All Classes and Interfaces
Class
Description
A partial implementation of the
Message interface which implements as many methods of
that interface as possible in terms of other methods.A partial implementation of the
Message.Builder interface which implements as many
methods of that interface as possible in terms of other methods.Interface for the parent of a Builder that allows the builder to communicate invalidations back
to the parent for use when using nested builders.
A partial implementation of the
MessageLite interface which implements as many methods of
that interface as possible in terms of other methods.A partial implementation of the
Message.Builder interface which implements as many
methods of that interface as possible in terms of other methods.An InputStream implementations which reads from some other InputStream but is limited to a
particular number of bytes.
Interface for an enum which signifies which field in a
oneof was specified.A partial implementation of the
Parser interface which implements as many methods of that
interface as possible in terms of other methods.An abstract implementation of
Internal.ProtobufList which manages mutability semantics.A buffer that was allocated by a
BufferAllocator.
`Any` contains an arbitrary serialized protocol buffer message along with a
URL that describes the type of the serialized message.
`Any` contains an arbitrary serialized protocol buffer message along with a
URL that describes the type of the serialized message.
Api is a light-weight descriptor for an API Interface.
Api is a light-weight descriptor for an API Interface.
Helper functions to decode protobuf wire format from a byte array.
A helper used to return multiple values in a Java function.
A
Reader that reads from a buffer containing a message serialized with the binary
protocol.A
BinaryReader implementation that operates on a heap ByteBuffer.A protobuf writer that serializes messages in their binary form.
Writer that uses safe operations on a target
ByteBuffer.Writer that uses safe operations on target array.
Writer that uses unsafe operations on a target
ByteBuffer.Writer that uses unsafe operations on a target array.
Abstract interface for a blocking RPC channel.
Blocking equivalent to
Service.An implementation of
Internal.BooleanList on top of a primitive array.
Wrapper message for `bool`.
Wrapper message for `bool`.
An object responsible for allocation of buffers.
Utility class to provide efficient writing of
ByteBuffers to OutputStreams.An output target for raw bytes.
Immutable sequence of bytes.
Implementation of
ByteArrayCopier which uses Arrays.copyOfRange(T[], int, int).This class is used to represent the substring of a
ByteString over a single byte array.An interface to efficiently copy
byte[].This interface extends
Iterator<Byte>, so that we can return an unboxed byte.Base class for leaf
ByteStrings (i.e.This class implements a
ByteString backed by a single array of
bytes, contiguous in memory.A
ByteString that wraps around a ByteBuffer.Outputs to a
ByteString instance.Implementation of
ByteArrayCopier which uses System.arraycopy(java.lang.Object, int, java.lang.Object, int, int).
Wrapper message for `bytes`.
Wrapper message for `bytes`.
Indicates that the return value of the annotated method can be safely ignored.
Indicates that the return value of the annotated method must be used.
Reads and decodes protocol message fields.
A
CodedInputStream implementation that uses a backing array as the input.Implementation of
CodedInputStream that uses an Implementation of
CodedInputStream that uses an InputStream as the data source.A
CodedInputStream implementation that uses a backing direct ByteBuffer as the input.An adapter between the
Reader interface and CodedInputStream.Encodes and writes protocol message fields.
Abstract base class for buffered encoders.
A
CodedOutputStream that writes directly to a byte array.A
CodedOutputStream that decorates a ByteOutput.A
CodedOutputStream that writes directly to a heap ByteBuffer.If you create a CodedOutputStream around a simple flat array, you must not attempt to write
more bytes than the array has space.
An
CodedOutputStream that decorates an OutputStream.A
CodedOutputStream that writes directly to a direct ByteBuffer, using only
safe operations..An adapter between the
Writer interface and CodedOutputStream.Annotation for method parameter and class field declarations, which denotes that corresponding
actual values must be compile-time constant expressions.
Provides an explicit API for unstable, redacting debug output suitable for debug logging.
A factory for message info based on protobuf descriptors for a
GeneratedMessage.A helper class to determine whether a message type needs to implement
isInitialized().
Describes a message type.
Describes a message type.
Protobuf type
google.protobuf.DescriptorProto.ExtensionRangeProtobuf type
google.protobuf.DescriptorProto.ExtensionRange
Range of reserved tag numbers.
Range of reserved tag numbers.
The full set of known editions.
