diff options
Diffstat (limited to 'vendor/github.com/dexon-foundation/dexon-consensus/core/total-ordering.go')
| -rw-r--r-- | vendor/github.com/dexon-foundation/dexon-consensus/core/total-ordering.go | 1321 |
1 files changed, 0 insertions, 1321 deletions
diff --git a/vendor/github.com/dexon-foundation/dexon-consensus/core/total-ordering.go b/vendor/github.com/dexon-foundation/dexon-consensus/core/total-ordering.go deleted file mode 100644 index 2e2158e7c..000000000 --- a/vendor/github.com/dexon-foundation/dexon-consensus/core/total-ordering.go +++ /dev/null @@ -1,1321 +0,0 @@ -// 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 ( - "errors" - "fmt" - "math" - "sort" - "sync" - "time" - - "github.com/dexon-foundation/dexon-consensus/common" - "github.com/dexon-foundation/dexon-consensus/core/types" -) - -const ( - infinity uint64 = math.MaxUint64 -) - -const ( - // TotalOrderingModeError returns mode error. - TotalOrderingModeError uint32 = iota - // TotalOrderingModeNormal returns mode normal. - TotalOrderingModeNormal - // TotalOrderingModeEarly returns mode early. - TotalOrderingModeEarly - // TotalOrderingModeFlush returns mode flush. - TotalOrderingModeFlush -) - -var ( - // ErrInvalidDAG is reported when block subbmitted to totalOrdering - // didn't form a DAG. - ErrInvalidDAG = errors.New("invalid dag") - // ErrFutureRoundDelivered means some blocks from later rounds are - // delivered, this means program error. - ErrFutureRoundDelivered = errors.New("future round delivered") - // ErrBlockFromPastRound means we receive some block from past round. - ErrBlockFromPastRound = errors.New("block from past round") - // ErrTotalOrderingHangs means total ordering hangs somewhere. - ErrTotalOrderingHangs = errors.New("total ordering hangs") - // ErrForwardAck means a block acking some blocks from newer round. - ErrForwardAck = errors.New("forward ack") - // ErrUnexpected means general (I'm lazy) errors. - ErrUnexpected = errors.New("unexpected") - // ErrTotalOrderingPhiRatio means invalid phi ratio - ErrTotalOrderingPhiRatio = errors.New("invalid total ordering phi ratio") -) - -// totalOrderingConfig is the configuration for total ordering. -type totalOrderingConfig struct { - roundBasedConfig - // k represents the k in 'k-level total ordering'. - // In short, only block height equals to (global minimum height + k) - // would be taken into consideration. - k uint64 - - // phi is a const to control how strong the leading preceding block - // should be. - phi uint64 - - numChains uint32 - isFlushRequired bool -} - -func (config *totalOrderingConfig) fromConfig(round uint64, cfg *types.Config) { - config.k = uint64(cfg.K) - config.numChains = cfg.NumChains - config.phi = uint64(float32(cfg.NumChains-1)*cfg.PhiRatio + 1) - config.setupRoundBasedFields(round, cfg) -} - -func newTotalOrderingConfig( - prev *totalOrderingConfig, cur *types.Config) *totalOrderingConfig { - c := &totalOrderingConfig{} - c.fromConfig(prev.roundID+1, cur) - c.setRoundBeginTime(prev.roundEndTime) - prev.isFlushRequired = c.k != prev.k || - c.phi != prev.phi || - c.numChains != prev.numChains - return c -} - -// totalOrderingWinRecord caches the comparison of candidates calculated by -// their height vector. -type totalOrderingWinRecord struct { - wins []int8 - count uint -} - -func (rec *totalOrderingWinRecord) reset() { - rec.count = 0 - for idx := range rec.wins { - rec.wins[idx] = 0 - } -} - -func newTotalOrderingWinRecord(numChains uint32) *totalOrderingWinRecord { - return &totalOrderingWinRecord{ - wins: make([]int8, numChains), - count: 0, - } -} - -// grade implements the 'grade' potential function in algorithm. -func (rec *totalOrderingWinRecord) grade( - numChains uint32, phi uint64, globalAnsLength uint64) int { - if uint64(rec.count) >= phi { - return 1 - } else if uint64(rec.count) < phi-uint64(numChains)+globalAnsLength { - return 0 - } else { - return -1 - } -} - -// totalOrderingHeightRecord records: -// - the minimum height of block which acks this block. -// - the count of blocks acking this block. -type totalOrderingHeightRecord struct{ minHeight, count uint64 } - -// totalOrderingCache caches objects for reuse