Integrated internal changes from Google

7 files changed, 1091 insertions, 36 deletions

diff --git a/java/core/src/main/java/com/google/protobuf/CodedInputStream.java b/java/core/src/main/java/com/google/protobuf/CodedInputStream.java
index d6a941b1..511501d4 100644
--- a/java/core/src/main/java/com/google/protobuf/CodedInputStream.java
+++ b/java/core/src/main/java/com/google/protobuf/CodedInputStream.java
@@ -44,6 +44,7 @@ import java.io.InputStream;
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Iterator;
 import java.util.List;
 
 /**
@@ -85,6 +86,43 @@ public abstract class CodedInputStream {
     return new StreamDecoder(input, bufferSize);
   }
 
+  /** Create a new CodedInputStream wrapping the given {@code Iterable <ByteBuffer>}. */
+  public static CodedInputStream newInstance(final Iterable<ByteBuffer> input) {
+    if (!UnsafeDirectNioDecoder.isSupported()) {
+      return newInstance(new IterableByteBufferInputStream(input));
+    }
+    return newInstance(input, false);
+  }
+
+  /** Create a new CodedInputStream wrapping the given {@code Iterable <ByteBuffer>}. */
+  static CodedInputStream newInstance(
+      final Iterable<ByteBuffer> bufs, final boolean bufferIsImmutable) {
+    // flag is to check the type of input's ByteBuffers.
+    // flag equals 1: all ByteBuffers have array.
+    // flag equals 2: all ByteBuffers are direct ByteBuffers.
+    // flag equals 3: some ByteBuffers are direct and some have array.
+    // flag greater than 3: other cases.
+    int flag = 0;
+    // Total size of the input
+    int totalSize = 0;
+    for (ByteBuffer buf : bufs) {
+      totalSize += buf.remaining();
+      if (buf.hasArray()) {
+        flag |= 1;
+      } else if (buf.isDirect()) {
+        flag |= 2;
+      } else {
+        flag |= 4;
+      }
+    }
+    if (flag == 2) {
+      return new IterableDirectByteBufferDecoder(bufs, totalSize, bufferIsImmutable);
+    } else {
+      // TODO(yilunchong): add another decoders to deal case 1 and 3.
+      return newInstance(new IterableByteBufferInputStream(bufs));
+    }
+  }
+
   /** Create a new CodedInputStream wrapping the given byte array. */
   public static CodedInputStream newInstance(final byte[] buf) {
     return newInstance(buf, 0, buf.length);
@@ -3022,4 +3060,848 @@ public abstract class CodedInputStream {
       pos = size - tempPos;
     }
   }
+
+  /**
+   * Implementation of {@link CodedInputStream} that uses an {@link Iterable <ByteBuffer>} as the
+   * data source. Requires the use of {@code sun.misc.Unsafe} to perform fast reads on the buffer.
+   */
+  private static final class IterableDirectByteBufferDecoder extends CodedInputStream {
+    /** The object that need to decode. */
+    private Iterable<ByteBuffer> input;
+    /** The {@link Iterator} with type {@link ByteBuffer} of {@code input} */
+    private Iterator<ByteBuffer> iterator;
+    /** The current ByteBuffer; */
+    private ByteBuffer currentByteBuffer;
+    /**
+     * If {@code true}, indicates that all the buffer are backing a {@link ByteString} and are
+     * therefore considered to be an immutable input source.
+     */
+    private boolean immutable;
+    /**
+     * If {@code true}, indicates that calls to read {@link ByteString} or {@code byte[]}
+     * <strong>may</strong> return slices of the underlying buffer, rather than copies.
+     */
+    private boolean enableAliasing;
+    /** The global total message length limit */
+    private int totalBufferSize;
+    /** The amount of available data in the input beyond {@link #currentLimit}. */
+    private int bufferSizeAfterCurrentLimit;
+    /** The absolute position of the end of the current message. */
+    private int currentLimit = Integer.MAX_VALUE;
+    /** The last tag that was read from this stream. */
+    private int lastTag;
+    /** Total Bytes have been Read from the {@link Iterable} {@link ByteBuffer} */
+    private int totalBytesRead;
+    /** The start position offset of the whole message, used as to reset the totalBytesRead */
+    private int startOffset;
+    /** The current position for current ByteBuffer */
+    private long currentByteBufferPos;
+
+    private long currentByteBufferStartPos;
+    /**
+     * If the current ByteBuffer is unsafe-direct based, currentAddress is the start address of this
+     * ByteBuffer; otherwise should be zero.
+     */
+    private long currentAddress;
+    /** The limit position for current ByteBuffer */
+    private long currentByteBufferLimit;
+
+    /**
+     * The constructor of {@code Iterable<ByteBuffer>} decoder.
+     *
+     * @param inputBufs The input data.
+     * @param size The total size of the input data.
+     * @param immutableFlag whether the input data is immutable.
+     */
+    private IterableDirectByteBufferDecoder(
+        Iterable<ByteBuffer> inputBufs, int size, boolean immutableFlag) {
+      totalBufferSize = size;
+      input = inputBufs;
+      iterator = input.iterator();
+      immutable = immutableFlag;
+      startOffset = totalBytesRead = 0;
+      if (size == 0) {
+        currentByteBuffer = EMPTY_BYTE_BUFFER;
+        currentByteBufferPos = 0;
+        currentByteBufferStartPos = 0;
+        currentByteBufferLimit = 0;
+        currentAddress = 0;
+      } else {
+        tryGetNextByteBuffer();
+      }
+    }
+
+    /** To get the next ByteBuffer from {@code input}, and then update the parameters */
+    private void getNextByteBuffer() throws InvalidProtocolBufferException {
+      if (!iterator.hasNext()) {
+        throw InvalidProtocolBufferException.truncatedMessage();
+      }
+      tryGetNextByteBuffer();
+    }
+
+    private void tryGetNextByteBuffer() {
+      currentByteBuffer = iterator.next();
+      totalBytesRead += (int) (currentByteBufferPos - currentByteBufferStartPos);
+      currentByteBufferPos = currentByteBuffer.position();
+      currentByteBufferStartPos = currentByteBufferPos;
+      currentByteBufferLimit = currentByteBuffer.limit();
+      currentAddress = UnsafeUtil.addressOffset(currentByteBuffer);
+      currentByteBufferPos += currentAddress;
+      currentByteBufferStartPos += currentAddress;
+      currentByteBufferLimit += currentAddress;
+    }
+
+    @Override
+    public int readTag() throws IOException {
+      if (isAtEnd()) {
+        lastTag = 0;
+        return 0;
+      }
+
+      lastTag = readRawVarint32();
+      if (WireFormat.getTagFieldNumber(lastTag) == 0) {
+        // If we actually read zero (or any tag number corresponding to field
+        // number zero), that's not a valid tag.
+        throw InvalidProtocolBufferException.invalidTag();
+      }
+      return lastTag;
+    }
+
+    @Override
+    public void checkLastTagWas(final int value) throws InvalidProtocolBufferException {
+      if (lastTag != value) {
+        throw InvalidProtocolBufferException.invalidEndTag();
+      }
+    }
+
+    @Override
+    public int getLastTag() {
+      return lastTag;
+    }
+
+    @Override
+    public boolean skipField(final int tag) throws IOException {
+      switch (WireFormat.getTagWireType(tag)) {
+        case WireFormat.WIRETYPE_VARINT:
+          skipRawVarint();
+          return true;
+        case WireFormat.WIRETYPE_FIXED64:
+          skipRawBytes(FIXED64_SIZE);
+          return true;
+        case WireFormat.WIRETYPE_LENGTH_DELIMITED:
+          skipRawBytes(readRawVarint32());
+          return true;
+        case WireFormat.WIRETYPE_START_GROUP:
+          skipMessage();
+          checkLastTagWas(
+              WireFormat.makeTag(WireFormat.getTagFieldNumber(tag), WireFormat.WIRETYPE_END_GROUP));
+          return true;
+        case WireFormat.WIRETYPE_END_GROUP:
+          return false;
+        case WireFormat.WIRETYPE_FIXED32:
+          skipRawBytes(FIXED32_SIZE);
+          return true;
