cmtLog

package
v0.5.0-alpha.3 Latest Latest
Warning

This package is not in the latest version of its module.

 Go to latest Published: Feb 13, 2023 License: Apache-2.0 Imports: 13 Imported by: 0

Documentation

Overview

package cmtLog is responsible for producing a log of chain's block decisions for a particular committee. The main tasks for this module are:

  • Track the head of the chain log for a committee.
  • Track which blocks are approved, pending or reverted.
  • Handle startup and recovery scenarios.

The algorithm at a high level:

> ON Startup: > Let prevLI <- TRY restoring the last started LogIndex ELSE 0 > MinLI <- prevLI + 1 > LogIndex.Start(prevLI) > TryProposeConsensus() > UPON AliasOutput (AO) {Confirmed | Rejected} by L1: > LocalView.Update(AO) > IF LocalView changed THEN > LogIndex.L1ReplacedBaseAliasOutput() > TryProposeConsensus() > ON ConsensusOutput/DONE (CD) > LocalView.Update(CD) > IF LocalView changed THEN > LogIndex.ConsensusOutput(CD.LogIndex) > TryProposeConsensus() > ON ConsensusOutput/SKIP (CS) > LogIndex.ConsensusOutput(CS.LogIndex) > TryProposeConsensus() > ON ConsensusTimeout (CT) > LogIndex.ConsensusTimeout(CT.LogIndex) > TryProposeConsensus() > ON Suspend: > Suspended <- TRUE > TryProposeConsensus() > ON Reception of ⟨NextLI, •⟩ message: > LogIndex.Receive(⟨NextLI, •⟩ message). > TryProposeConsensus() > PROCEDURE TryProposeConsensus: > IF ∧ LocalView.BaseAO ≠ NIL > ∧ LogIndex > ConsensusLI > ∧ LogIndex ≥ MinLI // ⇒ LogIndex ≠ NIL > ∧ ¬ Suspended > THEN > Persist LogIndex > ConsensusLI <- LogIndex > Propose LocalView.BaseAO for LogIndex > ELSE > Don't propose any consensus.

See `WaspChainRecovery.tla` for more precise specification.

Notes and invariants:

  • Here only a single consensus instance will be considered needed for this node at a time. Other instances may continue running, but their results will be ignored. That's because a consensus takes an input from the previous consensus output (the base alias ID and other parts that depend on it).
  • A consensus is started when we have new log index greater than that we have crashed with, and there is an alias output received.

## Summary.

Inputs expected:

  • Consensus: Start -> Done | Timeout.
  • AliasOutput: Confirmed | Rejected -> {}.
  • Suspend.

Messages exchanged:

  • NextLogIndex (private, between cmtLog instances).

Index

Constants

This section is empty.

Variables

View Source 
var ErrCmtLogStateNotFound = errors.New("errCmtLogStateNotFound")

Functions

func NewInputAliasOutputConfirmed 

func NewInputAliasOutputConfirmed(aliasOutput *isc.AliasOutputWithID) gpa.Input

func NewInputAliasOutputRejected 

func NewInputAliasOutputRejected(aliasOutput *isc.AliasOutputWithID) gpa.Input

func NewInputConsensusOutputDone 

func NewInputConsensusOutputDone(
	logIndex LogIndex,
	baseAliasOutputID iotago.OutputID,
	nextAliasOutput *isc.AliasOutputWithID,
) gpa.Input

This message is internal one, but should be sent by other components (e.g. consensus or the chain).

func NewInputConsensusOutputSkip 

func NewInputConsensusOutputSkip(
	logIndex LogIndex,
	baseAliasOutputID iotago.OutputID,
) gpa.Input

This message is internal one, but should be sent by other components (e.g. consensus or the chain).

func NewInputConsensusTimeout 

func NewInputConsensusTimeout(logIndex LogIndex) gpa.Input

This message is internal one, but should be sent by other components (e.g. consensus or the chain).

func NewInputSuspend 

func NewInputSuspend() gpa.Input

func UnmarshalMessage 

func UnmarshalMessage(data []byte) (gpa.Message, error)

Types

type CmtLog 

type CmtLog interface {
	AsGPA() gpa.GPA
}

Public interface for this algorithm.

func New 

func New(
	me gpa.NodeID,
	chainID isc.ChainID,
	dkShare tcrypto.DKShare,
	consensusStateRegistry ConsensusStateRegistry,
	nodeIDFromPubKey func(pubKey *cryptolib.PublicKey) gpa.NodeID,
	log *logger.Logger,
) (CmtLog, error)

Construct new node instance for this protocol.