Describes an enum type.
Describes an enum type.
Range of reserved numeric values.
Range of reserved numeric values.
Protobuf type
google.protobuf.EnumOptionsProtobuf type
google.protobuf.EnumOptions
Describes a value within an enum.
Describes a value within an enum.
Protobuf type
google.protobuf.EnumValueOptionsProtobuf type
google.protobuf.EnumValueOptionsProtobuf type
google.protobuf.ExtensionRangeOptionsProtobuf type
google.protobuf.ExtensionRangeOptionsProtobuf type
google.protobuf.ExtensionRangeOptions.DeclarationProtobuf type
google.protobuf.ExtensionRangeOptions.Declaration
The verification state of the extension range.
TODO Enums in C++ gencode (and potentially other languages) are
not well scoped.
TODO Enums in C++ gencode (and potentially other languages) are
not well scoped.
Protobuf enum
google.protobuf.FeatureSet.EnforceNamingStyleProtobuf enum
google.protobuf.FeatureSet.EnumTypeProtobuf enum
google.protobuf.FeatureSet.FieldPresenceProtobuf enum
google.protobuf.FeatureSet.JsonFormatProtobuf enum
google.protobuf.FeatureSet.MessageEncodingProtobuf enum
google.protobuf.FeatureSet.RepeatedFieldEncodingProtobuf enum
google.protobuf.FeatureSet.Utf8ValidationProtobuf type
google.protobuf.FeatureSet.VisibilityFeatureProtobuf type
google.protobuf.FeatureSet.VisibilityFeatureProtobuf enum
google.protobuf.FeatureSet.VisibilityFeature.DefaultSymbolVisibility
A compiled specification for the defaults of a set of features.
A compiled specification for the defaults of a set of features.
A map from every known edition with a unique set of defaults to its
defaults.
A map from every known edition with a unique set of defaults to its
defaults.
Describes a field within a message.
Describes a field within a message.
Protobuf enum
google.protobuf.FieldDescriptorProto.LabelProtobuf enum
google.protobuf.FieldDescriptorProto.TypeProtobuf type
google.protobuf.FieldOptionsProtobuf type
google.protobuf.FieldOptionsProtobuf enum
google.protobuf.FieldOptions.CTypeProtobuf type
google.protobuf.FieldOptions.EditionDefaultProtobuf type
google.protobuf.FieldOptions.EditionDefault
Information about the support window of a feature.
Information about the support window of a feature.
Protobuf enum
google.protobuf.FieldOptions.JSType
If set to RETENTION_SOURCE, the option will be omitted from the binary.
This indicates the types of entities that the field may apply to when used
as an option.
Describes a complete .proto file.
Describes a complete .proto file.
The protocol compiler can output a FileDescriptorSet containing the .proto
files it parses.
The protocol compiler can output a FileDescriptorSet containing the .proto
files it parses.
Protobuf type
google.protobuf.FileOptionsProtobuf type
google.protobuf.FileOptions
Generated classes can be optimized for speed or code size.
Describes the relationship between generated code and its original source
file.
Protobuf type
google.protobuf.GeneratedCodeInfo.AnnotationProtobuf type
google.protobuf.GeneratedCodeInfo.Annotation
Represents the identified object's effect on the element in the original
.proto file.
Describes the relationship between generated code and its original source
file.
Protobuf type
google.protobuf.MessageOptionsProtobuf type
google.protobuf.MessageOptions
Describes a method of a service.
Describes a method of a service.
Protobuf type
google.protobuf.MethodOptionsProtobuf type
google.protobuf.MethodOptions
Is this method side-effect-free (or safe in HTTP parlance), or idempotent,
or neither? HTTP based RPC implementation may choose GET verb for safe
methods, and PUT verb for idempotent methods instead of the default POST.
Describes a oneof.
Describes a oneof.
Protobuf type
google.protobuf.OneofOptionsProtobuf type
google.protobuf.OneofOptions
Describes a service.
Describes a service.
Protobuf type
google.protobuf.ServiceOptionsProtobuf type
google.protobuf.ServiceOptions
Encapsulates information about the original source file from which a
FileDescriptorProto was generated.
Encapsulates information about the original source file from which a
FileDescriptorProto was generated.
Protobuf type
google.protobuf.SourceCodeInfo.LocationProtobuf type
google.protobuf.SourceCodeInfo.Location
Describes the 'visibility' of a symbol with respect to the proto import
system.
