Nano protobufs.

Like micro protobufs except:

- No setter/getter/hazzer functions.
- Has state is not available. Outputs all fields != their default.
- CodedInputStream can only take byte[] (not InputStream).
- Repeated fields are in arrays, not ArrayList or Vector.
- Unset messages/groups are null, not "defaultInstance()".
- Required fields are always serialized.

To use:

- Link libprotobuf-java-2.3.0-nano runtime.
- Use LOCAL_PROTOC_OPTIMIZE_TYPE := nano

Change-Id: I7429015b3c5f7f38b7be01eb2d4927f7a9999c80

Android.mk

@@ -106,6 +106,15 @@ COMPILER_SRC_FILES :=  \
     src/google/protobuf/compiler/javamicro/javamicro_message.cc \
     src/google/protobuf/compiler/javamicro/javamicro_message_field.cc \
     src/google/protobuf/compiler/javamicro/javamicro_primitive_field.cc \
+    src/google/protobuf/compiler/javanano/javanano_enum.cc \
+    src/google/protobuf/compiler/javanano/javanano_enum_field.cc \
+    src/google/protobuf/compiler/javanano/javanano_field.cc \
+    src/google/protobuf/compiler/javanano/javanano_file.cc \
+    src/google/protobuf/compiler/javanano/javanano_generator.cc \
+    src/google/protobuf/compiler/javanano/javanano_helpers.cc \
+    src/google/protobuf/compiler/javanano/javanano_message.cc \
+    src/google/protobuf/compiler/javanano/javanano_message_field.cc \
+    src/google/protobuf/compiler/javanano/javanano_primitive_field.cc \
     src/google/protobuf/compiler/python/python_generator.cc \
     src/google/protobuf/io/coded_stream.cc \
     src/google/protobuf/io/gzip_stream.cc \
@@ -121,6 +130,29 @@ COMPILER_SRC_FILES :=  \
     src/google/protobuf/stubs/strutil.cc \
     src/google/protobuf/stubs/substitute.cc
 
+# Java nano library (for device-side users)
+# =======================================================
+include $(CLEAR_VARS)
+
+LOCAL_MODULE := libprotobuf-java-2.3.0-nano
+LOCAL_MODULE_TAGS := optional
+LOCAL_SDK_VERSION := 8
+
+LOCAL_SRC_FILES := $(call all-java-files-under, java/src/main/java/com/google/protobuf/nano)
+
+include $(BUILD_STATIC_JAVA_LIBRARY)
+
+# Java nano library (for host-side users)
+# =======================================================
+include $(CLEAR_VARS)
+
+LOCAL_MODULE := host-libprotobuf-java-2.3.0-nano
+LOCAL_MODULE_TAGS := optional
+
+LOCAL_SRC_FILES := $(call all-java-files-under, java/src/main/java/com/google/protobuf/nano)
+
+include $(BUILD_HOST_JAVA_LIBRARY)
+
 # Java micro library (for device-side users)
 # =======================================================
 include $(CLEAR_VARS)

java/README.txt

@@ -260,6 +260,57 @@ This could be compiled using:
 With the result will be com/example/TestMessages.java
 
 
+Nano version
+============================
+
+Nano is even smaller than micro, especially in the number of generated
+functions. It is like micro except:
+
+- No setter/getter/hazzer functions.
+- Has state is not available. Outputs all fields not equal to their
+  default. (See important implications below.)
+- CodedInputStreamMicro is renamed to CodedInputByteBufferNano and can
+  only take byte[] (not InputStream).
+- Similar rename from CodedOutputStreamMicro to
+  CodedOutputByteBufferNano.
+- Repeated fields are in arrays, not ArrayList or Vector.
+- Unset messages/groups are null, not an immutable empty default
+  instance.
+- Required fields are always serialized.
+- toByteArray(...) and mergeFrom(...) are now static functions of
+  MessageNano.
+- "bytes" are of java type byte[].
+
+IMPORTANT: If you have fields with defaults
+
+How fields with defaults are serialized has changed. Because we don't
+keep "has" state, any field equal to its default is assumed to be not
+set and therefore is not serialized. Consider the situation where we
+change the default value of a field. Senders compiled against an older
+version of the proto continue to match against the old default, and
+don't send values to the receiver even though the receiver assumes the
+new default value. Therefore, think carefully about the implications
+of changing the default value.
+
+IMPORTANT: If you have "bytes" fields with non-empty defaults
+
+Because the byte buffer is now of mutable type byte[], the default
+static final cannot be exposed through a public field. Each time a
+message's constructor or clear() function is called, the default value
+(kept in a private byte[]) is cloned. This causes a small memory
+penalty. This is not a problem if the field has no default or is an
+empty default.
+
+
+To use nano protobufs:
+
+- Link with the generated jar file
+  <protobuf-root>java/target/protobuf-java-2.3.0-nano.jar.
+- Invoke with --javanano_out, e.g.:
+
+../src/protoc '--javanano_out=java_package=src/test/proto/simple-data.proto|my_package,java_outer_classname=src/test/proto/simple-data.proto|OuterName:.' src/test/proto/simple-data.proto
+
+
 Usage
 =====
 

