CHANGES.txt - fp2-dev/platform/external/protobuf - Gitiles

 2009-01-08 version 2.3.0:

   General
   * Parsers for repeated numeric fields now always accept both packed and
     unpacked input.  The [packed=true] option only affects serializers.
     Therefore, it is possible to switch a field to packed format without
     breaking backwards-compatibility -- as long as all parties are using
     protobuf 2.3.0 or above, at least.
   * The generic RPC service code generated by the C++, Java, and Python
     generators can be disabled via file options:
       option cc_generic_services = false;
       option java_generic_services = false;
       option py_generic_services = false;
     This allows plugins to generate alternative code, possibly specific to some
     particular RPC implementation.

   protoc
   * Now supports a plugin system for code generators.  Plugins can generate
     code for new languages or inject additional code into the output of other
     code generators.  Plugins are just binaries which accept a protocol buffer
     on stdin and write a protocol buffer to stdout, so they may be written in
     any language.  See src/google/protobuf/compiler/plugin.proto.
     **WARNING**:  Plugins are experimental.  The interface may change in a
     future version.
   * If the output location ends in .zip or .jar, protoc will write its output
     to a zip/jar archive instead of a directory.  For example:
       protoc --java_out=myproto_srcs.jar --python_out=myproto.zip myproto.proto
     Currently the archive contents are not compressed, though this could change
     in the future.
   * inf, -inf, and nan can now be used as default values for float and double
     fields.

   C++
   * Various speed and code size optimizations.
   * DynamicMessageFactory is now fully thread-safe.
   * Message::Utf8DebugString() method is like DebugString() but avoids escaping
     UTF-8 bytes.
   * Compiled-in message types can now contain dynamic extensions, through use
     of CodedInputStream::SetExtensionRegistry().
   * Now compiles shared libraries (DLLs) by default on Cygwin and MinGW, to
     match other platforms.  Use --disable-shared to avoid this.

   Java
   * parseDelimitedFrom() and mergeDelimitedFrom() now detect EOF and return
     false/null instead of throwing an exception.
   * Fixed some initialization ordering bugs.
   * Fixes for OpenJDK 7.

   Python
   * 10-25 times faster than 2.2.0, still pure-Python.
   * Calling a mutating method on a sub-message always instantiates the message
     in its parent even if the mutating method doesn't actually mutate anything
     (e.g. parsing from an empty string).
   * Expanded descriptors a bit.

 2009-08-11 version 2.2.0:

   C++
   * Lite mode:  The "optimize_for = LITE_RUNTIME" option causes the compiler
     to generate code which only depends libprotobuf-lite, which is much smaller
     than libprotobuf but lacks descriptors, reflection, and some other features.
   * Fixed bug where Message.Swap(Message) was only implemented for
     optimize_for_speed.  Swap now properly implemented in both modes
     (Issue 91).
   * Added RemoveLast and SwapElements(index1, index2) to Reflection
     interface for repeated elements.
   * Added Swap(Message) to Reflection interface.
   * Floating-point literals in generated code that are intended to be
     single-precision now explicitly have 'f' suffix to avoid pedantic warnings
     produced by some compilers.
   * The [deprecated=true] option now causes the C++ code generator to generate
     a GCC-style deprecation annotation (no-op on other compilers).
   * google::protobuf::GetEnumDescriptor<SomeGeneratedEnumType>() returns the
     EnumDescriptor for that type -- useful for templates which cannot call
     SomeGeneratedEnumType_descriptor().
   * Various optimizations and obscure bug fixes.

   Java
   * Lite mode:  The "optimize_for = LITE_RUNTIME" option causes the compiler
     to generate code which only depends libprotobuf-lite, which is much smaller
     than libprotobuf but lacks descriptors, reflection, and some other features.
   * Lots of style cleanups.

   Python
   * Fixed endianness bug with floats and doubles.
   * Text format parsing support.
   * Fix bug with parsing packed repeated fields in embedded messages.
   * Ability to initialize fields by passing keyword args to constructor.
   * Support iterators in extend and __setslice__ for containers.

