1 files changed, 267 insertions, 0 deletions
diff --git a/java/core/src/main/java/com/google/protobuf/LiteralByteString.java b/java/core/src/main/java/com/google/protobuf/LiteralByteString.java
new file mode 100644
index 00000000..a18c2792
--- /dev/null
+++ b/java/core/src/main/java/com/google/protobuf/LiteralByteString.java
@@ -0,0 +1,267 @@
+// 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;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.nio.ByteBuffer;
+import java.nio.charset.Charset;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * 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 carlanton@google.com (Carl Haverl)
+ */
+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) {
+    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
+  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(nathanmittler): 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<ByteBuffer> 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
+  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 hashCode(h, bytes, getOffsetIntoBytes() + offset, length);
+  }
+
+  static int hashCode(int h, byte[] bytes, int offset, int length) {
+    for (int i = offset; i < offset + length; i++) {
+      h = h * 31 + bytes[i];
+    }
+    return h;
+  }
+
+  static int hashCode(byte[] bytes) {
+    int h = hashCode(bytes.length, bytes, 0, bytes.length);
+    return h == 0 ? 1 : h;
+  }
+
+  // =================================================================
+  // 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(this);
+  }
+
+  // =================================================================
+  // Internal methods
+
+  /**
+   * Offset into {@code bytes[]} to use, non-zero for substrings.
+   *
+   * @return always 0 for this class
+   */
+  protected int getOffsetIntoBytes() {
+    return 0;
+  }
+}