+        default:
+          throw InvalidProtocolBufferException.invalidWireType();
+      }
+    }
+
+    @Override
+    public boolean skipField(final int tag, final CodedOutputStream output) throws IOException {
+      switch (WireFormat.getTagWireType(tag)) {
+        case WireFormat.WIRETYPE_VARINT:
+          {
+            long value = readInt64();
+            output.writeRawVarint32(tag);
+            output.writeUInt64NoTag(value);
+            return true;
+          }
+        case WireFormat.WIRETYPE_FIXED64:
+          {
+            long value = readRawLittleEndian64();
+            output.writeRawVarint32(tag);
+            output.writeFixed64NoTag(value);
+            return true;
+          }
+        case WireFormat.WIRETYPE_LENGTH_DELIMITED:
+          {
+            ByteString value = readBytes();
+            output.writeRawVarint32(tag);
+            output.writeBytesNoTag(value);
+            return true;
+          }
+        case WireFormat.WIRETYPE_START_GROUP:
+          {
+            output.writeRawVarint32(tag);
+            skipMessage(output);
+            int endtag =
+                WireFormat.makeTag(
+                    WireFormat.getTagFieldNumber(tag), WireFormat.WIRETYPE_END_GROUP);
+            checkLastTagWas(endtag);
+            output.writeRawVarint32(endtag);
+            return true;
+          }
+        case WireFormat.WIRETYPE_END_GROUP:
+          {
+            return false;
+          }
+        case WireFormat.WIRETYPE_FIXED32:
+          {
+            int value = readRawLittleEndian32();
+            output.writeRawVarint32(tag);
+            output.writeFixed32NoTag(value);
+            return true;
+          }
+        default:
+          throw InvalidProtocolBufferException.invalidWireType();
+      }
+    }
+
+    @Override
+    public void skipMessage() throws IOException {
+      while (true) {
+        final int tag = readTag();
+        if (tag == 0 || !skipField(tag)) {
+          return;
+        }
+      }
+    }
+
+    @Override
+    public void skipMessage(CodedOutputStream output) throws IOException {
+      while (true) {
+        final int tag = readTag();
+        if (tag == 0 || !skipField(tag, output)) {
+          return;
+        }
+      }
+    }
+
+    // -----------------------------------------------------------------
+
+    @Override
+    public double readDouble() throws IOException {
+      return Double.longBitsToDouble(readRawLittleEndian64());
+    }
+
+    @Override
+    public float readFloat() throws IOException {
+      return Float.intBitsToFloat(readRawLittleEndian32());
+    }
+
+    @Override
+    public long readUInt64() throws IOException {
+      return readRawVarint64();
+    }
+
+    @Override
+    public long readInt64() throws IOException {
+      return readRawVarint64();
+    }
+
+    @Override
+    public int readInt32() throws IOException {
+      return readRawVarint32();
+    }
+
+    @Override
+    public long readFixed64() throws IOException {
+      return readRawLittleEndian64();
+    }
+
+    @Override
+    public int readFixed32() throws IOException {
+      return readRawLittleEndian32();
+    }
+
+    @Override
+    public boolean readBool() throws IOException {
+      return readRawVarint64() != 0;
+    }
+
+    @Override
+    public String readString() throws IOException {
+      final int size = readRawVarint32();
+      if (size > 0 && size <= currentByteBufferLimit - currentByteBufferPos) {
+        byte[] bytes = new byte[size];
+        UnsafeUtil.copyMemory(currentByteBufferPos, bytes, 0, size);
+        String result = new String(bytes, UTF_8);
+        currentByteBufferPos += size;
+        return result;
+      } else if (size > 0 && size <= remaining()) {
+        // TODO(yilunchong): To use an underlying bytes[] instead of allocating a new bytes[]
+        byte[] bytes = new byte[size];
+        readRawBytesTo(bytes, 0, size);
+        String result = new String(bytes, UTF_8);
+        return result;
+      }
+
+      if (size == 0) {
+        return "";
+      }
+      if (size < 0) {
+        throw InvalidProtocolBufferException.negativeSize();
+      }
+      throw InvalidProtocolBufferException.truncatedMessage();
+    }
+
+    @Override
+    public String readStringRequireUtf8() throws IOException {
+      final int size = readRawVarint32();
+      if (size > 0 && size <= currentByteBufferLimit - currentByteBufferPos) {
+        byte[] bytes = new byte[size];
+        UnsafeUtil.copyMemory(currentByteBufferPos, bytes, 0, size);
+        if (!Utf8.isValidUtf8(bytes)) {
+          throw InvalidProtocolBufferException.invalidUtf8();
+        }
+        String result = new String(bytes, UTF_8);
+        currentByteBufferPos += size;
+        return result;
+      }
+      if (size >= 0 && size <= remaining()) {
+        byte[] bytes = new byte[size];
+        readRawBytesTo(bytes, 0, size);
+        if (!Utf8.isValidUtf8(bytes)) {
+          throw InvalidProtocolBufferException.invalidUtf8();
+        }
+        String result = new String(bytes, UTF_8);
+        return result;
+      }
+
+      if (size == 0) {
+        return "";
+      }
+      if (size <= 0) {
+        throw InvalidProtocolBufferException.negativeSize();
+      }
+      throw InvalidProtocolBufferException.truncatedMessage();
+    }
+
+    @Override
+    public void readGroup(
+        final int fieldNumber,
+        final MessageLite.Builder builder,
+        final ExtensionRegistryLite extensionRegistry)
+        throws IOException {
+      if (recursionDepth >= recursionLimit) {
+        throw InvalidProtocolBufferException.recursionLimitExceeded();
+      }
+      ++recursionDepth;
+      builder.mergeFrom(this, extensionRegistry);
+      checkLastTagWas(WireFormat.makeTag(fieldNumber, WireFormat.WIRETYPE_END_GROUP));
+      --recursionDepth;
+    }
+
+
+    @Override
+    public <T extends MessageLite> T readGroup(
+        final int fieldNumber,
+        final Parser<T> parser,
+        final ExtensionRegistryLite extensionRegistry)
+        throws IOException {
+      if (recursionDepth >= recursionLimit) {
+        throw InvalidProtocolBufferException.recursionLimitExceeded();
+      }
+      ++recursionDepth;
+      T result = parser.parsePartialFrom(this, extensionRegistry);
+      checkLastTagWas(WireFormat.makeTag(fieldNumber, WireFormat.WIRETYPE_END_GROUP));
+      --recursionDepth;
+      return result;
+    }
+
+    @Deprecated
+    @Override
+    public void readUnknownGroup(final int fieldNumber, final MessageLite.Builder builder)
+        throws IOException {
+      readGroup(fieldNumber, builder, ExtensionRegistryLite.getEmptyRegistry());
+    }
+
+    @Override
+    public void readMessage(
+        final MessageLite.Builder builder, final ExtensionRegistryLite extensionRegistry)
+        throws IOException {
+      final int length = readRawVarint32();
+      if (recursionDepth >= recursionLimit) {
+        throw InvalidProtocolBufferException.recursionLimitExceeded();
+      }
+      final int oldLimit = pushLimit(length);
+      ++recursionDepth;
+      builder.mergeFrom(this, extensionRegistry);
+      checkLastTagWas(0);
+      --recursionDepth;
+      popLimit(oldLimit);
+    }
+
+
+    @Override
+    public <T extends MessageLite> T readMessage(
+        final Parser<T> parser, final ExtensionRegistryLite extensionRegistry) throws IOException {
+      int length = readRawVarint32();
+      if (recursionDepth >= recursionLimit) {
+        throw InvalidProtocolBufferException.recursionLimitExceeded();
+      }
+      final int oldLimit = pushLimit(length);
+      ++recursionDepth;
+      T result = parser.parsePartialFrom(this, extensionRegistry);
+      checkLastTagWas(0);
+      --recursionDepth;
+      popLimit(oldLimit);
+      return result;