 2009-05-13 version 2.1.0:

   General
   * Repeated fields of primitive types (types other that string, group, and
     nested messages) may now use the option [packed = true] to get a more
     efficient encoding.  In the new encoding, the entire list is written
     as a single byte blob using the "length-delimited" wire type.  Within
     this blob, the individual values are encoded the same way they would
     be normally except without a tag before each value (thus, they are
     tightly "packed").
   * For each field, the generated code contains an integer constant assigned
     to the field number.  For example, the .proto file:
       message Foo { optional int bar_baz = 123; }
     would generate the following constants, all with the integer value 123:
       C++:     Foo::kBarBazFieldNumber
       Java:    Foo.BAR_BAZ_FIELD_NUMBER
       Python:  Foo.BAR_BAZ_FIELD_NUMBER
     Constants are also generated for extensions, with the same naming scheme.
     These constants may be used as switch cases.
   * Updated bundled Google Test to version 1.3.0.  Google Test is now bundled
     in its verbatim form as a nested autoconf package, so you can drop in any
     other version of Google Test if needed.
   * optimize_for = SPEED is now the default, by popular demand.  Use
     optimize_for = CODE_SIZE if code size is more important in your app.
   * It is now an error to define a default value for a repeated field.
     Previously, this was silently ignored (it had no effect on the generated
     code).
   * Fields can now be marked deprecated like:
       optional int32 foo = 1 [deprecated = true];
     Currently this does not have any actual effect, but in the future the code
     generators may generate deprecation annotations in each language.
   * Cross-compiling should now be possible using the --with-protoc option to
     configure.  See README.txt for more info.

   protoc
   * --error_format=msvs option causes errors to be printed in Visual Studio
     format, which should allow them to be clicked on in the build log to go
     directly to the error location.
   * The type name resolver will no longer resolve type names to fields.  For
     example, this now works:
       message Foo {}
       message Bar {
         optional int32 Foo = 1;
         optional Foo baz = 2;
       }
     Previously, the type of "baz" would resolve to "Bar.Foo", and you'd get
     an error because Bar.Foo is a field, not a type.  Now the type of "baz"
     resolves to the message type Foo.  This change is unlikely to make a
     difference to anyone who follows the Protocol Buffers style guide.

   C++
   * Several optimizations, including but not limited to:
     - Serialization, especially to flat arrays, is 10%-50% faster, possibly
       more for small objects.
     - Several descriptor operations which previously required locking no longer
       do.
     - Descriptors are now constructed lazily on first use, rather than at
       process startup time.  This should save memory in programs which do not
       use descriptors or reflection.
     - UnknownFieldSet completely redesigned to be more efficient (especially in
       terms of memory usage).
     - Various optimizations to reduce code size (though the serialization speed
       optimizations increased code size).
   * Message interface has method ParseFromBoundedZeroCopyStream() which parses
     a limited number of bytes from an input stream rather than parsing until
     EOF.
   * GzipInputStream and GzipOutputStream support reading/writing gzip- or
     zlib-compressed streams if zlib is available.
     (google/protobuf/io/gzip_stream.h)
   * DescriptorPool::FindAllExtensions() and corresponding
     DescriptorDatabase::FindAllExtensions() can be used to enumerate all
     extensions of a given type.
   * For each enum type Foo, protoc will generate functions:
       const string& Foo_Name(Foo value);
       bool Foo_Parse(const string& name, Foo* result);
     The former returns the name of the enum constant corresponding to the given
     value while the latter finds the value corresponding to a name.
   * RepeatedField and RepeatedPtrField now have back-insertion iterators.
   * String fields now have setters that take a char* and a size, in addition
     to the existing ones that took char* or const string&.
   * DescriptorPool::AllowUnknownDependencies() may be used to tell
     DescriptorPool to create placeholder descriptors for unknown entities
     referenced in a FileDescriptorProto.  This can allow you to parse a .proto
     file without having access to other .proto files that it imports, for
     example.
   * Updated gtest to latest version.  The gtest package is now included as a
     nested autoconf package, so it should be able to drop new versions into the
     "gtest" subdirectory without modification.