A message representing a option the parser does not recognize.
A message representing a option the parser does not recognize.
The name of the uninterpreted option.
The name of the uninterpreted option.
Contains a collection of classes which describe protocol message types.
Describes a message type.
A private helper class which contains lookup tables containing all the descriptors defined in a
particular file.
Represents a package in the symbol table.
Defines what subclass of descriptors to search in the descriptor pool.
Thrown when building descriptors fails because the source DescriptorProtos are not valid.
Describes an enum type.
Describes one value within an enum type.
Describes a field of a message type.
Describes a
.proto file, including everything defined within.Deprecated.
All descriptors implement this to make it easier to implement tools like
DescriptorPool.Describes one method within a service type.
Describes a oneof of a message type.
Describes a service type.
Parsers to discard unknown fields during parsing.
An implementation of
Internal.DoubleList on top of a primitive array.
Wrapper message for `double`.
Wrapper message for `double`.
A Duration represents a signed, fixed-length span of time represented
as a count of seconds and fractions of seconds at nanosecond
resolution.
A Duration represents a signed, fixed-length span of time represented
as a count of seconds and fractions of seconds at nanosecond
resolution.
Utilities to help create/manipulate
protobuf/duration.proto.An implementation of
Message that can represent arbitrary types, given a Descriptors.Descriptor.Builder for
DynamicMessages.
A generic empty message that you can re-use to avoid defining duplicated
empty messages in your APIs.
A generic empty message that you can re-use to avoid defining duplicated
empty messages in your APIs.
Enum type definition.
Enum type definition.
Enum value definition.
Enum value definition.
Indicates a public API that can change at any time, and has no guarantee of API stability and
backward-compatibility.
Interface that generated extensions implement.
The API type that the extension is used for.
Type of a message extension.
Lite interface that generated extensions implement.
A table of known extensions, searchable by name or field number.
A (GenericDescriptor, int) pair, used as a map key.
A (Descriptor, Message) pair, returned by lookup methods.
A factory object to create instances of
ExtensionRegistryLite.Equivalent to
ExtensionRegistry but supports only "lite" types.A (Object, int) pair, used as a map key.
A single field of a message type.
A single field of a message type.
Whether a field is optional, required, or repeated.
Basic field types.
Information for a single field in a protobuf message class.
A builder for
FieldInfo instances.
`FieldMask` represents a set of symbolic field paths, for example:
paths: "f.a"
paths: "f.b.d"
Here `f` represents a field in some root message, `a` and `b`
fields in the message found in `f`, and `d` a field found in the
message in `f.b`.
`FieldMask` represents a set of symbolic field paths, for example:
paths: "f.a"
paths: "f.b.d"
Here `f` represents a field in some root message, `a` and `b`
fields in the message found in `f`, and `d` a field found in the
message in `f.b`.
A tree representation of a FieldMask.
Utility helper functions to work with
FieldMask.Options to customize merging behavior.
A class which represents an arbitrary set of fields of some message type.
A FieldSet Builder that accept a
MessageLite.Builder as a field value.Interface for a FieldDescriptor or lite extension descriptor.
Enumeration identifying all relevant type information for a protobuf field.
An implementation of
Internal.FloatList on top of a primitive array.
Wrapper message for `float`.
Wrapper message for `float`.
Marks protobuf implementations generated by the
protoc compiler.All generated protocol message classes extend this class.
Builder class for
GeneratedMessage.Generated message builders for message types that contain extension ranges subclass this.
Generated message classes for message types that contain extension ranges subclass this.
Used by subclasses to serialize extensions.
No-op implementation that writes nothing, for messages with no extensions.
Extends
MessageOrBuilder with extension-related functions.Gets the descriptor for an extension.
Users should ignore this class.
Abstract interface that provides access to a single field.
OneofAccessor provides access to a single oneof.
RealOneofAccessor provides access to a single real oneof.
Field accessor for string fields.
SyntheticOneofAccessor provides access to a single synthetic oneof.
Type used to represent generated extensions.
This class is used to make a generated protected method inaccessible from user's code (e.g.,
the
GeneratedMessage.newInstance(com.google.protobuf.GeneratedMessage.UnusedPrivateParameter) method below).A factory for message info that is generated into the message itself.