+    }
+
+    @Override
+    public ByteString readBytes() throws IOException {
+      final int size = readRawVarint32();
+      if (size > 0 && size <= currentByteBufferLimit - currentByteBufferPos) {
+        if (immutable && enableAliasing) {
+          final int idx = (int) (currentByteBufferPos - currentAddress);
+          final ByteString result = ByteString.wrap(slice(idx, idx + size));
+          currentByteBufferPos += size;
+          return result;
+        } else {
+          byte[] bytes;
+          bytes = new byte[size];
+          UnsafeUtil.copyMemory(currentByteBufferPos, bytes, 0, size);
+          currentByteBufferPos += size;
+          return ByteString.wrap(bytes);
+        }
+      } else if (size > 0 && size <= remaining()) {
+        byte[] temp = new byte[size];
+        readRawBytesTo(temp, 0, size);
+        return ByteString.wrap(temp);
+      }
+
+      if (size == 0) {
+        return ByteString.EMPTY;
+      }
+      if (size < 0) {
+        throw InvalidProtocolBufferException.negativeSize();
+      }
+      throw InvalidProtocolBufferException.truncatedMessage();
+    }
+
+    @Override
+    public byte[] readByteArray() throws IOException {
+      return readRawBytes(readRawVarint32());
+    }
+
+    @Override
+    public ByteBuffer readByteBuffer() throws IOException {
+      final int size = readRawVarint32();
+      if (size > 0 && size <= currentRemaining()) {
+        if (!immutable && enableAliasing) {
+          currentByteBufferPos += size;
+          return slice(
+              (int) (currentByteBufferPos - currentAddress - size),
+              (int) (currentByteBufferPos - currentAddress));
+        } else {
+          byte[] bytes = new byte[size];
+          UnsafeUtil.copyMemory(currentByteBufferPos, bytes, 0, size);
+          currentByteBufferPos += size;
+          return ByteBuffer.wrap(bytes);
+        }
+      } else if (size > 0 && size <= remaining()) {
+        byte[] temp = new byte[size];
+        readRawBytesTo(temp, 0, size);
+        return ByteBuffer.wrap(temp);
+      }
+
+      if (size == 0) {
+        return EMPTY_BYTE_BUFFER;
+      }
+      if (size < 0) {
+        throw InvalidProtocolBufferException.negativeSize();
+      }
+      throw InvalidProtocolBufferException.truncatedMessage();
+    }
+
+    @Override
+    public int readUInt32() throws IOException {
+      return readRawVarint32();
+    }
+
+    @Override
+    public int readEnum() throws IOException {
+      return readRawVarint32();
+    }
+
+    @Override
+    public int readSFixed32() throws IOException {
+      return readRawLittleEndian32();
+    }
+
+    @Override
+    public long readSFixed64() throws IOException {
+      return readRawLittleEndian64();
+    }
+
+    @Override
+    public int readSInt32() throws IOException {
+      return decodeZigZag32(readRawVarint32());
+    }
+
+    @Override
+    public long readSInt64() throws IOException {
+      return decodeZigZag64(readRawVarint64());
+    }
+
+    @Override
+    public int readRawVarint32() throws IOException {
+      fastpath:
+      {
+        long tempPos = currentByteBufferPos;
+
+        if (currentByteBufferLimit == currentByteBufferPos) {
+          break fastpath;
+        }
+
+        int x;
+        if ((x = UnsafeUtil.getByte(tempPos++)) >= 0) {
+          currentByteBufferPos++;
+          return x;
+        } else if (currentByteBufferLimit - currentByteBufferPos < 10) {
+          break fastpath;
+        } else if ((x ^= (UnsafeUtil.getByte(tempPos++) << 7)) < 0) {
+          x ^= (~0 << 7);
+        } else if ((x ^= (UnsafeUtil.getByte(tempPos++) << 14)) >= 0) {
+          x ^= (~0 << 7) ^ (~0 << 14);
+        } else if ((x ^= (UnsafeUtil.getByte(tempPos++) << 21)) < 0) {
+          x ^= (~0 << 7) ^ (~0 << 14) ^ (~0 << 21);
+        } else {
+          int y = UnsafeUtil.getByte(tempPos++);
+          x ^= y << 28;
+          x ^= (~0 << 7) ^ (~0 << 14) ^ (~0 << 21) ^ (~0 << 28);
+          if (y < 0
+              && UnsafeUtil.getByte(tempPos++) < 0
+              && UnsafeUtil.getByte(tempPos++) < 0
+              && UnsafeUtil.getByte(tempPos++) < 0
+              && UnsafeUtil.getByte(tempPos++) < 0
+              && UnsafeUtil.getByte(tempPos++) < 0) {
+            break fastpath; // Will throw malformedVarint()
+          }
+        }
+        currentByteBufferPos = tempPos;
+        return x;
+      }
+      return (int) readRawVarint64SlowPath();
+    }
+
+    @Override
+    public long readRawVarint64() throws IOException {
+      fastpath:
+      {
+        long tempPos = currentByteBufferPos;
+
+        if (currentByteBufferLimit == currentByteBufferPos) {
+          break fastpath;
+        }
+
+        long x;
+        int y;
+        if ((y = UnsafeUtil.getByte(tempPos++)) >= 0) {
+          currentByteBufferPos++;
+          return y;
+        } else if (currentByteBufferLimit - currentByteBufferPos < 10) {
+          break fastpath;
+        } else if ((y ^= (UnsafeUtil.getByte(tempPos++) << 7)) < 0) {
+          x = y ^ (~0 << 7);
+        } else if ((y ^= (UnsafeUtil.getByte(tempPos++) << 14)) >= 0) {
+          x = y ^ ((~0 << 7) ^ (~0 << 14));
+        } else if ((y ^= (UnsafeUtil.getByte(tempPos++) << 21)) < 0) {
+          x = y ^ ((~0 << 7) ^ (~0 << 14) ^ (~0 << 21));
+        } else if ((x = y ^ ((long) UnsafeUtil.getByte(tempPos++) << 28)) >= 0L) {
+          x ^= (~0L << 7) ^ (~0L << 14) ^ (~0L << 21) ^ (~0L << 28);
+        } else if ((x ^= ((long) UnsafeUtil.getByte(tempPos++) << 35)) < 0L) {
+          x ^= (~0L << 7) ^ (~0L << 14) ^ (~0L << 21) ^ (~0L << 28) ^ (~0L << 35);
+        } else if ((x ^= ((long) UnsafeUtil.getByte(tempPos++) << 42)) >= 0L) {
+          x ^= (~0L << 7) ^ (~0L << 14) ^ (~0L << 21) ^ (~0L << 28) ^ (~0L << 35) ^ (~0L << 42);
+        } else if ((x ^= ((long) UnsafeUtil.getByte(tempPos++) << 49)) < 0L) {
+          x ^=
+              (~0L << 7)
+                  ^ (~0L << 14)
+                  ^ (~0L << 21)
+                  ^ (~0L << 28)
+                  ^ (~0L << 35)
+                  ^ (~0L << 42)
+                  ^ (~0L << 49);
+        } else {
+          x ^= ((long) UnsafeUtil.getByte(tempPos++) << 56);
+          x ^=
+              (~0L << 7)
+                  ^ (~0L << 14)
+                  ^ (~0L << 21)
+                  ^ (~0L << 28)
+                  ^ (~0L << 35)
+                  ^ (~0L << 42)
+                  ^ (~0L << 49)
+                  ^ (~0L << 56);
+          if (x < 0L) {
+            if (UnsafeUtil.getByte(tempPos++) < 0L) {
+              break fastpath; // Will throw malformedVarint()
+            }
+          }
+        }
+        currentByteBufferPos = tempPos;
+        return x;
+      }
+      return readRawVarint64SlowPath();
+    }
+
+    @Override
+    long readRawVarint64SlowPath() throws IOException {
+      long result = 0;
+      for (int shift = 0; shift < 64; shift += 7) {
+        final byte b = readRawByte();
+        result |= (long) (b & 0x7F) << shift;
+        if ((b & 0x80) == 0) {
+          return result;
+        }
+      }
+      throw InvalidProtocolBufferException.malformedVarint();
+    }
+
+    @Override
+    public int readRawLittleEndian32() throws IOException {
+      if (currentRemaining() >= FIXED32_SIZE) {
+        long tempPos = currentByteBufferPos;
+        currentByteBufferPos += FIXED32_SIZE;
+        return (((UnsafeUtil.getByte(tempPos) & 0xff))
+            | ((UnsafeUtil.getByte(tempPos + 1) & 0xff) << 8)
+            | ((UnsafeUtil.getByte(tempPos + 2) & 0xff) << 16)
+            | ((UnsafeUtil.getByte(tempPos + 3) & 0xff) << 24));
+      }
+      return ((readRawByte() & 0xff)
+          | ((readRawByte() & 0xff) << 8)
+          | ((readRawByte() & 0xff) << 16)
+          | ((readRawByte() & 0xff) << 24));
+    }
+
