Documentation ¶
Index ¶
Constants ¶
This section is empty.
Variables ¶
var ErrNoStore = errors.New("result store not found within batch context")
ErrNoStore is an error returned by components attempting to write a message batch to a ResultStore but are unable to locate the store within the batch context.
Functions ¶
func AddResultStore ¶
func AddResultStore(msg message.Batch, store ResultStore)
AddResultStore sets a result store within the context of the provided message that allows a roundtrip.Writer or any other component to propagate a resulting message back to the origin.
func SetAsResponse ¶
SetAsResponse takes a mutated message and stores it as a response message, this action fails if the message does not contain a valid ResultStore within its context.
Types ¶
type ResultStore ¶
type ResultStore interface { // Add a message to the store. The message will be deep copied and have its // context wiped before storing, and is therefore safe to add even when // ownership of the message is about to be yielded. Add(msg message.Batch) // Get the stored slice of messages. Get() []message.Batch // Clear any currently stored messages. Clear() }
ResultStore is a type designed to be propagated along with a message as a way for an output destination to store the final version of the message payload as it saw it.
It is intended that this structure is placed within a message via an attached context, usually under the key 'result_store'.
func NewResultStore ¶
func NewResultStore() ResultStore
NewResultStore returns an implementation of ResultStore.
type ResultStoreKeyType ¶
type ResultStoreKeyType int
ResultStoreKeyType is the recommended type of a context key for adding ResultStores to a message context.
const ResultStoreKey ResultStoreKeyType = iota
ResultStoreKey is the recommended key value for adding ResultStores to a message context.
type Tracked ¶
type Tracked struct {
// contains filtered or unexported fields
}
Tracked is a transaction type that adds identifying tags to messages such that an error returned resulting from multiple transaction messages can be reduced.
func NewTracked ¶
NewTracked creates a transaction from a message batch and a response channel. The message is tagged with an identifier for the transaction, and if an error is returned from a downstream component that merged messages from other transactions the tag can be used in order to determine whether the message owned by this transaction succeeded.