> ON Startup: > Let prevLI <- TRY restoring the last started LogIndex ELSE 0 > MinLI <- prevLI + 1 > ...

type ConsensusStateRegistry 

type ConsensusStateRegistry interface {
	Get(chainID isc.ChainID, committeeAddress iotago.Address) (*State, error) // Can return ErrCmtLogStateNotFound.
	Set(chainID isc.ChainID, committeeAddress iotago.Address, state *State) error
}

Interface used to store and recover the existing persistent state. To be implemented by the registry.

type LogIndex 

type LogIndex uint32

LogIndex starts from 1. 0 is used as a nil value.

func MaxLogIndex 

func MaxLogIndex(a, b LogIndex) LogIndex

func NilLogIndex 

func NilLogIndex() LogIndex

func (LogIndex) AsUint32 

func (li LogIndex) AsUint32() uint32

func (LogIndex) Bytes 

func (li LogIndex) Bytes() []byte

func (LogIndex) IsNil 

func (li LogIndex) IsNil() bool

func (LogIndex) Next 

func (li LogIndex) Next() LogIndex

type Output 

type Output struct {
	// contains filtered or unexported fields
}

Output for this protocol indicates, what instance of a consensus is currently required to be run. The unique identifier here is the logIndex (there will be no different baseAliasOutputs for the same logIndex).

func (*Output) GetBaseAliasOutput 

func (o *Output) GetBaseAliasOutput() *isc.AliasOutputWithID

func (*Output) GetLogIndex 

func (o *Output) GetLogIndex() LogIndex

func (*Output) String 

func (o *Output) String() string

type State 

type State struct {
	LogIndex LogIndex
}

type VarLocalView 

type VarLocalView interface {
	//
	// Returns alias output to produce next transaction on, or nil if we should wait.
	// In the case of nil, we either wait for the first AO to receive, or we are
	// still recovering from a TX rejection.
	GetBaseAliasOutput() *isc.AliasOutputWithID
	//
	// Corresponds to the `ao_received` event in the specification.
	// Returns true, if the proposed BaseAliasOutput has changed.
	AliasOutputConfirmed(confirmed *isc.AliasOutputWithID) bool
	//
	// Corresponds to the `tx_rejected` event in the specification.
	// Returns true, if the proposed BaseAliasOutput has changed.
	AliasOutputRejected(rejected *isc.AliasOutputWithID) bool
	//
	// Corresponds to the `tx_posted` event in the specification.
	// Returns true, if the proposed BaseAliasOutput has changed.
	ConsensusOutputDone(consumed iotago.OutputID, published *isc.AliasOutputWithID) bool
	//
	// Support functions.
	StatusString() string
}

func NewVarLocalView 

func NewVarLocalView() VarLocalView

type VarLogIndex 

type VarLogIndex interface {
	// Returns the latest agreed LI/AO.
	// There is no output value, if LogIndex=⊥.
	Value() (LogIndex, *isc.AliasOutputWithID)
	// Consensus terminated with either with DONE or SKIP.
	// NextAO is the same as before for the SKIP case.
	// NextAO = nil means we don't know the latest AO from L1 (either startup or reject of a chain is happening).
	ConsensusOutputReceived(consensusLI LogIndex, consensusStatus cons.OutputStatus, nextBaseAO *isc.AliasOutputWithID) gpa.OutMessages
	// Consensus decided, that its maybe time to attempt another run.
	// The timeout-ed consensus will be still running, so they will race for the result.
	ConsensusTimeoutReceived(consensusLI LogIndex) gpa.OutMessages
	// This might get a nil alias output in the case when a TX gets rejected and it was not the latest TX in the active chain.
	// NextAO = nil means we don't know the latest AO from L1 (either startup or reject of a chain is happening).
	L1ReplacedBaseAliasOutput(nextBaseAO *isc.AliasOutputWithID) gpa.OutMessages
	// Messages are exchanged, so this function handles them.
	MsgNextLogIndexReceived(msg *msgNextLogIndex) gpa.OutMessages
}

func NewVarLogIndex 

func NewVarLogIndex(
	nodeIDs []gpa.NodeID,
	n int,
	f int,
	persistedLI LogIndex,
	outputCB func(li LogIndex, ao *isc.AliasOutputWithID),
	log *logger.Logger,
) VarLogIndex

> ON Init(persistedLI): > latestAO ← ⊥ > proposedLI, agreedLI ← 0 > minLI ← persistedLI + 1 > maxPeerLIs ← ∅

Source Files

View all Source files

Jump to

Keyboard shortcuts

? : This menu
/ : Search site
f or F : Jump to
y or Y : Canonical URL
go.dev uses cookies from Google to deliver and enhance the quality of its services and to analyze traffic. Learn more.