java/src/main/java/com/google/protobuf/nano/InternalNano.java

+// 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.nano;
+
+import java.io.UnsupportedEncodingException;
+
+/**
+ * The classes contained within are used internally by the Protocol Buffer
+ * library and generated message implementations. They are public only because
+ * those generated messages do not reside in the {@code protobuf} package.
+ * Others should not use this class directly.
+ *
+ * @author kenton@google.com (Kenton Varda)
+ */
+public class InternalNano {
+  /**
+   * Helper called by generated code to construct default values for string
+   * fields.
+   * <p>
+   * The protocol compiler does not actually contain a UTF-8 decoder -- it
+   * just pushes UTF-8-encoded text around without touching it.  The one place
+   * where this presents a problem is when generating Java string literals.
+   * Unicode characters in the string literal would normally need to be encoded
+   * using a Unicode escape sequence, which would require decoding them.
+   * To get around this, protoc instead embeds the UTF-8 bytes into the
+   * generated code and leaves it to the runtime library to decode them.
+   * <p>
+   * It gets worse, though.  If protoc just generated a byte array, like:
+   *   new byte[] {0x12, 0x34, 0x56, 0x78}
+   * Java actually generates *code* which allocates an array and then fills
+   * in each value.  This is much less efficient than just embedding the bytes
+   * directly into the bytecode.  To get around this, we need another
+   * work-around.  String literals are embedded directly, so protoc actually
+   * generates a string literal corresponding to the bytes.  The easiest way
+   * to do this is to use the ISO-8859-1 character set, which corresponds to
+   * the first 256 characters of the Unicode range.  Protoc can then use
+   * good old CEscape to generate the string.
+   * <p>
+   * So we have a string literal which represents a set of bytes which
+   * represents another string.  This function -- stringDefaultValue --
+   * converts from the generated string to the string we actually want.  The
+   * generated code calls this automatically.
+   */
+  public static final String stringDefaultValue(String bytes) {
+    try {
+      return new String(bytes.getBytes("ISO-8859-1"), "UTF-8");
+    } catch (UnsupportedEncodingException e) {
+      // This should never happen since all JVMs are required to implement
+      // both of the above character sets.
+      throw new IllegalStateException(
+          "Java VM does not support a standard character set.", e);
+    }
+  }
+
+  /**
+   * Helper called by generated code to construct default values for bytes
+   * fields.
+   * <p>
+   * This is a lot like {@link #stringDefaultValue}, but for bytes fields.
+   * In this case we only need the second of the two hacks -- allowing us to
+   * embed raw bytes as a string literal with ISO-8859-1 encoding.
+   */
+  public static final byte[] bytesDefaultValue(String bytes) {
+    try {
+      return bytes.getBytes("ISO-8859-1");
+    } catch (UnsupportedEncodingException e) {
+      // This should never happen since all JVMs are required to implement
+      // ISO-8859-1.
+      throw new IllegalStateException(
+          "Java VM does not support a standard character set.", e);
+    }
+  }
+
+  /**
+   * Helper function to convert a string into UTF-8 while turning the
+   * UnsupportedEncodingException to a RuntimeException.
+   */
+  public static final byte[] copyFromUtf8(final String text) {
+    try {
+      return text.getBytes("UTF-8");
+    } catch (UnsupportedEncodingException e) {
+      throw new RuntimeException("UTF-8 not supported?");
+    }
+  }
+}

java/src/main/java/com/google/protobuf/nano/InvalidProtocolBufferNanoException.java

