Merge pull request #10 from filecoin-project/feat/mining-interface

WIP: thoughts on apis needed for mining process

chain/types.go

@@ -425,6 +425,10 @@ func (ts *TipSet) Height() uint64 {
 	return ts.height
 }
 
+func (ts *TipSet) Weight() uint64 {
+	panic("if tipsets are going to have weight on them, we need to wire that through")
+}
+
 func (ts *TipSet) Parents() []cid.Cid {
 	return ts.blks[0].Parents
 }

miner/miner.go

@@ -0,0 +1,161 @@
+package miner
+
+import (
+	"context"
+	"time"
+
+	logging "github.com/ipfs/go-log"
+	"github.com/pkg/errors"
+
+	chain "github.com/filecoin-project/go-lotus/chain"
+)
+
+var log = logging.Logger("miner")
+
+type api interface {
+	SubmitNewBlock(blk *chain.BlockMsg) error
+
+	// returns a set of messages that havent been included in the chain as of
+	// the given tipset
+	PendingMessages(base *chain.TipSet) ([]*chain.SignedMessage, error)
+
+	// Returns the best tipset for the miner to mine on top of.
+	// TODO: Not sure this feels right (including the messages api). Miners
+	// will likely want to have more control over exactly which blocks get
+	// mined on, and which messages are included.
+	GetBestTipset() (*chain.TipSet, error)
+
+	// returns the lookback randomness from the chain used for the election
+	GetChainRandomness(ts *chain.TipSet) ([]byte, error)
+
+	// create a block
+	// it seems realllllly annoying to do all the actions necessary to build a
+	// block through the API. so, we just add the block creation to the API
+	// now, all the 'miner' does is check if they win, and call create block
+	CreateBlock(base *chain.TipSet, tickets []chain.Ticket, eproof chain.ElectionProof, msgs []*chain.SignedMessage) (*chain.BlockMsg, error)
+}
+
+type Miner struct {
+	api api
+
+	// time between blocks, network parameter
+	Delay time.Duration
+
+	lastWork *MiningBase
+}
+
+func (m *Miner) Mine(ctx context.Context) {
+	for {
+		base, err := m.GetBestMiningCandidate()
+		if err != nil {
+			log.Errorf("failed to get best mining candidate: %s", err)
+			continue
+		}
+
+		b, err := m.mineOne(ctx, base)
+		if err != nil {
+			log.Errorf("mining block failed: %s", err)
+			continue
+		}
+
+		if b != nil {
+			if err := m.api.SubmitNewBlock(b); err != nil {
+				log.Errorf("failed to submit newly mined block: %s", err)
+			}
+		}
+	}
+}
+
+type MiningBase struct {
+	ts      *chain.TipSet
+	tickets []chain.Ticket
+}
+
+func (m *Miner) GetBestMiningCandidate() (*MiningBase, error) {
+	bts, err := m.api.GetBestTipset()
+	if err != nil {
+		return nil, err
+	}
+
+	if m.lastWork != nil {
+		if m.lastWork.ts.Equals(bts) {
+			return m.lastWork, nil
+		}
+
+		if bts.Weight() <= m.lastWork.ts.Weight() {
+			return m.lastWork, nil
+		}
+	}
+
+	return &MiningBase{
+		ts: bts,
+	}, nil
+}
+
+func (m *Miner) mineOne(ctx context.Context, base *MiningBase) (*chain.BlockMsg, error) {
+	log.Info("mine one")
+	ticket, err := m.scratchTicket(ctx, base)
+	if err != nil {
+		return nil, errors.Wrap(err, "scratching ticket failed")
+	}
+
+	win, proof, err := m.isWinnerNextRound(base)
+	if err != nil {
+		return nil, errors.Wrap(err, "failed to check if we win next round")
+	}
+
+	if !win {
+		m.submitNullTicket(base, ticket)
+		return nil, nil
+	}
+
+	b, err := m.createBlock(base, ticket, proof)
+	if err != nil {
+		return nil, errors.Wrap(err, "failed to create block")
+	}
+	log.Infof("created new block: %s", b.Cid())
+
+	return b, nil
+}
+
+func (m *Miner) submitNullTicket(base *MiningBase, ticket chain.Ticket) {
+	base.tickets = append(base.tickets, ticket)
+	m.lastWork = base
+}
+
+func (m *Miner) isWinnerNextRound(base *MiningBase) (bool, chain.ElectionProof, error) {
+	r, err := m.api.GetChainRandomness(base.ts)
+	if err != nil {
+		return false, nil, err
+	}
+
+	_ = r // TODO: use this to properly compute the election proof
+
+	return true, []byte("election prooooof"), nil
+}
+
+func (m *Miner) scratchTicket(ctx context.Context, base *MiningBase) (chain.Ticket, error) {
+	select {
+	case <-ctx.Done():
+		return nil, ctx.Err()
+	case <-time.After(m.Delay):
+	}
+
+	return []byte("this is a ticket"), nil
+}
+
+func (m *Miner) createBlock(base *MiningBase, ticket chain.Ticket, proof chain.ElectionProof) (*chain.BlockMsg, error) {
+
+	pending, err := m.api.PendingMessages(base.ts)
+	if err != nil {
+		return nil, errors.Wrapf(err, "failed to get pending messages")
+	}
+
+	// why even return this? that api call could just submit it for us
+	return m.api.CreateBlock(base.ts, append(base.tickets, ticket), proof, pending)
+}
+
+func (m *Miner) selectMessages(msgs []*chain.SignedMessage) []*chain.SignedMessage {
+	// TODO: filter and select 'best' message if too many to fit in one block
+	return msgs
+}