   Java
   * Fixed bug where Message.mergeFrom(Message) failed to merge extensions.
   * Message interface has new method toBuilder() which is equivalent to
     newBuilderForType().mergeFrom(this).
   * All enums now implement the ProtocolMessageEnum interface.
   * Setting a field to null now throws NullPointerException.
   * Fixed tendency for TextFormat's parsing to overflow the stack when
     parsing large string values.  The underlying problem is with Java's
     regex implementation (which unfortunately uses recursive backtracking
     rather than building an NFA).  Worked around by making use of possesive
     quantifiers.
   * Generated service classes now also generate pure interfaces.  For a service
     Foo, Foo.Interface is a pure interface containing all of the service's
     defined methods.  Foo.newReflectiveService() can be called to wrap an
     instance of this interface in a class that implements the generic
     RpcService interface, which provides reflection support that is usually
     needed by RPC server implementations.
   * RPC interfaces now support blocking operation in addition to non-blocking.
     The protocol compiler generates separate blocking and non-blocking stubs
     which operate against separate blocking and non-blocking RPC interfaces.
     RPC implementations will have to implement the new interfaces in order to
     support blocking mode.
   * New I/O methods parseDelimitedFrom(), mergeDelimitedFrom(), and
     writeDelimitedTo() read and write "delemited" messages from/to a stream,
     meaning that the message size precedes the data.  This way, you can write
     multiple messages to a stream without having to worry about delimiting
     them yourself.
   * Throw a more descriptive exception when build() is double-called.
   * Add a method to query whether CodedInputStream is at the end of the input
     stream.
   * Add a method to reset a CodedInputStream's size counter; useful when
     reading many messages with the same stream.
   * equals() and hashCode() now account for unknown fields.

   Python
   * Added slicing support for repeated scalar fields. Added slice retrieval and
     removal of repeated composite fields.
   * Updated RPC interfaces to allow for blocking operation.  A client may
     now pass None for a callback when making an RPC, in which case the
     call will block until the response is received, and the response
     object will be returned directly to the caller.  This interface change
     cannot be used in practice until RPC implementations are updated to
     implement it.
   * Changes to input_stream.py should make protobuf compatible with appengine.

 2008-11-25 version 2.0.3:

   protoc
   * Enum values may now have custom options, using syntax similar to field
     options.
   * Fixed bug where .proto files which use custom options but don't actually
     define them (i.e. they import another .proto file defining the options)
     had to explicitly import descriptor.proto.
   * Adjacent string literals in .proto files will now be concatenated, like in
     C.
   * If an input file is a Windows absolute path (e.g. "C:\foo\bar.proto") and
     the import path only contains "." (or contains "." but does not contain
     the file), protoc incorrectly thought that the file was under ".", because
     it thought that the path was relative (since it didn't start with a slash).
     This has been fixed.

   C++
   * Generated message classes now have a Swap() method which efficiently swaps
     the contents of two objects.
   * All message classes now have a SpaceUsed() method which returns an estimate
     of the number of bytes of allocated memory currently owned by the object.
     This is particularly useful when you are reusing a single message object
     to improve performance but want to make sure it doesn't bloat up too large.
   * New method Message::SerializeAsString() returns a string containing the
     serialized data.  May be more convenient than calling
     SerializeToString(string*).
   * In debug mode, log error messages when string-type fields are found to
     contain bytes that are not valid UTF-8.
   * Fixed bug where a message with multiple extension ranges couldn't parse
     extensions.
   * Fixed bug where MergeFrom(const Message&) didn't do anything if invoked on
     a message that contained no fields (but possibly contained extensions).
   * Fixed ShortDebugString() to not be O(n^2).  Durr.
   * Fixed crash in TextFormat parsing if the first token in the input caused a
     tokenization error.
   * Fixed obscure bugs in zero_copy_stream_impl.cc.
   * Added support for HP C++ on Tru64.
   * Only build tests on "make check", not "make".
   * Fixed alignment issue that caused crashes when using DynamicMessage on
     64-bit Sparc machines.
   * Simplify template usage to work with MSVC 2003.
   * Work around GCC 4.3.x x86_64 compiler bug that caused crashes on startup.
     (This affected Fedora 9 in particular.)
   * Now works on "Solaris 10 using recent Sun Studio".

   Java
   * New overload of mergeFrom() which parses a slice of a byte array instead
     of the whole thing.
   * New method ByteString.asReadOnlyByteBuffer() does what it sounds like.
   * Improved performance of isInitialized() when optimizing for code size.

