Add support for Java micro protobuf's to protobuf-2.3.0.

See README.android for additional information.

Change-Id: I6693e405c0d651eacacd3227a876129865dd0d3c

7 files changed, 2410 insertions, 0 deletions

diff --git a/java/src/main/java/com/google/protobuf/micro/ByteStringMicro.java b/java/src/main/java/com/google/protobuf/micro/ByteStringMicro.java
new file mode 100644
index 0000000..6e87dc9
--- /dev/null
+++ b/java/src/main/java/com/google/protobuf/micro/ByteStringMicro.java
@@ -0,0 +1,227 @@
+// 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.micro;
+
+import java.io.UnsupportedEncodingException;
+
+/**
+ * Immutable array of bytes.
+ *
+ * @author crazybob@google.com Bob Lee
+ * @author kenton@google.com Kenton Varda
+ */
+public final class ByteStringMicro {
+  private final byte[] bytes;
+
+  private ByteStringMicro(final byte[] bytes) {
+    this.bytes = bytes;
+  }
+
+  /**
+   * Gets the byte at the given index.
+   *
+   * @throws ArrayIndexOutOfBoundsException {@code index} is < 0 or >= size
+   */
+  public byte byteAt(final int index) {
+    return bytes[index];
+  }
+
+  /**
+   * Gets the number of bytes.
+   */
+  public int size() {
+    return bytes.length;
+  }
+
+  /**
+   * Returns {@code true} if the size is {@code 0}, {@code false} otherwise.
+   */
+  public boolean isEmpty() {
+    return bytes.length == 0;
+  }
+
+  // =================================================================
+  // byte[] -> ByteStringMicro
+
+  /**
+   * Empty ByteStringMicro.
+   */
+  public static final ByteStringMicro EMPTY = new ByteStringMicro(new byte[0]);
+
+  /**
+   * Copies the given bytes into a {@code ByteStringMicro}.
+   */
+  public static ByteStringMicro copyFrom(final byte[] bytes, final int offset,
+                                    final int size) {
+    final byte[] copy = new byte[size];
+    System.arraycopy(bytes, offset, copy, 0, size);
+    return new ByteStringMicro(copy);
+  }
+
+  /**
+   * Copies the given bytes into a {@code ByteStringMicro}.
+   */
+  public static ByteStringMicro copyFrom(final 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 ByteStringMicro}.
+   */
+  public static ByteStringMicro copyFrom(final String text, final String charsetName)
+      throws UnsupportedEncodingException {
+    return new ByteStringMicro(text.getBytes(charsetName));
+  }
+
+  /**
+   * Encodes {@code text} into a sequence of UTF-8 bytes and returns the
+   * result as a {@code ByteStringMicro}.
+   */
+  public static ByteStringMicro copyFromUtf8(final String text) {
+    try {
+      return new ByteStringMicro(text.getBytes("UTF-8"));
+    } catch (UnsupportedEncodingException e) {
+      throw new RuntimeException("UTF-8 not supported?");
+    }
+  }
+
+  // =================================================================
+  // ByteStringMicro -> 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(final byte[] target, final 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(final byte[] target, final int sourceOffset,
+                     final int targetOffset,
+      final int size) {
+    System.arraycopy(bytes, sourceOffset, target, targetOffset, size);
+  }
+
+  /**
+   * Copies bytes to a {@code byte[]}.
+   */
+  public byte[] toByteArray() {
+    final int size = bytes.length;
+    final byte[] copy = new byte[size];
+    System.arraycopy(bytes, 0, copy, 0, size);
+    return copy;
+  }
+
+  /**
+   * Constructs a new {@code String} by decoding the bytes using the
+   * specified charset.
+   */
+  public String toString(final String charsetName)
+      throws UnsupportedEncodingException {
+    return new String(bytes, charsetName);
+  }
+
+  /**
+   * Constructs a new {@code String} by decoding the bytes as UTF-8.
+   */
+  public String toStringUtf8() {
+    try {
+      return new String(bytes, "UTF-8");
+    } catch (UnsupportedEncodingException e) {
+      throw new RuntimeException("UTF-8 not supported?");
+    }
+  }
+
+  // =================================================================
+  // equals() and hashCode()
+
+  //@Override for compatibility with Java 1.3 code we can't use annotations
+  public boolean equals(final Object o) {
+    if (o == this) {
+      return true;
+    }
+
+    if (!(o instanceof ByteStringMicro)) {
+      return false;
+    }
+
+    final ByteStringMicro other = (ByteStringMicro) o;
+    final int size = bytes.length;
+    if (size != other.bytes.length) {
+      return false;
+    }
+
+    final byte[] thisBytes = bytes;
+    final byte[] otherBytes = other.bytes;
+    for (int i = 0; i < size; i++) {
+      if (thisBytes[i] != otherBytes[i]) {
+        return false;
+      }
+    }
+
+    return true;
+  }
+
+  private volatile int hash = 0;
+
+  //@Override for compatibility with Java 1.3 code we can't use annotations
+  public int hashCode() {
+    int h = hash;
+
+    if (h == 0) {
+      final byte[] thisBytes = bytes;
+      final int size = bytes.length;
+
+      h = size;
+      for (int i = 0; i < size; i++) {
+        h = h * 31 + thisBytes[i];
+      }
+      if (h == 0) {
+        h = 1;
+      }
+
+      hash = h;
+    }
+
+    return h;
+  }
+}
diff --git a/java/src/main/java/com/google/protobuf/micro/CodedInputStreamMicro.java b/java/src/main/java/com/google/protobuf/micro/CodedInputStreamMicro.java
new file mode 100644
index 0000000..0791b8f
--- /dev/null
+++ b/java/src/main/java/com/google/protobuf/micro/CodedInputStreamMicro.java
@@ -0,0 +1,804 @@
+// 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.micro;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * Reads and decodes protocol message fields.
+ *
+ * This class contains two kinds of methods:  methods that read specific
+ * protocol message constructs and field types (e.g. {@link #readTag()} and
+ * {@link #readInt32()}) and methods that read low-level values (e.g.
+ * {@link #readRawVarint32()} and {@link #readRawBytes}).  If you are reading
+ * encoded protocol messages, you should use the former methods, but if you are
+ * reading some other format of your own design, use the latter.
+ *
+ * @author kenton@google.com Kenton Varda
+ */
+public final class CodedInputStreamMicro {
+  /**
+   * Create a new CodedInputStream wrapping the given InputStream.
+   */
+  public static CodedInputStreamMicro newInstance(final InputStream input) {
+    return new CodedInputStreamMicro(input);
+  }
+
+  /**
+   * Create a new CodedInputStream wrapping the given byte array.
+   */
+  public static CodedInputStreamMicro newInstance(final byte[] buf) {
+    return newInstance(buf, 0, buf.length);
+  }
+
+  /**
+   * Create a new CodedInputStream wrapping the given byte array slice.
+   */
+  public static CodedInputStreamMicro newInstance(final byte[] buf, final int off,
+                                             final int len) {
+    return new CodedInputStreamMicro(buf, off, len);
+  }
+
+  // -----------------------------------------------------------------
+
+  /**
+   * Attempt to read a field tag, returning zero if we have reached EOF.
+   * Protocol message parsers use this to read tags, since a protocol message
+   * may legally end wherever a tag occurs, and zero is not a valid tag number.
+   */
+  public int readTag() throws IOException {
+    if (isAtEnd()) {
+      lastTag = 0;
+      return 0;
+    }
+
+    lastTag = readRawVarint32();
+    if (lastTag == 0) {
+      // If we actually read zero, that's not a valid tag.
+      throw InvalidProtocolBufferMicroException.invalidTag();
+    }
+    return lastTag;
+  }
+
+  /**
+   * Verifies that the last call to readTag() returned the given tag value.
+   * This is used to verify that a nested group ended with the correct
+   * end tag.
+   *
+   * @throws InvalidProtocolBufferMicroException {@code value} does not match the
+   *                                        last tag.
+   */
+  public void checkLastTagWas(final int value)
+                              throws InvalidProtocolBufferMicroException {
+    if (lastTag != value) {
+      throw InvalidProtocolBufferMicroException.invalidEndTag();
+    }
+  }
+
+  /**
+   * Reads and discards a single field, given its tag value.
+   *
+   * @return {@code false} if the tag is an endgroup tag, in which case
+   *         nothing is skipped.  Otherwise, returns {@code true}.
+   */
+  public boolean skipField(final int tag) throws IOException {
+    switch (WireFormatMicro.getTagWireType(tag)) {
+      case WireFormatMicro.WIRETYPE_VARINT:
+        readInt32();
+        return true;
+      case WireFormatMicro.WIRETYPE_FIXED64:
+        readRawLittleEndian64();
+        return true;
+      case WireFormatMicro.WIRETYPE_LENGTH_DELIMITED:
+        skipRawBytes(readRawVarint32());
+        return true;
+      case WireFormatMicro.WIRETYPE_START_GROUP:
+        skipMessage();
+        checkLastTagWas(
+          WireFormatMicro.makeTag(WireFormatMicro.getTagFieldNumber(tag),
+                             WireFormatMicro.WIRETYPE_END_GROUP));
+        return true;
+      case WireFormatMicro.WIRETYPE_END_GROUP:
+        return false;
+      case WireFormatMicro.WIRETYPE_FIXED32:
+        readRawLittleEndian32();
+        return true;
+      default:
+        throw InvalidProtocolBufferMicroException.invalidWireType();
+    }
+  }
+
+  /**
+   * Reads and discards an entire message.  This will read either until EOF
+   * or until an endgroup tag, whichever comes first.