+    @Override
+    public long readRawLittleEndian64() throws IOException {
+      if (currentRemaining() >= FIXED64_SIZE) {
+        long tempPos = currentByteBufferPos;
+        currentByteBufferPos += FIXED64_SIZE;
+        return (((UnsafeUtil.getByte(tempPos) & 0xffL))
+            | ((UnsafeUtil.getByte(tempPos + 1) & 0xffL) << 8)
+            | ((UnsafeUtil.getByte(tempPos + 2) & 0xffL) << 16)
+            | ((UnsafeUtil.getByte(tempPos + 3) & 0xffL) << 24)
+            | ((UnsafeUtil.getByte(tempPos + 4) & 0xffL) << 32)
+            | ((UnsafeUtil.getByte(tempPos + 5) & 0xffL) << 40)
+            | ((UnsafeUtil.getByte(tempPos + 6) & 0xffL) << 48)
+            | ((UnsafeUtil.getByte(tempPos + 7) & 0xffL) << 56));
+      }
+      return ((readRawByte() & 0xffL)
+          | ((readRawByte() & 0xffL) << 8)
+          | ((readRawByte() & 0xffL) << 16)
+          | ((readRawByte() & 0xffL) << 24)
+          | ((readRawByte() & 0xffL) << 32)
+          | ((readRawByte() & 0xffL) << 40)
+          | ((readRawByte() & 0xffL) << 48)
+          | ((readRawByte() & 0xffL) << 56));
+    }
+
+    @Override
+    public void enableAliasing(boolean enabled) {
+      this.enableAliasing = enabled;
+    }
+
+    @Override
+    public void resetSizeCounter() {
+      startOffset = (int) (totalBytesRead + currentByteBufferPos - currentByteBufferStartPos);
+    }
+
+    @Override
+    public int pushLimit(int byteLimit) throws InvalidProtocolBufferException {
+      if (byteLimit < 0) {
+        throw InvalidProtocolBufferException.negativeSize();
+      }
+      byteLimit += getTotalBytesRead();
+      final int oldLimit = currentLimit;
+      if (byteLimit > oldLimit) {
+        throw InvalidProtocolBufferException.truncatedMessage();
+      }
+      currentLimit = byteLimit;
+
+      recomputeBufferSizeAfterLimit();
+
+      return oldLimit;
+    }
+
+    private void recomputeBufferSizeAfterLimit() {
+      totalBufferSize += bufferSizeAfterCurrentLimit;
+      final int bufferEnd = totalBufferSize - startOffset;
+      if (bufferEnd > currentLimit) {
+        // Limit is in current buffer.
+        bufferSizeAfterCurrentLimit = bufferEnd - currentLimit;
+        totalBufferSize -= bufferSizeAfterCurrentLimit;
+      } else {
+        bufferSizeAfterCurrentLimit = 0;
+      }
+    }
+
+    @Override
+    public void popLimit(final int oldLimit) {
+      currentLimit = oldLimit;
+      recomputeBufferSizeAfterLimit();
+    }
+
+    @Override
+    public int getBytesUntilLimit() {
+      if (currentLimit == Integer.MAX_VALUE) {
+        return -1;
+      }
+
+      return currentLimit - getTotalBytesRead();
+    }
+
+    @Override
+    public boolean isAtEnd() throws IOException {
+      return totalBytesRead + currentByteBufferPos - currentByteBufferStartPos == totalBufferSize;
+    }
+
+    @Override
+    public int getTotalBytesRead() {
+      return (int)
+          (totalBytesRead - startOffset + currentByteBufferPos - currentByteBufferStartPos);
+    }
+
+    @Override
+    public byte readRawByte() throws IOException {
+      if (currentRemaining() == 0) {
+        getNextByteBuffer();
+      }
+      return UnsafeUtil.getByte(currentByteBufferPos++);
+    }
+
+    @Override
+    public byte[] readRawBytes(final int length) throws IOException {
+      if (length >= 0 && length <= currentRemaining()) {
+        byte[] bytes = new byte[length];
+        UnsafeUtil.copyMemory(currentByteBufferPos, bytes, 0, length);
+        currentByteBufferPos += length;
+        return bytes;
+      }
+      if (length >= 0 && length <= remaining()) {
+        byte[] bytes = new byte[length];
+        readRawBytesTo(bytes, 0, length);
+        return bytes;
+      }
+
+      if (length <= 0) {
+        if (length == 0) {
+          return EMPTY_BYTE_ARRAY;
+        } else {
+          throw InvalidProtocolBufferException.negativeSize();
+        }
+      }
+
+      throw InvalidProtocolBufferException.truncatedMessage();
+    }
+
+    /**
+     * Try to get raw bytes from {@code input} with the size of {@code length} and copy to {@code
+     * bytes} array. If the size is bigger than the number of remaining bytes in the input, then
+     * throw {@code truncatedMessage} exception.
+     *
+     * @param bytes
+     * @param offset
+     * @param length
+     * @throws IOException
+     */
+    private void readRawBytesTo(byte[] bytes, int offset, final int length) throws IOException {
+      if (length >= 0 && length <= remaining()) {
+        int l = length;
+        while (l > 0) {
+          if (currentRemaining() == 0) {
+            getNextByteBuffer();
+          }
+          int bytesToCopy = Math.min(l, (int) currentRemaining());
+          UnsafeUtil.copyMemory(currentByteBufferPos, bytes, length - l + offset, bytesToCopy);
+          l -= bytesToCopy;
+          currentByteBufferPos += bytesToCopy;
+        }
+        return;
+      }
+
+      if (length <= 0) {
+        if (length == 0) {
+          return;
+        } else {
+          throw InvalidProtocolBufferException.negativeSize();
+        }
+      }
+      throw InvalidProtocolBufferException.truncatedMessage();
+    }
+
+    @Override
+    public void skipRawBytes(final int length) throws IOException {
+      if (length >= 0
+          && length
+              <= (totalBufferSize
+                  - totalBytesRead
+                  - currentByteBufferPos
+                  + currentByteBufferStartPos)) {
+        // We have all the bytes we need already.
+        int l = length;
+        while (l > 0) {
+          if (currentRemaining() == 0) {
+            getNextByteBuffer();
+          }
+          int rl = Math.min(l, (int) currentRemaining());
+          l -= rl;
+          currentByteBufferPos += rl;
+        }
+        return;
+      }
+
+      if (length < 0) {
+        throw InvalidProtocolBufferException.negativeSize();
+      }
+      throw InvalidProtocolBufferException.truncatedMessage();
+    }
+
+    // TODO: optimize to fastpath
+    private void skipRawVarint() throws IOException {
+      for (int i = 0; i < MAX_VARINT_SIZE; i++) {
+        if (readRawByte() >= 0) {
+          return;
+        }
+      }
+      throw InvalidProtocolBufferException.malformedVarint();
+    }
+
+    /**
+     * Try to get the number of remaining bytes in {@code input}.
+     *
+     * @return the number of remaining bytes in {@code input}.
+     */
+    private int remaining() {
+      return (int)
+          (totalBufferSize - totalBytesRead - currentByteBufferPos + currentByteBufferStartPos);
+    }
+
+    /**
+     * Try to get the number of remaining bytes in {@code currentByteBuffer}.
+     *
+     * @return the number of remaining bytes in {@code currentByteBuffer}
+     */
+    private long currentRemaining() {
+      return (currentByteBufferLimit - currentByteBufferPos);
+    }
+
+    private ByteBuffer slice(int begin, int end) throws IOException {
+      int prevPos = currentByteBuffer.position();
+      int prevLimit = currentByteBuffer.limit();
+      try {
+        currentByteBuffer.position(begin);
+        currentByteBuffer.limit(end);
+        return currentByteBuffer.slice();
+      } catch (IllegalArgumentException e) {
+        throw InvalidProtocolBufferException.truncatedMessage();
+      } finally {
+        currentByteBuffer.position(prevPos);
+        currentByteBuffer.limit(prevLimit);
+      }
+    }
+  }
 }
diff --git a/java/core/src/main/java/com/google/protobuf/GeneratedMessageLite.java b/java/core/src/main/java/com/google/protobuf/GeneratedMessageLite.java
index 7116ae1c..99864964 100644
--- a/java/core/src/main/java/com/google/protobuf/GeneratedMessageLite.java
+++ b/java/core/src/main/java/com/google/protobuf/GeneratedMessageLite.java
@@ -220,7 +220,7 @@ public abstract class GeneratedMessageLite<
 