   Python
   * Corrected ListFields() signature in Message base class to match what
     subclasses actually implement.
   * Some minor refactoring.
   * Don't pass self as first argument to superclass constructor (no longer
     allowed in Python 2.6).

 2008-09-29 version 2.0.2:

   General
   * License changed from Apache 2.0 to New BSD.
   * It is now possible to define custom "options", which are basically
     annotations which may be placed on definitions in a .proto file.
     For example, you might define a field option called "foo" like so:
       import "google/protobuf/descriptor.proto"
       extend google.protobuf.FieldOptions {
         optional string foo = 12345;
       }
     Then you annotate a field using the "foo" option:
       message MyMessage {
         optional int32 some_field = 1 [(foo) = "bar"]
       }
     The value of this option is then visible via the message's
     Descriptor:
       const FieldDescriptor* field =
         MyMessage::descriptor()->FindFieldByName("some_field");
       assert(field->options().GetExtension(foo) == "bar");
     This feature has been implemented and tested in C++ and Java.
     Other languages may or may not need to do extra work to support
     custom options, depending on how they construct descriptors.

   C++
   * Fixed some GCC warnings that only occur when using -pedantic.
   * Improved static initialization code, making ordering more
     predictable among other things.
   * TextFormat will no longer accept messages which contain multiple
     instances of a singular field.  Previously, the latter instance
     would overwrite the former.
   * Now works on systems that don't have hash_map.

   Java
   * Print @Override annotation in generated code where appropriate.

   Python
   * Strings now use the "unicode" type rather than the "str" type.
     String fields may still be assigned ASCII "str" values; they will
     automatically be converted.
   * Adding a property to an object representing a repeated field now
     raises an exception.  For example:
       # No longer works (and never should have).
       message.some_repeated_field.foo = 1

   Windows
   * We now build static libraries rather than DLLs by default on MSVC.
     See vsprojects/readme.txt for more information.

 2008-08-15 version 2.0.1:

   protoc
   * New flags --encode and --decode can be used to convert between protobuf text
     format and binary format from the command-line.
   * New flag --descriptor_set_out can be used to write FileDescriptorProtos for
     all parsed files directly into a single output file.  This is particularly
     useful if you wish to parse .proto files from programs written in languages
     other than C++: just run protoc as a background process and have it output
     a FileDescriptorList, then parse that natively.
   * Improved error message when an enum value's name conflicts with another
     symbol defined in the enum type's scope, e.g. if two enum types declared
     in the same scope have values with the same name.  This is disallowed for
     compatibility with C++, but this wasn't clear from the error.
   * Fixed absolute output paths on Windows.
   * Allow trailing slashes in --proto_path mappings.

   C++
   * Reflection objects are now per-class rather than per-instance.  To make this
     possible, the Reflection interface had to be changed such that all methods
     take the Message instance as a parameter.  This change improves performance
     significantly in memory-bandwidth-limited use cases, since it makes the
     message objects smaller.  Note that source-incompatible interface changes
     like this will not be made again after the library leaves beta.
   * Heuristically detect sub-messages when printing unknown fields.
   * Fix static initialization ordering bug that caused crashes at startup when
     compiling on Mac with static linking.
   * Fixed TokenizerTest when compiling with -DNDEBUG on Linux.
   * Fixed incorrect definition of kint32min.
   * Fix bytes type setter to work with byte sequences with embedded NULLs.
   * Other irrelevant tweaks.

   Java
   * Fixed UnknownFieldSet's parsing of varints larger than 32 bits.
   * Fixed TextFormat's parsing of "inf" and "nan".
   * Fixed TextFormat's parsing of comments.
   * Added info to Java POM that will be required when we upload the
     package to a Maven repo.

   Python
   * MergeFrom(message) and CopyFrom(message) are now implemented.
   * SerializeToString() raises an exception if the message is missing required
     fields.
   * Code organization improvements.
   * Fixed doc comments for RpcController and RpcChannel, which had somehow been
     swapped.
   * Fixed text_format_test on Windows where floating-point exponents sometimes
     contain extra zeros.
   * Fix Python service CallMethod() implementation.

   Other
   * Improved readmes.
   * VIM syntax highlighting improvements.

