Inter Step Buffer (isb)

Data payload.

Watermark Barrier.

DefaultPartitionIdx Default partition index.

Body is the body of the message.

BufferReadErr when we cannot read from the buffer.

BufferWriteErr when we cannot write to the buffer because of a full buffer.

Header is the header of the message.

Message is inter step message.

MessageAckErr is for acknowledgement errors.

MessageID is the message ID of the message which is used for exactly-once-semantics.

MessageInfo is the message information window of the payload.

MessageMetadata is the metadata of the message.

MessageReadErr is associated with message read errors.

MessageWriteErr is associated with message write errors.

NonRetryableBufferWriteErr indicates that the buffer is full and the writer, based on user specification, decides to not retry.

ReadMessage is the message read from the buffer.

ReadWriteMessagePair is a pair of ReadMessage and a list of WriteMessage which will be used to map the read message to a list of write messages that the udf returns.

WriteMessage is a wrapper for an isb message with tag information which will be used for conditional forwarding.

BufferReader is the buffer from which we are reading.

BufferReaderInformation has information regarding the buffer we are reading from.

BufferWriter is the buffer to which we are writing.

BufferWriterInformation has information regarding the buffer we are writing to.

LagReader is the interface that wraps the Pending method and GetName method.

Offset is an interface used in the ReadMessage referencing offset information.

MessageKind represents the message type of the payload.

SimpleIntOffset is an Offset convenient function for implementations without needing AckIt() when offset is a int64.

SimpleStringOffset is an Offset convenient function for implementations without needing AckIt() when offset is a string.