   @Override
   public final boolean isInitialized() {
-    return dynamicMethod(MethodToInvoke.IS_INITIALIZED, Boolean.TRUE) != null;
+    return isInitialized((MessageType) this, Boolean.TRUE);
   }
 
   @Override
@@ -240,6 +240,8 @@ public abstract class GeneratedMessageLite<
   public static enum MethodToInvoke {
     // Rely on/modify instance state
     IS_INITIALIZED,
+    GET_MEMOIZED_IS_INITIALIZED,
+    SET_MEMOIZED_IS_INITIALIZED,
     VISIT,
     MERGE_FROM_STREAM,
     MAKE_IMMUTABLE,
@@ -256,25 +258,30 @@ public abstract class GeneratedMessageLite<
    * Theses different kinds of operations are required to implement message-level operations for
    * builders in the runtime. This method bundles those operations to reduce the generated methods
    * count.
+   *
    * <ul>
-   * <li>{@code MERGE_FROM_STREAM} is parameterized with an {@link CodedInputStream} and
-   * {@link ExtensionRegistryLite}. It consumes the input stream, parsing the contents into the
-   * returned protocol buffer. If parsing throws an {@link InvalidProtocolBufferException}, the
-   * implementation wraps it in a RuntimeException.
-   * <li>{@code NEW_INSTANCE} returns a new instance of the protocol buffer that has not yet been
-   * made immutable. See {@code MAKE_IMMUTABLE}.
-   * <li>{@code IS_INITIALIZED} is parameterized with a {@code Boolean} detailing whether to
-   * memoize. It returns {@code null} for false and the default instance for true. We optionally
-   * memoize to support the Builder case, where memoization is not desired.
-   * <li>{@code NEW_BUILDER} returns a {@code BuilderType} instance.
-   * <li>{@code VISIT} is parameterized with a {@code Visitor} and a {@code MessageType} and
-   * recursively iterates through the fields side by side between this and the instance.
-   * <li>{@code MAKE_IMMUTABLE} sets all internal fields to an immutable state.
+   *   <li>{@code MERGE_FROM_STREAM} is parameterized with an {@link CodedInputStream} and {@link
+   *       ExtensionRegistryLite}. It consumes the input stream, parsing the contents into the
+   *       returned protocol buffer. If parsing throws an {@link InvalidProtocolBufferException},
+   *       the implementation wraps it in a RuntimeException.
+   *   <li>{@code NEW_INSTANCE} returns a new instance of the protocol buffer that has not yet been
+   *       made immutable. See {@code MAKE_IMMUTABLE}.
+   *   <li>{@code IS_INITIALIZED} returns {@code null} for false and the default instance for true.
+   *       It doesn't use or modify any memoized value.
+   *   <li>{@code GET_MEMOIZED_IS_INITIALIZED} returns the memoized {@code isInitialized} byte
+   *       value.
+   *   <li>{@code SET_MEMOIZED_IS_INITIALIZED} sets the memoized {@code isInitilaized} byte value to
+   *       1 if the first parameter is not null, or to 0 if the first parameter is null.
+   *   <li>{@code NEW_BUILDER} returns a {@code BuilderType} instance.
+   *   <li>{@code VISIT} is parameterized with a {@code Visitor} and a {@code MessageType} and
+   *       recursively iterates through the fields side by side between this and the instance.
+   *   <li>{@code MAKE_IMMUTABLE} sets all internal fields to an immutable state.
    * </ul>
+   *
    * This method, plus the implementation of the Builder, enables the Builder class to be proguarded
    * away entirely on Android.
-   * <p>
-   * For use by generated code only.
+   *
+   * <p>For use by generated code only.
    */
   protected abstract Object dynamicMethod(MethodToInvoke method, Object arg0, Object arg1);
 