 2008-07-07 version 2.0.0:

   * First public release.
	2009-01-08 version 2.3.0:

	General
	* Parsers for repeated numeric fields now always accept both packed and
	unpacked input. The [packed=true] option only affects serializers.
	Therefore, it is possible to switch a field to packed format without
	breaking backwards-compatibility -- as long as all parties are using
	protobuf 2.3.0 or above, at least.
	* The generic RPC service code generated by the C++, Java, and Python
	generators can be disabled via file options:
	option cc_generic_services = false;
	option java_generic_services = false;
	option py_generic_services = false;
	This allows plugins to generate alternative code, possibly specific to some
	particular RPC implementation.

	protoc
	* Now supports a plugin system for code generators. Plugins can generate
	code for new languages or inject additional code into the output of other
	code generators. Plugins are just binaries which accept a protocol buffer
	on stdin and write a protocol buffer to stdout, so they may be written in
	any language. See src/google/protobuf/compiler/plugin.proto.
	WARNING: Plugins are experimental. The interface may change in a
	future version.
	* If the output location ends in .zip or .jar, protoc will write its output
	to a zip/jar archive instead of a directory. For example:
	protoc --java_out=myproto_srcs.jar --python_out=myproto.zip myproto.proto
	Currently the archive contents are not compressed, though this could change
	in the future.
	* inf, -inf, and nan can now be used as default values for float and double
	fields.

	C++
	* Various speed and code size optimizations.
	* DynamicMessageFactory is now fully thread-safe.
	* Message::Utf8DebugString() method is like DebugString() but avoids escaping
	UTF-8 bytes.
	* Compiled-in message types can now contain dynamic extensions, through use
	of CodedInputStream::SetExtensionRegistry().
	* Now compiles shared libraries (DLLs) by default on Cygwin and MinGW, to
	match other platforms. Use --disable-shared to avoid this.

	Java
	* parseDelimitedFrom() and mergeDelimitedFrom() now detect EOF and return
	false/null instead of throwing an exception.
	* Fixed some initialization ordering bugs.
	* Fixes for OpenJDK 7.

	Python
	* 10-25 times faster than 2.2.0, still pure-Python.
	* Calling a mutating method on a sub-message always instantiates the message
	in its parent even if the mutating method doesn't actually mutate anything
	(e.g. parsing from an empty string).
	* Expanded descriptors a bit.

	2009-08-11 version 2.2.0:

	C++
	* Lite mode: The "optimize_for = LITE_RUNTIME" option causes the compiler
	to generate code which only depends libprotobuf-lite, which is much smaller
	than libprotobuf but lacks descriptors, reflection, and some other features.
	* Fixed bug where Message.Swap(Message) was only implemented for
	optimize_for_speed. Swap now properly implemented in both modes
	(Issue 91).
	* Added RemoveLast and SwapElements(index1, index2) to Reflection
	interface for repeated elements.
	* Added Swap(Message) to Reflection interface.
	* Floating-point literals in generated code that are intended to be
	single-precision now explicitly have 'f' suffix to avoid pedantic warnings
	produced by some compilers.
	* The [deprecated=true] option now causes the C++ code generator to generate
	a GCC-style deprecation annotation (no-op on other compilers).
	* google::protobuf::GetEnumDescriptor<SomeGeneratedEnumType>() returns the
	EnumDescriptor for that type -- useful for templates which cannot call
	SomeGeneratedEnumType_descriptor().
	* Various optimizations and obscure bug fixes.

	Java
	* Lite mode: The "optimize_for = LITE_RUNTIME" option causes the compiler
	to generate code which only depends libprotobuf-lite, which is much smaller
	than libprotobuf but lacks descriptors, reflection, and some other features.
	* Lots of style cleanups.

	Python
	* Fixed endianness bug with floats and doubles.
	* Text format parsing support.
	* Fix bug with parsing packed repeated fields in embedded messages.
	* Ability to initialize fields by passing keyword args to constructor.
	* Support iterators in extend and __setslice__ for containers.

