Integrate from google internal.

Java files are moved to un-do the hack in the prevous commit, which
moved the java files to the original position for integration.

1 files changed, 669 insertions, 0 deletions

diff --git a/java/core/src/main/java/com/google/protobuf/Internal.java b/java/core/src/main/java/com/google/protobuf/Internal.java
new file mode 100644
index 00000000..dca5f23b
--- /dev/null
+++ b/java/core/src/main/java/com/google/protobuf/Internal.java
@@ -0,0 +1,669 @@
+// Copyright 2007 Google Inc. All rights reserved.
+
+package com.google.protobuf;
+
+import java.io.IOException;
+import java.lang.reflect.Method;
+import java.nio.ByteBuffer;
+import java.nio.charset.Charset;
+import java.util.AbstractList;
+import java.util.AbstractMap;
+import java.util.AbstractSet;
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * The classes contained within are used internally by the Protocol Buffer
+ * library and generated message implementations. They are public only because
+ * those generated messages do not reside in the {@code protobuf} package.
+ * Others should not use this class directly.
+ *
+ * @author kenton@google.com (Kenton Varda)
+ */
+public class Internal {
+
+  protected static final Charset UTF_8 = Charset.forName("UTF-8");
+  protected static final Charset ISO_8859_1 = Charset.forName("ISO-8859-1");
+
+  /**
+   * Helper called by generated code to construct default values for string
+   * fields.
+   * <p>
+   * The protocol compiler does not actually contain a UTF-8 decoder -- it
+   * just pushes UTF-8-encoded text around without touching it.  The one place
+   * where this presents a problem is when generating Java string literals.
+   * Unicode characters in the string literal would normally need to be encoded
+   * using a Unicode escape sequence, which would require decoding them.
+   * To get around this, protoc instead embeds the UTF-8 bytes into the
+   * generated code and leaves it to the runtime library to decode them.
+   * <p>
+   * It gets worse, though.  If protoc just generated a byte array, like:
+   *   new byte[] {0x12, 0x34, 0x56, 0x78}
+   * Java actually generates *code* which allocates an array and then fills
+   * in each value.  This is much less efficient than just embedding the bytes
+   * directly into the bytecode.  To get around this, we need another
+   * work-around.  String literals are embedded directly, so protoc actually
+   * generates a string literal corresponding to the bytes.  The easiest way
+   * to do this is to use the ISO-8859-1 character set, which corresponds to
+   * the first 256 characters of the Unicode range.  Protoc can then use
+   * good old CEscape to generate the string.
+   * <p>
+   * So we have a string literal which represents a set of bytes which
+   * represents another string.  This function -- stringDefaultValue --
+   * converts from the generated string to the string we actually want.  The
+   * generated code calls this automatically.
+   */
+  public static String stringDefaultValue(String bytes) {
+    return new String(bytes.getBytes(ISO_8859_1), UTF_8);
+  }
+
+  /**
+   * Helper called by generated code to construct default values for bytes
+   * fields.
+   * <p>
+   * This is a lot like {@link #stringDefaultValue}, but for bytes fields.
+   * In this case we only need the second of the two hacks -- allowing us to
+   * embed raw bytes as a string literal with ISO-8859-1 encoding.
+   */
+  public static ByteString bytesDefaultValue(String bytes) {
+    return ByteString.copyFrom(bytes.getBytes(ISO_8859_1));
+  }
+  /**
+   * Helper called by generated code to construct default values for bytes
+   * fields.
+   * <p>
+   * This is like {@link #bytesDefaultValue}, but returns a byte array.
+   */
+  public static byte[] byteArrayDefaultValue(String bytes) {
+    return bytes.getBytes(ISO_8859_1);
+  }
+
+  /**
+   * Helper called by generated code to construct default values for bytes
+   * fields.
+   * <p>
+   * This is like {@link #bytesDefaultValue}, but returns a ByteBuffer.
+   */
+  public static ByteBuffer byteBufferDefaultValue(String bytes) {
+    return ByteBuffer.wrap(byteArrayDefaultValue(bytes));
+  }
+
+  /**
+   * Create a new ByteBuffer and copy all the content of {@code source}
+   * ByteBuffer to the new ByteBuffer. The new ByteBuffer's limit and
+   * capacity will be source.capacity(), and its position will be 0.
+   * Note that the state of {@code source} ByteBuffer won't be changed.
+   */
+  public static ByteBuffer copyByteBuffer(ByteBuffer source) {
+    // Make a duplicate of the source ByteBuffer and read data from the
+    // duplicate. This is to avoid affecting the source ByteBuffer's state.
