output(CONCATENATE_BY_COPY_SIZE); } /** * Outputs to a {@code ByteString} instance. Call {@link #toByteString()} to create the {@code * ByteString} instance. */ public static final class Output extends OutputStream { // Implementation note. // The public methods of this class must be synchronized. ByteStrings // are guaranteed to be immutable. Without some sort of locking, it could // be possible for one thread to call toByteSring(), while another thread // is still modifying the underlying byte array. private static final byte[] EMPTY_BYTE_ARRAY = new byte[0]; // argument passed by user, indicating initial capacity. private final int initialCapacity; // ByteStrings to be concatenated to create the result private final ArrayList flushedBuffers; // Total number of bytes in the ByteStrings of flushedBuffers private int flushedBuffersTotalBytes; // Current buffer to which we are writing private byte[] buffer; // Location in buffer[] to which we write the next byte. private int bufferPos; /** * Creates a new ByteString output stream with the specified initial capacity. * * @param initialCapacity the initial capacity of the output stream. */ Output(int initialCapacity) { if (initialCapacity < 0) { throw new IllegalArgumentException("Buffer size < 0"); } this.initialCapacity = initialCapacity; this.flushedBuffers = new ArrayList(); this.buffer = new byte[initialCapacity]; } @Override public synchronized void write(int b) { if (bufferPos == buffer.length) { flushFullBuffer(1); } buffer[bufferPos++] = (byte) b; } @Override public synchronized void write(byte[] b, int offset, int length) { if (length <= buffer.length - bufferPos) { // The bytes can fit into the current buffer. System.arraycopy(b, offset, buffer, bufferPos, length); bufferPos += length; } else { // Use up the current buffer int copySize = buffer.length - bufferPos; System.arraycopy(b, offset, buffer, bufferPos, copySize); offset += copySize; length -= copySize; // Flush the buffer, and get a new buffer at least big enough to cover // what we still need to output flushFullBuffer(length); System.arraycopy(b, offset, buffer, /* count= */ 0, length); bufferPos = length; } } /** * Creates a byte string with the size and contents of this output stream. This does not create * a new copy of the underlying bytes. If the stream size grows dynamically, the runtime is * O(log n) in respect to the number of bytes written to the {@link Output}. If the stream size * stays within the initial capacity, the runtime is O(1). * * @return the current contents of this output stream, as a byte string. */ public synchronized ByteString toByteString() { flushLastBuffer(); return ByteString.copyFrom(flushedBuffers); } /** * Writes the complete contents of this byte array output stream to the specified output stream * argument. * * @param out the output stream to which to write the data. * @throws IOException if an I/O error occurs. */ public void writeTo(OutputStream out) throws IOException { ByteString[] cachedFlushBuffers; byte[] cachedBuffer; int cachedBufferPos; synchronized (this) { // Copy the information we need into local variables so as to hold // the lock for as short a time as possible. cachedFlushBuffers = flushedBuffers.toArray(new ByteString[0]); cachedBuffer = buffer; cachedBufferPos = bufferPos; } for (ByteString byteString : cachedFlushBuffers) { byteString.writeTo(out); } out.write(Arrays.copyOf(cachedBuffer, cachedBufferPos)); } /** * Returns the current size of the output stream. * * @return the current size of the output stream */ public synchronized int size() { return flushedBuffersTotalBytes + bufferPos; } /** * Resets this stream, so that all currently accumulated output in the output stream is * discarded. The output stream can be used again, reusing the already allocated buffer space. */ public synchronized void reset() { flushedBuffers.clear(); flushedBuffersTotalBytes = 0; bufferPos = 0; } @Override public String toString() { return String.format( "", Integer.toHexString(System.identityHashCode(this)), size()); } /** * Internal function used by writers. The current buffer is full, and the writer needs a new * buffer whose size is at least the specified minimum size. */ private void flushFullBuffer(int minSize) { flushedBuffers.add(new LiteralByteString(buffer)); flushedBuffersTotalBytes += buffer.length; // We want to increase our total capacity by 50%, but as a minimum, // the new buffer should also at least be >= minSize and // >= initial Capacity. int newSize = Math.max(initialCapacity, Math.max(minSize, flushedBuffersTotalBytes >>> 1)); buffer = new byte[newSize]; bufferPos = 0; } /** * Internal function used by {@link #toByteString()}. The current buffer may or may not be full, * but it needs to be flushed. */ private void flushLastBuffer() { if (bufferPos < buffer.length) { if (bufferPos > 0) { byte[] bufferCopy = Arrays.copyOf(buffer, bufferPos); flushedBuffers.add(new LiteralByteString(bufferCopy)); } // We reuse this buffer for further writes. } else { // Buffer is completely full. Huzzah. flushedBuffers.add(new LiteralByteString(buffer)); // 99% of the time, we're not going to use this OutputStream again. // We set buffer to an empty byte stream so that we're handling this // case without wasting space. In the rare case that more writes // *do* occur, this empty buffer will be flushed and an appropriately // sized new buffer will be created. buffer = EMPTY_BYTE_ARRAY; } flushedBuffersTotalBytes += bufferPos; bufferPos = 0; } } /** * Constructs a new {@code ByteString} builder, which allows you to efficiently construct a {@code * ByteString} by writing to a {@link CodedOutputStream}. Using this is much more efficient than * calling {@code newOutput()} and wrapping that in a {@code CodedOutputStream}. * *