@@ -297,9 +304,9 @@ public abstract class GeneratedMessageLite<
     unknownFields = visitor.visitUnknownFields(unknownFields, other.unknownFields);
   }
 
+
   /**
-   * Merge some unknown fields into the {@link UnknownFieldSetLite} for this
-   * message.
+   * Merge some unknown fields into the {@link UnknownFieldSetLite} for this message.
    *
    * <p>For use by generated code only.
    */
@@ -1403,7 +1410,21 @@ public abstract class GeneratedMessageLite<
    */
   protected static final <T extends GeneratedMessageLite<T, ?>> boolean isInitialized(
       T message, boolean shouldMemoize) {
-    return message.dynamicMethod(MethodToInvoke.IS_INITIALIZED, shouldMemoize) != null;
+    byte memoizedIsInitialized =
+        (Byte) message.dynamicMethod(MethodToInvoke.GET_MEMOIZED_IS_INITIALIZED);
+    if (memoizedIsInitialized == 1) {
+      return true;
+    }
+    if (memoizedIsInitialized == 0) {
+      return false;
+    }
+    boolean isInitialized =
+        message.dynamicMethod(MethodToInvoke.IS_INITIALIZED, Boolean.FALSE) != null;
+    if (shouldMemoize) {
+      message.dynamicMethod(
+          MethodToInvoke.SET_MEMOIZED_IS_INITIALIZED, isInitialized ? message : null);
+    }
+    return isInitialized;
   }
 