+    ByteBuffer temp = source.duplicate();
+    // We want to copy all the data in the source ByteBuffer, not just the
+    // remaining bytes.
+    temp.clear();
+    ByteBuffer result = ByteBuffer.allocate(temp.capacity());
+    result.put(temp);
+    result.clear();
+    return result;
+  }
+
+  /**
+   * Helper called by generated code to determine if a byte array is a valid
+   * UTF-8 encoded string such that the original bytes can be converted to
+   * a String object and then back to a byte array round tripping the bytes
+   * without loss.  More precisely, returns {@code true} whenever:
+   * <pre>   {@code
+   * Arrays.equals(byteString.toByteArray(),
+   *     new String(byteString.toByteArray(), "UTF-8").getBytes("UTF-8"))
+   * }</pre>
+   *
+   * <p>This method rejects "overlong" byte sequences, as well as
+   * 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 currently (2011) still accepts 3-byte surrogate character
+   * byte sequences.
+   *
+   * <p>See the Unicode Standard,<br>
+   * Table 3-6. <em>UTF-8 Bit Distribution</em>,<br>
+   * Table 3-7. <em>Well Formed UTF-8 Byte Sequences</em>.
+   *
+   * <p>As of 2011-02, this method simply returns the result of {@link
+   * ByteString#isValidUtf8()}.  Calling that method directly is preferred.
+   *
+   * @param byteString the string to check
+   * @return whether the byte array is round trippable
+   */
+  public static boolean isValidUtf8(ByteString byteString) {
+    return byteString.isValidUtf8();
+  }
+
+  /**
+   * Like {@link #isValidUtf8(ByteString)} but for byte arrays.
+   */
+  public static boolean isValidUtf8(byte[] byteArray) {
+    return Utf8.isValidUtf8(byteArray);
+  }
+
+  /**
+   * Helper method to get the UTF-8 bytes of a string.
+   */
+  public static byte[] toByteArray(String value) {
+    return value.getBytes(UTF_8);
+  }
+
+  /**
+   * Helper method to convert a byte array to a string using UTF-8 encoding.
+   */
+  public static String toStringUtf8(byte[] bytes) {
+    return new String(bytes, UTF_8);
+  }
+
+  /**
+   * Interface for an enum value or value descriptor, to be used in FieldSet.
+   * The lite library stores enum values directly in FieldSets but the full
+   * library stores EnumValueDescriptors in order to better support reflection.
+   */
+  public interface EnumLite {
+    int getNumber();
+  }
+
+  /**
+   * Interface for an object which maps integers to {@link EnumLite}s.
+   * {@link Descriptors.EnumDescriptor} implements this interface by mapping
+   * numbers to {@link Descriptors.EnumValueDescriptor}s.  Additionally,
+   * every generated enum type has a static method internalGetValueMap() which
+   * returns an implementation of this type that maps numbers to enum values.
+   */
+  public interface EnumLiteMap<T extends EnumLite> {
+    T findValueByNumber(int number);
+  }
+
+  /**
+   * Helper method for implementing {@link Message#hashCode()} for longs.
+   * @see Long#hashCode()
+   */
+  public static int hashLong(long n) {
+    return (int) (n ^ (n >>> 32));
+  }
+
+  /**
+   * Helper method for implementing {@link Message#hashCode()} for
+   * booleans.
+   * @see Boolean#hashCode()
+   */
+  public static int hashBoolean(boolean b) {
+    return b ? 1231 : 1237;
+  }
+
+  /**
+   * Helper method for implementing {@link Message#hashCode()} for enums.
+   * <p>
+   * This is needed because {@link java.lang.Enum#hashCode()} is final, but we
+   * need to use the field number as the hash code to ensure compatibility
+   * between statically and dynamically generated enum objects.
+   */
+  public static int hashEnum(EnumLite e) {
+    return e.getNumber();
+  }
+
+  /**
+   * Helper method for implementing {@link Message#hashCode()} for
+   * enum lists.
+   */
+  public static int hashEnumList(List<? extends EnumLite> list) {
+    int hash = 1;
+    for (EnumLite e : list) {
+      hash = 31 * hash + hashEnum(e);
+    }
+    return hash;
+  }
+
+  /**
+   * Helper method for implementing {@link Message#equals(Object)} for bytes field.