+   */
+  public void skipMessage() throws IOException {
+    while (true) {
+      final int tag = readTag();
+      if (tag == 0 || !skipField(tag)) {
+        return;
+      }
+    }
+  }
+
+  // -----------------------------------------------------------------
+
+  /** Read a {@code double} field value from the stream. */
+  public double readDouble() throws IOException {
+    return Double.longBitsToDouble(readRawLittleEndian64());
+  }
+
+  /** Read a {@code float} field value from the stream. */
+  public float readFloat() throws IOException {
+    return Float.intBitsToFloat(readRawLittleEndian32());
+  }
+
+  /** Read a {@code uint64} field value from the stream. */
+  public long readUInt64() throws IOException {
+    return readRawVarint64();
+  }
+
+  /** Read an {@code int64} field value from the stream. */
+  public long readInt64() throws IOException {
+    return readRawVarint64();
+  }
+
+  /** Read an {@code int32} field value from the stream. */
+  public int readInt32() throws IOException {
+    return readRawVarint32();
+  }
+
+  /** Read a {@code fixed64} field value from the stream. */
+  public long readFixed64() throws IOException {
+    return readRawLittleEndian64();
+  }
+
+  /** Read a {@code fixed32} field value from the stream. */
+  public int readFixed32() throws IOException {
+    return readRawLittleEndian32();
+  }
+
+  /** Read a {@code bool} field value from the stream. */
+  public boolean readBool() throws IOException {
+    return readRawVarint32() != 0;
+  }
+
+  /** Read a {@code string} field value from the stream. */
+  public String readString() throws IOException {
+    final int size = readRawVarint32();
+    if (size <= (bufferSize - bufferPos) && size > 0) {
+      // Fast path:  We already have the bytes in a contiguous buffer, so
+      //   just copy directly from it.
+      final String result = new String(buffer, bufferPos, size, "UTF-8");
+      bufferPos += size;
+      return result;
+    } else {
+      // Slow path:  Build a byte array first then copy it.
+      return new String(readRawBytes(size), "UTF-8");
+    }
+  }
+
+  /** Read a {@code group} field value from the stream. */
+  public void readGroup(final MessageMicro msg, final int fieldNumber)
+      throws IOException {
+    if (recursionDepth >= recursionLimit) {
+      throw InvalidProtocolBufferMicroException.recursionLimitExceeded();
+    }
+    ++recursionDepth;
+    msg.mergeFrom(this);
+    checkLastTagWas(
+      WireFormatMicro.makeTag(fieldNumber, WireFormatMicro.WIRETYPE_END_GROUP));
+    --recursionDepth;
+  }
+
+  public void readMessage(final MessageMicro msg)
+      throws IOException {
+    final int length = readRawVarint32();
+    if (recursionDepth >= recursionLimit) {
+      throw InvalidProtocolBufferMicroException.recursionLimitExceeded();
+    }
+    final int oldLimit = pushLimit(length);
+    ++recursionDepth;
+    msg.mergeFrom(this);
+    checkLastTagWas(0);
+    --recursionDepth;
+    popLimit(oldLimit);
+  }
+
+  /** Read a {@code bytes} field value from the stream. */
+  public ByteStringMicro readBytes() throws IOException {
+    final int size = readRawVarint32();
+    if (size <= (bufferSize - bufferPos) && size > 0) {
+      // Fast path:  We already have the bytes in a contiguous buffer, so
+      //   just copy directly from it.
+      final ByteStringMicro result = ByteStringMicro.copyFrom(buffer, bufferPos, size);
+      bufferPos += size;
+      return result;
+    } else {
+      // Slow path:  Build a byte array first then copy it.
+      return ByteStringMicro.copyFrom(readRawBytes(size));
+    }
+  }
+
+  /** Read a {@code uint32} field value from the stream. */
+  public int readUInt32() throws IOException {
+    return readRawVarint32();
+  }
+
+  /**
+   * Read an enum field value from the stream.  Caller is responsible
+   * for converting the numeric value to an actual enum.
+   */
+  public int readEnum() throws IOException {
+    return readRawVarint32();
+  }
+
+  /** Read an {@code sfixed32} field value from the stream. */
+  public int readSFixed32() throws IOException {
+    return readRawLittleEndian32();
+  }
+
+  /** Read an {@code sfixed64} field value from the stream. */
+  public long readSFixed64() throws IOException {
+    return readRawLittleEndian64();
+  }
+
+  /** Read an {@code sint32} field value from the stream. */
+  public int readSInt32() throws IOException {
+    return decodeZigZag32(readRawVarint32());
+  }
+
+  /** Read an {@code sint64} field value from the stream. */
+  public long readSInt64() throws IOException {
+    return decodeZigZag64(readRawVarint64());
+  }
+
+  // =================================================================
+
+  /**
+   * Read a raw Varint from the stream.  If larger than 32 bits, discard the
+   * upper bits.
+   */
+  public int readRawVarint32() throws IOException {
+    byte tmp = readRawByte();
+    if (tmp >= 0) {
+      return tmp;
+    }
+    int result = tmp & 0x7f;
+    if ((tmp = readRawByte()) >= 0) {
+      result |= tmp << 7;
+    } else {
+      result |= (tmp & 0x7f) << 7;
+      if ((tmp = readRawByte()) >= 0) {
+        result |= tmp << 14;
+      } else {
+        result |= (tmp & 0x7f) << 14;
+        if ((tmp = readRawByte()) >= 0) {
+          result |= tmp << 21;
+        } else {
+          result |= (tmp & 0x7f) << 21;
+          result |= (tmp = readRawByte()) << 28;
+          if (tmp < 0) {
+            // Discard upper 32 bits.
+            for (int i = 0; i < 5; i++) {
+              if (readRawByte() >= 0) {
+                return result;
+              }
+            }
+            throw InvalidProtocolBufferMicroException.malformedVarint();
+          }
+        }
+      }
+    }
+    return result;
+  }
+
+  /**
+   * Reads a varint from the input one byte at a time, so that it does not
+   * read any bytes after the end of the varint.  If you simply wrapped the
+   * stream in a CodedInputStream and used {@link #readRawVarint32(InputStream)}
+   * then you would probably end up reading past the end of the varint since
+   * CodedInputStream buffers its input.
+   */
+  static int readRawVarint32(final InputStream input) throws IOException {
+    int result = 0;
+    int offset = 0;
+    for (; offset < 32; offset += 7) {
+      final int b = input.read();
+      if (b == -1) {
+        throw InvalidProtocolBufferMicroException.truncatedMessage();
+      }
+      result |= (b & 0x7f) << offset;
+      if ((b & 0x80) == 0) {
+        return result;
+      }
+    }
+    // Keep reading up to 64 bits.
+    for (; offset < 64; offset += 7) {
+      final int b = input.read();
+      if (b == -1) {
+        throw InvalidProtocolBufferMicroException.truncatedMessage();
+      }
+      if ((b & 0x80) == 0) {
+        return result;
+      }
+    }
+    throw InvalidProtocolBufferMicroException.malformedVarint();
+  }
+
+  /** Read a raw Varint from the stream. */
+  public long readRawVarint64() throws IOException {
+    int shift = 0;
+    long result = 0;
+    while (shift < 64) {
+      final byte b = readRawByte();
+      result |= (long)(b & 0x7F) << shift;
+      if ((b & 0x80) == 0) {
+        return result;
+      }
+      shift += 7;
+    }
+    throw InvalidProtocolBufferMicroException.malformedVarint();
+  }
+
+  /** Read a 32-bit little-endian integer from the stream. */
+  public int readRawLittleEndian32() throws IOException {
+    final byte b1 = readRawByte();
+    final byte b2 = readRawByte();
+    final byte b3 = readRawByte();
+    final byte b4 = readRawByte();
+    return ((b1 & 0xff)      ) |
+           ((b2 & 0xff) <<  8) |
+           ((b3 & 0xff) << 16) |
+           ((b4 & 0xff) << 24);
+  }
+
+  /** Read a 64-bit little-endian integer from the stream. */
+  public long readRawLittleEndian64() throws IOException {
+    final byte b1 = readRawByte();
+    final byte b2 = readRawByte();
+    final byte b3 = readRawByte();
+    final byte b4 = readRawByte();
+    final byte b5 = readRawByte();
+    final byte b6 = readRawByte();
+    final byte b7 = readRawByte();
+    final byte b8 = readRawByte();
+    return (((long)b1 & 0xff)      ) |
+           (((long)b2 & 0xff) <<  8) |
+           (((long)b3 & 0xff) << 16) |
+           (((long)b4 & 0xff) << 24) |
+           (((long)b5 & 0xff) << 32) |
+           (((long)b6 & 0xff) << 40) |
+           (((long)b7 & 0xff) << 48) |
+           (((long)b8 & 0xff) << 56);
+  }
+
+  /**
+   * Decode a ZigZag-encoded 32-bit value.  ZigZag encodes signed integers
+   * into values that can be efficiently encoded with varint.  (Otherwise,
+   * negative values must be sign-extended to 64 bits to be varint encoded,
+   * thus always taking 10 bytes on the wire.)
+   *
+   * @param n An unsigned 32-bit integer, stored in a signed int because
+   *          Java has no explicit unsigned support.
+   * @return A signed 32-bit integer.
