package messageset

Import Path
	google.golang.org/protobuf/internal/encoding/messageset (on go.dev)

Dependency Relation
	imports 4 packages, and imported by 5 packages


Involved Source Files

	
		Package messageset encodes and decodes the obsolete MessageSet wire format.


Package-Level Functions (total 9, all are exported)


	
		AppendFieldEnd appends the trailing end group marker for a MessageSet item field.


	
		AppendFieldStart appends the start of a MessageSet item field containing
		an extension with the given number. The caller must add the message
		subfield (including the tag).


	
		AppendUnknown appends unknown fields to b in MessageSet format.

		For historic reasons, unresolved items in a MessageSet are stored in a
		message's unknown fields section in non-MessageSet format. That is, an
		unknown item with typeID T and value V appears in the unknown fields as
		a field with number T and value V.

		This function converts the unknown fields back into MessageSet form.


	
		ConsumeFieldValue parses b as a MessageSet item field value until and including
		the trailing end group marker. It assumes the start group tag has already been parsed.
		It returns the contents of the type_id and message subfields and the total
		item length.

		If wantLen is true, the returned message value includes the length prefix.


	
		IsMessageSet returns whether the message uses the MessageSet wire format.


	
		IsMessageSetExtension reports this field properly extends a MessageSet.


	
		SizeField returns the size of a MessageSet item field containing an extension
		with the given field number, not counting the contents of the message subfield.


	
		SizeUnknown returns the size of an unknown fields section in MessageSet format.

		See AppendUnknown.


	
		Unmarshal parses a MessageSet.

		It calls fn with the type ID and value of each item in the MessageSet.
		Unknown fields are discarded.

		If wantLen is true, the item values include the varint length prefix.
		This is ugly, but simplifies the fast-path decoder in internal/impl.




Package-Level Constants (total 4, all are exported)


	
		ExtensionName is the field name for extensions of MessageSet.

		A valid MessageSet extension must be of the form:
			message MyMessage {
				extend proto2.bridge.MessageSet {
					optional MyMessage message_set_extension = 1234;
				}
				...
			}


	
		The MessageSet wire format is equivalent to a message defined as follows,
		where each Item defines an extension field with a field number of 'type_id'
		and content of 'message'. MessageSet extensions must be non-repeated message
		fields.

			message MessageSet {
				repeated group Item = 1 {
					required int32 type_id = 2;
					required string message = 3;
				}
			}


	
		The MessageSet wire format is equivalent to a message defined as follows,
		where each Item defines an extension field with a field number of 'type_id'
		and content of 'message'. MessageSet extensions must be non-repeated message
		fields.

			message MessageSet {
				repeated group Item = 1 {
					required int32 type_id = 2;
					required string message = 3;
				}
			}


	
		The MessageSet wire format is equivalent to a message defined as follows,
		where each Item defines an extension field with a field number of 'type_id'
		and content of 'message'. MessageSet extensions must be non-repeated message
		fields.

			message MessageSet {
				repeated group Item = 1 {
					required int32 type_id = 2;
					required string message = 3;
				}
			}