+// Protocol Buffers - Google's data interchange format
+// Copyright 2013 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.nano;
+
+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 InvalidProtocolBufferNanoException extends IOException {
+  private static final long serialVersionUID = -1616151763072450476L;
+
+  public InvalidProtocolBufferNanoException(final String description) {
+    super(description);
+  }
+
+  static InvalidProtocolBufferNanoException truncatedMessage() {
+    return new InvalidProtocolBufferNanoException(
+      "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 InvalidProtocolBufferNanoException negativeSize() {
+    return new InvalidProtocolBufferNanoException(
+      "CodedInputStream encountered an embedded string or message " +
+      "which claimed to have negative size.");
+  }
+
+  static InvalidProtocolBufferNanoException malformedVarint() {
+    return new InvalidProtocolBufferNanoException(
+      "CodedInputStream encountered a malformed varint.");
+  }
+
+  static InvalidProtocolBufferNanoException invalidTag() {
+    return new InvalidProtocolBufferNanoException(
+      "Protocol message contained an invalid tag (zero).");
+  }
+
+  static InvalidProtocolBufferNanoException invalidEndTag() {
+    return new InvalidProtocolBufferNanoException(
+      "Protocol message end-group tag did not match expected tag.");
+  }
+
+  static InvalidProtocolBufferNanoException invalidWireType() {
+    return new InvalidProtocolBufferNanoException(
+      "Protocol message tag had invalid wire type.");
+  }
+
+  static InvalidProtocolBufferNanoException recursionLimitExceeded() {
+    return new InvalidProtocolBufferNanoException(
+      "Protocol message had too many levels of nesting.  May be malicious.  " +
+      "Use CodedInputStream.setRecursionLimit() to increase the depth limit.");
+  }
+
+  static InvalidProtocolBufferNanoException sizeLimitExceeded() {
+    return new InvalidProtocolBufferNanoException(
+      "Protocol message was too large.  May be malicious.  " +
+      "Use CodedInputStream.setSizeLimit() to increase the size limit.");
+  }
+}

java/src/main/java/com/google/protobuf/nano/MessageNano.java

+// Protocol Buffers - Google's data interchange format
+// Copyright 2013 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.nano;
+
+import java.io.IOException;
+
+/**
+ * Abstract interface implemented by Protocol Message objects.
+ *
+ * @author wink@google.com Wink Saville
+ */
+public abstract class MessageNano {
+    /**
+     * 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(CodedOutputByteBufferNano output) throws java.io.IOException;
+
+    /**
+     * Parse {@code input} as a message of this type and merge it with the
+     * message being built.
+     */
+    abstract public MessageNano mergeFrom(final CodedInputByteBufferNano input) throws IOException;
+
+    /**
+     * Serialize to a byte array.
+     * @return byte array with the serialized data.
+     */
+    public static final byte[] toByteArray(MessageNano msg) {
+        final byte[] result = new byte[msg.getSerializedSize()];
+        toByteArray(msg, 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 static final void toByteArray(MessageNano msg, byte [] data, int offset, int length) {
+        try {
+            final CodedOutputByteBufferNano output =
+                CodedOutputByteBufferNano.newInstance(data, offset, length);
+            msg.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 static final MessageNano mergeFrom(MessageNano msg, final byte[] data)
+        throws InvalidProtocolBufferNanoException {
+        return mergeFrom(msg, data, 0, data.length);
+    }
+
+    /**
+     * Parse {@code data} as a message of this type and merge it with the
+     * message being built.
+     */
+    public static final MessageNano mergeFrom(MessageNano msg, final byte[] data, final int off,
+        final int len) throws InvalidProtocolBufferNanoException {
+        try {
+            final CodedInputByteBufferNano input =
+                CodedInputByteBufferNano.newInstance(data, off, len);
+            msg.mergeFrom(input);
+            input.checkLastTagWas(0);
+            return msg;
+        } catch (InvalidProtocolBufferNanoException e) {
+            throw e;
+        } catch (IOException e) {
+            throw new RuntimeException("Reading from a byte array threw an IOException (should "
+                    + "never happen).");
+        }
+    }
+}