   protected static final <T extends GeneratedMessageLite<T, ?>> void makeImmutable(T message) {
diff --git a/java/core/src/main/java/com/google/protobuf/IterableByteBufferInputStream.java b/java/core/src/main/java/com/google/protobuf/IterableByteBufferInputStream.java
new file mode 100644
index 00000000..713e8064
--- /dev/null
+++ b/java/core/src/main/java/com/google/protobuf/IterableByteBufferInputStream.java
@@ -0,0 +1,150 @@
+// 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 static com.google.protobuf.Internal.EMPTY_BYTE_BUFFER;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.ByteBuffer;
+import java.util.Iterator;
+
+class IterableByteBufferInputStream extends InputStream {
+  /** The {@link Iterator} with type {@link ByteBuffer} of {@code input} */
+  private Iterator<ByteBuffer> iterator;
+  /** The current ByteBuffer; */
+  private ByteBuffer currentByteBuffer;
+  /** The number of ByteBuffers in the input data. */
+  private int dataSize;
+  /**
+   * Current {@code ByteBuffer}'s index
+   *
+   * <p>If index equals dataSize, then all the data in the InputStream has been consumed
+   */
+  private int currentIndex;
+  /** The current position for current ByteBuffer */
+  private int currentByteBufferPos;
+  /** Whether current ByteBuffer has an array */
+  private boolean hasArray;
+  /**
+   * If the current ByteBuffer is unsafe-direct based, currentArray is null; otherwise should be the
+   * array inside ByteBuffer.
+   */
+  private byte[] currentArray;
+  /** Current ByteBuffer's array offset */
+  private int currentArrayOffset;
+  /**
+   * If the current ByteBuffer is unsafe-direct based, currentAddress is the start address of this
+   * ByteBuffer; otherwise should be zero.
+   */
+  private long currentAddress;
+
+  IterableByteBufferInputStream(Iterable<ByteBuffer> data) {
+    iterator = data.iterator();
+    dataSize = 0;
+    for (ByteBuffer unused : data) {
+      dataSize++;
+    }
+    currentIndex = -1;
+
+    if (!getNextByteBuffer()) {
+      currentByteBuffer = EMPTY_BYTE_BUFFER;
+      currentIndex = 0;
+      currentByteBufferPos = 0;
+      currentAddress = 0;
+    }
+  }
+
+  private boolean getNextByteBuffer() {
+    currentIndex++;
+    if (!iterator.hasNext()) {
+      return false;
+    }
+    currentByteBuffer = iterator.next();
+    currentByteBufferPos = currentByteBuffer.position();
+    if (currentByteBuffer.hasArray()) {
+      hasArray = true;
+      currentArray = currentByteBuffer.array();
+      currentArrayOffset = currentByteBuffer.arrayOffset();
+    } else {
+      hasArray = false;
+      currentAddress = UnsafeUtil.addressOffset(currentByteBuffer);
+      currentArray = null;
+    }
+    return true;
+  }
+
+  private void updateCurrentByteBufferPos(int numberOfBytesRead) {
+    currentByteBufferPos += numberOfBytesRead;
+    if (currentByteBufferPos == currentByteBuffer.limit()) {
+      getNextByteBuffer();
+    }
+  }
+
+  @Override
+  public int read() throws IOException {
+    if (currentIndex == dataSize) {
+      return -1;
+    }
+    if (hasArray) {
+      int result = currentArray[currentByteBufferPos + currentArrayOffset] & 0xFF;
+      updateCurrentByteBufferPos(1);
+      return result;
+    } else {
+      int result = UnsafeUtil.getByte(currentByteBufferPos + currentAddress) & 0xFF;
+      updateCurrentByteBufferPos(1);
+      return result;
+    }
+  }
+
+  @Override
+  public int read(byte[] output, int offset, int length) throws IOException {
+    if (currentIndex == dataSize) {
+      return -1;
+    }
+    int remaining = currentByteBuffer.limit() - currentByteBufferPos;
+    if (length > remaining) {
+      length = remaining;
+    }
+    if (hasArray) {
+      System.arraycopy(
+          currentArray, currentByteBufferPos + currentArrayOffset, output, offset, length);
+      updateCurrentByteBufferPos(length);
+    } else {
+      int prevPos = currentByteBuffer.position();
+      currentByteBuffer.position(currentByteBufferPos);
+      currentByteBuffer.get(output, offset, length);
+      currentByteBuffer.position(prevPos);
+      updateCurrentByteBufferPos(length);
+    }
+    return length;
+  }
+}
diff --git a/java/core/src/main/java/com/google/protobuf/SmallSortedMap.java b/java/core/src/main/java/com/google/protobuf/SmallSortedMap.java
index 66033f58..279edc4d 100644
--- a/java/core/src/main/java/com/google/protobuf/SmallSortedMap.java
+++ b/java/core/src/main/java/com/google/protobuf/SmallSortedMap.java
@@ -540,8 +540,8 @@ class SmallSortedMap<K extends Comparable<K>, V> extends AbstractMap<K, V> {
 