This is package-private because it's a somewhat confusing interface. Users can call {@link * Message#toByteString()} instead of calling this directly. * * @param size The target byte size of the {@code ByteString}. You must write exactly this many * bytes before building the result. * @return the builder */ static CodedBuilder newCodedBuilder(int size) { return new CodedBuilder(size); } /** See {@link ByteString#newCodedBuilder(int)}. */ static final class CodedBuilder { private final CodedOutputStream output; private final byte[] buffer; private CodedBuilder(int size) { buffer = new byte[size]; output = CodedOutputStream.newInstance(buffer); } public ByteString build() { output.checkNoSpaceLeft(); // We can be confident that the CodedOutputStream will not modify the // underlying bytes anymore because it already wrote all of them. So, // no need to make a copy. return new LiteralByteString(buffer); } public CodedOutputStream getCodedOutput() { return output; } } // ================================================================= // Methods {@link RopeByteString} needs on instances, which aren't part of the // public API. /** * Return the depth of the tree representing this {@code ByteString}, if any, whose root is this * node. If this is a leaf node, return 0. * * @return tree depth or zero */ protected abstract int getTreeDepth(); /** * Return {@code true} if this ByteString is literal (a leaf node) or a flat-enough tree in the * sense of {@link RopeByteString}. * * @return true if the tree is flat enough */ protected abstract boolean isBalanced(); /** * Return the cached hash code if available. * * @return value of cached hash code or 0 if not computed yet */ protected final int peekCachedHashCode() { return hash; } /** * Compute the hash across the value bytes starting with the given hash, and return the result. * This is used to compute the hash across strings represented as a set of pieces by allowing the * hash computation to be continued from piece to piece. * * @param h starting hash value * @param offset offset into this value to start looking at data values * @param length number of data values to include in the hash computation * @return ending hash value */ protected abstract int partialHash(int h, int offset, int length); /** * Checks that the given index falls within the specified array size. * * @param index the index position to be tested * @param size the length of the array * @throws IndexOutOfBoundsException if the index does not fall within the array. */ static void checkIndex(int index, int size) { if ((index | (size - (index + 1))) < 0) { if (index < 0) { throw new ArrayIndexOutOfBoundsException("Index < 0: " + index); } throw new ArrayIndexOutOfBoundsException("Index > length: " + index + ", " + size); } } /** * Checks that the given range falls within the bounds of an array * * @param startIndex the start index of the range (inclusive) * @param endIndex the end index of the range (exclusive) * @param size the size of the array. * @return the length of the range. * @throws IndexOutOfBoundsException some or all of the range falls outside of the array. */ @CanIgnoreReturnValue static int checkRange(int startIndex, int endIndex, int size) { final int length = endIndex - startIndex; if ((startIndex | endIndex | length | (size - endIndex)) < 0) { if (startIndex < 0) { throw new IndexOutOfBoundsException("Beginning index: " + startIndex + " < 0"); } if (endIndex < startIndex) { throw new IndexOutOfBoundsException( "Beginning index larger than ending index: " + startIndex + ", " + endIndex); } // endIndex >= size throw new IndexOutOfBoundsException("End index: " + endIndex + " >= " + size); } return length; } @Override public final String toString() { return String.format( Locale.ROOT, "", toHexString(identityHashCode(this)), size(), truncateAndEscapeForDisplay()); } private String truncateAndEscapeForDisplay() { final int limit = 50; return size() <= limit ? escapeBytes(this) : escapeBytes(substring(0, limit - 3)) + "..."; } /** * This class implements a {@link com.google.protobuf.ByteString} backed by a single array of * bytes, contiguous in memory. It supports substring by pointing to only a sub-range of the * underlying byte array, meaning that a substring will reference the full byte-array of the * string it's made from, exactly as with {@link String}. * * @author [email protected] (Carl Haverl) */ // Keep this class private to avoid deadlocks in classloading across threads as ByteString's // static initializer loads LiteralByteString and another thread loads LiteralByteString. private static class LiteralByteString extends ByteString.LeafByteString { private static final long serialVersionUID = 1L; protected final byte[] bytes; /** * Creates a {@code LiteralByteString} backed by the given array, without copying. * * @param bytes array to wrap */ LiteralByteString(byte[] bytes) { if (bytes == null) { throw new NullPointerException(); } this.bytes = bytes; } @Override public byte byteAt(int index) { // Unlike most methods in this class, this one is a direct implementation // ignoring the potential offset because we need to do range-checking in the // substring case anyway. return bytes[index]; } @Override byte internalByteAt(int index) { return bytes[index]; } @Override public int size() { return bytes.length; } // ================================================================= // ByteString -> substring @Override public final ByteString substring(int beginIndex, int endIndex) { final int length = checkRange(beginIndex, endIndex, size()); if (length == 0) { return ByteString.EMPTY; } return new BoundedByteString(bytes, getOffsetIntoBytes() + beginIndex, length); } // ================================================================= // ByteString -> byte[] @Override protected void copyToInternal( byte[] target, int sourceOffset, int targetOffset, int numberToCopy) { // Optimized form, not for subclasses, since we don't call // getOffsetIntoBytes() or check the 'numberToCopy' parameter. // TODO: Is not calling getOffsetIntoBytes really saving that much? System.arraycopy(bytes, sourceOffset, target, targetOffset, numberToCopy); } @Override public final void copyTo(ByteBuffer target) { target.put(bytes, getOffsetIntoBytes(), size()); // Copies bytes } @Override public final ByteBuffer asReadOnlyByteBuffer() { return ByteBuffer.wrap(bytes, getOffsetIntoBytes(), size()).asReadOnlyBuffer(); } @Override public final List asReadOnlyByteBufferList() { return Collections.singletonList(asReadOnlyByteBuffer()); } @Override public final void writeTo(OutputStream outputStream) throws IOException { outputStream.write(toByteArray()); } @Override final void writeToInternal(OutputStream outputStream, int sourceOffset, int numberToWrite) throws IOException { outputStream.write(bytes, getOffsetIntoBytes() + sourceOffset, numberToWrite); } @Override final void writeTo(ByteOutput output) throws IOException { output.writeLazy(bytes, getOffsetIntoBytes(), size()); } @Override protected final String toStringInternal(Charset charset) { return new String(bytes, getOffsetIntoBytes(), size(), charset); } // ================================================================= // UTF-8 decoding @Override public final boolean isValidUtf8() { int offset = getOffsetIntoBytes(); return Utf8.isValidUtf8(bytes, offset, offset + size()); } @Override protected final int partialIsValidUtf8(int state, int offset, int length) { int index = getOffsetIntoBytes() + offset; return Utf8.partialIsValidUtf8(state, bytes, index, index + length); } // ================================================================= // equals() and hashCode() @Override public final boolean equals(Object other) { if (other == this) { return true; } if (!(other instanceof ByteString)) { return false; } if (size() != ((ByteString) other).size()) { return false; } if (size() == 0) { return true; } if (other instanceof LiteralByteString) { LiteralByteString otherAsLiteral = (LiteralByteString) other; // If we know the hash codes and they are not equal, we know the byte // strings are not equal. int thisHash = peekCachedHashCode(); int thatHash = otherAsLiteral.peekCachedHashCode(); if (thisHash != 0 && thatHash != 0 && thisHash != thatHash) { return false; } return equalsRange((LiteralByteString) other, 0, size()); } else { // RopeByteString and NioByteString. return other.equals(this); } } /** * Check equality of the substring of given length of this object starting at zero with another * {@code LiteralByteString} substring starting at offset. * * @param other what to compare a substring in * @param offset offset into other * @param length number of bytes to compare * @return true for equality of substrings, else false. */ @Override final boolean equalsRange(ByteString other, int offset, int length) { if (length > other.size()) { throw new IllegalArgumentException("Length too large: " + length + size()); } if (offset + length > other.size()) { throw new IllegalArgumentException( "Ran off end of other: " + offset + ", " + length + ", " + other.size()); } if (other instanceof LiteralByteString) { LiteralByteString lbsOther = (LiteralByteString) other; byte[] thisBytes = bytes; byte[] otherBytes = lbsOther.bytes; int thisLimit = getOffsetIntoBytes() + length; for (int thisIndex = getOffsetIntoBytes(), otherIndex = lbsOther.getOffsetIntoBytes() + offset; (thisIndex < thisLimit); ++thisIndex, ++otherIndex) { if (thisBytes[thisIndex] != otherBytes[otherIndex]) { return false; } } return true; } return other.substring(offset, offset + length).equals(substring(0, length)); } @Override protected final int partialHash(int h, int offset, int length) { return Internal.partialHash(h, bytes, getOffsetIntoBytes() + offset, length); } // ================================================================= // Input stream @Override public final InputStream newInput() { return new ByteArrayInputStream(bytes, getOffsetIntoBytes(), size()); // No copy } @Override public final CodedInputStream newCodedInput() { // We trust CodedInputStream not to modify the bytes, or to give anyone // else access to them. return CodedInputStream.newInstance( bytes, getOffsetIntoBytes(), size(), /* bufferIsImmutable= */ true); } // ================================================================= // Internal methods /** * Offset into {@code bytes[]} to use, non-zero for substrings. * * @return always 0 for this class */ protected int getOffsetIntoBytes() { return 0; } } /** * This class is used to represent the substring of a {@link ByteString} over a single byte array. * In terms of the public API of {@link ByteString}, you end up here by calling {@link * ByteString#copyFrom(byte[])} followed by {@link ByteString#substring(int, int)}. * *

This class contains most of the overhead involved in creating a substring from a {@link * LiteralByteString}. The overhead involves some range-checking and two extra fields. * * @author [email protected] (Carl Haverl) */ // Keep this class private to avoid deadlocks in classloading across threads as ByteString's // static initializer loads LiteralByteString and another thread loads BoundedByteString. private static final class BoundedByteString extends LiteralByteString { private final int bytesOffset; private final int bytesLength; /** * Creates a {@code BoundedByteString} backed by the sub-range of given array, without copying. * * @param bytes array to wrap * @param offset index to first byte to use in bytes * @param length number of bytes to use from bytes * @throws IllegalArgumentException if {@code offset < 0}, {@code length < 0}, or if {@code * offset + length > bytes.length}. */ BoundedByteString(byte[] bytes, int offset, int length) { super(bytes); checkRange(offset, offset + length, bytes.length); this.bytesOffset = offset; this.bytesLength = length; } /** * Gets the byte at the given index. Throws {@link ArrayIndexOutOfBoundsException} for * backwards-compatibility reasons although it would more properly be {@link * IndexOutOfBoundsException}. * * @param index index of byte * @return the value * @throws ArrayIndexOutOfBoundsException {@code index} is < 0 or >= size */ @Override public byte byteAt(int index) { // We must check the index ourselves as we cannot rely on Java array index // checking for substrings. checkIndex(index, size()); return bytes[bytesOffset + index]; } @Override byte internalByteAt(int index) { return bytes[bytesOffset + index]; } @Override public int size() { return bytesLength; } @Override protected int getOffsetIntoBytes() { return bytesOffset; } // ================================================================= // ByteString -> byte[] @Override protected void copyToInternal( byte[] target, int sourceOffset, int targetOffset, int numberToCopy) { System.arraycopy( bytes, getOffsetIntoBytes() + sourceOffset, target, targetOffset, numberToCopy); } // ================================================================= // Serializable private static final long serialVersionUID = 1L; Object writeReplace() { return ByteString.wrap(toByteArray()); } private void readObject(@SuppressWarnings("unused") ObjectInputStream in) throws IOException { throw new InvalidObjectException( "BoundedByteStream instances are not to be serialized directly"); } } /** A {@link ByteString} that wraps around a {@link ByteBuffer}. */ // Keep this class private to avoid deadlocks in classloading across threads as ByteString's // static initializer loads LiteralByteString and another thread loads BoundedByteString. private static final class NioByteString extends ByteString.LeafByteString { private final ByteBuffer buffer; NioByteString(ByteBuffer buffer) { checkNotNull(buffer, "buffer"); // Use native byte order for fast fixed32/64 operations. this.buffer = buffer.slice().order(ByteOrder.nativeOrder()); } // ================================================================= // Serializable /** Magic method that lets us override serialization behavior. */ private Object writeReplace() { return ByteString.copyFrom(buffer.slice()); } /** Magic method that lets us override deserialization behavior. */ private void readObject(@SuppressWarnings("unused") ObjectInputStream in) throws IOException { throw new InvalidObjectException("NioByteString instances are not to be serialized directly"); } // ================================================================= @Override