java/src/main/java/com/google/protobuf/nano/WireFormatNano.java

+// Protocol Buffers - Google's data interchange format
+// Copyright 2013 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.nano;
+
+import java.io.IOException;
+
+/**
+ * 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 WireFormatNano {
+  // Do not allow instantiation.
+  private WireFormatNano() {}
+
+  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);
+
+  public static final int EMPTY_INT_ARRAY[] = {};
+  public static final long EMPTY_LONG_ARRAY[] = {};
+  public static final float EMPTY_FLOAT_ARRAY[] = {};
+  public static final double EMPTY_DOUBLE_ARRAY[] = {};
+  public static final boolean EMPTY_BOOLEAN_ARRAY[] = {};
+  public static final String EMPTY_STRING_ARRAY[] = {};
+  public static final byte[] EMPTY_BYTES_ARRAY[] = {};
+  public static final byte[] EMPTY_BYTES = {};
+
+  /**
+   * Called by subclasses to parse an unknown field.
+   * @return {@code true} unless the tag is an end-group tag.
+   */
+  public static boolean parseUnknownField(
+      final CodedInputByteBufferNano input,
+      final int tag) throws IOException {
+    return input.skipField(tag);
+  }
+
+  /**
+   * Computes the array length of a repeated field. We assume that in the common case repeated
+   * fields are contiguously serialized but we still correctly handle interspersed values of a
+   * repeated field (but with extra allocations).
+   *
+   * Rewinds to current input position before returning.
+   *
+   * @param input stream input, pointing to the byte after the first tag
+   * @param tag repeated field tag just read
+   * @return length of array
+   * @throws IOException
+   */
+  public static final int getRepeatedFieldArrayLength(
+      final CodedInputByteBufferNano input,
+      final int tag) throws IOException {
+    int arrayLength = 1;
+    int startPos = input.getPosition();
+    input.skipField(tag);
+    while (input.getBytesUntilLimit() > 0) {
+      int thisTag = input.readTag();
+      if (thisTag != tag) {
+        break;
+      }
+      input.skipField(tag);
+      arrayLength++;
+    }
+    input.rewindToPosition(startPos);
+    return arrayLength;
+  }
+}

src/google/protobuf/compiler/javanano/javanano_enum.cc

+// 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.
+
+// Author: kenton@google.com (Kenton Varda)
+//  Based on original Protocol Buffers design by
+//  Sanjay Ghemawat, Jeff Dean, and others.
+
+#include <map>
+#include <string>
+
+#include <google/protobuf/compiler/javanano/javanano_params.h>
+#include <google/protobuf/compiler/javanano/javanano_enum.h>
+#include <google/protobuf/compiler/javanano/javanano_helpers.h>
+#include <google/protobuf/io/printer.h>
+#include <google/protobuf/descriptor.pb.h>
+#include <google/protobuf/stubs/strutil.h>
+
+namespace google {
+namespace protobuf {
+namespace compiler {
+namespace javanano {
+
+EnumGenerator::EnumGenerator(const EnumDescriptor* descriptor, const Params& params)
+  : params_(params), descriptor_(descriptor) {
+  for (int i = 0; i < descriptor_->value_count(); i++) {
+    const EnumValueDescriptor* value = descriptor_->value(i);
+    const EnumValueDescriptor* canonical_value =
+      descriptor_->FindValueByNumber(value->number());
+
+    if (value == canonical_value) {
+      canonical_values_.push_back(value);
+    } else {
+      Alias alias;
+      alias.value = value;
+      alias.canonical_value = canonical_value;
+      aliases_.push_back(alias);
+    }
+  }
+}
+
+EnumGenerator::~EnumGenerator() {}
+
+void EnumGenerator::Generate(io::Printer* printer) {
+  printer->Print("// enum $classname$\n", "classname", descriptor_->name());
+  for (int i = 0; i < canonical_values_.size(); i++) {
+    map<string, string> vars;
+    vars["name"] = canonical_values_[i]->name();
+    vars["canonical_value"] = SimpleItoa(canonical_values_[i]->number());
+    printer->Print(vars,
+      "public static final int $name$ = $canonical_value$;\n");
+  }
+
+  // -----------------------------------------------------------------
+
+  for (int i = 0; i < aliases_.size(); i++) {
+    map<string, string> vars;
+    vars["name"] = aliases_[i].value->name();
+    vars["canonical_name"] = aliases_[i].canonical_value->name();
+    printer->Print(vars,
+      "public static final int $name$ = $canonical_name$;\n");
+  }
+
+  printer->Print("\n");
+}
+
+}  // namespace javanano
+}  // namespace compiler
+}  // namespace protobuf
+}  // namespace google

src/google/protobuf/compiler/javanano/javanano_enum.h

+// 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.
+
+// Author: kenton@google.com (Kenton Varda)
+//  Based on original Protocol Buffers design by
+//  Sanjay Ghemawat, Jeff Dean, and others.
+
+#ifndef GOOGLE_PROTOBUF_COMPILER_JAVA_ENUM_H__
+#define GOOGLE_PROTOBUF_COMPILER_JAVA_ENUM_H__
+
+#include <string>
+#include <vector>
+
+#include <google/protobuf/compiler/javanano/javanano_params.h>
+#include <google/protobuf/descriptor.h>
+
+namespace google {
+namespace protobuf {
+  namespace io {
+    class Printer;             // printer.h
+  }
+}
+
+namespace protobuf {
+namespace compiler {
+namespace javanano {
+
+class EnumGenerator {
+ public:
+  explicit EnumGenerator(const EnumDescriptor* descriptor, const Params& params);
+  ~EnumGenerator();
+
+  void Generate(io::Printer* printer);
+
+ private:
+  const Params& params_;
+  const EnumDescriptor* descriptor_;
+
+  // The proto language allows multiple enum constants to have the same numeric
+  // value.  Java, however, does not allow multiple enum constants to be
+  // considered equivalent.  We treat the first defined constant for any
+  // given numeric value as "canonical" and the rest as aliases of that
+  // canonical value.
+  vector<const EnumValueDescriptor*> canonical_values_;
+
+  struct Alias {
+    const EnumValueDescriptor* value;
+    const EnumValueDescriptor* canonical_value;
+  };
+  vector<Alias> aliases_;
+
+  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(EnumGenerator);
+};
+
+}  // namespace javanano
+}  // namespace compiler
+}  // namespace protobuf
+
+}  // namespace google
+#endif  // GOOGLE_PROTOBUF_COMPILER_JAVA_ENUM_H__