+   */
+  public static boolean equals(List<byte[]> a, List<byte[]> b) {
+    if (a.size() != b.size()) return false;
+    for (int i = 0; i < a.size(); ++i) {
+      if (!Arrays.equals(a.get(i), b.get(i))) {
+        return false;
+      }
+    }
+    return true;
+  }
+
+  /**
+   * Helper method for implementing {@link Message#hashCode()} for bytes field.
+   */
+  public static int hashCode(List<byte[]> list) {
+    int hash = 1;
+    for (byte[] bytes : list) {
+      hash = 31 * hash + hashCode(bytes);
+    }
+    return hash;
+  }
+
+  /**
+   * Helper method for implementing {@link Message#hashCode()} for bytes field.
+   */
+  public static int hashCode(byte[] bytes) {
+    // The hash code for a byte array should be the same as the hash code for a
+    // ByteString with the same content. This is to ensure that the generated
+    // hashCode() method will return the same value as the pure reflection
+    // based hashCode() method.
+    return Internal.hashCode(bytes, 0, bytes.length);
+  }
+  
+  /**
+   * Helper method for implementing {@link LiteralByteString#hashCode()}.
+   */
+  static int hashCode(byte[] bytes, int offset, int length) {
+    // The hash code for a byte array should be the same as the hash code for a
+    // ByteString with the same content. This is to ensure that the generated
+    // hashCode() method will return the same value as the pure reflection
+    // based hashCode() method.
+    int h = Internal.partialHash(length, bytes, offset, length);
+    return h == 0 ? 1 : h;
+  }
+
+  /**
+   * Helper method for continuously hashing bytes.
+   */
+  static int partialHash(int h, byte[] bytes, int offset, int length) {
+    for (int i = offset; i < offset + length; i++) {
+      h = h * 31 + bytes[i];
+    }
+    return h;
+  }
+  
+  /**
+   * Helper method for implementing {@link Message#equals(Object)} for bytes
+   * field.
+   */
+  public static boolean equalsByteBuffer(ByteBuffer a, ByteBuffer b) {
+    if (a.capacity() != b.capacity()) {
+      return false;
+    }
+    // ByteBuffer.equals() will only compare the remaining bytes, but we want to
+    // compare all the content.
+    return a.duplicate().clear().equals(b.duplicate().clear());
+  }
+
+  /**
+   * Helper method for implementing {@link Message#equals(Object)} for bytes
+   * field.
+   */
+  public static boolean equalsByteBuffer(
+      List<ByteBuffer> a, List<ByteBuffer> b) {
+    if (a.size() != b.size()) {
+      return false;
+    }
+    for (int i = 0; i < a.size(); ++i) {
+      if (!equalsByteBuffer(a.get(i), b.get(i))) {
+        return false;
+      }
+    }
+    return true;
+  }
+
+  /**
+   * Helper method for implementing {@link Message#hashCode()} for bytes
+   * field.
+   */
+  public static int hashCodeByteBuffer(List<ByteBuffer> list) {
+    int hash = 1;
+    for (ByteBuffer bytes : list) {
+      hash = 31 * hash + hashCodeByteBuffer(bytes);
+    }
+    return hash;
+  }
+
+  private static final int DEFAULT_BUFFER_SIZE = 4096;
+
+  /**
+   * Helper method for implementing {@link Message#hashCode()} for bytes
+   * field.
+   */
+  public static int hashCodeByteBuffer(ByteBuffer bytes) {
+    if (bytes.hasArray()) {
+      // Fast path.
+      int h = partialHash(bytes.capacity(), bytes.array(), bytes.arrayOffset(), bytes.capacity());
+      return h == 0 ? 1 : h;
+    } else {
+      // Read the data into a temporary byte array before calculating the
+      // hash value.
+      final int bufferSize = bytes.capacity() > DEFAULT_BUFFER_SIZE
+          ? DEFAULT_BUFFER_SIZE : bytes.capacity();
+      final byte[] buffer = new byte[bufferSize];
+      final ByteBuffer duplicated = bytes.duplicate();
+      duplicated.clear();
+      int h = bytes.capacity();
+      while (duplicated.remaining() > 0) {
+        final int length = duplicated.remaining() <= bufferSize ?
+            duplicated.remaining() : bufferSize;
+        duplicated.get(buffer, 0, length);
+        h = partialHash(h, buffer, 0, length);
+      }
+      return h == 0 ? 1 : h;
+    }
+  }
+
+  @SuppressWarnings("unchecked")
+  public static <T extends MessageLite> T getDefaultInstance(Class<T> clazz) {
+    try {
+      Method method = clazz.getMethod("getDefaultInstance");
+      return (T) method.invoke(method);
+    } catch (Exception e) {
+      throw new RuntimeException(
+          "Failed to get default instance for " + clazz, e);
+    }
+  }
+
+  /**
+   * An empty byte array constant used in generated code.