Lite version of
GeneratedMessage.A
Parser implementation that delegates to the default instance.Lite equivalent of
GeneratedMessage.ExtendableBuilder.Lite equivalent of
GeneratedMessage.ExtendableMessage.Lite equivalent of
GeneratedMessage.ExtendableMessageOrBuilder.Lite equivalent to
GeneratedMessage.GeneratedExtension.Defines which method path to invoke in
#dynamicMethod(MethodToInvoke, Object...).A serialized (serializable) form of the generated message.
Deprecated.
This class is deprecated, and slated for removal in the next Java breaking change
(5.x).
Deprecated.
This class is deprecated, and slated for removal in the next Java breaking change
(5.x).
Deprecated.
Deprecated.
This class is deprecated, and slated for removal in the next Java breaking change
(5.x).
Deprecated.
This class is deprecated, and slated for removal in the next Java breaking change
(5.x).
Deprecated.
This class is deprecated, and slated for removal in the next Java breaking change
(5.x).
Deprecated.
This class is deprecated, and slated for removal in the next Java breaking change
(5.x).
Deprecated.
This method is deprecated, and slated for removal in the next Java breaking change
(5.x).
Indicates that callers of this API should be inlined.
Wrapper message for `int32`.
Wrapper message for `int32`.
Wrapper message for `int64`.
Wrapper message for `int64`.
An implementation of
Internal.IntList on top of a primitive array.The classes contained within are used internally by the Protocol Buffer library and generated
message implementations.
A
List implementation that avoids boxing the elements into Booleans if
possible.A
List implementation that avoids boxing the elements into Doubles if
possible.Interface for an enum value or value descriptor, to be used in FieldSet.
Interface for an object which maps integers to
Internal.EnumLites.Interface for an object which verifies integers are in range.
A
List implementation that avoids boxing the elements into Floats if
possible.A
List implementation that avoids boxing the elements into Integers if
possible.Provides an immutable view of
List<T> around an IntList.Convert individual elements of the List from int to T.
Provides an immutable view of
List<T> around a List<F>.Convert individual elements of the List from F to T.
A
List implementation that avoids boxing the elements into Longs if possible.Wrap around a
Map<K, RealValue> and provide a Map<K, V> interface.An interface used to convert between two types.
Extends
List to add the capability to make the list immutable and inspect if it is
modifiable.Thrown when a protocol message being parsed is invalid in some way.
Exception indicating that an unexpected wire type was encountered for a field.
Wrappers around
Buffer methods that are covariantly overridden in Java 9+.Protobuf type
pb.JavaFeaturesProtobuf type
pb.JavaFeaturesProtobuf type
pb.JavaFeatures.NestInFileClassFeatureProtobuf type
pb.JavaFeatures.NestInFileClassFeatureProtobuf enum
pb.JavaFeatures.NestInFileClassFeature.NestInFileClass
The UTF8 validation strategy to use.
Enum that identifies the Java types required to store protobuf fields.
Utility class to convert protobuf messages to/from the Proto3 JSON format.
Only proto3 features are supported.
Format the JSON without indentation
A Parser parses the proto3 JSON format into a protobuf message.
A TextGenerator adds indentation when writing formatted text.
A Printer converts a protobuf message to the proto3 JSON format.
A Printer converts protobuf messages to the proto3 JSON format.
An interface for JSON formatting that can be used in
combination with the omittingInsignificantWhitespace() method.
A TypeRegistry is used to resolve Any messages in the JSON conversion.
A Builder is used to build
JsonFormat.TypeRegistry.LazyField encapsulates the logic of lazily parsing message fields.
LazyEntry and LazyIterator are used to encapsulate the LazyField, when users iterate all fields
from FieldSet.
LazyFieldLite encapsulates the logic of lazily parsing message fields.
An implementation of
LazyStringList that wraps an ArrayList.An interface extending
List<String> that also provides access to the items of the list as
UTF8-encoded ByteString or byte[] objects.The legacy APIs preserve the existing toString() behavior (output TextFormat), which allows us to
migrate toString callers that expect TextFormat output off toString.
Utility class that aids in properly manipulating list fields for either the lite or full runtime.
Utility class that aids in properly manipulating list fields for either the lite or full runtime.
Utility class that aids in properly manipulating list fields for either the lite or full runtime.
