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Diffstat (limited to 'java/src/main/java/com/google/protobuf/BoundedByteString.java')
-rw-r--r-- | java/src/main/java/com/google/protobuf/BoundedByteString.java | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/java/src/main/java/com/google/protobuf/BoundedByteString.java b/java/src/main/java/com/google/protobuf/BoundedByteString.java new file mode 100644 index 00000000..cd4982c3 --- /dev/null +++ b/java/src/main/java/com/google/protobuf/BoundedByteString.java @@ -0,0 +1,163 @@ +// 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 +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +package com.google.protobuf; + +import java.util.NoSuchElementException; + +/** + * 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)}. + * + * <p>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 carlanton@google.com (Carl Haverl) + */ +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); + if (offset < 0) { + throw new IllegalArgumentException("Offset too small: " + offset); + } + if (length < 0) { + throw new IllegalArgumentException("Length too small: " + offset); + } + if ((long) offset + length > bytes.length) { + throw new IllegalArgumentException( + "Offset+Length too large: " + offset + "+" + 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. + if (index < 0) { + throw new ArrayIndexOutOfBoundsException("Index too small: " + index); + } + if (index >= size()) { + throw new ArrayIndexOutOfBoundsException( + "Index too large: " + index + ", " + size()); + } + + 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); + } + + // ================================================================= + // ByteIterator + + @Override + public ByteIterator iterator() { + return new BoundedByteIterator(); + } + + private class BoundedByteIterator implements ByteIterator { + + private int position; + private final int limit; + + private BoundedByteIterator() { + position = getOffsetIntoBytes(); + limit = position + size(); + } + + public boolean hasNext() { + return (position < limit); + } + + public Byte next() { + // Boxing calls Byte.valueOf(byte), which does not instantiate. + return nextByte(); + } + + public byte nextByte() { + if (position >= limit) { + throw new NoSuchElementException(); + } + return bytes[position++]; + } + + public void remove() { + throw new UnsupportedOperationException(); + } + } +} |