+   */
+  public static int decodeZigZag32(final int n) {
+    return (n >>> 1) ^ -(n & 1);
+  }
+
+  /**
+   * Decode a ZigZag-encoded 64-bit value.  ZigZag encodes signed integers
+   * into values that can be efficiently encoded with varint.  (Otherwise,
+   * negative values must be sign-extended to 64 bits to be varint encoded,
+   * thus always taking 10 bytes on the wire.)
+   *
+   * @param n An unsigned 64-bit integer, stored in a signed int because
+   *          Java has no explicit unsigned support.
+   * @return A signed 64-bit integer.
+   */
+  public static long decodeZigZag64(final long n) {
+    return (n >>> 1) ^ -(n & 1);
+  }
+
+  // -----------------------------------------------------------------
+
+  private final byte[] buffer;
+  private int bufferSize;
+  private int bufferSizeAfterLimit;
+  private int bufferPos;
+  private final InputStream input;
+  private int lastTag;
+
+  /**
+   * The total number of bytes read before the current buffer.  The total
+   * bytes read up to the current position can be computed as
+   * {@code totalBytesRetired + bufferPos}.
+   */
+  private int totalBytesRetired;
+
+  /** The absolute position of the end of the current message. */
+  private int currentLimit = Integer.MAX_VALUE;
+
+  /** See setRecursionLimit() */
+  private int recursionDepth;
+  private int recursionLimit = DEFAULT_RECURSION_LIMIT;
+
+  /** See setSizeLimit() */
+  private int sizeLimit = DEFAULT_SIZE_LIMIT;
+
+  private static final int DEFAULT_RECURSION_LIMIT = 64;
+  private static final int DEFAULT_SIZE_LIMIT = 64 << 20;  // 64MB
+  private static final int BUFFER_SIZE = 4096;
+
+  private CodedInputStreamMicro(final byte[] buffer, final int off, final int len) {
+    this.buffer = buffer;
+    bufferSize = off + len;
+    bufferPos = off;
+    input = null;
+  }
+
+  private CodedInputStreamMicro(final InputStream input) {
+    buffer = new byte[BUFFER_SIZE];
+    bufferSize = 0;
+    bufferPos = 0;
+    this.input = input;
+  }
+
+  /**
+   * Set the maximum message recursion depth.  In order to prevent malicious
+   * messages from causing stack overflows, {@code CodedInputStream} limits
+   * how deeply messages may be nested.  The default limit is 64.
+   *
+   * @return the old limit.
+   */
+  public int setRecursionLimit(final int limit) {
+    if (limit < 0) {
+      throw new IllegalArgumentException(
+        "Recursion limit cannot be negative: " + limit);
+    }
+    final int oldLimit = recursionLimit;
+    recursionLimit = limit;
+    return oldLimit;
+  }
+
+  /**
+   * Set the maximum message size.  In order to prevent malicious
+   * messages from exhausting memory or causing integer overflows,
+   * {@code CodedInputStream} limits how large a message may be.
+   * The default limit is 64MB.  You should set this limit as small
+   * as you can without harming your app's functionality.  Note that
+   * size limits only apply when reading from an {@code InputStream}, not
+   * when constructed around a raw byte array (nor with
+   * {@link ByteStringMicro#newCodedInput}).
+   * <p>
+   * If you want to read several messages from a single CodedInputStream, you
+   * could call {@link #resetSizeCounter()} after each one to avoid hitting the
+   * size limit.
+   *
+   * @return the old limit.
+   */
+  public int setSizeLimit(final int limit) {
+    if (limit < 0) {
+      throw new IllegalArgumentException(
+        "Size limit cannot be negative: " + limit);
+    }
+    final int oldLimit = sizeLimit;
+    sizeLimit = limit;
+    return oldLimit;
+  }
+
+  /**
+   * Resets the current size counter to zero (see {@link #setSizeLimit(int)}).
+   */
+  public void resetSizeCounter() {
+    totalBytesRetired = 0;
+  }
+
+  /**
+   * Sets {@code currentLimit} to (current position) + {@code byteLimit}.  This
+   * is called when descending into a length-delimited embedded message.
+   *
+   * @return the old limit.
+   */
+  public int pushLimit(int byteLimit) throws InvalidProtocolBufferMicroException {
+    if (byteLimit < 0) {
+      throw InvalidProtocolBufferMicroException.negativeSize();
+    }
+    byteLimit += totalBytesRetired + bufferPos;
+    final int oldLimit = currentLimit;
+    if (byteLimit > oldLimit) {
+      throw InvalidProtocolBufferMicroException.truncatedMessage();
+    }
+    currentLimit = byteLimit;
+
+    recomputeBufferSizeAfterLimit();
+
+    return oldLimit;
+  }
+
+  private void recomputeBufferSizeAfterLimit() {
+    bufferSize += bufferSizeAfterLimit;
+    final int bufferEnd = totalBytesRetired + bufferSize;
+    if (bufferEnd > currentLimit) {
+      // Limit is in current buffer.
+      bufferSizeAfterLimit = bufferEnd - currentLimit;
+      bufferSize -= bufferSizeAfterLimit;
+    } else {
+      bufferSizeAfterLimit = 0;
+    }
+  }
+
+  /**
+   * Discards the current limit, returning to the previous limit.
+   *
+   * @param oldLimit The old limit, as returned by {@code pushLimit}.
+   */
+  public void popLimit(final int oldLimit) {
+    currentLimit = oldLimit;
+    recomputeBufferSizeAfterLimit();
+  }
+
+  /**
+   * Returns the number of bytes to be read before the current limit.
+   * If no limit is set, returns -1.
+   */
+  public int getBytesUntilLimit() {
+    if (currentLimit == Integer.MAX_VALUE) {
+      return -1;
+    }
+
+    final int currentAbsolutePosition = totalBytesRetired + bufferPos;
+    return currentLimit - currentAbsolutePosition;
+  }
+
+  /**
+   * Returns true if the stream has reached the end of the input.  This is the
+   * case if either the end of the underlying input source has been reached or
+   * if the stream has reached a limit created using {@link #pushLimit(int)}.
+   */
+  public boolean isAtEnd() throws IOException {
+    return bufferPos == bufferSize && !refillBuffer(false);
+  }
+
+  /**
+   * Called with {@code this.buffer} is empty to read more bytes from the
+   * input.  If {@code mustSucceed} is true, refillBuffer() gurantees that
+   * either there will be at least one byte in the buffer when it returns
+   * or it will throw an exception.  If {@code mustSucceed} is false,
+   * refillBuffer() returns false if no more bytes were available.
+   */
+  private boolean refillBuffer(final boolean mustSucceed) throws IOException {
+    if (bufferPos < bufferSize) {
+      throw new IllegalStateException(
+        "refillBuffer() called when buffer wasn't empty.");
+    }
+
+    if (totalBytesRetired + bufferSize == currentLimit) {
+      // Oops, we hit a limit.
+      if (mustSucceed) {
+        throw InvalidProtocolBufferMicroException.truncatedMessage();
+      } else {
+        return false;
+      }
+    }
+
+    totalBytesRetired += bufferSize;
+
+    bufferPos = 0;
+    bufferSize = (input == null) ? -1 : input.read(buffer);
+    if (bufferSize == 0 || bufferSize < -1) {
+      throw new IllegalStateException(
+          "InputStream#read(byte[]) returned invalid result: " + bufferSize +
+          "\nThe InputStream implementation is buggy.");
+    }
+    if (bufferSize == -1) {
+      bufferSize = 0;
+      if (mustSucceed) {
+        throw InvalidProtocolBufferMicroException.truncatedMessage();
+      } else {
+        return false;
+      }
+    } else {
+      recomputeBufferSizeAfterLimit();
+      final int totalBytesRead =
+        totalBytesRetired + bufferSize + bufferSizeAfterLimit;
+      if (totalBytesRead > sizeLimit || totalBytesRead < 0) {
+        throw InvalidProtocolBufferMicroException.sizeLimitExceeded();
+      }
+      return true;
+    }
+  }
+
+  /**
+   * Read one byte from the input.
+   *
+   * @throws InvalidProtocolBufferMicroException The end of the stream or the current
+   *                                        limit was reached.
+   */
+  public byte readRawByte() throws IOException {
+    if (bufferPos == bufferSize) {
+      refillBuffer(true);
+    }
+    return buffer[bufferPos++];
+  }
+
+  /**
+   * Read a fixed size of bytes from the input.
+   *
+   * @throws InvalidProtocolBufferMicroException The end of the stream or the current
+   *                                        limit was reached.
+   */
+  public byte[] readRawBytes(final int size) throws IOException {
+    if (size < 0) {
+      throw InvalidProtocolBufferMicroException.negativeSize();
+    }
+
+    if (totalBytesRetired + bufferPos + size > currentLimit) {
+      // Read to the end of the stream anyway.
+      skipRawBytes(currentLimit - totalBytesRetired - bufferPos);
+      // Then fail.
+      throw InvalidProtocolBufferMicroException.truncatedMessage();
+    }
+
+    if (size <= bufferSize - bufferPos) {
+      // We have all the bytes we need already.
+      final byte[] bytes = new byte[size];
+      System.arraycopy(buffer, bufferPos, bytes, 0, size);
+      bufferPos += size;
+      return bytes;
+    } else if (size < BUFFER_SIZE) {
+      // Reading more bytes than are in the buffer, but not an excessive number
+      // of bytes.  We can safely allocate the resulting array ahead of time.