public byte byteAt(int index) { try { return buffer.get(index); } catch (ArrayIndexOutOfBoundsException e) { throw e; } catch (IndexOutOfBoundsException e) { throw new ArrayIndexOutOfBoundsException(e.getMessage()); } } @Override public byte internalByteAt(int index) { // it isn't possible to avoid the bounds checking inside of ByteBuffer, so just use the // default // implementation. return byteAt(index); } @Override public int size() { return buffer.remaining(); } @Override public ByteString substring(int beginIndex, int endIndex) { try { ByteBuffer slice = slice(beginIndex, endIndex); return new NioByteString(slice); } catch (ArrayIndexOutOfBoundsException e) { throw e; } catch (IndexOutOfBoundsException e) { throw new ArrayIndexOutOfBoundsException(e.getMessage()); } } @Override protected void copyToInternal( byte[] target, int sourceOffset, int targetOffset, int numberToCopy) { ByteBuffer slice = buffer.slice(); Java8Compatibility.position(slice, sourceOffset); slice.get(target, targetOffset, numberToCopy); } @Override public void copyTo(ByteBuffer target) { target.put(buffer.slice()); } @Override public void writeTo(OutputStream out) throws IOException { out.write(toByteArray()); } @Override boolean equalsRange(ByteString other, int offset, int length) { return substring(0, length).equals(other.substring(offset, offset + length)); } @Override void writeToInternal(OutputStream out, int sourceOffset, int numberToWrite) throws IOException { if (buffer.hasArray()) { // Optimized write for array-backed buffers. // Note that we're taking the risk that a malicious OutputStream could modify the array. int bufferOffset = buffer.arrayOffset() + buffer.position() + sourceOffset; out.write(buffer.array(), bufferOffset, numberToWrite); return; } ByteBufferWriter.write(slice(sourceOffset, sourceOffset + numberToWrite), out); } @Override void writeTo(ByteOutput output) throws IOException { output.writeLazy(buffer.slice()); } @Override public ByteBuffer asReadOnlyByteBuffer() { return buffer.asReadOnlyBuffer(); } @Override public List asReadOnlyByteBufferList() { return Collections.singletonList(asReadOnlyByteBuffer()); } @Override protected String toStringInternal(Charset charset) { final byte[] bytes; final int offset; final int length; if (buffer.hasArray()) { bytes = buffer.array(); offset = buffer.arrayOffset() + buffer.position(); length = buffer.remaining(); } else { // TODO: Can we optimize this? bytes = toByteArray(); offset = 0; length = bytes.length; } return new String(bytes, offset, length, charset); } @Override public boolean isValidUtf8() { return Utf8.isValidUtf8(buffer); } @Override protected int partialIsValidUtf8(int state, int offset, int length) { return Utf8.partialIsValidUtf8(state, buffer, offset, offset + length); } @Override public boolean equals(Object other) { if (other == this) { return true; } if (!(other instanceof ByteString)) { return false; } ByteString otherString = ((ByteString) other); if (size() != otherString.size()) { return false; } if (size() == 0) { return true; } if (other instanceof NioByteString) { return buffer.equals(((NioByteString) other).buffer); } if (other instanceof RopeByteString) { return other.equals(this); } return buffer.equals(otherString.asReadOnlyByteBuffer()); } @Override protected int partialHash(int h, int offset, int length) { for (int i = offset; i < offset + length; i++) { h = h * 31 + buffer.get(i); } return h; } @Override public InputStream newInput() { return new InputStream() { private final ByteBuffer buf = buffer.slice(); @Override public void mark(int readlimit) { Java8Compatibility.mark(buf); } @Override public boolean markSupported() { return true; } @Override public void reset() throws IOException { try { Java8Compatibility.reset(buf); } catch (InvalidMarkException e) { throw new IOException(e); } } @Override public int available() throws IOException { return buf.remaining(); } @Override public int read() throws IOException { if (!buf.hasRemaining()) { return -1; } return buf.get() & 0xFF; } @Override public int read(byte[] bytes, int off, int len) throws IOException { if (!buf.hasRemaining()) { return -1; } len = Math.min(len, buf.remaining()); buf.get(bytes, off, len); return len; } }; } @Override public CodedInputStream newCodedInput() { return CodedInputStream.newInstance(buffer, true); } /** * Creates a slice of a range of this buffer. * * @param beginIndex the beginning index of the slice (inclusive). * @param endIndex the end index of the slice (exclusive). * @return the requested slice. */ private ByteBuffer slice(int beginIndex, int endIndex) { if (beginIndex < buffer.position() || endIndex > buffer.limit() || beginIndex > endIndex) { throw new IllegalArgumentException( String.format("Invalid indices [%d, %d]", beginIndex, endIndex)); } ByteBuffer slice = buffer.slice(); Java8Compatibility.position(slice, beginIndex - buffer.position()); Java8Compatibility.limit(slice, endIndex - buffer.position()); return slice; } } }





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