     @Override
     public boolean hasNext() {
-      return (pos + 1) < entryList.size() ||
-          getOverflowIterator().hasNext();
+      return (pos + 1) < entryList.size()
+          || (!overflowEntries.isEmpty() && getOverflowIterator().hasNext());
     }
 
     @Override
diff --git a/java/core/src/main/java/com/google/protobuf/TextFormat.java b/java/core/src/main/java/com/google/protobuf/TextFormat.java
index 64094d09..ab9acf2f 100644
--- a/java/core/src/main/java/com/google/protobuf/TextFormat.java
+++ b/java/core/src/main/java/com/google/protobuf/TextFormat.java
@@ -279,9 +279,21 @@ public final class TextFormat {
         generator.print(String.format((Locale) null, "0x%016x", (Long) value));
         break;
       case WireFormat.WIRETYPE_LENGTH_DELIMITED:
-        generator.print("\"");
-        generator.print(escapeBytes((ByteString) value));
-        generator.print("\"");
+        try {
+          // Try to parse and print the field as an embedded message
+          UnknownFieldSet message = UnknownFieldSet.parseFrom((ByteString) value);
+          generator.print("{");
+          generator.eol();
+          generator.indent();
+          Printer.DEFAULT.printUnknownFields(message, generator);
+          generator.outdent();
+          generator.print("}");
+        } catch (InvalidProtocolBufferException e) {
+          // If not parseable as a message, print as a String
+          generator.print("\"");
+          generator.print(escapeBytes((ByteString) value));
+          generator.print("\"");
+        }
         break;
       case WireFormat.WIRETYPE_START_GROUP:
         Printer.DEFAULT.printUnknownFields((UnknownFieldSet) value, generator);
diff --git a/java/core/src/main/java/com/google/protobuf/UnknownFieldSetLite.java b/java/core/src/main/java/com/google/protobuf/UnknownFieldSetLite.java
index d6226fc7..2a614c84 100644
--- a/java/core/src/main/java/com/google/protobuf/UnknownFieldSetLite.java
+++ b/java/core/src/main/java/com/google/protobuf/UnknownFieldSetLite.java
@@ -81,7 +81,7 @@ public final class UnknownFieldSetLite {
     System.arraycopy(second.objects, 0, objects, first.count, second.count);
     return new UnknownFieldSetLite(count, tags, objects, true /* isMutable */);
   }
-  
+
   /**
    * The number of elements in the set.
    */
@@ -323,6 +323,7 @@ public final class UnknownFieldSetLite {
 
   // Package private for unsafe experimental runtime.
   void storeField(int tag, Object value) {
+    checkMutable();
     ensureCapacity();
     
     tags[count] = tag;
diff --git a/java/core/src/main/java/com/google/protobuf/UnsafeUtil.java b/java/core/src/main/java/com/google/protobuf/UnsafeUtil.java
index acc03a7c..88315cb6 100644
--- a/java/core/src/main/java/com/google/protobuf/UnsafeUtil.java
+++ b/java/core/src/main/java/com/google/protobuf/UnsafeUtil.java
@@ -252,10 +252,6 @@ final class UnsafeUtil {
     MEMORY_ACCESSOR.putLong(address, value);
   }
 
-  static void copyMemory(long srcAddress, long targetAddress, long length) {
-    MEMORY_ACCESSOR.copyMemory(srcAddress, targetAddress, length);
-  }
-
   /**
    * Gets the offset of the {@code address} field of the given direct {@link ByteBuffer}.
    */
@@ -478,8 +474,6 @@ final class UnsafeUtil {
 
     public abstract void putLong(long address, long value);
 
-    public abstract void copyMemory(long srcAddress, long targetAddress, long length);
-
     public abstract Object getStaticObject(Field field);
     
     public abstract void copyMemory(long srcOffset, byte[] target, long targetIndex, long length);
@@ -562,11 +556,6 @@ final class UnsafeUtil {
     public void putDouble(Object target, long offset, double value) {
       unsafe.putDouble(target, offset, value);
     }
-
-    @Override
-    public void copyMemory(long srcAddress, long targetAddress, long length) {
-      unsafe.copyMemory(srcAddress, targetAddress, length);
-    }
     
     @Override 
     public void copyMemory(long srcOffset, byte[] target, long targetIndex, long length) {