src/google/protobuf/compiler/javanano/javanano_enum_field.cc

+// 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.
+
+// Author: kenton@google.com (Kenton Varda)
+//  Based on original Protocol Buffers design by
+//  Sanjay Ghemawat, Jeff Dean, and others.
+
+#include <map>
+#include <string>
+
+#include <google/protobuf/compiler/javanano/javanano_enum_field.h>
+#include <google/protobuf/stubs/common.h>
+#include <google/protobuf/compiler/javanano/javanano_helpers.h>
+#include <google/protobuf/io/printer.h>
+#include <google/protobuf/wire_format.h>
+#include <google/protobuf/stubs/strutil.h>
+
+namespace google {
+namespace protobuf {
+namespace compiler {
+namespace javanano {
+
+namespace {
+
+// TODO(kenton):  Factor out a "SetCommonFieldVariables()" to get rid of
+//   repeat code between this and the other field types.
+void SetEnumVariables(const Params& params,
+    const FieldDescriptor* descriptor, map<string, string>* variables) {
+  (*variables)["name"] =
+    UnderscoresToCamelCase(descriptor);
+  (*variables)["capitalized_name"] =
+    UnderscoresToCapitalizedCamelCase(descriptor);
+  (*variables)["number"] = SimpleItoa(descriptor->number());
+  (*variables)["type"] = "int";
+  (*variables)["default"] = DefaultValue(params, descriptor);
+  (*variables)["tag"] = SimpleItoa(internal::WireFormat::MakeTag(descriptor));
+  (*variables)["tag_size"] = SimpleItoa(
+      internal::WireFormat::TagSize(descriptor->number(), descriptor->type()));
+  (*variables)["message_name"] = descriptor->containing_type()->name();
+}
+
+}  // namespace
+
+// ===================================================================
+
+EnumFieldGenerator::
+EnumFieldGenerator(const FieldDescriptor* descriptor, const Params& params)
+  : FieldGenerator(params), descriptor_(descriptor) {
+  SetEnumVariables(params, descriptor, &variables_);
+}
+
+EnumFieldGenerator::~EnumFieldGenerator() {}
+
+void EnumFieldGenerator::
+GenerateMembers(io::Printer* printer) const {
+  printer->Print(variables_,
+    "public int $name$ = $default$;\n");
+}
+
+void EnumFieldGenerator::
+GenerateMergingCode(io::Printer* printer) const {
+  printer->Print(variables_, "$name$ = other.$name$;\n");
+}
+
+void EnumFieldGenerator::
+GenerateParsingCode(io::Printer* printer) const {
+  printer->Print(variables_,
+    "  $name$ = input.readInt32();\n");
+}
+
+void EnumFieldGenerator::
+GenerateSerializationCode(io::Printer* printer) const {
+  if (descriptor_->is_required()) {
+    printer->Print(variables_,
+      "output.writeInt32($number$, $name$);\n");
+  } else {
+    printer->Print(variables_,
+      "if ($name$ != $default$) {\n"
+      "  output.writeInt32($number$, $name$);\n"
+      "}\n");
+  }
+}
+
+void EnumFieldGenerator::
+GenerateSerializedSizeCode(io::Printer* printer) const {
+  if (descriptor_->is_required()) {
+    printer->Print(variables_,
+      "size += com.google.protobuf.nano.CodedOutputByteBufferNano\n"
+      "  .computeInt32Size($number$, $name$);\n");
+  } else {
+    printer->Print(variables_,
+      "if ($name$ != $default$) {\n"
+      "  size += com.google.protobuf.nano.CodedOutputByteBufferNano\n"
+      "    .computeInt32Size($number$, $name$);\n"
+      "}\n");
+  }
+}
+
+string EnumFieldGenerator::GetBoxedType() const {
+  return ClassName(params_, descriptor_->enum_type());
+}
+
+// ===================================================================
+
+RepeatedEnumFieldGenerator::
+RepeatedEnumFieldGenerator(const FieldDescriptor* descriptor, const Params& params)
+  : FieldGenerator(params), descriptor_(descriptor) {
+  SetEnumVariables(params, descriptor, &variables_);
+}
+
+RepeatedEnumFieldGenerator::~RepeatedEnumFieldGenerator() {}
+
+void RepeatedEnumFieldGenerator::
+GenerateMembers(io::Printer* printer) const {
+  printer->Print(variables_,
+    "public int[] $name$ = com.google.protobuf.nano.WireFormatNano.EMPTY_INT_ARRAY;\n");
+  if (descriptor_->options().packed()) {
