Reference: google.protobuf

Standalone Message Types

FileDescriptorSet

The protocol compiler can output a FileDescriptorSet containing the .proto files it parses.

Fields

file

Type: repeated google.protobuf.FileDescriptorProto


FileDescriptorProto

Describes a complete .proto file.

Fields

name

Type: optional string

package

Type: optional string

dependency

Type: repeated string

Names of files imported by this file.

public_dependency

Type: repeated int32

Indexes of the public imported files in the dependency list above.

weak_dependency

Type: repeated int32

Indexes of the weak imported files in the dependency list. For Google-internal migration only. Do not use.

message_type

Type: repeated google.protobuf.DescriptorProto

All top-level definitions in this file.

enum_type

Type: repeated google.protobuf.EnumDescriptorProto

service

Type: repeated google.protobuf.ServiceDescriptorProto

extension

Type: repeated google.protobuf.FieldDescriptorProto

options

Type: optional google.protobuf.FileOptions

source_code_info

Type: optional google.protobuf.SourceCodeInfo

This field contains optional information about the original source code. You may safely remove this entire field without harming runtime functionality of the descriptors – the information is needed only by development tools.

syntax

Type: optional string

The syntax of the proto file. The supported values are “proto2” and “proto3”.


DescriptorProto

Describes a message type.

Fields

name

Type: optional string

field

Type: repeated google.protobuf.FieldDescriptorProto

extension

Type: repeated google.protobuf.FieldDescriptorProto

nested_type

Type: repeated google.protobuf.DescriptorProto

enum_type

Type: repeated google.protobuf.EnumDescriptorProto

extension_range

Type: repeated google.protobuf.DescriptorProto.ExtensionRange

oneof_decl

Type: repeated google.protobuf.OneofDescriptorProto

options

Type: optional google.protobuf.MessageOptions

reserved_range

Type: repeated google.protobuf.DescriptorProto.ReservedRange

reserved_name

Type: repeated string

Reserved field names, which may not be used by fields in the same message. A given name may only be reserved once.


DescriptorProto.ExtensionRange

Fields

start

Type: optional int32

end

Type: optional int32

options

Type: optional google.protobuf.ExtensionRangeOptions


DescriptorProto.ReservedRange

Fields

start

Type: optional int32

end

Type: optional int32


ExtensionRangeOptions

Fields

uninterpreted_option

Type: repeated google.protobuf.UninterpretedOption

The parser stores options it doesn’t recognize here. See above.


FieldDescriptorProto

Describes a field within a message.

Fields

name

Type: optional string

number

Type: optional int32

label

Type: UNHANDLED | TYPE

type

Type: UNHANDLED | TYPE

If type_name is set, this need not be set. If both this and type_name are set, this must be one of TYPE_ENUM, TYPE_MESSAGE or TYPE_GROUP.

type_name

Type: optional string

For message and enum types, this is the name of the type. If the name starts with a ‘.’, it is fully-qualified. Otherwise, C++-like scoping rules are used to find the type (i.e. first the nested types within this message are searched, then within the parent, on up to the root namespace).

extendee

Type: optional string

For extensions, this is the name of the type being extended. It is resolved in the same manner as type_name.

default_value

Type: optional string

For numeric types, contains the original text representation of the value. For booleans, “true” or “false”. For strings, contains the default text contents (not escaped in any way). For bytes, contains the C escaped value. All bytes >= 128 are escaped. TODO(kenton): Base-64 encode?

oneof_index

Type: optional int32

If set, gives the index of a oneof in the containing type’s oneof_decl list. This field is a member of that oneof.

json_name

Type: optional string

JSON name of this field. The value is set by protocol compiler. If the user has set a “json_name” option on this field, that option’s value will be used. Otherwise, it’s deduced from the field’s name by converting it to camelCase.

options

Type: optional google.protobuf.FieldOptions

proto3_optional

Type: optional bool

If true, this is a proto3 “optional”. When a proto3 field is optional, it tracks presence regardless of field type.