	2009-05-13 version 2.1.0:

	General
	* Repeated fields of primitive types (types other that string, group, and
	nested messages) may now use the option [packed = true] to get a more
	efficient encoding. In the new encoding, the entire list is written
	as a single byte blob using the "length-delimited" wire type. Within
	this blob, the individual values are encoded the same way they would
	be normally except without a tag before each value (thus, they are
	tightly "packed").
	* For each field, the generated code contains an integer constant assigned
	to the field number. For example, the .proto file:
	message Foo { optional int bar_baz = 123; }
	would generate the following constants, all with the integer value 123:
	C++: Foo::kBarBazFieldNumber
	Java: Foo.BAR_BAZ_FIELD_NUMBER
	Python: Foo.BAR_BAZ_FIELD_NUMBER
	Constants are also generated for extensions, with the same naming scheme.
	These constants may be used as switch cases.
	* Updated bundled Google Test to version 1.3.0. Google Test is now bundled
	in its verbatim form as a nested autoconf package, so you can drop in any
	other version of Google Test if needed.
	* optimize_for = SPEED is now the default, by popular demand. Use
	optimize_for = CODE_SIZE if code size is more important in your app.
	* It is now an error to define a default value for a repeated field.
	Previously, this was silently ignored (it had no effect on the generated
	code).
	* Fields can now be marked deprecated like:
	optional int32 foo = 1 [deprecated = true];
	Currently this does not have any actual effect, but in the future the code
	generators may generate deprecation annotations in each language.
	* Cross-compiling should now be possible using the --with-protoc option to
	configure. See README.txt for more info.

	protoc
	* --error_format=msvs option causes errors to be printed in Visual Studio
	format, which should allow them to be clicked on in the build log to go
	directly to the error location.
	* The type name resolver will no longer resolve type names to fields. For
	example, this now works:
	message Foo {}
	message Bar {
	optional int32 Foo = 1;
	optional Foo baz = 2;
	}
	Previously, the type of "baz" would resolve to "Bar.Foo", and you'd get
	an error because Bar.Foo is a field, not a type. Now the type of "baz"
	resolves to the message type Foo. This change is unlikely to make a
	difference to anyone who follows the Protocol Buffers style guide.

	C++
	* Several optimizations, including but not limited to:
	- Serialization, especially to flat arrays, is 10%-50% faster, possibly
	more for small objects.
	- Several descriptor operations which previously required locking no longer
	do.
	- Descriptors are now constructed lazily on first use, rather than at
	process startup time. This should save memory in programs which do not
	use descriptors or reflection.
	- UnknownFieldSet completely redesigned to be more efficient (especially in
	terms of memory usage).
	- Various optimizations to reduce code size (though the serialization speed
	optimizations increased code size).
	* Message interface has method ParseFromBoundedZeroCopyStream() which parses
	a limited number of bytes from an input stream rather than parsing until
	EOF.
	* GzipInputStream and GzipOutputStream support reading/writing gzip- or
	zlib-compressed streams if zlib is available.
	(google/protobuf/io/gzip_stream.h)
	* DescriptorPool::FindAllExtensions() and corresponding
	DescriptorDatabase::FindAllExtensions() can be used to enumerate all
	extensions of a given type.
	* For each enum type Foo, protoc will generate functions:
	const string& Foo_Name(Foo value);
	bool Foo_Parse(const string& name, Foo* result);
	The former returns the name of the enum constant corresponding to the given
	value while the latter finds the value corresponding to a name.
	* RepeatedField and RepeatedPtrField now have back-insertion iterators.
	* String fields now have setters that take a char* and a size, in addition
	to the existing ones that took char* or const string&.
	* DescriptorPool::AllowUnknownDependencies() may be used to tell
	DescriptorPool to create placeholder descriptors for unknown entities
	referenced in a FileDescriptorProto. This can allow you to parse a .proto
	file without having access to other .proto files that it imports, for
	example.
	* Updated gtest to latest version. The gtest package is now included as a
	nested autoconf package, so it should be able to drop new versions into the
	"gtest" subdirectory without modification.