+   */
+  public static final byte[] EMPTY_BYTE_ARRAY = new byte[0];
+
+  /**
+   * An empty byte array constant used in generated code.
+   */
+  public static final ByteBuffer EMPTY_BYTE_BUFFER =
+      ByteBuffer.wrap(EMPTY_BYTE_ARRAY);
+
+  /** An empty coded input stream constant used in generated code. */
+  public static final CodedInputStream EMPTY_CODED_INPUT_STREAM =
+      CodedInputStream.newInstance(EMPTY_BYTE_ARRAY);
+
+  /**
+   * Provides an immutable view of {@code List<T>} around a {@code List<F>}.
+   *
+   * Protobuf internal. Used in protobuf generated code only.
+   */
+  public static class ListAdapter<F, T> extends AbstractList<T> {
+    /**
+     * Convert individual elements of the List from F to T.
+     */
+    public interface Converter<F, T> {
+      T convert(F from);
+    }
+
+    private final List<F> fromList;
+    private final Converter<F, T> converter;
+
+    public ListAdapter(List<F> fromList, Converter<F, T> converter) {
+      this.fromList = fromList;
+      this.converter = converter;
+    }
+
+    @Override
+    public T get(int index) {
+      return converter.convert(fromList.get(index));
+    }
+
+    @Override
+    public int size() {
+      return fromList.size();
+    }
+  }
+
+  /**
+   * Wrap around a {@code Map<K, RealValue>} and provide a {@code Map<K, V>}
+   * interface.
+   */
+  public static class MapAdapter<K, V, RealValue> extends AbstractMap<K, V> {
+    /**
+     * An interface used to convert between two types.
+     */
+    public interface Converter<A, B> {
+      B doForward(A object);
+      A doBackward(B object);
+    }
+
+    public static <T extends EnumLite> Converter<Integer, T> newEnumConverter(
+        final EnumLiteMap<T> enumMap, final T unrecognizedValue) {
+      return new Converter<Integer, T>() {
+        public T doForward(Integer value) {
+          T result = enumMap.findValueByNumber(value);
+          return result == null ? unrecognizedValue : result;
+        }
+        public Integer doBackward(T value) {
+          return value.getNumber();
+        }
+      };
+    }
+
+    private final Map<K, RealValue> realMap;
+    private final Converter<RealValue, V> valueConverter;
+
+    public MapAdapter(Map<K, RealValue> realMap,
+        Converter<RealValue, V> valueConverter) {
+      this.realMap = realMap;
+      this.valueConverter = valueConverter;
+    }
+
+    @SuppressWarnings("unchecked")
+    @Override
+    public V get(Object key) {
+      RealValue result = realMap.get(key);
+      if (result == null) {
+        return null;
+      }
+      return valueConverter.doForward(result);
+    }
+
+    @Override
+    public V put(K key, V value) {
+      RealValue oldValue = realMap.put(key, valueConverter.doBackward(value));
+      if (oldValue == null) {
+        return null;
+      }
+      return valueConverter.doForward(oldValue);
+    }
+
+    @Override
+    public Set<java.util.Map.Entry<K, V>> entrySet() {
+      return new SetAdapter(realMap.entrySet());
+    }
+
+    private class SetAdapter extends AbstractSet<Map.Entry<K, V>> {
+      private final Set<Map.Entry<K, RealValue>> realSet;
+      public SetAdapter(Set<Map.Entry<K, RealValue>> realSet) {
+        this.realSet = realSet;
+      }
+
+      @Override
+      public Iterator<java.util.Map.Entry<K, V>> iterator() {
+        return new IteratorAdapter(realSet.iterator());
+      }
+
+      @Override
+      public int size() {
+        return realSet.size();
+      }
+    }
+
+    private class IteratorAdapter implements Iterator<Map.Entry<K, V>> {
+      private final Iterator<Map.Entry<K, RealValue>> realIterator;
+
+      public IteratorAdapter(
+          Iterator<Map.Entry<K, RealValue>> realIterator) {
+        this.realIterator = realIterator;
+      }
+
+      @Override
+      public boolean hasNext() {
+        return realIterator.hasNext();
+      }
+
+      @Override
+      public java.util.Map.Entry<K, V> next() {
+        return new EntryAdapter(realIterator.next());
+      }
+
+      @Override
+      public void remove() {
+        realIterator.remove();
+      }
+    }
+
+    private class EntryAdapter implements Map.Entry<K, V> {
+      private final Map.Entry<K, RealValue> realEntry;
+
+      public EntryAdapter(Map.Entry<K, RealValue> realEntry) {
+        this.realEntry = realEntry;
+      }
+
+      @Override
+      public K getKey() {
+        return realEntry.getKey();
+      }
+
+      @Override
+      public V getValue() {
+        return valueConverter.doForward(realEntry.getValue());
+      }
+
+      @Override
+      public V setValue(V value) {
+        RealValue oldValue = realEntry.setValue(
+            valueConverter.doBackward(value));
+        if (oldValue == null) {
+          return null;
+        }
+        return valueConverter.doForward(oldValue);
+      }
+    }
+  }
+
+  /**
+   * Extends {@link List} to add the capability to make the list immutable and inspect if it is
+   * modifiable.
