Order Chain at Hyper ledger Fabric

OrderChain.go

// Chain defines a way to inject messages for ordering.
// Note, that in order to allow flexibility in the implementation, it is the responsibility of the implementer
// to take the ordered messages, send them through the blockcutter.Receiver supplied via HandleChain to cut blocks,
// and ultimately write the ledger also supplied via HandleChain.  This design allows for two primary flows
// 1. Messages are ordered into a stream, the stream is cut into blocks, the blocks are committed (solo, kafka)
// 2. Messages are cut into blocks, the blocks are ordered, then the blocks are committed (sbft)
type Chain interface {
	// Order accepts a message which has been processed at a given configSeq.
	// If the configSeq advances, it is the responsibility of the consenter
	// to revalidate and potentially discard the message
	// The consenter may return an error, indicating the message was not accepted
	Order(env *cb.Envelope, configSeq uint64) error

	// Configure accepts a message which reconfigures the channel and will
	// trigger an update to the configSeq if committed.  The configuration must have
	// been triggered by a ConfigUpdate message. If the config sequence advances,
	// it is the responsibility of the consenter to recompute the resulting config,
	// discarding the message if the reconfiguration is no longer valid.
	// The consenter may return an error, indicating the message was not accepted
	Configure(config *cb.Envelope, configSeq uint64) error

	// WaitReady blocks waiting for consenter to be ready for accepting new messages.
	// This is useful when consenter needs to temporarily block ingress messages so
	// that in-flight messages can be consumed. It could return error if consenter is
	// in erroneous states. If this blocking behavior is not desired, consenter could
	// simply return nil.
	WaitReady() error

	// Errored returns a channel which will close when an error has occurred.
	// This is especially useful for the Deliver client, who must terminate waiting
	// clients when the consenter is not up to date.
	Errored() <-chan struct{}

	// Start should allocate whatever resources are needed for staying up to date with the chain.
	// Typically, this involves creating a thread which reads from the ordering source, passes those
	// messages to a block cutter, and writes the resulting blocks to the ledger.
	Start()

	// Halt frees the resources which were allocated for this Chain.
	Halt()
}