+
+      // First copy what we have.
+      final byte[] bytes = new byte[size];
+      int pos = bufferSize - bufferPos;
+      System.arraycopy(buffer, bufferPos, bytes, 0, pos);
+      bufferPos = bufferSize;
+
+      // We want to use refillBuffer() and then copy from the buffer into our
+      // byte array rather than reading directly into our byte array because
+      // the input may be unbuffered.
+      refillBuffer(true);
+
+      while (size - pos > bufferSize) {
+        System.arraycopy(buffer, 0, bytes, pos, bufferSize);
+        pos += bufferSize;
+        bufferPos = bufferSize;
+        refillBuffer(true);
+      }
+
+      System.arraycopy(buffer, 0, bytes, pos, size - pos);
+      bufferPos = size - pos;
+
+      return bytes;
+    } else {
+      // The size is very large.  For security reasons, we can't allocate the
+      // entire byte array yet.  The size comes directly from the input, so a
+      // maliciously-crafted message could provide a bogus very large size in
+      // order to trick the app into allocating a lot of memory.  We avoid this
+      // by allocating and reading only a small chunk at a time, so that the
+      // malicious message must actually *be* extremely large to cause
+      // problems.  Meanwhile, we limit the allowed size of a message elsewhere.
+
+      // Remember the buffer markers since we'll have to copy the bytes out of
+      // it later.
+      final int originalBufferPos = bufferPos;
+      final int originalBufferSize = bufferSize;
+
+      // Mark the current buffer consumed.
+      totalBytesRetired += bufferSize;
+      bufferPos = 0;
+      bufferSize = 0;
+
+      // Read all the rest of the bytes we need.
+      int sizeLeft = size - (originalBufferSize - originalBufferPos);
+
+      // For compatibility with Java 1.3 use Vector
+      final java.util.Vector chunks = new java.util.Vector();
+
+      while (sizeLeft > 0) {
+        final byte[] chunk = new byte[Math.min(sizeLeft, BUFFER_SIZE)];
+        int pos = 0;
+        while (pos < chunk.length) {
+          final int n = (input == null) ? -1 :
+            input.read(chunk, pos, chunk.length - pos);
+          if (n == -1) {
+            throw InvalidProtocolBufferMicroException.truncatedMessage();
+          }
+          totalBytesRetired += n;
+          pos += n;
+        }
+        sizeLeft -= chunk.length;
+        chunks.addElement(chunk);
+      }
+
+      // OK, got everything.  Now concatenate it all into one buffer.
+      final byte[] bytes = new byte[size];
+
+      // Start by copying the leftover bytes from this.buffer.
+      int pos = originalBufferSize - originalBufferPos;
+      System.arraycopy(buffer, originalBufferPos, bytes, 0, pos);
+
+      // And now all the chunks.
+      for (int i = 0; i < chunks.size(); i++) {
+        byte [] chunk = (byte [])chunks.elementAt(i);
+        System.arraycopy(chunk, 0, bytes, pos, chunk.length);
+        pos += chunk.length;
+      }
+
+      // Done.
+      return bytes;
+    }
+  }
+
+  /**
+   * Reads and discards {@code size} bytes.
+   *
+   * @throws InvalidProtocolBufferMicroException The end of the stream or the current
+   *                                        limit was reached.
+   */
+  public void skipRawBytes(final int size) throws IOException {
+    if (size < 0) {
+      throw InvalidProtocolBufferMicroException.negativeSize();
+    }
+
+    if (totalBytesRetired + bufferPos + size > currentLimit) {
+      // Read to the end of the stream anyway.
+      skipRawBytes(currentLimit - totalBytesRetired - bufferPos);
+      // Then fail.
+      throw InvalidProtocolBufferMicroException.truncatedMessage();
+    }
+
+    if (size <= bufferSize - bufferPos) {
+      // We have all the bytes we need already.
+      bufferPos += size;
+    } else {
+      // Skipping more bytes than are in the buffer.  First skip what we have.
+      int pos = bufferSize - bufferPos;
+      totalBytesRetired += pos;
+      bufferPos = 0;
+      bufferSize = 0;
+
+      // Then skip directly from the InputStream for the rest.
+      while (pos < size) {
+        final int n = (input == null) ? -1 : (int) input.skip(size - pos);
+        if (n <= 0) {
+          throw InvalidProtocolBufferMicroException.truncatedMessage();
+        }
+        pos += n;
+        totalBytesRetired += n;
+      }
+    }
+  }
+}
diff --git a/java/src/main/java/com/google/protobuf/micro/CodedOutputStreamMicro.java b/java/src/main/java/com/google/protobuf/micro/CodedOutputStreamMicro.java
new file mode 100644
index 0000000..68b6e97
--- /dev/null
+++ b/java/src/main/java/com/google/protobuf/micro/CodedOutputStreamMicro.java
@@ -0,0 +1,996 @@
+// 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.micro;
+
+import java.io.OutputStream;
+import java.io.IOException;
+import java.io.UnsupportedEncodingException;
+
+/**
+ * Encodes and writes protocol message fields.
+ *
+ * <p>This class contains two kinds of methods:  methods that write specific
+ * protocol message constructs and field types (e.g. {@link #writeTag} and
+ * {@link #writeInt32}) and methods that write low-level values (e.g.
+ * {@link #writeRawVarint32} and {@link #writeRawBytes}).  If you are
+ * writing encoded protocol messages, you should use the former methods, but if
+ * you are writing some other format of your own design, use the latter.
+ *
+ * <p>This class is totally unsynchronized.
+ *
+ * @author kneton@google.com Kenton Varda
+ */
+public final class CodedOutputStreamMicro {
+  private final byte[] buffer;
+  private final int limit;
+  private int position;
+
+  private final OutputStream output;
+
+  /**
+   * The buffer size used in {@link #newInstance(OutputStream)}.
+   */
+  public static final int DEFAULT_BUFFER_SIZE = 4096;
+
+  private CodedOutputStreamMicro(final byte[] buffer, final int offset,
+                            final int length) {
+    output = null;
+    this.buffer = buffer;
+    position = offset;
+    limit = offset + length;
+  }
+
+  private CodedOutputStreamMicro(final OutputStream output, final byte[] buffer) {
+    this.output = output;
+    this.buffer = buffer;
+    position = 0;
+    limit = buffer.length;
+  }
+
+  /**
+   * Create a new {@code CodedOutputStream} wrapping the given
+   * {@code OutputStream}.
+   */
+  public static CodedOutputStreamMicro newInstance(final OutputStream output) {
+    return newInstance(output, DEFAULT_BUFFER_SIZE);
+  }
+
+  /**
+   * Create a new {@code CodedOutputStream} wrapping the given
+   * {@code OutputStream} with a given buffer size.
+   */
+  public static CodedOutputStreamMicro newInstance(final OutputStream output,
+      final int bufferSize) {
+    return new CodedOutputStreamMicro(output, new byte[bufferSize]);
+  }
+
+  /**
+   * Create a new {@code CodedOutputStream} that writes directly to the given
+   * byte array.  If more bytes are written than fit in the array,
+   * {@link OutOfSpaceException} will be thrown.  Writing directly to a flat
+   * array is faster than writing to an {@code OutputStream}.
+   */
+  public static CodedOutputStreamMicro newInstance(final byte[] flatArray) {
+    return newInstance(flatArray, 0, flatArray.length);
+  }
+
+  /**
+   * Create a new {@code CodedOutputStream} that writes directly to the given
+   * byte array slice.  If more bytes are written than fit in the slice,
+   * {@link OutOfSpaceException} will be thrown.  Writing directly to a flat
+   * array is faster than writing to an {@code OutputStream}.