When proto3_optional is true, this field must be belong to a oneof to signal to old proto3 clients that presence is tracked for this field. This oneof is known as a “synthetic” oneof, and this field must be its sole member (each proto3 optional field gets its own synthetic oneof). Synthetic oneofs exist in the descriptor only, and do not generate any API. Synthetic oneofs must be ordered after all “real” oneofs.

For message fields, proto3_optional doesn’t create any semantic change, since non-repeated message fields always track presence. However it still indicates the semantic detail of whether the user wrote “optional” or not. This can be useful for round-tripping the .proto file. For consistency we give message fields a synthetic oneof also, even though it is not required to track presence. This is especially important because the parser can’t tell if a field is a message or an enum, so it must always create a synthetic oneof.

Proto2 optional fields do not set this flag, because they already indicate optional with LABEL_OPTIONAL.


OneofDescriptorProto

Describes a oneof.

Fields

name

Type: optional string

options

Type: optional google.protobuf.OneofOptions


EnumDescriptorProto

Describes an enum type.

Fields

name

Type: optional string

value

Type: repeated google.protobuf.EnumValueDescriptorProto

options

Type: optional google.protobuf.EnumOptions

reserved_range

Type: repeated google.protobuf.EnumDescriptorProto.EnumReservedRange

Range of reserved numeric values. Reserved numeric values may not be used by enum values in the same enum declaration. Reserved ranges may not overlap.

reserved_name

Type: repeated string

Reserved enum value names, which may not be reused. A given name may only be reserved once.


EnumDescriptorProto.EnumReservedRange

Fields

start

Type: optional int32

end

Type: optional int32


EnumValueDescriptorProto

Describes a value within an enum.

Fields

name

Type: optional string

number

Type: optional int32

options

Type: optional google.protobuf.EnumValueOptions


ServiceDescriptorProto

Describes a service.

Fields

name

Type: optional string

method

Type: repeated google.protobuf.MethodDescriptorProto

options

Type: optional google.protobuf.ServiceOptions


MethodDescriptorProto

Describes a method of a service.

Fields

name

Type: optional string

input_type

Type: optional string

Input and output type names. These are resolved in the same way as FieldDescriptorProto.type_name, but must refer to a message type.

output_type

Type: optional string

options

Type: optional google.protobuf.MethodOptions

client_streaming

Type: optional bool

Identifies if client streams multiple client messages

server_streaming

Type: optional bool

Identifies if server streams multiple server messages


FileOptions

Fields

java_package

Type: optional string

Sets the Java package where classes generated from this .proto will be placed. By default, the proto package is used, but this is often inappropriate because proto packages do not normally start with backwards domain names.

java_outer_classname

Type: optional string

Controls the name of the wrapper Java class generated for the .proto file. That class will always contain the .proto file’s getDescriptor() method as well as any top-level extensions defined in the .proto file. If java_multiple_files is disabled, then all the other classes from the .proto file will be nested inside the single wrapper outer class.

java_multiple_files

Type: optional bool

If enabled, then the Java code generator will generate a separate .java file for each top-level message, enum, and service defined in the .proto file. Thus, these types will not be nested inside the wrapper class named by java_outer_classname. However, the wrapper class will still be generated to contain the file’s getDescriptor() method as well as any top-level extensions defined in the file.

java_generate_equals_and_hash

Type: optional bool

This option does nothing.

java_string_check_utf8

Type: optional bool

If set true, then the Java2 code generator will generate code that throws an exception whenever an attempt is made to assign a non-UTF-8 byte sequence to a string field. Message reflection will do the same. However, an extension field still accepts non-UTF-8 byte sequences. This option has no effect on when used with the lite runtime.

optimize_for

Type: UNHANDLED | TYPE

go_package

Type: optional string

Sets the Go package where structs generated from this .proto will be placed. If omitted, the Go package will be derived from the following:

  • The basename of the package import path, if provided.
  • Otherwise, the package statement in the .proto file, if present.
  • Otherwise, the basename of the .proto file, without extension.

cc_generic_services

Type: optional bool

Should generic services be generated in each language? “Generic” services are not specific to any particular RPC system. They are generated by the main code generators in each language (without additional plugins). Generic services were the only kind of service generation supported by early versions of google.protobuf.

