path: root/core/interfaces.go

// Copyright 2018 The dexon-consensus Authors
// This file is part of the dexon-consensus library.
//
// The dexon-consensus library is free software: you can redistribute it
// and/or modify it under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation, either version 3 of the License,
// or (at your option) any later version.
//
// The dexon-consensus library is distributed in the hope that it will be
// useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
// General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the dexon-consensus library. If not, see
// <http://www.gnu.org/licenses/>.

package core

import (
    "time"

    "github.com/dexon-foundation/dexon-consensus/common"
    "github.com/dexon-foundation/dexon-consensus/core/crypto"
    "github.com/dexon-foundation/dexon-consensus/core/types"
    typesDKG "github.com/dexon-foundation/dexon-consensus/core/types/dkg"
)

// Application describes the application interface that interacts with DEXON
// consensus core.
type Application interface {
    // PreparePayload is called when consensus core is preparing a block.
    PreparePayload(position types.Position) ([]byte, error)

    // PrepareWitness will return the witness data no lower than consensusHeight.
    PrepareWitness(consensusHeight uint64) (types.Witness, error)

    // VerifyBlock verifies if the block is valid.
    VerifyBlock(block *types.Block) types.BlockVerifyStatus

    // BlockConfirmed is called when a block is confirmed and added to lattice.
    BlockConfirmed(block types.Block)

    // BlockDelivered is called when a block is added to the compaction chain.
    BlockDelivered(hash common.Hash, position types.Position, rand []byte)
}

// Debug describes the application interface that requires
// more detailed consensus execution.
type Debug interface {
    // BlockReceived is called when the block received in agreement.
    BlockReceived(common.Hash)
    // BlockReady is called when the block's randomness is ready.
    BlockReady(common.Hash)
}

// Network describs the network interface that interacts with DEXON consensus
// core.
type Network interface {
    // PullBlocks tries to pull blocks from the DEXON network.
    PullBlocks(hashes common.Hashes)

    // PullVotes tries to pull votes from the DEXON network.
    PullVotes(position types.Position)

    // BroadcastVote broadcasts vote to all nodes in DEXON network.
    BroadcastVote(vote *types.Vote)

    // BroadcastBlock broadcasts block to all nodes in DEXON network.
    BroadcastBlock(block *types.Block)

    // BroadcastAgreementResult broadcasts agreement result to DKG set.
    BroadcastAgreementResult(randRequest *types.AgreementResult)

    // SendDKGPrivateShare sends PrivateShare to a DKG participant.
    SendDKGPrivateShare(pub crypto.PublicKey, prvShare *typesDKG.PrivateShare)

    // BroadcastDKGPrivateShare broadcasts PrivateShare to all DKG participants.
    BroadcastDKGPrivateShare(prvShare *typesDKG.PrivateShare)

    // BroadcastDKGPartialSignature broadcasts partialSignature to all
    // DKG participants.
    BroadcastDKGPartialSignature(psig *typesDKG.PartialSignature)

    // ReceiveChan returns a channel to receive messages from DEXON network.
    ReceiveChan() <-chan types.Msg

    // ReportBadPeerChan returns a channel to report bad peer.
    ReportBadPeerChan() chan<- interface{}
}

// Governance interface specifies interface to control the governance contract.
// Note that there are a lot more methods in the governance contract, that this
// interface only define those that are required to run the consensus algorithm.
type Governance interface {
    // Configuration returns the configuration at a given round.
    // Return the genesis configuration if round == 0.
    Configuration(round uint64) *types.Config

    // CRS returns the CRS for a given round. Return the genesis CRS if
    // round == 0.
    //
    // The CRS returned is the proposed or latest reseted one, it would be
    // changed later if corresponding DKG set failed to generate group public
    // key.
    CRS(round uint64) common.Hash

    // Propose a CRS of round.
    ProposeCRS(round uint64, signedCRS []byte)

    // NodeSet returns the node set at a given round.
    // Return the genesis node set if round == 0.
    NodeSet(round uint64) []crypto.PublicKey

    // Get the begin height of a round.
    GetRoundHeight(round uint64) uint64

    //// DKG-related methods.

    // AddDKGComplaint adds a DKGComplaint.
    AddDKGComplaint(complaint *typesDKG.Complaint)

    // DKGComplaints gets all the DKGComplaints of round.
    DKGComplaints(round uint64) []*typesDKG.Complaint

    // AddDKGMasterPublicKey adds a DKGMasterPublicKey.
    AddDKGMasterPublicKey(masterPublicKey *typesDKG.MasterPublicKey)

    // DKGMasterPublicKeys gets all the DKGMasterPublicKey of round.
    DKGMasterPublicKeys(round uint64) []*typesDKG.MasterPublicKey

    // AddDKGMPKReady adds a DKG ready message.
    AddDKGMPKReady(ready *typesDKG.MPKReady)

    // IsDKGMPKReady checks if DKG's master public key preparation is ready.
    IsDKGMPKReady(round uint64) bool

    // AddDKGFinalize adds a DKG finalize message.
    AddDKGFinalize(final *typesDKG.Finalize)

    // IsDKGFinal checks if DKG is final.
    IsDKGFinal(round uint64) bool

    // AddDKGSuccess adds a DKG success message.
    AddDKGSuccess(success *typesDKG.Success)

    // IsDKGSuccess checks if DKG is success.
    IsDKGSuccess(round uint64) bool

    // ReportForkVote reports a node for forking votes.
    ReportForkVote(vote1, vote2 *types.Vote)

    // ReportForkBlock reports a node for forking blocks.
    ReportForkBlock(block1, block2 *types.Block)

    // ResetDKG resets latest DKG data and propose new CRS.
    ResetDKG(newSignedCRS []byte)

    // DKGResetCount returns the reset count for DKG of given round.
    DKGResetCount(round uint64) uint64
}

// Ticker define the capability to tick by interval.
type Ticker interface {
    // Tick would return a channel, which would be triggered until next tick.
    Tick() <-chan time.Time

    // Stop the ticker.
    Stop()

    // Retart the ticker and clear all internal data.
    Restart()
}

// Recovery interface for interacting with recovery information.
type Recovery interface {
    // ProposeSkipBlock proposes a skip block.
    ProposeSkipBlock(height uint64) error

    // Votes gets the number of votes of given height.
    Votes(height uint64) (uint64, error)
}