`ListValue` is a wrapper around a repeated field of values.
`ListValue` is a wrapper around a repeated field of values.
An implementation of
Internal.LongList on top of a primitive array.Dynamically generates a manifest-based (i.e.
Implements MapEntry messages.
Builder to create
MapEntry messages.Implements the lite version of map entry messages.
Internal representation of map fields in generated messages.
An internal map that checks for mutability before delegating.
An internal collection that checks for mutability before delegating.
An internal iterator that checks for mutability before delegating.
An internal set that checks for mutability before delegating.
Indicates where the data of this map field is currently stored.
Internal representation of map fields in generated builders.
Convert a MessageOrBuilder to a Message regardless of which it holds.
Internal representation of map fields in generated lite-runtime messages.
A base class for package private shared methods between MapField and MapFieldBuilder to allow
reflection to access both.
Abstract interface implemented by Protocol Message objects.
Abstract interface implemented by Protocol Message builders.
A MessageInfo object describes a proto message type.
A factory that creates
MessageInfo instances for message types.Abstract interface implemented by Protocol Message objects.
Abstract interface implemented by Protocol Message builders.
Base interface for methods common to
MessageLite and MessageLite.Builder to
provide type equivalency.Helps generate
String representations of MessageLite protos.Base interface for methods common to
Message and Message.Builder to provide type
equivalency.Reflection utility methods shared by both mutable and immutable messages.
Schema used for standard messages.
Schema used for proto2 messages using message_set_wireformat.
Method represents a method of an API interface.
Method represents a method of an API interface.
Declares an API Interface to be included in this interface.
Declares an API Interface to be included in this interface.
Verifies that an object is mutable, throwing if not.
`NullValue` is a singleton enumeration to represent the null value for the
`Value` type union.
Information for a oneof within a protobuf message.
A protocol buffer option, which can be attached to a message, field,
enumeration, etc.
A protocol buffer option, which can be attached to a message, field,
enumeration, etc.
Abstract interface for parsing Protocol Messages.
An encoded CodeGeneratorRequest is written to the plugin's stdin.
An encoded CodeGeneratorRequest is written to the plugin's stdin.
The plugin writes an encoded CodeGeneratorResponse to stdout.
The plugin writes an encoded CodeGeneratorResponse to stdout.
Sync with code_generator.h.
Represents a single generated file.
Represents a single generated file.
The version number of protocol compiler.
The version number of protocol compiler.
A marker interface indicating that the collection supports primitives and is non-boxing.
Main runtime interface for protobuf.
Implements
Internal.ProtobufList for non-primitive and String types.ProtobufToStringOutput controls the output format of
Message.toString().Interface of useful methods added to all enums generated by the protocol compiler.
An interface extending
List<String> used for repeated string fields to provide optional
access to the data as a list of ByteStrings.Utility helper functions to work with
.
invalid reference
com.google.protobuf.FileDescriptorProtoRepresents the syntax version of the message.
RawMessageInfo stores the same amount of information as
MessageInfo but in a more compact
format.A reader of fields from a serialized protobuf message.
RepeatedFieldBuilder implements a structure that a protocol message uses to hold a
repeated field of other protocol messages.Provides a live view of the builder as a list of builders.
Provides a live view of the builder as a list of messages.
Provides a live view of the builder as a list of builders.
Deprecated.
This class is deprecated, and slated for removal in the next breaking change.
Class to represent
ByteStrings formed by concatenation of other ByteStrings, without
copying the data in the pieces.This class implements the balancing algorithm of BAP95.
This class is a continuable tree traversal, which keeps the state information which would exist
on the stack in a recursive traversal instead on a stack of "Bread Crumbs".
Interface for an RPC callback, normally called when an RPC completes.
Abstract interface for an RPC channel.
An
RpcController mediates a single method call.Grab-bag of utility functions useful when dealing with RPCs.
Exception thrown when a one-time callback is called more than once.
Provides the version of this Protobuf Java runtime, and methods for Protobuf Java gencode to
validate that versions are compatible.
A runtime exception to be thrown by the version validator if version is not well defined or
versions mismatch.
Indicates the domain of the Protobuf artifact.
A runtime schema for a single protobuf message.
A factory that manufactures
Schema instances for protobuf messages.Helper methods used by schemas.
Abstract base interface for protocol-buffer-based RPC services.
