Package org.infinispan.protostream

Interface UnknownFieldSet

All Superinterfaces:

Serializable

All Known Implementing Classes:

UnknownFieldSetImpl

public interface UnknownFieldSet
extends Serializable

UnknownFieldSet keeps track of fields seen during parsing of a protocol message but whose field numbers are not recognized by the user provided marshallers (are never requested by them). This usually occurs when new fields are added to a message type and then messages containing those fields are read by old versions of software that was built before the new fields were added.

This is also used to handle the case when fields are requested in a different order than they were written to the stream (lowers performance but still works). In this case all fields that are encountered while parsing the stream up to the point where the requested field is finally encountered are cached/buffered in this data structure.

Instances of UnknownFieldSet are never to be created by the user. They will be created by the library and handed over to the message marshaller via the UnknownFieldSetHandler mechanism. Instances are serializable according to Java serialization.

Since:

1.0

Author:

[email protected]

Method Summary

Modifier and Type	Method	Description
<A> A	consumeTag(int tag)	Reads and removes a field value from the set.
boolean	hasTag(int tag)	Checks if a tag is present.
boolean	isEmpty()	Checks if there are any fields in this set.
void	putVarintField(int tag, int value)	Convenience method for merging a new field containing a single varint value.
void	readAllFields(RawProtoStreamReader input)	Parse an entire message from input and merge its fields into this set.
boolean	readSingleField(int tag, RawProtoStreamReader input)	Parse a single field from input and merge it into this set.
void	writeTo(RawProtoStreamWriter output)	Writes all fields from this set to the output stream.

Method Detail

isEmpty

boolean isEmpty()

Checks if there are any fields in this set.

readAllFields

void readAllFields(RawProtoStreamReader input)
            throws IOException

Parse an entire message from input and merge its fields into this set.

Throws:

IOException

readSingleField

boolean readSingleField(int tag,
                        RawProtoStreamReader input)
                 throws IOException

Parse a single field from input and merge it into this set.

Parameters:

tag - The field's tag number, which was already parsed (tag contains both field id and wire type).

Returns:

false if the tag is an end group tag.

Throws:

IOException

putVarintField

void putVarintField(int tag,
                    int value)

Convenience method for merging a new field containing a single varint value. This is used in particular when an unknown enum value is encountered.

Parameters:

tag - the field tag (containing both field id and wire type).

writeTo

void writeTo(RawProtoStreamWriter output)
      throws IOException

Writes all fields from this set to the output stream.

Throws:

IOException

consumeTag

<A> A consumeTag(int tag)

Reads and removes a field value from the set. The field is specified as a tag value composed of the numeric id of the field and the wire type. It's possible that the tag has repeated values; in that case the first one is returned.

Type Parameters:

A - The expected type of the tag value.

Parameters:

tag - the field tag (containing both field id and wire type).

Returns:

the first seen value or null if the tag was not found.

hasTag

boolean hasTag(int tag)

Checks if a tag is present.

Parameters:

tag - the field tag (containing both field id and wire type).

Returns:

true if present, false otherwise