	Java
	* Fixed bug where Message.mergeFrom(Message) failed to merge extensions.
	* Message interface has new method toBuilder() which is equivalent to
	newBuilderForType().mergeFrom(this).
	* All enums now implement the ProtocolMessageEnum interface.
	* Setting a field to null now throws NullPointerException.
	* Fixed tendency for TextFormat's parsing to overflow the stack when
	parsing large string values. The underlying problem is with Java's
	regex implementation (which unfortunately uses recursive backtracking
	rather than building an NFA). Worked around by making use of possesive
	quantifiers.
	* Generated service classes now also generate pure interfaces. For a service
	Foo, Foo.Interface is a pure interface containing all of the service's
	defined methods. Foo.newReflectiveService() can be called to wrap an
	instance of this interface in a class that implements the generic
	RpcService interface, which provides reflection support that is usually
	needed by RPC server implementations.
	* RPC interfaces now support blocking operation in addition to non-blocking.
	The protocol compiler generates separate blocking and non-blocking stubs
	which operate against separate blocking and non-blocking RPC interfaces.
	RPC implementations will have to implement the new interfaces in order to
	support blocking mode.
	* New I/O methods parseDelimitedFrom(), mergeDelimitedFrom(), and
	writeDelimitedTo() read and write "delemited" messages from/to a stream,
	meaning that the message size precedes the data. This way, you can write
	multiple messages to a stream without having to worry about delimiting
	them yourself.
	* Throw a more descriptive exception when build() is double-called.
	* Add a method to query whether CodedInputStream is at the end of the input
	stream.
	* Add a method to reset a CodedInputStream's size counter; useful when
	reading many messages with the same stream.
	* equals() and hashCode() now account for unknown fields.

	Python
	* Added slicing support for repeated scalar fields. Added slice retrieval and
	removal of repeated composite fields.
	* Updated RPC interfaces to allow for blocking operation. A client may
	now pass None for a callback when making an RPC, in which case the
	call will block until the response is received, and the response
	object will be returned directly to the caller. This interface change
	cannot be used in practice until RPC implementations are updated to
	implement it.
	* Changes to input_stream.py should make protobuf compatible with appengine.

	2008-11-25 version 2.0.3:

	protoc
	* Enum values may now have custom options, using syntax similar to field
	options.
	* Fixed bug where .proto files which use custom options but don't actually
	define them (i.e. they import another .proto file defining the options)
	had to explicitly import descriptor.proto.
	* Adjacent string literals in .proto files will now be concatenated, like in
	C.
	* If an input file is a Windows absolute path (e.g. "C:\foo\bar.proto") and
	the import path only contains "." (or contains "." but does not contain
	the file), protoc incorrectly thought that the file was under ".", because
	it thought that the path was relative (since it didn't start with a slash).
	This has been fixed.

	C++
	* Generated message classes now have a Swap() method which efficiently swaps
	the contents of two objects.
	* All message classes now have a SpaceUsed() method which returns an estimate
	of the number of bytes of allocated memory currently owned by the object.
	This is particularly useful when you are reusing a single message object
	to improve performance but want to make sure it doesn't bloat up too large.
	* New method Message::SerializeAsString() returns a string containing the
	serialized data. May be more convenient than calling
	SerializeToString(string*).
	* In debug mode, log error messages when string-type fields are found to
	contain bytes that are not valid UTF-8.
	* Fixed bug where a message with multiple extension ranges couldn't parse
	extensions.
	* Fixed bug where MergeFrom(const Message&) didn't do anything if invoked on
	a message that contained no fields (but possibly contained extensions).
	* Fixed ShortDebugString() to not be O(n^2). Durr.
	* Fixed crash in TextFormat parsing if the first token in the input caused a
	tokenization error.
	* Fixed obscure bugs in zero_copy_stream_impl.cc.
	* Added support for HP C++ on Tru64.
	* Only build tests on "make check", not "make".
	* Fixed alignment issue that caused crashes when using DynamicMessage on
	64-bit Sparc machines.
	* Simplify template usage to work with MSVC 2003.
	* Work around GCC 4.3.x x86_64 compiler bug that caused crashes on startup.
	(This affected Fedora 9 in particular.)
	* Now works on "Solaris 10 using recent Sun Studio".

	Java
	* New overload of mergeFrom() which parses a slice of a byte array instead
	of the whole thing.
	* New method ByteString.asReadOnlyByteBuffer() does what it sounds like.
	* Improved performance of isInitialized() when optimizing for code size.

