1 files changed, 318 insertions, 0 deletions
diff --git a/java/src/main/java/com/google/protobuf/ByteString.java b/java/src/main/java/com/google/protobuf/ByteString.java
new file mode 100644
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--- /dev/null
+++ b/java/src/main/java/com/google/protobuf/ByteString.java
@@ -0,0 +1,318 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.
+// http://code.google.com/p/protobuf/
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.protobuf;
+
+import java.io.InputStream;
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.FilterOutputStream;
+import java.io.UnsupportedEncodingException;
+
+/**
+ * Immutable array of bytes.
+ *
+ * @author crazybob@google.com Bob Lee
+ * @author kenton@google.com Kenton Varda
+ */
+public final class ByteString {
+  private final byte[] bytes;
+
+  private ByteString(byte[] bytes) {
+    this.bytes = bytes;
+  }
+
+  /**
+   * Gets the byte at the given index.
+   *
+   * @throws ArrayIndexOutOfBoundsException {@code index} is < 0 or >= size
+   */
+  public byte byteAt(int index) {
+    return bytes[index];
+  }
+
+  /**
+   * Gets the number of bytes.
+   */
+  public int size() {
+    return this.bytes.length;
+  }
+
+  /**
+   * Returns {@code true} if the size is {@code 0}, {@code false} otherwise.
+   */
+  public boolean isEmpty() {
+    return this.bytes.length == 0;
+  }
+
+  // =================================================================
+  // byte[] -> ByteString
+
+  /**
+   * Empty ByteString.
+   */
+  public static final ByteString EMPTY = new ByteString(new byte[0]);
+
+  /**
+   * Copies the given bytes into a {@code ByteString}.
+   */
+  public static ByteString copyFrom(byte[] bytes, int offset, int size) {
+    byte[] copy = new byte[size];
+    System.arraycopy(bytes, offset, copy, 0, size);
+    return new ByteString(copy);
+  }
+
+  /**
+   * Copies the given bytes into a {@code ByteString}.
+   */
+  public static ByteString copyFrom(byte[] bytes) {
+    return copyFrom(bytes, 0, bytes.length);
+  }
+
+  /**
+   * Encodes {@code text} into a sequence of bytes using the named charset
+   * and returns the result as a {@code ByteString}.
+   */
+  public static ByteString copyFrom(String text, String charsetName)
+      throws UnsupportedEncodingException {
+    return new ByteString(text.getBytes(charsetName));
+  }
+
+  /**
+   * Encodes {@code text} into a sequence of UTF-8 bytes and returns the
+   * result as a {@code ByteString}.
+   */
+  public static ByteString copyFromUtf8(String text) {
+    try {
+      return new ByteString(text.getBytes("UTF-8"));
+    } catch (UnsupportedEncodingException e) {
+      throw new RuntimeException("UTF-8 not supported?", e);
+    }
+  }
+
+  // =================================================================
+  // ByteString -> byte[]
+
+  /**
+   * Copies bytes into a buffer at the given offset.
+   *
+   * @param target buffer to copy into
+   * @param offset in the target buffer
+   */
+  public void copyTo(byte[] target, int offset) {
+    System.arraycopy(bytes, 0, target, offset, bytes.length);
+  }
+
+  /**
+   * 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 size number of bytes to copy
+   */
+  public void copyTo(byte[] target, int sourceOffset, int targetOffset,
+      int size) {
+    System.arraycopy(bytes, sourceOffset, target, targetOffset, size);
+  }
+
+  /**
+   * Copies bytes to a {@code byte[]}.
+   */
+  public byte[] toByteArray() {
+    int size = this.bytes.length;
+    byte[] copy = new byte[size];
+    System.arraycopy(this.bytes, 0, copy, 0, size);
+    return copy;
+  }
+
+  /**
+   * Constructs a new {@code String} by decoding the bytes using the
+   * specified charset.
+   */
+  public String toString(String charsetName)
+      throws UnsupportedEncodingException {
+    return new String(this.bytes, charsetName);
+  }
+
+  /**
+   * Constructs a new {@code String} by decoding the bytes as UTF-8.
+   */
+  public String toStringUtf8() {
+    try {
+      return new String(this.bytes, "UTF-8");
+    } catch (UnsupportedEncodingException e) {
+      throw new RuntimeException("UTF-8 not supported?", e);
+    }
+  }
+
+  // =================================================================
+  // equals() and hashCode()
+
+  @Override
+  public boolean equals(Object o) {
+    if (o == this) {
+      return true;
+    }
+
+    if (!(o instanceof ByteString)) {
+      return false;
+    }
+
+    ByteString other = (ByteString) o;
+    int size = this.bytes.length;
+    if (size != other.bytes.length) {
+      return false;
+    }
+
+    byte[] bytes = this.bytes;
+    byte[] otherBytes = other.bytes;
+    for (int i = 0; i < size; i++) {
+      if (bytes[i] != otherBytes[i]) {
+        return false;
+      }
+    }
+
+    return true;
+  }
+
+  volatile int hash = 0;
+
+  @Override
+  public int hashCode() {
+    int h = this.hash;
+
+    if (h == 0) {
+      byte[] bytes = this.bytes;
+      int size = this.bytes.length;
+
+      h = size;
+      for (int i = 0; i < size; i++) {
+        h = h * 31 + bytes[i];
+      }
+      if (h == 0) {
+        h = 1;
+      }
+
+      this.hash = h;
+    }
+
+    return h;
+  }
+
+  // =================================================================
+  // Input stream
+
+  /**
+   * Creates an {@code InputStream} which can be used to read the bytes.
+   */
+  public InputStream newInput() {
+    return new ByteArrayInputStream(bytes);
+  }
+
+  /**
+   * Creates a {@link CodedInputStream} which can be used to read the bytes.
+   * Using this is more efficient than creating a {@link CodedInputStream}
+   * wrapping the result of {@link #newInput()}.
+   */
+  public CodedInputStream newCodedInput() {
+    // We trust CodedInputStream not to modify the bytes, or to give anyone
+    // else access to them.
+    return CodedInputStream.newInstance(bytes);
+  }
+
+  // =================================================================
+  // Output stream
+
+  /**
+   * Creates a new {@link Output} with the given initial capacity.
+   */
+  public static Output newOutput(int initialCapacity) {
+    return new Output(new ByteArrayOutputStream(initialCapacity));
+  }
+
+  /**
+   * Creates a new {@link Output}.
+   */
+  public static Output newOutput() {
+    return newOutput(32);
+  }
+
+  /**
+   * Outputs to a {@code ByteString} instance. Call {@link #toByteString()} to
+   * create the {@code ByteString} instance.
+   */
+  public static final class Output extends FilterOutputStream {
+    private final ByteArrayOutputStream bout;
+
+    /**
+     * Constructs a new output with the given initial capacity.
+     */
+    private Output(ByteArrayOutputStream bout) {
+      super(bout);
+      this.bout = bout;
+    }
+
+    /**
+     * Creates a {@code ByteString} instance from this {@code Output}.
+     */
+    public ByteString toByteString() {
+      byte[] byteArray = bout.toByteArray();
+      return new ByteString(byteArray);
+    }
+  }
+
+  /**
+   * Constructs a new ByteString builder, which allows you to efficiently
+   * construct a {@code ByteString} by writing to a {@link CodedOutputSteam}.
+   * Using this is much more efficient than calling {@code newOutput()} and
+   * wrapping that in a {@code CodedOutputStream}.
+   *
+   * <p>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.
+   */
+  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 ByteString(buffer);
+    }
+
+    public CodedOutputStream getCodedOutput() {
+      return output;
+    }
+  }
+}