+    printer->Print(variables_,
+      "private int $name$MemoizedSerializedSize;\n");
+  }
+}
+
+void RepeatedEnumFieldGenerator::
+GenerateMergingCode(io::Printer* printer) const {
+  printer->Print(variables_,
+    "if (other.$name$.length > 0) {\n"
+    "  int[] merged = java.util.Arrays.copyOf(result.$name$, result.$name$.length + other.$name$.length);\n"
+    "  java.lang.System.arraycopy(other.$name$, 0, merged, results.$name$.length, other.$name$.length);\n"
+    "  result.$name$ = merged;\n"
+    "}\n");
+}
+
+void RepeatedEnumFieldGenerator::
+GenerateParsingCode(io::Printer* printer) const {
+  // First, figure out the length of the array, then parse.
+  if (descriptor_->options().packed()) {
+    printer->Print(variables_,
+      "int length = input.readRawVarint32();\n"
+      "int limit = input.pushLimit(length);\n"
+      "// First pass to compute array length.\n"
+      "int arrayLength = 0;\n"
+      "int startPos = input.getPosition();\n"
+      "while (input.getBytesUntilLimit() > 0) {\n"
+      "  input.readInt32();\n"
+      "  arrayLength++;\n"
+      "}\n"
+      "input.rewindToPosition(startPos);\n"
+      "$name$ = new $type$[arrayLength];\n"
+      "for (int i = 0; i < arrayLength; i++) {\n"
+      "  $name$[i] = input.readInt32();\n"
+      "}\n"
+      "input.popLimit(limit);\n");
+  } else {
+    printer->Print(variables_,
+      "int arrayLength = com.google.protobuf.nano.WireFormatNano.getRepeatedFieldArrayLength(input, $tag$);\n"
+      "int i = $name$.length;\n"
+      "$name$ = java.util.Arrays.copyOf($name$, $name$.length + arrayLength);\n"
+      "for (; i < $name$.length - 1; i++) {\n"
+      "  $name$[i] = input.readInt32();\n"
+      "  input.readTag();\n"
+      "}\n"
+      "// Last one without readTag.\n"
+      "$name$[i] = input.readInt32();\n");
+  }
+}
+
+void RepeatedEnumFieldGenerator::
+GenerateSerializationCode(io::Printer* printer) const {
+  printer->Print(variables_,
+    "if ($name$.length > 0) {\n");
+  printer->Indent();
+
+  if (descriptor_->options().packed()) {
+    printer->Print(variables_,
+      "output.writeRawVarint32($tag$);\n"
+      "output.writeRawVarint32($name$MemoizedSerializedSize);\n"
+      "for (int element : $name$) {\n"
+      "  output.writeRawVarint32(element);\n"
+      "}\n");
+  } else {
+    printer->Print(variables_,
+      "for (int element : $name$) {\n"
+      "  output.writeInt32($number$, element);\n"
+      "}\n");
+  }
+  printer->Outdent();
+  printer->Print(variables_,
+    "}\n");
+}
+
+void RepeatedEnumFieldGenerator::
+GenerateSerializedSizeCode(io::Printer* printer) const {
+  printer->Print(variables_,
+    "if ($name$.length > 0) {\n");
+  printer->Indent();
+
+  printer->Print(variables_,
+    "int dataSize = 0;\n"
+    "for (int element : $name$) {\n"
+    "  dataSize += com.google.protobuf.nano.CodedOutputByteBufferNano\n"
+    "    .computeInt32SizeNoTag(element);\n"
+    "}\n");
+
+  printer->Print(
+    "size += dataSize;\n");
+  if (descriptor_->options().packed()) {
+    // cache the data size for packed fields.
+    printer->Print(variables_,
+      "size += $tag_size$;\n"
+      "size += com.google.protobuf.nano.CodedOutputByteBufferNano\n"
+      "  .computeRawVarint32Size(dataSize);\n"
+      "$name$MemoizedSerializedSize = dataSize;\n");
+  } else {
+    printer->Print(variables_,
+        "size += $tag_size$ * $name$.length;\n");
+  }
+
+  printer->Outdent();
+
+  // set cached size to 0 for empty packed fields.
+  if (descriptor_->options().packed()) {
+    printer->Print(variables_,
+      "} else {\n"
+      "  $name$MemoizedSerializedSize = 0;\n"
+      "}\n");
+  } else {
+    printer->Print(
+      "}\n");
+  }
+}
+
+string RepeatedEnumFieldGenerator::GetBoxedType() const {
+  return ClassName(params_, descriptor_->enum_type());
+}
+
+}  // namespace javanano
+}  // namespace compiler
+}  // namespace protobuf
+}  // namespace google