Generic services are now considered deprecated in favor of using plugins that generate code specific to your particular RPC system. Therefore, these default to false. Old code which depends on generic services should explicitly set them to true.

java_generic_services

Type: optional bool

py_generic_services

Type: optional bool

php_generic_services

Type: optional bool

deprecated

Type: optional bool

Is this file deprecated? Depending on the target platform, this can emit Deprecated annotations for everything in the file, or it will be completely ignored; in the very least, this is a formalization for deprecating files.

cc_enable_arenas

Type: optional bool

Enables the use of arenas for the proto messages in this file. This applies only to generated classes for C++.

objc_class_prefix

Type: optional string

Sets the objective c class prefix which is prepended to all objective c generated classes from this .proto. There is no default.

csharp_namespace

Type: optional string

Namespace for generated classes; defaults to the package.

swift_prefix

Type: optional string

By default Swift generators will take the proto package and CamelCase it replacing ‘.’ with underscore and use that to prefix the types/symbols defined. When this options is provided, they will use this value instead to prefix the types/symbols defined.

php_class_prefix

Type: optional string

Sets the php class prefix which is prepended to all php generated classes from this .proto. Default is empty.

php_namespace

Type: optional string

Use this option to change the namespace of php generated classes. Default is empty. When this option is empty, the package name will be used for determining the namespace.

php_metadata_namespace

Type: optional string

Use this option to change the namespace of php generated metadata classes. Default is empty. When this option is empty, the proto file name will be used for determining the namespace.

ruby_package

Type: optional string

Use this option to change the package of ruby generated classes. Default is empty. When this option is not set, the package name will be used for determining the ruby package.

uninterpreted_option

Type: repeated google.protobuf.UninterpretedOption

The parser stores options it doesn’t recognize here. See the documentation for the “Options” section above.


MessageOptions

Fields

message_set_wire_format

Type: optional bool

Set true to use the old proto1 MessageSet wire format for extensions. This is provided for backwards-compatibility with the MessageSet wire format. You should not use this for any other reason: It’s less efficient, has fewer features, and is more complicated.

The message must be defined exactly as follows: message Foo { option message_set_wire_format = true; extensions 4 to max; } Note that the message cannot have any defined fields; MessageSets only have extensions.

All extensions of your type must be singular messages; e.g. they cannot be int32s, enums, or repeated messages.

Because this is an option, the above two restrictions are not enforced by the protocol compiler.

no_standard_descriptor_accessor

Type: optional bool

Disables the generation of the standard “descriptor()” accessor, which can conflict with a field of the same name. This is meant to make migration from proto1 easier; new code should avoid fields named “descriptor”.

deprecated

Type: optional bool

Is this message deprecated? Depending on the target platform, this can emit Deprecated annotations for the message, or it will be completely ignored; in the very least, this is a formalization for deprecating messages.

map_entry

Type: optional bool

Whether the message is an automatically generated map entry type for the maps field.

For maps fields: map<KeyType, ValueType> map_field = 1; The parsed descriptor looks like: message MapFieldEntry { option map_entry = true; optional KeyType key = 1; optional ValueType value = 2; } repeated MapFieldEntry map_field = 1;

Implementations may choose not to generate the map_entry=true message, but use a native map in the target language to hold the keys and values. The reflection APIs in such implementations still need to work as if the field is a repeated message field.

NOTE: Do not set the option in .proto files. Always use the maps syntax instead. The option should only be implicitly set by the proto compiler parser.

uninterpreted_option

Type: repeated google.protobuf.UninterpretedOption

The parser stores options it doesn’t recognize here. See above.