and not being colloected by GC. -// Each cached target has "get-" and "put-" functions for getting and reusing -// of objects. -type totalOrderingCache struct { - ackedStatus [][]*totalOrderingHeightRecord - heightVectors [][]uint64 - winRecords [][]*totalOrderingWinRecord - winRecordPool sync.Pool - ackedVectors []map[common.Hash]struct{} - numChains uint32 -} - -// newTotalOrderingObjectCache constructs an totalOrderingCache instance. -func newTotalOrderingObjectCache(numChains uint32) *totalOrderingCache { - return &totalOrderingCache{ - winRecordPool: sync.Pool{ - New: func() interface{} { - return newTotalOrderingWinRecord(numChains) - }, - }, - numChains: numChains, - } -} - -// resize makes sure internal storage of totalOrdering instance can handle -// maximum possible numChains in future configs. -func (cache *totalOrderingCache) resize(numChains uint32) { - // Basically, everything in cache needs to be cleaned. - if cache.numChains >= numChains { - return - } - cache.ackedStatus = nil - cache.heightVectors = nil - cache.winRecords = nil - cache.ackedVectors = nil - cache.numChains = numChains - cache.winRecordPool = sync.Pool{ - New: func() interface{} { - return newTotalOrderingWinRecord(numChains) - }, - } -} - -func (cache *totalOrderingCache) getAckedStatus() ( - acked []*totalOrderingHeightRecord) { - - if len(cache.ackedStatus) == 0 { - acked = make([]*totalOrderingHeightRecord, cache.numChains) - for idx := range acked { - acked[idx] = &totalOrderingHeightRecord{count: 0} - } - } else { - acked = cache.ackedStatus[len(cache.ackedStatus)-1] - cache.ackedStatus = cache.ackedStatus[:len(cache.ackedStatus)-1] - // Reset acked status. - for idx := range acked { - acked[idx].count = 0 - } - } - return -} - -func (cache *totalOrderingCache) putAckedStatus( - acked []*totalOrderingHeightRecord) { - // If the recycled objects supports lower numChains than we required, - // don't recycle it. - if uint32(len(acked)) != cache.numChains { - return - } - cache.ackedStatus = append(cache.ackedStatus, acked) -} - -func (cache *totalOrderingCache) getWinRecord() ( - win *totalOrderingWinRecord) { - win = cache.winRecordPool.Get().(*totalOrderingWinRecord) - win.reset() - return -} - -func (cache *totalOrderingCache) putWinRecord(win *totalOrderingWinRecord) { - if win == nil { - return - } - // If the recycled objects supports lower numChains than we required, - // don't recycle it. - if uint32(len(win.wins)) != cache.numChains { - return - } - cache.winRecordPool.Put(win) -} - -func (cache *totalOrderingCache) getHeightVector() (hv []uint64) { - if len(cache.heightVectors) == 0 { - hv = make([]uint64, cache.numChains) - } else { - hv = cache.heightVectors[len(cache.heightVectors)-1] - cache.heightVectors = cache.heightVectors[:len(cache.heightVectors)-1] - } - for idx := range hv { - hv[idx] = infinity - } - return -} - -func (cache *totalOrderingCache) putHeightVector(hv []uint64) { - if uint32(len(hv)) != cache.numChains { - return - } - cache.heightVectors = append(cache.heightVectors, hv) -} - -func (cache *totalOrderingCache) getWinRecords() (w []*totalOrderingWinRecord) { - if len(cache.winRecords) == 0 { - w = make([]*totalOrderingWinRecord, cache.numChains) - } else { - w = cache.winRecords[len(cache.winRecords)-1] - cache.winRecords = cache.winRecords[:len(cache.winRecords)-1] - for idx := range w { - w[idx] = nil - } - } - return -} - -func (cache *totalOrderingCache) putWinRecords(w []*totalOrderingWinRecord) { - if uint32(len(w)) != cache.numChains { - return - } - cache.winRecords = append(cache.winRecords, w) -} - -func (cache *totalOrderingCache) getAckedVector() ( - acked map[common.Hash]struct{}) { - if len(cache.ackedVectors) == 0 { - acked = make(map[common.Hash]struct{}) - } else { - acked, cache.ackedVectors = - cache.ackedVectors[len(cache.ackedVectors)-1], - cache.ackedVectors[:len(cache.ackedVectors)-1] - for k := range acked { - delete(acked, k) - } - } - return -} - -func (cache *totalOrderingCache) putAckedVector( - acked map[common.Hash]struct{}) { - if acked != nil { - cache.ackedVectors = append(cache.ackedVectors, acked) - } -} - -// totalOrderingCandidateInfo stores proceding