+   */
+  public static CodedOutputStreamMicro newInstance(final byte[] flatArray,
+                                              final int offset,
+                                              final int length) {
+    return new CodedOutputStreamMicro(flatArray, offset, length);
+  }
+
+  // -----------------------------------------------------------------
+
+  /** Write a {@code double} field, including tag, to the stream. */
+  public void writeDouble(final int fieldNumber, final double value)
+                          throws IOException {
+    writeTag(fieldNumber, WireFormatMicro.WIRETYPE_FIXED64);
+    writeDoubleNoTag(value);
+  }
+
+  /** Write a {@code float} field, including tag, to the stream. */
+  public void writeFloat(final int fieldNumber, final float value)
+                         throws IOException {
+    writeTag(fieldNumber, WireFormatMicro.WIRETYPE_FIXED32);
+    writeFloatNoTag(value);
+  }
+
+  /** Write a {@code uint64} field, including tag, to the stream. */
+  public void writeUInt64(final int fieldNumber, final long value)
+                          throws IOException {
+    writeTag(fieldNumber, WireFormatMicro.WIRETYPE_VARINT);
+    writeUInt64NoTag(value);
+  }
+
+  /** Write an {@code int64} field, including tag, to the stream. */
+  public void writeInt64(final int fieldNumber, final long value)
+                         throws IOException {
+    writeTag(fieldNumber, WireFormatMicro.WIRETYPE_VARINT);
+    writeInt64NoTag(value);
+  }
+
+  /** Write an {@code int32} field, including tag, to the stream. */
+  public void writeInt32(final int fieldNumber, final int value)
+                         throws IOException {
+    writeTag(fieldNumber, WireFormatMicro.WIRETYPE_VARINT);
+    writeInt32NoTag(value);
+  }
+
+  /** Write a {@code fixed64} field, including tag, to the stream. */
+  public void writeFixed64(final int fieldNumber, final long value)
+                           throws IOException {
+    writeTag(fieldNumber, WireFormatMicro.WIRETYPE_FIXED64);
+    writeFixed64NoTag(value);
+  }
+
+  /** Write a {@code fixed32} field, including tag, to the stream. */
+  public void writeFixed32(final int fieldNumber, final int value)
+                           throws IOException {
+    writeTag(fieldNumber, WireFormatMicro.WIRETYPE_FIXED32);
+    writeFixed32NoTag(value);
+  }
+
+  /** Write a {@code bool} field, including tag, to the stream. */
+  public void writeBool(final int fieldNumber, final boolean value)
+                        throws IOException {
+    writeTag(fieldNumber, WireFormatMicro.WIRETYPE_VARINT);
+    writeBoolNoTag(value);
+  }
+
+  /** Write a {@code string} field, including tag, to the stream. */
+  public void writeString(final int fieldNumber, final String value)
+                          throws IOException {
+    writeTag(fieldNumber, WireFormatMicro.WIRETYPE_LENGTH_DELIMITED);
+    writeStringNoTag(value);
+  }
+
+  /** Write a {@code StringUtf8Micro} field, including tag, to the stream. */
+  public void writeStringUtf8(final int fieldNumber, final StringUtf8Micro value)
+                          throws IOException {
+    writeTag(fieldNumber, WireFormatMicro.WIRETYPE_LENGTH_DELIMITED);
+    writeStringUtf8NoTag(value);
+  }
+
+  /** Write a {@code group} field, including tag, to the stream. */
+  public void writeGroup(final int fieldNumber, final MessageMicro value)
+                         throws IOException {
+    writeTag(fieldNumber, WireFormatMicro.WIRETYPE_START_GROUP);
+    writeGroupNoTag(value);
+    writeTag(fieldNumber, WireFormatMicro.WIRETYPE_END_GROUP);
+  }
+
+  /** Write an embedded message field, including tag, to the stream. */
+  public void writeMessage(final int fieldNumber, final MessageMicro value)
+                           throws IOException {
+    writeTag(fieldNumber, WireFormatMicro.WIRETYPE_LENGTH_DELIMITED);
+    writeMessageNoTag(value);
+  }
+
+  /** Write a {@code bytes} field, including tag, to the stream. */
+  public void writeBytes(final int fieldNumber, final ByteStringMicro value)
+                         throws IOException {
+    writeTag(fieldNumber, WireFormatMicro.WIRETYPE_LENGTH_DELIMITED);
+    writeBytesNoTag(value);
+  }
+
+  /** Write a {@code uint32} field, including tag, to the stream. */
+  public void writeUInt32(final int fieldNumber, final int value)
+                          throws IOException {
+    writeTag(fieldNumber, WireFormatMicro.WIRETYPE_VARINT);
+    writeUInt32NoTag(value);
+  }
+
+  /**
+   * Write an enum field, including tag, to the stream.  Caller is responsible
+   * for converting the enum value to its numeric value.
+   */
+  public void writeEnum(final int fieldNumber, final int value)
+                        throws IOException {
+    writeTag(fieldNumber, WireFormatMicro.WIRETYPE_VARINT);
+    writeEnumNoTag(value);
+  }
+
+  /** Write an {@code sfixed32} field, including tag, to the stream. */
+  public void writeSFixed32(final int fieldNumber, final int value)
+                            throws IOException {
+    writeTag(fieldNumber, WireFormatMicro.WIRETYPE_FIXED32);
+    writeSFixed32NoTag(value);
+  }
+
+  /** Write an {@code sfixed64} field, including tag, to the stream. */
+  public void writeSFixed64(final int fieldNumber, final long value)
+                            throws IOException {
+    writeTag(fieldNumber, WireFormatMicro.WIRETYPE_FIXED64);
+    writeSFixed64NoTag(value);
+  }
+
+  /** Write an {@code sint32} field, including tag, to the stream. */
+  public void writeSInt32(final int fieldNumber, final int value)
+                          throws IOException {
+    writeTag(fieldNumber, WireFormatMicro.WIRETYPE_VARINT);
+    writeSInt32NoTag(value);
+  }
+
+  /** Write an {@code sint64} field, including tag, to the stream. */
+  public void writeSInt64(final int fieldNumber, final long value)
+                          throws IOException {
+    writeTag(fieldNumber, WireFormatMicro.WIRETYPE_VARINT);
+    writeSInt64NoTag(value);
+  }
+
+  /**
+   * Write a MessageSet extension field to the stream.  For historical reasons,
+   * the wire format differs from normal fields.
+   */
+//  public void writeMessageSetExtension(final int fieldNumber,
+//                                       final MessageMicro value)
+//                                       throws IOException {
+//    writeTag(WireFormatMicro.MESSAGE_SET_ITEM, WireFormatMicro.WIRETYPE_START_GROUP);
+//    writeUInt32(WireFormatMicro.MESSAGE_SET_TYPE_ID, fieldNumber);
+//    writeMessage(WireFormatMicro.MESSAGE_SET_MESSAGE, value);
+//    writeTag(WireFormatMicro.MESSAGE_SET_ITEM, WireFormatMicro.WIRETYPE_END_GROUP);
+//  }
+
+  /**
+   * Write an unparsed MessageSet extension field to the stream.  For
+   * historical reasons, the wire format differs from normal fields.
+   */
+//  public void writeRawMessageSetExtension(final int fieldNumber,
+//                                          final ByteStringMicro value)
+//                                          throws IOException {
+//    writeTag(WireFormatMicro.MESSAGE_SET_ITEM, WireFormatMicro.WIRETYPE_START_GROUP);
+//    writeUInt32(WireFormatMicro.MESSAGE_SET_TYPE_ID, fieldNumber);
+//    writeBytes(WireFormatMicro.MESSAGE_SET_MESSAGE, value);
+//    writeTag(WireFormatMicro.MESSAGE_SET_ITEM, WireFormatMicro.WIRETYPE_END_GROUP);
+//  }
+
+  // -----------------------------------------------------------------
+
+  /** Write a {@code double} field to the stream. */
+  public void writeDoubleNoTag(final double value) throws IOException {
+    writeRawLittleEndian64(Double.doubleToLongBits(value));
+  }
+
+  /** Write a {@code float} field to the stream. */
+  public void writeFloatNoTag(final float value) throws IOException {
+    writeRawLittleEndian32(Float.floatToIntBits(value));
+  }
+
+  /** Write a {@code uint64} field to the stream. */
+  public void writeUInt64NoTag(final long value) throws IOException {
+    writeRawVarint64(value);
+  }
+
+  /** Write an {@code int64} field to the stream. */
+  public void writeInt64NoTag(final long value) throws IOException {
+    writeRawVarint64(value);
+  }
+
+  /** Write an {@code int32} field to the stream. */
+  public void writeInt32NoTag(final int value) throws IOException {
+    if (value >= 0) {
+      writeRawVarint32(value);
+    } else {
+      // Must sign-extend.
+      writeRawVarint64(value);
+    }
+  }
+
+  /** Write a {@code fixed64} field to the stream. */
+  public void writeFixed64NoTag(final long value) throws IOException {
+    writeRawLittleEndian64(value);
+  }
+
+  /** Write a {@code fixed32} field to the stream. */
+  public void writeFixed32NoTag(final int value) throws IOException {
+    writeRawLittleEndian32(value);
+  }
+
+  /** Write a {@code bool} field to the stream. */
+  public void writeBoolNoTag(final boolean value) throws IOException {
+    writeRawByte(value ? 1 : 0);
+  }
+
+  /** Write a {@code string} field to the stream. */
+  public void writeStringNoTag(final String value) throws IOException {
+    // Unfortunately there does not appear to be any way to tell Java to encode
+    // UTF-8 directly into our buffer, so we have to let it create its own byte
+    // array and then copy.
+    final byte[] bytes = value.getBytes("UTF-8");
+    writeRawVarint32(bytes.length);
+    writeRawBytes(bytes);
+  }
+
+  /** Write a {@code StringUtf8Micro} field to the stream. */
+  public void writeStringUtf8NoTag(final StringUtf8Micro value) throws IOException {
+    final byte[] bytes = value.getBytes();
+    writeRawVarint32(bytes.length);
+    writeRawBytes(bytes);
+  }
+
+  /** Write a {@code group} field to the stream. */
+  public void writeGroupNoTag(final MessageMicro value) throws IOException {
+    value.writeTo(this);
+  }
+
+  /** Write an embedded message field to the stream. */
+  public void writeMessageNoTag(final MessageMicro value) throws IOException {
+    writeRawVarint32(value.getCachedSize());
+    value.writeTo(this);
+  }
+
+  /** Write a {@code bytes} field to the stream. */
+  public void writeBytesNoTag(final ByteStringMicro value) throws IOException {
+    final byte[] bytes = value.toByteArray();
+    writeRawVarint32(bytes.length);
+    writeRawBytes(bytes);
+  }
+
+  /** Write a {@code uint32} field to the stream. */
+  public void writeUInt32NoTag(final int value) throws IOException {
+    writeRawVarint32(value);
+  }
+
+  /**
+   * Write an enum field to the stream.  Caller is responsible
+   * for converting the enum value to its numeric value.