Thrown by blocking RPC methods when a failure occurs.
SingleFieldBuilder implements a structure that a protocol message uses to hold a single
field of another protocol message.Deprecated.
This class is deprecated, and slated for removal in the next breaking change.
A custom map implementation from FieldDescriptor to Object optimized to minimize the number of
memory allocations for instances with a small number of mappings.
`SourceContext` represents information about the source of a
protobuf element, like the file in which it is defined.
`SourceContext` represents information about the source of a
protobuf element, like the file in which it is defined.
Wrapper message for `string`.
Wrapper message for `string`.
`Struct` represents a structured data value, consisting of fields
which map to dynamically typed values.
`Struct` represents a structured data value, consisting of fields
which map to dynamically typed values.
Utilities to help create
google.protobuf.Struct messages.Information for the layout of a protobuf message class.
A builder of
MessageInfo instances.
The syntax in which a protocol buffer element is defined.
Provide text parsing and formatting support for proto2 instances.
Thrown by
TextFormat.unescapeBytes(java.lang.CharSequence) and TextFormat.unescapeText(java.lang.String) when an invalid
escape sequence is seen.Thrown when parsing an invalid text format message.
Parser for text-format proto2 instances.
Builder that can be used to obtain new instances of
TextFormat.Parser.Determines if repeated values for non-repeated fields and oneofs are permitted.
Helper class for converting protobufs to text.
A list of the public APIs that output human-readable text from a message.
An adapter class that can take a
MapEntry and returns its key and entry.An inner class for writing text to the output stream.
Represents a stream of tokens parsed from a
String.Deprecated.
This exception is unused and will be removed in the next breaking release
(v5.x.x).
Provide text format escaping of proto instances.
Data structure which is populated with the locations of each field value parsed from the text.
Builder for a
TextFormatParseInfoTree.A location in the source code.
A Timestamp represents a point in time independent of any time zone or local
calendar, encoded as a count of seconds and fractions of seconds at
nanosecond resolution.
A Timestamp represents a point in time independent of any time zone or local
calendar, encoded as a count of seconds and fractions of seconds at
nanosecond resolution.
Utilities to help create/manipulate
protobuf/timestamp.proto.
A protocol buffer message type.
A protocol buffer message type.
A TypeRegistry is used to resolve Any messages.
A Builder is used to build
TypeRegistry.
Wrapper message for `uint32`.
Wrapper message for `uint32`.
Wrapper message for `uint64`.
Wrapper message for `uint64`.
Thrown when attempting to build a protocol message that is missing required fields.
UnknownFieldSet keeps track of fields which were seen when parsing a protocol
message but whose field numbers or types are unrecognized.Builder for
UnknownFieldSets.Represents a single field in an
UnknownFieldSet.Used to build a
UnknownFieldSet.Field within an UnknownFieldSet.Parser to implement MessageLite interface.
UnknownFieldSetLite is used to keep track of fields which were seen when parsing a
protocol message but whose field numbers or types are unrecognized.Deprecated.
use
AbstractProtobufList.makeImmutable() instead.These APIs are restricted to test-only targets, and are suitable for test purposes where it is
impractical to compare protos directly via ProtoTruth (e.g.
Provides a number of unsafe byte operations to be used by advanced applications with high
performance requirements.
Utility class for working with unsafe operations.
A set of low-level, high-performance static utility methods related to the UTF-8 character
encoding.
Utility methods for decoding bytes into
String.A processor of UTF-8 strings, providing methods for checking validity and encoding.
Utf8.Processor implementation that does not use any sun.misc.Unsafe methods.Utf8.Processor that uses sun.misc.Unsafe where possible to improve performance.
`Value` represents a dynamically typed value which can be either
null, a number, a string, a boolean, a recursive struct value, or a
list of values.
`Value` represents a dynamically typed value which can be either
null, a number, a string, a boolean, a recursive struct value, or a
list of values.
Utilities to help create
google.protobuf.Value messages.This class is used internally by the Protocol Buffer library and generated message
implementations.
Lite equivalent to
Descriptors.FieldDescriptor.Type.Lite equivalent to
Descriptors.FieldDescriptor.JavaType.Validation level for handling incoming string field data which potentially contain non-UTF8
bytes.
A writer that performs serialization of protobuf message fields.
The order in which the fields are written by a
Writer.