FieldOptions

Fields

ctype

Type: UNHANDLED | TYPE

The ctype option instructs the C++ code generator to use a different representation of the field than it normally would. See the specific options below. This option is not yet implemented in the open source release – sorry, we’ll try to include it in a future version!

packed

Type: optional bool

The packed option can be enabled for repeated primitive fields to enable a more efficient representation on the wire. Rather than repeatedly writing the tag and type for each element, the entire array is encoded as a single length-delimited blob. In proto3, only explicit setting it to false will avoid using packed encoding.

jstype

Type: UNHANDLED | TYPE

The jstype option determines the JavaScript type used for values of the field. The option is permitted only for 64 bit integral and fixed types (int64, uint64, sint64, fixed64, sfixed64). A field with jstype JS_STRING is represented as JavaScript string, which avoids loss of precision that can happen when a large value is converted to a floating point JavaScript. Specifying JS_NUMBER for the jstype causes the generated JavaScript code to use the JavaScript “number” type. The behavior of the default option JS_NORMAL is implementation dependent.

This option is an enum to permit additional types to be added, e.g. goog.math.Integer.

lazy

Type: optional bool

Should this field be parsed lazily? Lazy applies only to message-type fields. It means that when the outer message is initially parsed, the inner message’s contents will not be parsed but instead stored in encoded form. The inner message will actually be parsed when it is first accessed.

This is only a hint. Implementations are free to choose whether to use eager or lazy parsing regardless of the value of this option. However, setting this option true suggests that the protocol author believes that using lazy parsing on this field is worth the additional bookkeeping overhead typically needed to implement it.

This option does not affect the public interface of any generated code; all method signatures remain the same. Furthermore, thread-safety of the interface is not affected by this option; const methods remain safe to call from multiple threads concurrently, while non-const methods continue to require exclusive access.

Note that implementations may choose not to check required fields within a lazy sub-message. That is, calling IsInitialized() on the outer message may return true even if the inner message has missing required fields. This is necessary because otherwise the inner message would have to be parsed in order to perform the check, defeating the purpose of lazy parsing. An implementation which chooses not to check required fields must be consistent about it. That is, for any particular sub-message, the implementation must either always check its required fields, or never check its required fields, regardless of whether or not the message has been parsed.

deprecated

Type: optional bool

Is this field deprecated? Depending on the target platform, this can emit Deprecated annotations for accessors, or it will be completely ignored; in the very least, this is a formalization for deprecating fields.

weak

Type: optional bool

For Google-internal migration only. Do not use.

uninterpreted_option

Type: repeated google.protobuf.UninterpretedOption

The parser stores options it doesn’t recognize here. See above.


OneofOptions

Fields

uninterpreted_option

Type: repeated google.protobuf.UninterpretedOption

The parser stores options it doesn’t recognize here. See above.


EnumOptions

Fields

allow_alias

Type: optional bool

Set this option to true to allow mapping different tag names to the same value.

deprecated

Type: optional bool

Is this enum deprecated? Depending on the target platform, this can emit Deprecated annotations for the enum, or it will be completely ignored; in the very least, this is a formalization for deprecating enums.

uninterpreted_option

Type: repeated google.protobuf.UninterpretedOption

The parser stores options it doesn’t recognize here. See above.


EnumValueOptions

Fields

deprecated

Type: optional bool

Is this enum value deprecated? Depending on the target platform, this can emit Deprecated annotations for the enum value, or it will be completely ignored; in the very least, this is a formalization for deprecating enum values.

uninterpreted_option

Type: repeated google.protobuf.UninterpretedOption

The parser stores options it doesn’t recognize here. See above.


ServiceOptions

Fields

deprecated

Type: optional bool

Is this service deprecated? Depending on the target platform, this can emit Deprecated annotations for the service, or it will be completely ignored; in the very least, this is a formalization for deprecating services.

uninterpreted_option

Type: repeated google.protobuf.UninterpretedOption

The parser stores options it doesn’t recognize here. See above.


MethodOptions

Fields

deprecated

Type: optional bool

Is this method deprecated? Depending on the target platform, this can emit Deprecated annotations for the method, or it will be completely ignored; in the very least, this is a formalization for deprecating methods.

idempotency_level

Type: UNHANDLED | TYPE

uninterpreted_option

Type: repeated google.protobuf.UninterpretedOption

The parser stores options it doesn’t recognize here. See above.


UninterpretedOption

A message representing a option the parser does not recognize. This only appears in options protos created by the compiler::Parser class. DescriptorPool resolves these when building Descriptor objects. Therefore, options protos in descriptor objects (e.g. returned by Descriptor::options(), or produced by Descriptor::CopyTo()) will never have UninterpretedOptions in them.