+   */
+  public void writeEnumNoTag(final int value) throws IOException {
+    writeRawVarint32(value);
+  }
+
+  /** Write an {@code sfixed32} field to the stream. */
+  public void writeSFixed32NoTag(final int value) throws IOException {
+    writeRawLittleEndian32(value);
+  }
+
+  /** Write an {@code sfixed64} field to the stream. */
+  public void writeSFixed64NoTag(final long value) throws IOException {
+    writeRawLittleEndian64(value);
+  }
+
+  /** Write an {@code sint32} field to the stream. */
+  public void writeSInt32NoTag(final int value) throws IOException {
+    writeRawVarint32(encodeZigZag32(value));
+  }
+
+  /** Write an {@code sint64} field to the stream. */
+  public void writeSInt64NoTag(final long value) throws IOException {
+    writeRawVarint64(encodeZigZag64(value));
+  }
+
+  // =================================================================
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code double} field, including tag.
+   */
+  public static int computeDoubleSize(final int fieldNumber,
+                                      final double value) {
+    return computeTagSize(fieldNumber) + computeDoubleSizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code float} field, including tag.
+   */
+  public static int computeFloatSize(final int fieldNumber, final float value) {
+    return computeTagSize(fieldNumber) + computeFloatSizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code uint64} field, including tag.
+   */
+  public static int computeUInt64Size(final int fieldNumber, final long value) {
+    return computeTagSize(fieldNumber) + computeUInt64SizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code int64} field, including tag.
+   */
+  public static int computeInt64Size(final int fieldNumber, final long value) {
+    return computeTagSize(fieldNumber) + computeInt64SizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code int32} field, including tag.
+   */
+  public static int computeInt32Size(final int fieldNumber, final int value) {
+    return computeTagSize(fieldNumber) + computeInt32SizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code fixed64} field, including tag.
+   */
+  public static int computeFixed64Size(final int fieldNumber,
+                                       final long value) {
+    return computeTagSize(fieldNumber) + computeFixed64SizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code fixed32} field, including tag.
+   */
+  public static int computeFixed32Size(final int fieldNumber,
+                                       final int value) {
+    return computeTagSize(fieldNumber) + computeFixed32SizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code bool} field, including tag.
+   */
+  public static int computeBoolSize(final int fieldNumber,
+                                    final boolean value) {
+    return computeTagSize(fieldNumber) + computeBoolSizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code string} field, including tag.
+   */
+  public static int computeStringSize(final int fieldNumber,
+                                      final String value) {
+    return computeTagSize(fieldNumber) + computeStringSizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code StringUtf8Micro} field, including tag.
+   */
+  public static int computeStringUtf8Size(final int fieldNumber,
+                                      final StringUtf8Micro value) {
+    return computeTagSize(fieldNumber) + computeStringUtf8SizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code group} field, including tag.
+   */
+  public static int computeGroupSize(final int fieldNumber,
+                                     final MessageMicro value) {
+    return computeTagSize(fieldNumber) * 2 + computeGroupSizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * embedded message field, including tag.
+   */
+  public static int computeMessageSize(final int fieldNumber,
+                                       final MessageMicro value) {
+    return computeTagSize(fieldNumber) + computeMessageSizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code bytes} field, including tag.
+   */
+  public static int computeBytesSize(final int fieldNumber,
+                                     final ByteStringMicro value) {
+    return computeTagSize(fieldNumber) + computeBytesSizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code uint32} field, including tag.
+   */
+  public static int computeUInt32Size(final int fieldNumber, final int value) {
+    return computeTagSize(fieldNumber) + computeUInt32SizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * enum field, including tag.  Caller is responsible for converting the
+   * enum value to its numeric value.
+   */
+  public static int computeEnumSize(final int fieldNumber, final int value) {
+    return computeTagSize(fieldNumber) + computeEnumSizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code sfixed32} field, including tag.
+   */
+  public static int computeSFixed32Size(final int fieldNumber,
+                                        final int value) {
+    return computeTagSize(fieldNumber) + computeSFixed32SizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code sfixed64} field, including tag.
+   */
+  public static int computeSFixed64Size(final int fieldNumber,
+                                        final long value) {
+    return computeTagSize(fieldNumber) + computeSFixed64SizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code sint32} field, including tag.
+   */
+  public static int computeSInt32Size(final int fieldNumber, final int value) {
+    return computeTagSize(fieldNumber) + computeSInt32SizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code sint64} field, including tag.
+   */
+  public static int computeSInt64Size(final int fieldNumber, final long value) {
+    return computeTagSize(fieldNumber) + computeSInt64SizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * MessageSet extension to the stream.  For historical reasons,
+   * the wire format differs from normal fields.
+   */
+//  public static int computeMessageSetExtensionSize(
+//      final int fieldNumber, final MessageMicro value) {
+//    return computeTagSize(WireFormatMicro.MESSAGE_SET_ITEM) * 2 +
+//           computeUInt32Size(WireFormatMicro.MESSAGE_SET_TYPE_ID, fieldNumber) +
+//           computeMessageSize(WireFormatMicro.MESSAGE_SET_MESSAGE, value);
+//  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * unparsed MessageSet extension field to the stream.  For
+   * historical reasons, the wire format differs from normal fields.
+   */
+//  public static int computeRawMessageSetExtensionSize(
+//      final int fieldNumber, final ByteStringMicro value) {
+//    return computeTagSize(WireFormatMicro.MESSAGE_SET_ITEM) * 2 +
+//           computeUInt32Size(WireFormatMicro.MESSAGE_SET_TYPE_ID, fieldNumber) +
+//           computeBytesSize(WireFormatMicro.MESSAGE_SET_MESSAGE, value);
+//  }
+
+  // -----------------------------------------------------------------
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code double} field, including tag.
+   */
+  public static int computeDoubleSizeNoTag(final double value) {
+    return LITTLE_ENDIAN_64_SIZE;
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code float} field, including tag.
+   */
+  public static int computeFloatSizeNoTag(final float value) {
+    return LITTLE_ENDIAN_32_SIZE;
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code uint64} field, including tag.
+   */
+  public static int computeUInt64SizeNoTag(final long value) {
+    return computeRawVarint64Size(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code int64} field, including tag.
+   */
+  public static int computeInt64SizeNoTag(final long value) {
+    return computeRawVarint64Size(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code int32} field, including tag.
+   */
+  public static int computeInt32SizeNoTag(final int value) {
+    if (value >= 0) {
+      return computeRawVarint32Size(value);
+    } else {
+      // Must sign-extend.
+      return 10;
+    }
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code fixed64} field.
+   */
+  public static int computeFixed64SizeNoTag(final long value) {
+    return LITTLE_ENDIAN_64_SIZE;
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code fixed32} field.
+   */
+  public static int computeFixed32SizeNoTag(final int value) {
+    return LITTLE_ENDIAN_32_SIZE;
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code bool} field.
+   */
+  public static int computeBoolSizeNoTag(final boolean value) {
+    return 1;
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code string} field.
+   */
+  public static int computeStringSizeNoTag(final String value) {
+    try {
+      final byte[] bytes = value.getBytes("UTF-8");
+      return computeRawVarint32Size(bytes.length) +
+             bytes.length;
+    } catch (UnsupportedEncodingException e) {
+      throw new RuntimeException("UTF-8 not supported.");
+    }
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code StringUtf8Micro} field.
+   */
+  public static int computeStringUtf8SizeNoTag(final StringUtf8Micro value) {
+    final byte[] bytes = value.getBytes();
+    return computeRawVarint32Size(bytes.length) +
+             bytes.length;
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code group} field.
+   */
+  public static int computeGroupSizeNoTag(final MessageMicro value) {
+    return value.getCachedSize();
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an embedded
+   * message field.
+   */
+  public static int computeMessageSizeNoTag(final MessageMicro value) {
+    final int size = value.getCachedSize();
+    return computeRawVarint32Size(size) + size;
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code bytes} field.
+   */
+  public static int computeBytesSizeNoTag(final ByteStringMicro value) {
+    return computeRawVarint32Size(value.size()) +
+           value.size();
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code uint32} field.
+   */
+  public static int computeUInt32SizeNoTag(final int value) {
+    return computeRawVarint32Size(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an enum field.
+   * Caller is responsible for converting the enum value to its numeric value.
+   */
+  public static int computeEnumSizeNoTag(final int value) {
+    return computeRawVarint32Size(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code sfixed32} field.
+   */
+  public static int computeSFixed32SizeNoTag(final int value) {
+    return LITTLE_ENDIAN_32_SIZE;
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code sfixed64} field.
+   */
+  public static int computeSFixed64SizeNoTag(final long value) {
+    return LITTLE_ENDIAN_64_SIZE;
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code sint32} field.
+   */
+  public static int computeSInt32SizeNoTag(final int value) {
+    return computeRawVarint32Size(encodeZigZag32(value));
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code sint64} field.
+   */
+  public static int computeSInt64SizeNoTag(final long value) {
+    return computeRawVarint64Size(encodeZigZag64(value));
+  }
+
+  // =================================================================
+
+  /**
+   * Internal helper that writes the current buffer to the output. The
+   * buffer position is reset to its initial value when this returns.
+   */
+  private void refreshBuffer() throws IOException {
+    if (output == null) {
+      // We're writing to a single buffer.
+      throw new OutOfSpaceException();
+    }
+
+    // Since we have an output stream, this is our buffer
+    // and buffer offset == 0
+    output.write(buffer, 0, position);
+    position = 0;
+  }
+
+  /**
+   * Flushes the stream and forces any buffered bytes to be written.  This
+   * does not flush the underlying OutputStream.