	Python
	* Corrected ListFields() signature in Message base class to match what
	subclasses actually implement.
	* Some minor refactoring.
	* Don't pass self as first argument to superclass constructor (no longer
	allowed in Python 2.6).

	2008-09-29 version 2.0.2:

	General
	* License changed from Apache 2.0 to New BSD.
	* It is now possible to define custom "options", which are basically
	annotations which may be placed on definitions in a .proto file.
	For example, you might define a field option called "foo" like so:
	import "google/protobuf/descriptor.proto"
	extend google.protobuf.FieldOptions {
	optional string foo = 12345;
	}
	Then you annotate a field using the "foo" option:
	message MyMessage {
	optional int32 some_field = 1 [(foo) = "bar"]
	}
	The value of this option is then visible via the message's
	Descriptor:
	const FieldDescriptor* field =
	MyMessage::descriptor()->FindFieldByName("some_field");
	assert(field->options().GetExtension(foo) == "bar");
	This feature has been implemented and tested in C++ and Java.
	Other languages may or may not need to do extra work to support
	custom options, depending on how they construct descriptors.

	C++
	* Fixed some GCC warnings that only occur when using -pedantic.
	* Improved static initialization code, making ordering more
	predictable among other things.
	* TextFormat will no longer accept messages which contain multiple
	instances of a singular field. Previously, the latter instance
	would overwrite the former.
	* Now works on systems that don't have hash_map.

	Java
	* Print @Override annotation in generated code where appropriate.

	Python
	* Strings now use the "unicode" type rather than the "str" type.
	String fields may still be assigned ASCII "str" values; they will
	automatically be converted.
	* Adding a property to an object representing a repeated field now
	raises an exception. For example:
	# No longer works (and never should have).
	message.some_repeated_field.foo = 1

	Windows
	* We now build static libraries rather than DLLs by default on MSVC.
	See vsprojects/readme.txt for more information.

	2008-08-15 version 2.0.1:

	protoc
	* New flags --encode and --decode can be used to convert between protobuf text
	format and binary format from the command-line.
	* New flag --descriptor_set_out can be used to write FileDescriptorProtos for
	all parsed files directly into a single output file. This is particularly
	useful if you wish to parse .proto files from programs written in languages
	other than C++: just run protoc as a background process and have it output
	a FileDescriptorList, then parse that natively.
	* Improved error message when an enum value's name conflicts with another
	symbol defined in the enum type's scope, e.g. if two enum types declared
	in the same scope have values with the same name. This is disallowed for
	compatibility with C++, but this wasn't clear from the error.
	* Fixed absolute output paths on Windows.
	* Allow trailing slashes in --proto_path mappings.

	C++
	* Reflection objects are now per-class rather than per-instance. To make this
	possible, the Reflection interface had to be changed such that all methods
	take the Message instance as a parameter. This change improves performance
	significantly in memory-bandwidth-limited use cases, since it makes the
	message objects smaller. Note that source-incompatible interface changes
	like this will not be made again after the library leaves beta.
	* Heuristically detect sub-messages when printing unknown fields.
	* Fix static initialization ordering bug that caused crashes at startup when
	compiling on Mac with static linking.
	* Fixed TokenizerTest when compiling with -DNDEBUG on Linux.
	* Fixed incorrect definition of kint32min.
	* Fix bytes type setter to work with byte sequences with embedded NULLs.
	* Other irrelevant tweaks.

	Java
	* Fixed UnknownFieldSet's parsing of varints larger than 32 bits.
	* Fixed TextFormat's parsing of "inf" and "nan".
	* Fixed TextFormat's parsing of comments.
	* Added info to Java POM that will be required when we upload the
	package to a Maven repo.

	Python
	* MergeFrom(message) and CopyFrom(message) are now implemented.
	* SerializeToString() raises an exception if the message is missing required
	fields.
	* Code organization improvements.
	* Fixed doc comments for RpcController and RpcChannel, which had somehow been
	swapped.
	* Fixed text_format_test on Windows where floating-point exponents sometimes
	contain extra zeros.
	* Fix Python service CallMethod() implementation.

	Other
	* Improved readmes.
	* VIM syntax highlighting improvements.

	2008-07-07 version 2.0.0:

	* First public release.