Fields

name

Type: repeated google.protobuf.UninterpretedOption.NamePart

identifier_value

Type: optional string

The value of the uninterpreted option, in whatever type the tokenizer identified it as during parsing. Exactly one of these should be set.

positive_int_value

Type: optional uint64

negative_int_value

Type: optional int64

double_value

Type: optional double

string_value

Type: optional bytes

aggregate_value

Type: optional string


UninterpretedOption.NamePart

Fields

name_part

Type: string

is_extension

Type: bool


SourceCodeInfo

Encapsulates information about the original source file from which a FileDescriptorProto was generated.

Fields

location

Type: repeated google.protobuf.SourceCodeInfo.Location

A Location identifies a piece of source code in a .proto file which corresponds to a particular definition. This information is intended to be useful to IDEs, code indexers, documentation generators, and similar tools.

For example, say we have a file like: message Foo { optional string foo = 1; } Let’s look at just the field definition: optional string foo = 1; ^ ^^ ^^ ^ ^^^ a bc de f ghi We have the following locations: span path represents [a,i) [ 4, 0, 2, 0 ] The whole field definition. [a,b) [ 4, 0, 2, 0, 4 ] The label (optional). [c,d) [ 4, 0, 2, 0, 5 ] The type (string). [e,f) [ 4, 0, 2, 0, 1 ] The name (foo). [g,h) [ 4, 0, 2, 0, 3 ] The number (1).

Notes:

  • A location may refer to a repeated field itself (i.e. not to any particular index within it). This is used whenever a set of elements are logically enclosed in a single code segment. For example, an entire extend block (possibly containing multiple extension definitions) will have an outer location whose path refers to the “extensions” repeated field without an index.
  • Multiple locations may have the same path. This happens when a single logical declaration is spread out across multiple places. The most obvious example is the “extend” block again – there may be multiple extend blocks in the same scope, each of which will have the same path.
  • A location’s span is not always a subset of its parent’s span. For example, the “extendee” of an extension declaration appears at the beginning of the “extend” block and is shared by all extensions within the block.
  • Just because a location’s span is a subset of some other location’s span does not mean that it is a descendant. For example, a “group” defines both a type and a field in a single declaration. Thus, the locations corresponding to the type and field and their components will overlap.
  • Code which tries to interpret locations should probably be designed to ignore those that it doesn’t understand, as more types of locations could be recorded in the future.

SourceCodeInfo.Location

Fields

path

Type: repeated int32

span

Type: repeated int32

leading_comments

Type: optional string

trailing_comments

Type: optional string

leading_detached_comments

Type: repeated string


GeneratedCodeInfo

Describes the relationship between generated code and its original source file. A GeneratedCodeInfo message is associated with only one generated source file, but may contain references to different source .proto files.

Fields

annotation

Type: repeated google.protobuf.GeneratedCodeInfo.Annotation

An Annotation connects some span of text in generated code to an element of its generating .proto file.


GeneratedCodeInfo.Annotation

Fields

path

Type: repeated int32

source_file

Type: optional string

begin

Type: optional int32

end

Type: optional int32

Enums

Type

TYPE_DOUBLE

TYPE_FLOAT

TYPE_INT64

TYPE_UINT64

TYPE_INT32

TYPE_FIXED64

TYPE_FIXED32

TYPE_BOOL

TYPE_STRING

TYPE_GROUP

TYPE_MESSAGE

TYPE_BYTES

TYPE_UINT32

TYPE_ENUM

TYPE_SFIXED32

TYPE_SFIXED64

TYPE_SINT32

TYPE_SINT64


Label

LABEL_OPTIONAL

LABEL_REQUIRED

LABEL_REPEATED


OptimizeMode

SPEED

CODE_SIZE

LITE_RUNTIME


CType

STRING

CORD

STRING_PIECE


JSType

JS_NORMAL

JS_STRING

JS_NUMBER


IdempotencyLevel

IDEMPOTENCY_UNKNOWN

NO_SIDE_EFFECTS

IDEMPOTENT