+   */
+  public void flush() throws IOException {
+    if (output != null) {
+      refreshBuffer();
+    }
+  }
+
+  /**
+   * If writing to a flat array, return the space left in the array.
+   * Otherwise, throws {@code UnsupportedOperationException}.
+   */
+  public int spaceLeft() {
+    if (output == null) {
+      return limit - position;
+    } else {
+      throw new UnsupportedOperationException(
+        "spaceLeft() can only be called on CodedOutputStreams that are " +
+        "writing to a flat array.");
+    }
+  }
+
+  /**
+   * Verifies that {@link #spaceLeft()} returns zero.  It's common to create
+   * a byte array that is exactly big enough to hold a message, then write to
+   * it with a {@code CodedOutputStream}.  Calling {@code checkNoSpaceLeft()}
+   * after writing verifies that the message was actually as big as expected,
+   * which can help catch bugs.
+   */
+  public void checkNoSpaceLeft() {
+    if (spaceLeft() != 0) {
+      throw new IllegalStateException(
+        "Did not write as much data as expected.");
+    }
+  }
+
+  /**
+   * If you create a CodedOutputStream around a simple flat array, you must
+   * not attempt to write more bytes than the array has space.  Otherwise,
+   * this exception will be thrown.
+   */
+  public static class OutOfSpaceException extends IOException {
+    private static final long serialVersionUID = -6947486886997889499L;
+
+    OutOfSpaceException() {
+      super("CodedOutputStream was writing to a flat byte array and ran " +
+            "out of space.");
+    }
+  }
+
+  /** Write a single byte. */
+  public void writeRawByte(final byte value) throws IOException {
+    if (position == limit) {
+      refreshBuffer();
+    }
+
+    buffer[position++] = value;
+  }
+
+  /** Write a single byte, represented by an integer value. */
+  public void writeRawByte(final int value) throws IOException {
+    writeRawByte((byte) value);
+  }
+
+  /** Write an array of bytes. */
+  public void writeRawBytes(final byte[] value) throws IOException {
+    writeRawBytes(value, 0, value.length);
+  }
+
+  /** Write part of an array of bytes. */
+  public void writeRawBytes(final byte[] value, int offset, int length)
+                            throws IOException {
+    if (limit - position >= length) {
+      // We have room in the current buffer.
+      System.arraycopy(value, offset, buffer, position, length);
+      position += length;
+    } else {
+      // Write extends past current buffer.  Fill the rest of this buffer and
+      // flush.
+      final int bytesWritten = limit - position;
+      System.arraycopy(value, offset, buffer, position, bytesWritten);
+      offset += bytesWritten;
+      length -= bytesWritten;
+      position = limit;
+      refreshBuffer();
+
+      // Now deal with the rest.
+      // Since we have an output stream, this is our buffer
+      // and buffer offset == 0
+      if (length <= limit) {
+        // Fits in new buffer.
+        System.arraycopy(value, offset, buffer, 0, length);
+        position = length;
+      } else {
+        // Write is very big.  Let's do it all at once.
+        output.write(value, offset, length);
+      }
+    }
+  }
+
+  /** Encode and write a tag. */
+  public void writeTag(final int fieldNumber, final int wireType)
+                       throws IOException {
+    writeRawVarint32(WireFormatMicro.makeTag(fieldNumber, wireType));
+  }
+
+  /** Compute the number of bytes that would be needed to encode a tag. */
+  public static int computeTagSize(final int fieldNumber) {
+    return computeRawVarint32Size(WireFormatMicro.makeTag(fieldNumber, 0));
+  }
+
+  /**
+   * Encode and write a varint.  {@code value} is treated as
+   * unsigned, so it won't be sign-extended if negative.
+   */
+  public void writeRawVarint32(int value) throws IOException {
+    while (true) {
+      if ((value & ~0x7F) == 0) {
+        writeRawByte(value);
+        return;
+      } else {
+        writeRawByte((value & 0x7F) | 0x80);
+        value >>>= 7;
+      }
+    }
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a varint.
+   * {@code value} is treated as unsigned, so it won't be sign-extended if
+   * negative.
+   */
+  public static int computeRawVarint32Size(final int value) {
+    if ((value & (0xffffffff <<  7)) == 0) return 1;
+    if ((value & (0xffffffff << 14)) == 0) return 2;
+    if ((value & (0xffffffff << 21)) == 0) return 3;
+    if ((value & (0xffffffff << 28)) == 0) return 4;
+    return 5;
+  }
+
+  /** Encode and write a varint. */
+  public void writeRawVarint64(long value) throws IOException {
+    while (true) {
+      if ((value & ~0x7FL) == 0) {
+        writeRawByte((int)value);
+        return;
+      } else {
+        writeRawByte(((int)value & 0x7F) | 0x80);
+        value >>>= 7;
+      }
+    }
+  }
+
+  /** Compute the number of bytes that would be needed to encode a varint. */
+  public static int computeRawVarint64Size(final long value) {
+    if ((value & (0xffffffffffffffffL <<  7)) == 0) return 1;
+    if ((value & (0xffffffffffffffffL << 14)) == 0) return 2;
+    if ((value & (0xffffffffffffffffL << 21)) == 0) return 3;
+    if ((value & (0xffffffffffffffffL << 28)) == 0) return 4;
+    if ((value & (0xffffffffffffffffL << 35)) == 0) return 5;
+    if ((value & (0xffffffffffffffffL << 42)) == 0) return 6;
+    if ((value & (0xffffffffffffffffL << 49)) == 0) return 7;
+    if ((value & (0xffffffffffffffffL << 56)) == 0) return 8;
+    if ((value & (0xffffffffffffffffL << 63)) == 0) return 9;
+    return 10;
+  }
+
+  /** Write a little-endian 32-bit integer. */
+  public void writeRawLittleEndian32(final int value) throws IOException {
+    writeRawByte((value      ) & 0xFF);
+    writeRawByte((value >>  8) & 0xFF);
+    writeRawByte((value >> 16) & 0xFF);
+    writeRawByte((value >> 24) & 0xFF);
+  }
+
+  public static final int LITTLE_ENDIAN_32_SIZE = 4;
+
+  /** Write a little-endian 64-bit integer. */
+  public void writeRawLittleEndian64(final long value) throws IOException {
+    writeRawByte((int)(value      ) & 0xFF);
+    writeRawByte((int)(value >>  8) & 0xFF);
+    writeRawByte((int)(value >> 16) & 0xFF);
+    writeRawByte((int)(value >> 24) & 0xFF);
+    writeRawByte((int)(value >> 32) & 0xFF);
+    writeRawByte((int)(value >> 40) & 0xFF);
+    writeRawByte((int)(value >> 48) & 0xFF);
+    writeRawByte((int)(value >> 56) & 0xFF);
+  }
+
+  public static final int LITTLE_ENDIAN_64_SIZE = 8;
+
+  /**
+   * Encode a ZigZag-encoded 32-bit value.  ZigZag encodes signed integers
+   * into values that can be efficiently encoded with varint.  (Otherwise,
+   * negative values must be sign-extended to 64 bits to be varint encoded,
+   * thus always taking 10 bytes on the wire.)
+   *
+   * @param n A signed 32-bit integer.
+   * @return An unsigned 32-bit integer, stored in a signed int because
+   *         Java has no explicit unsigned support.
+   */
+  public static int encodeZigZag32(final int n) {
+    // Note:  the right-shift must be arithmetic
+    return (n << 1) ^ (n >> 31);
+  }
+
+  /**
+   * Encode a ZigZag-encoded 64-bit value.  ZigZag encodes signed integers
+   * into values that can be efficiently encoded with varint.  (Otherwise,
+   * negative values must be sign-extended to 64 bits to be varint encoded,
+   * thus always taking 10 bytes on the wire.)
+   *
+   * @param n A signed 64-bit integer.
+   * @return An unsigned 64-bit integer, stored in a signed int because
+   *         Java has no explicit unsigned support.
+   */
+  public static long encodeZigZag64(final long n) {
+    // Note:  the right-shift must be arithmetic
+    return (n << 1) ^ (n >> 63);
+  }
+}
diff --git a/java/src/main/java/com/google/protobuf/micro/InvalidProtocolBufferMicroException.java b/java/src/main/java/com/google/protobuf/micro/InvalidProtocolBufferMicroException.java
new file mode 100644
index 0000000..050f99b
--- /dev/null
+++ b/java/src/main/java/com/google/protobuf/micro/InvalidProtocolBufferMicroException.java
@@ -0,0 +1,93 @@
+// 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.micro;
+
+import java.io.IOException;
+
+/**
+ * Thrown when a protocol message being parsed is invalid in some way,
+ * e.g. it contains a malformed varint or a negative byte length.