src/google/protobuf/compiler/javanano/javanano_enum_field.h

+// 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.
+
+// Author: kenton@google.com (Kenton Varda)
+//  Based on original Protocol Buffers design by
+//  Sanjay Ghemawat, Jeff Dean, and others.
+
+#ifndef GOOGLE_PROTOBUF_COMPILER_JAVA_ENUM_FIELD_H__
+#define GOOGLE_PROTOBUF_COMPILER_JAVA_ENUM_FIELD_H__
+
+#include <map>
+#include <string>
+#include <google/protobuf/compiler/javanano/javanano_field.h>
+
+namespace google {
+namespace protobuf {
+namespace compiler {
+namespace javanano {
+
+class EnumFieldGenerator : public FieldGenerator {
+ public:
+  explicit EnumFieldGenerator(const FieldDescriptor* descriptor, const Params& params);
+  ~EnumFieldGenerator();
+
+  // implements FieldGenerator ---------------------------------------
+  void GenerateMembers(io::Printer* printer) const;
+  void GenerateMergingCode(io::Printer* printer) const;
+  void GenerateParsingCode(io::Printer* printer) const;
+  void GenerateSerializationCode(io::Printer* printer) const;
+  void GenerateSerializedSizeCode(io::Printer* printer) const;
+
+  string GetBoxedType() const;
+
+ private:
+  const FieldDescriptor* descriptor_;
+  map<string, string> variables_;
+
+  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(EnumFieldGenerator);
+};
+
+class RepeatedEnumFieldGenerator : public FieldGenerator {
+ public:
+  explicit RepeatedEnumFieldGenerator(const FieldDescriptor* descriptor, const Params& params);
+  ~RepeatedEnumFieldGenerator();
+
+  // implements FieldGenerator ---------------------------------------
+  void GenerateMembers(io::Printer* printer) const;
+  void GenerateMergingCode(io::Printer* printer) const;
+  void GenerateParsingCode(io::Printer* printer) const;
+  void GenerateSerializationCode(io::Printer* printer) const;
+  void GenerateSerializedSizeCode(io::Printer* printer) const;
+
+  string GetBoxedType() const;
+
+ private:
+  const FieldDescriptor* descriptor_;
+  map<string, string> variables_;
+
+  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(RepeatedEnumFieldGenerator);
+};
+
+}  // namespace javanano
+}  // namespace compiler
+}  // namespace protobuf
+
+}  // namespace google
+#endif  // GOOGLE_PROTOBUF_COMPILER_JAVA_ENUM_FIELD_H__