+   */
+  public static interface ProtobufList<E> extends List<E> {
+
+    /**
+     * Makes this list immutable. All subsequent modifications will throw an
+     * {@link UnsupportedOperationException}.
+     */
+    void makeImmutable();
+
+    /**
+     * Returns whether this list can be modified via the publicly accessible {@link List} methods.
+     */
+    boolean isModifiable();
+  }
+
+  /**
+   * A {@link java.util.List} implementation that avoids boxing the elements into Integers if
+   * possible. Does not support null elements.
+   */
+  public static interface IntList extends ProtobufList<Integer> {
+
+    /**
+     * Like {@link #get(int)} but more efficient in that it doesn't box the returned value.
+     */
+    int getInt(int index);
+
+    /**
+     * Like {@link #add(Object)} but more efficient in that it doesn't box the element.
+     */
+    void addInt(int element);
+
+    /**
+     * Like {@link #set(int, Object)} but more efficient in that it doesn't box the element.
+     */
+    int setInt(int index, int element);
+  }
+
+  /**
+   * A {@link java.util.List} implementation that avoids boxing the elements into Booleans if
+   * possible. Does not support null elements.
+   */
+  public static interface BooleanList extends ProtobufList<Boolean> {
+
+    /**
+     * Like {@link #get(int)} but more efficient in that it doesn't box the returned value.
+     */
+    boolean getBoolean(int index);
+
+    /**
+     * Like {@link #add(Object)} but more efficient in that it doesn't box the element.
+     */
+    void addBoolean(boolean element);
+
+    /**
+     * Like {@link #set(int, Object)} but more efficient in that it doesn't box the element.
+     */
+    boolean setBoolean(int index, boolean element);
+  }
+
+  /**
+   * A {@link java.util.List} implementation that avoids boxing the elements into Longs if
+   * possible. Does not support null elements.
+   */
+  public static interface LongList extends ProtobufList<Long> {
+
+    /**
+     * Like {@link #get(int)} but more efficient in that it doesn't box the returned value.
+     */
+    long getLong(int index);
+
+    /**
+     * Like {@link #add(Object)} but more efficient in that it doesn't box the element.
+     */
+    void addLong(long element);
+
+    /**
+     * Like {@link #set(int, Object)} but more efficient in that it doesn't box the element.
+     */
+    long setLong(int index, long element);
+  }
+
+  /**
+   * A {@link java.util.List} implementation that avoids boxing the elements into Doubles if
+   * possible. Does not support null elements.
+   */
+  public static interface DoubleList extends ProtobufList<Double> {
+
+    /**
+     * Like {@link #get(int)} but more efficient in that it doesn't box the returned value.
+     */
+    double getDouble(int index);
+
+    /**
+     * Like {@link #add(Object)} but more efficient in that it doesn't box the element.
+     */
+    void addDouble(double element);
+
+    /**
+     * Like {@link #set(int, Object)} but more efficient in that it doesn't box the element.
+     */
+    double setDouble(int index, double element);
+  }
+
+  /**
+   * A {@link java.util.List} implementation that avoids boxing the elements into Floats if
+   * possible. Does not support null elements.
+   */
+  public static interface FloatList extends ProtobufList<Float> {
+
+    /**
+     * Like {@link #get(int)} but more efficient in that it doesn't box the returned value.
+     */
+    float getFloat(int index);
+
+    /**
+     * Like {@link #add(Object)} but more efficient in that it doesn't box the element.
+     */
+    void addFloat(float element);
+
+    /**
+     * Like {@link #set(int, Object)} but more efficient in that it doesn't box the element.
+     */
+    float setFloat(int index, float element);
+  }
+}