+ *
+ * @author kenton@google.com Kenton Varda
+ */
+public class InvalidProtocolBufferMicroException extends IOException {
+  private static final long serialVersionUID = -1616151763072450476L;
+
+  public InvalidProtocolBufferMicroException(final String description) {
+    super(description);
+  }
+
+  static InvalidProtocolBufferMicroException truncatedMessage() {
+    return new InvalidProtocolBufferMicroException(
+      "While parsing a protocol message, the input ended unexpectedly " +
+      "in the middle of a field.  This could mean either than the " +
+      "input has been truncated or that an embedded message " +
+      "misreported its own length.");
+  }
+
+  static InvalidProtocolBufferMicroException negativeSize() {
+    return new InvalidProtocolBufferMicroException(
+      "CodedInputStream encountered an embedded string or message " +
+      "which claimed to have negative size.");
+  }
+
+  static InvalidProtocolBufferMicroException malformedVarint() {
+    return new InvalidProtocolBufferMicroException(
+      "CodedInputStream encountered a malformed varint.");
+  }
+
+  static InvalidProtocolBufferMicroException invalidTag() {
+    return new InvalidProtocolBufferMicroException(
+      "Protocol message contained an invalid tag (zero).");
+  }
+
+  static InvalidProtocolBufferMicroException invalidEndTag() {
+    return new InvalidProtocolBufferMicroException(
+      "Protocol message end-group tag did not match expected tag.");
+  }
+
+  static InvalidProtocolBufferMicroException invalidWireType() {
+    return new InvalidProtocolBufferMicroException(
+      "Protocol message tag had invalid wire type.");
+  }
+
+  static InvalidProtocolBufferMicroException recursionLimitExceeded() {
+    return new InvalidProtocolBufferMicroException(
+      "Protocol message had too many levels of nesting.  May be malicious.  " +
+      "Use CodedInputStream.setRecursionLimit() to increase the depth limit.");
+  }
+
+  static InvalidProtocolBufferMicroException sizeLimitExceeded() {
+    return new InvalidProtocolBufferMicroException(
+      "Protocol message was too large.  May be malicious.  " +
+      "Use CodedInputStream.setSizeLimit() to increase the size limit.");
+  }
+}
diff --git a/java/src/main/java/com/google/protobuf/micro/MessageMicro.java b/java/src/main/java/com/google/protobuf/micro/MessageMicro.java
new file mode 100644
index 0000000..0c02793
--- /dev/null
+++ b/java/src/main/java/com/google/protobuf/micro/MessageMicro.java
@@ -0,0 +1,136 @@
+// 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.micro;
+
+import com.google.protobuf.micro.CodedOutputStreamMicro;
+import java.io.IOException;
+
+/**
+ * Abstract interface implemented by Protocol Message objects.
+ *
+ * @author wink@google.com Wink Saville
+ */
+public abstract class MessageMicro {
+    /**
+     * Get the number of bytes required to encode this message.
+     * Returns the cached size or calls getSerializedSize which
+     * sets the cached size. This is used internally when serializing
+     * so the size is only computed once. If a member is modified
+     * then this could be stale call getSerializedSize if in doubt.
+     */
+    abstract public int getCachedSize();
+
+    /**
+     * Computes the number of bytes required to encode this message.
+     * The size is cached and the cached result can be retrieved
+     * using getCachedSize().
+     */
+    abstract public int getSerializedSize();
+
+    /**
+     * Serializes the message and writes it to {@code output}.  This does not
+     * flush or close the stream.
+     */
+    abstract public void writeTo(CodedOutputStreamMicro output) throws java.io.IOException;
+
+    /**
+     * Parse {@code input} as a message of this type and merge it with the
+     * message being built.
+     */
+    abstract public MessageMicro mergeFrom(final CodedInputStreamMicro input) throws IOException;
+
+    /**
+     * Serialize to a byte array.
+     * @return byte array with the serialized data.
+     */
+    public byte[] toByteArray() {
+        final byte[] result = new byte[getSerializedSize()];
+        toByteArray(result, 0, result.length);
+        return result;
+    }
+
+    /**
+     * Serialize to a byte array starting at offset through length. The
+     * method getSerializedSize must have been called prior to calling
+     * this method so the proper length is know.  If an attempt to
+     * write more than length bytes OutOfSpaceException will be thrown
+     * and if length bytes are not written then IllegalStateException
+     * is thrown.
+     * @return byte array with the serialized data.
+     */
+    public void toByteArray(byte [] data, int offset, int length) {
+        try {
+            final CodedOutputStreamMicro output = CodedOutputStreamMicro.newInstance(data, offset, length);
+            writeTo(output);
+            output.checkNoSpaceLeft();
+        } catch (IOException e) {
+            throw new RuntimeException("Serializing to a byte array threw an IOException "
+                    + "(should never happen).");
+        }
+    }
+
+    /**
+     * Parse {@code data} as a message of this type and merge it with the
+     * message being built.
+     */
+    public MessageMicro mergeFrom(final byte[] data) throws InvalidProtocolBufferMicroException {
+        return mergeFrom(data, 0, data.length);
+    }
+
+    /**
+     * Parse {@code data} as a message of this type and merge it with the
+     * message being built.
+     */
+    public MessageMicro mergeFrom(final byte[] data, final int off, final int len)
+            throws InvalidProtocolBufferMicroException {
+        try {
+            final CodedInputStreamMicro input = CodedInputStreamMicro.newInstance(data, off, len);
+            mergeFrom(input);
+            input.checkLastTagWas(0);
+            return this;
+        } catch (InvalidProtocolBufferMicroException e) {
+            throw e;
+        } catch (IOException e) {
+            throw new RuntimeException("Reading from a byte array threw an IOException (should "
+                    + "never happen).");
+        }
+    }
+
+    /**
+     * Called by subclasses to parse an unknown field.
+     * @return {@code true} unless the tag is an end-group tag.
+     */
+    protected boolean parseUnknownField(
+        final CodedInputStreamMicro input,
+        final int tag) throws IOException {
+      return input.skipField(tag);
+    }
+}
diff --git a/java/src/main/java/com/google/protobuf/micro/StringUtf8Micro.java b/java/src/main/java/com/google/protobuf/micro/StringUtf8Micro.java
new file mode 100644
index 0000000..0c43e54
--- /dev/null
+++ b/java/src/main/java/com/google/protobuf/micro/StringUtf8Micro.java
@@ -0,0 +1,67 @@
+// 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.micro;
+
+/**
+ * A surogate for a String with a UTF8 representation.
+ *
+ * @author wink@google.com Wink Saville
+ */
+public final class StringUtf8Micro {
+  private String string;
+  private byte[] bytes;
+
+  public StringUtf8Micro(String string) {
+    setString(string);
+  }
+
+  public static final StringUtf8Micro EMPTY = new StringUtf8Micro("");
+
+  public String getString() {
+    return string;
+  }
+
+  public void setString(String string) {
+    this.string = string;
+    bytes = null;
+  }
+
+  public byte [] getBytes() {
+    if (bytes == null) {
+      try {
+        bytes = string.getBytes("UTF-8");
+      } catch (java.io.UnsupportedEncodingException e) {
+        throw new RuntimeException("UTF-8 not supported.");
+      }
+    }
+    return bytes;
+  }
+}
diff --git a/java/src/main/java/com/google/protobuf/micro/WireFormatMicro.java b/java/src/main/java/com/google/protobuf/micro/WireFormatMicro.java
new file mode 100644
index 0000000..d8a88bd
--- /dev/null
+++ b/java/src/main/java/com/google/protobuf/micro/WireFormatMicro.java
@@ -0,0 +1,87 @@
+// 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.micro;
+
+/**
+ * This class is used internally by the Protocol Buffer library and generated
+ * message implementations.  It is public only because those generated messages
+ * do not reside in the {@code protobuf} package.  Others should not use this
+ * class directly.
+ *
+ * This class contains constants and helper functions useful for dealing with
+ * the Protocol Buffer wire format.
+ *
+ * @author kenton@google.com Kenton Varda
+ */
+public final class WireFormatMicro {
+  // Do not allow instantiation.
+  private WireFormatMicro() {}
+
+  static final int WIRETYPE_VARINT           = 0;
+  static final int WIRETYPE_FIXED64          = 1;
+  static final int WIRETYPE_LENGTH_DELIMITED = 2;
+  static final int WIRETYPE_START_GROUP      = 3;
+  static final int WIRETYPE_END_GROUP        = 4;
+  static final int WIRETYPE_FIXED32          = 5;
+
+  static final int TAG_TYPE_BITS = 3;
+  static final int TAG_TYPE_MASK = (1 << TAG_TYPE_BITS) - 1;
+
+  /** Given a tag value, determines the wire type (the lower 3 bits). */
+  static int getTagWireType(final int tag) {
+    return tag & TAG_TYPE_MASK;
+  }
+
+  /** Given a tag value, determines the field number (the upper 29 bits). */
+  public static int getTagFieldNumber(final int tag) {
+    return tag >>> TAG_TYPE_BITS;
+  }
+
+  /** Makes a tag value given a field number and wire type. */
+  static int makeTag(final int fieldNumber, final int wireType) {
+    return (fieldNumber << TAG_TYPE_BITS) | wireType;
+  }
+
+  // Field numbers for feilds in MessageSet wire format.
+  static final int MESSAGE_SET_ITEM    = 1;
+  static final int MESSAGE_SET_TYPE_ID = 2;
+  static final int MESSAGE_SET_MESSAGE = 3;
+
+  // Tag numbers.
+  static final int MESSAGE_SET_ITEM_TAG =
+    makeTag(MESSAGE_SET_ITEM, WIRETYPE_START_GROUP);
+  static final int MESSAGE_SET_ITEM_END_TAG =
+    makeTag(MESSAGE_SET_ITEM, WIRETYPE_END_GROUP);
+  static final int MESSAGE_SET_TYPE_ID_TAG =
+    makeTag(MESSAGE_SET_TYPE_ID, WIRETYPE_VARINT);
+  static final int MESSAGE_SET_MESSAGE_TAG =
+    makeTag(MESSAGE_SET_MESSAGE, WIRETYPE_LENGTH_DELIMITED);
+}