src/google/protobuf/compiler/javanano/javanano_field.cc

+// 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.
+
+// Author: kenton@google.com (Kenton Varda)
+//  Based on original Protocol Buffers design by
+//  Sanjay Ghemawat, Jeff Dean, and others.
+
+#include <google/protobuf/compiler/javanano/javanano_field.h>
+#include <google/protobuf/compiler/javanano/javanano_helpers.h>
+#include <google/protobuf/compiler/javanano/javanano_primitive_field.h>
+#include <google/protobuf/compiler/javanano/javanano_enum_field.h>
+#include <google/protobuf/compiler/javanano/javanano_message_field.h>
+#include <google/protobuf/stubs/common.h>
+
+namespace google {
+namespace protobuf {
+namespace compiler {
+namespace javanano {
+
+FieldGenerator::~FieldGenerator() {}
+
+FieldGeneratorMap::FieldGeneratorMap(const Descriptor* descriptor, const Params &params)
+  : descriptor_(descriptor),
+    field_generators_(
+      new scoped_ptr<FieldGenerator>[descriptor->field_count()]),
+    extension_generators_(
+      new scoped_ptr<FieldGenerator>[descriptor->extension_count()]) {
+
+  // Construct all the FieldGenerators.
+  for (int i = 0; i < descriptor->field_count(); i++) {
+    field_generators_[i].reset(MakeGenerator(descriptor->field(i), params));
+  }
+  for (int i = 0; i < descriptor->extension_count(); i++) {
+    extension_generators_[i].reset(MakeGenerator(descriptor->extension(i), params));
+  }
+}
+
+FieldGenerator* FieldGeneratorMap::MakeGenerator(const FieldDescriptor* field, const Params &params) {
+  if (field->is_repeated()) {
+    switch (GetJavaType(field)) {
+      case JAVATYPE_MESSAGE:
+        return new RepeatedMessageFieldGenerator(field, params);
+      case JAVATYPE_ENUM:
+        return new RepeatedEnumFieldGenerator(field, params);
+      default:
+        return new RepeatedPrimitiveFieldGenerator(field, params);
+    }
+  } else {
+    switch (GetJavaType(field)) {
+      case JAVATYPE_MESSAGE:
+        return new MessageFieldGenerator(field, params);
+      case JAVATYPE_ENUM:
+        return new EnumFieldGenerator(field, params);
+      default:
+        return new PrimitiveFieldGenerator(field, params);
+    }
+  }
+}
+
+FieldGeneratorMap::~FieldGeneratorMap() {}
+
+const FieldGenerator& FieldGeneratorMap::get(
+    const FieldDescriptor* field) const {
+  GOOGLE_CHECK_EQ(field->containing_type(), descriptor_);
+  return *field_generators_[field->index()];
+}
+
+const FieldGenerator& FieldGeneratorMap::get_extension(int index) const {
+  return *extension_generators_[index];
+}
+
+}  // namespace javanano
+}  // namespace compiler
+}  // namespace protobuf
+}  // namespace google

src/google/protobuf/compiler/javanano/javanano_field.h

+// 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.
+
+// Author: kenton@google.com (Kenton Varda)
+//  Based on original Protocol Buffers design by
+//  Sanjay Ghemawat, Jeff Dean, and others.
+
+#ifndef GOOGLE_PROTOBUF_COMPILER_JAVA_FIELD_H__
+#define GOOGLE_PROTOBUF_COMPILER_JAVA_FIELD_H__
+
+#include <string>
+#include <google/protobuf/stubs/common.h>
+#include <google/protobuf/descriptor.h>
+#include <google/protobuf/compiler/javanano/javanano_params.h>
+
+namespace google {
+namespace protobuf {
+  namespace io {
+    class Printer;             // printer.h
+  }
+}
+
+namespace protobuf {
+namespace compiler {
+namespace javanano {
+
+class FieldGenerator {
+ public:
+  //FieldGenerator() {}
+  FieldGenerator(const Params& params) : params_(params) {}
+  virtual ~FieldGenerator();
+
+  virtual void GenerateMembers(io::Printer* printer) const = 0;
+  virtual void GenerateMergingCode(io::Printer* printer) const = 0;
+  virtual void GenerateParsingCode(io::Printer* printer) const = 0;
+  virtual void GenerateSerializationCode(io::Printer* printer) const = 0;
+  virtual void GenerateSerializedSizeCode(io::Printer* printer) const = 0;
+
+  virtual string GetBoxedType() const = 0;
+
+ protected:
+  const Params& params_;
+ private:
+  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(FieldGenerator);
+};
+
+// Convenience class which constructs FieldGenerators for a Descriptor.
+class FieldGeneratorMap {
+ public:
+  explicit FieldGeneratorMap(const Descriptor* descriptor, const Params &params);
+  ~FieldGeneratorMap();
+
+  const FieldGenerator& get(const FieldDescriptor* field) const;
+  const FieldGenerator& get_extension(int index) const;
+
+ private:
+  const Descriptor* descriptor_;
+  scoped_array<scoped_ptr<FieldGenerator> > field_generators_;
+  scoped_array<scoped_ptr<FieldGenerator> > extension_generators_;
+
+  static FieldGenerator* MakeGenerator(const FieldDescriptor* field, const Params &params);
+
+  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(FieldGeneratorMap);
+};
+
+}  // namespace javanano
+}  // namespace compiler
+}  // namespace protobuf
+
+}  // namespace google
+#endif  // GOOGLE_PROTOBUF_COMPILER_JAVA_FIELD_H__

src/google/protobuf/unittest_stringutf8_nano.proto

+// 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.
+
+// Author: wink@google.com (Wink Saville)
+//
+
+package protobuf_unittest_import;
+
+option java_package = "com.google.protobuf.nano";
+
+message StringUtf8 {
+  optional string id = 1;
+  repeated string rs = 2;
+}