status for a candidate including -// - acked status as height records, which keeps the number of blocks from other -// chains acking this candidate. -// - cached height vector, which valids height based on K-level used for -// comparison in 'grade' function. -// - cached result of grade function to other candidates. -// -// Height Record: -// When block A acks block B, all blocks proposed from the same proposer as -// block A with higher height also acks block B. Thus records below is needed -// - the minimum height of acking block from that proposer -// - count of acking blocks from that proposer -// to repsent the acking status for block A. -type totalOrderingCandidateInfo struct { - ackedStatus []*totalOrderingHeightRecord - cachedHeightVector []uint64 - winRecords []*totalOrderingWinRecord - hash common.Hash -} - -// newTotalOrderingCandidateInfo creates an totalOrderingCandidateInfo instance. -func newTotalOrderingCandidateInfo( - candidateHash common.Hash, - objCache *totalOrderingCache) *totalOrderingCandidateInfo { - return &totalOrderingCandidateInfo{ - ackedStatus: objCache.getAckedStatus(), - winRecords: objCache.getWinRecords(), - hash: candidateHash, - } -} - -// clean clears information related to another candidate, which should be called -// when that candidate is selected in deliver set. -func (v *totalOrderingCandidateInfo) clean(otherCandidateChainID uint32) { - v.winRecords[otherCandidateChainID] = nil -} - -// recycle recycles objects for later usage, this eases GC's work. -func (v *totalOrderingCandidateInfo) recycle(objCache *totalOrderingCache) { - if v.winRecords != nil { - for _, win := range v.winRecords { - objCache.putWinRecord(win) - } - objCache.putWinRecords(v.winRecords) - } - if v.cachedHeightVector != nil { - objCache.putHeightVector(v.cachedHeightVector) - } - objCache.putAckedStatus(v.ackedStatus) -} - -// addBlock would update totalOrderingCandidateInfo, it's caller's duty -// to make sure the input block acutally acking the target block. -func (v *totalOrderingCandidateInfo) addBlock(b *types.Block) error { - rec := v.ackedStatus[b.Position.ChainID] - if rec.count == 0 { - rec.minHeight = b.Position.Height - rec.count = 1 - } else { - if b.Position.Height <= rec.minHeight { - return ErrInvalidDAG - } - rec.count++ - } - return nil -} - -// getAckingNodeSetLength returns the size of acking node set. Only heights -// larger than "global minimum height + k" are counted. For example, global -// minimum acking height is 1 and k is 1, only block heights which is larger or -// equal to 2 are added into acking node set. -func (v *totalOrderingCandidateInfo) getAckingNodeSetLength( - global *totalOrderingCandidateInfo, - k uint64, - numChains uint32) (count uint64) { - - var rec *totalOrderingHeightRecord - for idx, gRec := range global.ackedStatus[:numChains] { - if gRec.count == 0 { - continue - } - rec = v.ackedStatus[idx] - if rec.count == 0 { - continue - } - if rec.minHeight+rec.count-1 >= gRec.minHeight+k { - count++ - } - } - return -} - -// updateAckingHeightVector would cached acking height vector. -// -// Only block height equals to (global minimum block height + k) would be -// taken into consideration. -func (v *totalOrderingCandidateInfo) updateAckingHeightVector( - global *totalOrderingCandidateInfo, - k uint64, - dirtyChainIDs []int, - objCache *totalOrderingCache) { - - var ( - idx int - gRec, rec *totalOrderingHeightRecord - ) - // The reason for not merging two loops is that the performance impact of map - // iteration is large if the size is large. Iteration of dirty chains is - // faster the map. - // TODO(mission): merge the code in this if/else if the performance won't be - // downgraded when adding a function for the shared part. - if v.cachedHeightVector == nil { - // Generate height vector from scratch. - v.cachedHeightVector = objCache.getHeightVector() - for idx, gRec = range global.ackedStatus { - if gRec.count <= k { - continue - } - rec = v.ackedStatus[idx] - if rec.count == 0 { - v.cachedHeightVector[idx] = infinity - } else if rec.minHeight <= gRec.minHeight+k { - // This check is sufficient to make sure the block height: - // - // gRec.minHeight + k - // - // would be included in this totalOrderingCandidateInfo. - v.cachedHeightVector[idx] = gRec.minHeight + k - } else { - v.cachedHeightVector[idx] = infinity - } - } - } else { - // Return the cached one, only update dirty fields. - for _, idx = range dirtyChainIDs { - gRec = global.ackedStatus[idx] - if gRec.count == 0 || gRec.count <= k { - v.cachedHeightVector[idx] = infinity - continue - } - rec = v.ackedStatus[idx] - if rec.count == 0 { - v.cachedHeightVector[idx] = infinity - } else if rec.minHeight <= gRec.minHeight+k { - v.cachedHeightVector[idx] = gRec.minHeight + k - } else { - v.cachedHeightVector[idx] = infinity - } - } - } - return -} - -// updateWinRecord setups win records from two candidates. -func (v *totalOrderingCandidateInfo) updateWinRecord( - otherChainID uint32, - other *totalOrderingCandidateInfo, - dirtyChainIDs []int, - objCache *totalOrderingCache, - numChains uint32) { - var ( - idx int - height uint64 - ) - // The reason not to merge two loops is that the iteration of map is - // expensive when chain count is large, iterating of dirty chains is cheaper. - // TODO(mission): merge the code in this if/else if adding a function won't - // affect the performance. - win := v.winRecords[otherChainID] - if win == nil { - win = objCache.getWinRecord() - v.winRecords[otherChainID] = win - for idx, height = range v.cachedHeightVector[:numChains] { - if height == infinity { - continue - } - if other.cachedHeightVector[idx] == infinity { - win.wins[idx] = 1 - win.count++ - } - } - } else { - for _, idx = range dirtyChainIDs { - if v.cachedHeightVector[idx] == infinity { - if win.wins[idx] == 1 { - win.wins[idx] = 0 - win.count-- - } - continue - } - if other.cachedHeightVector[idx] == infinity { - if win.wins[idx] == 0 { - win.wins[idx] = 1 - win.count++ - } - } else { - if win.wins[idx] == 1 { - win.wins[idx] = 0 - win.count-- - } - } - } - } -} - -// totalOrderingBreakpoint is a record of height discontinuity on a chain -type totalOrderingBreakpoint struct { - roundID uint64 - // height of last block. - lastHeight uint64 -} - -// totalOrderingGroupVector keeps global status of current pending set. -type totalOrderingGlobalVector struct { - // blocks stores all blocks grouped by their proposers and sorted by height. - // TODO(mission): slice used here reallocates frequently. - blocks [][]*types.Block - - // breakpoints stores rounds for chains that blocks' height on them are - // not consecutive, for example in chain i - // Round Height - // 0 0 - // 0 1 - // 1 2 - // 1 3 - // 1 4 - // 2 - <- a config change of chain number occured - // 2 - - // 3 - - // 3 - - // 4 0 <- a breakpoint for round 3 is cached here - // 5 - - // 5 - - // 6 0 <- breakpoint again - // breakpoints[i][0] == &totalOrderingBreakpoint{roundID: 4, lastHeight: 4} - // breakpoints[i][1] == &totalOrderingBreakpoint{roundID: 6, lastHeight: 0} - breakpoints [][]*totalOrderingBreakpoint - - // curRound stores the last round ID used for purging breakpoints. - curRound uint64 - - // tips records the last seen block for each chain. - tips []*types.Block - - // Only ackedStatus in cachedCandidateInfo is used. - cachedCandidateInfo *totalOrderingCandidateInfo -} - -func newTotalOrderingGlobalVector( - initRound uint64, numChains uint32) *totalOrderingGlobalVector { - return &totalOrderingGlobalVector{ - blocks: make([][]*types.Block, numChains), - tips: make([]*types.Block, numChains), - breakpoints: make([][]*totalOrderingBreakpoint, numChains), - curRound: initRound, - } -} - -func (global *totalOrderingGlobalVector) resize(numChains uint32) { - if len(global.blocks) >= int(numChains) { - return - } - // Resize blocks. - newBlocks := make([][]*types.Block, numChains) - copy(newBlocks, global.blocks) - global.blocks = newBlocks - // Resize breakpoints. - newBreakPoints := make([][]*totalOrderingBreakpoint, numChains) - copy(newBreakPoints, global.breakpoints) - global.breakpoints = newBreakPoints - // Resize tips. - newTips := make([]*types.Block, numChains) - copy(newTips, global.tips) - global.tips = newTips -} - -func (global *totalOrderingGlobalVector) switchRound(roundID uint64) { - if global.curRound+1 != roundID { - panic(ErrUnexpected) - } - global.curRound = roundID - for chainID, bs := range global.breakpoints { - if len(bs) == 0 { - continue - } - if bs[0].roundID == roundID { - global.breakpoints[chainID] = bs[1:] - } - } -} - -func (global *totalOrderingGlobalVector) prepareHeightRecord( - candidate *types.Block, - info *totalOrderingCandidateInfo, - acked map[common.Hash]struct{}) { - - var ( - chainID = candidate.Position.ChainID - breakpoints = global.breakpoints[chainID] - breakpoint *totalOrderingBreakpoint - rec *totalOrderingHeightRecord - ) - // Setup height record for own chain. - rec = &totalOrderingHeightRecord{ - minHeight: candidate.Position.Height, - } - if len(breakpoints) == 0 { - // If no breakpoint, count is the amount of blocks. - rec.count = uint64(len(global.blocks[chainID])) - } else { - // If there are breakpoints, only the first counts. - rec.count = breakpoints[0].lastHeight - candidate.Position.Height + 1 - } - info.ackedStatus[chainID] = rec - if acked == nil { - return - } - for idx, blocks := range global.blocks { - if idx == int(chainID) { - continue - } - breakpoint = nil - if len(global.breakpoints[idx]) > 0 { - breakpoint = global.breakpoints[idx][0] - } - for i, b := range blocks { - if breakpoint != nil && b.Position.Round >= breakpoint.roundID { - break - } - if _, acked := acked[b.Hash]; !acked { - continue - } - // If this block acks the candidate, all newer blocks from the same chain - // also 'indirectly' acks the candidate. - rec = info.ackedStatus[idx] - rec.minHeight = b.Position.Height - if breakpoint == nil { - rec.count = uint64(len(blocks) - i) - } else { - rec.count = breakpoint.lastHeight - b.Position.Height + 1 - } - break - } - } -} - -func (global *totalOrderingGlobalVector) addBlock( - b *types.Block) (isOldest bool, pending bool, err error) { - // isOldest implies the block is the oldest in global vector - chainID := b.Position.ChainID - tip := global.tips[chainID] - isOldest = len(global.blocks[chainID]) == 0 - if tip != nil { - // Perform light weight sanity check based on tip. - if tip.Position.Round > b.Position.Round { - err = ErrInvalidDAG - return - } - if DiffUint64(tip.Position.Round, b.Position.Round) > 1 { - if b.Position.Height != 0 { - err = ErrInvalidDAG - return - } - // Add breakpoint. - if b.Position.Round > global.curRound { - global.breakpoints[chainID] = append( - global.breakpoints[chainID], - &totalOrderingBreakpoint{ - roundID: b.Position.Round, - lastHeight: tip.Position.Height, - }) - } - } else { - if b.Position.Height != tip.Position.Height+1 { - err = ErrInvalidDAG - return - } - } - } else { - if b.Position.Round < global.curRound { - err = ErrBlockFromPastRound - return - } - if b.Position.Round > global.curRound { - // Add breakpoint. - bp := &totalOrderingBreakpoint{ - roundID: b.Position.Round, - lastHeight: 0, - } - global.breakpoints[chainID] = append(global.breakpoints[chainID], bp) - } - } - bps := global.breakpoints[chainID] - pending = len(bps) > 0 && bps[0].roundID <= b.Position.Round - global.blocks[chainID] = append(global.blocks[chainID], b) - global.tips[chainID] = b - return -} - -// updateCandidateInfo udpates cached candidate info. -func (global *totalOrderingGlobalVector) updateCandidateInfo( - dirtyChainIDs []int, objCache *totalOrderingCache) { - var ( - idx int - blocks []*types.Block - block *types.Block - info *totalOrderingCandidateInfo - rec *totalOrderingHeightRecord - breakpoint *totalOrderingBreakpoint - ) - if global.cachedCandidateInfo == nil { - info = newTotalOrderingCandidateInfo(common.Hash{}, objCache) - for idx, blocks = range global.blocks { - if len(blocks) == 0 { - continue - } - rec = info.ackedStatus[idx] - if len(global.breakpoints[idx]) > 0 { - breakpoint = global.breakpoints[idx][0] - block = blocks[0] - if block.Position.Round >= breakpoint.roundID { - continue - } - rec.minHeight = block.Position.Height - rec.count = breakpoint.lastHeight - block.Position.Height + 1 - } else { - rec.minHeight = blocks[0].Position.Height - rec.count = uint64(len(blocks)) - } - } - global.cachedCandidateInfo = info - } else { - info = global.cachedCandidateInfo - for _, idx = range dirtyChainIDs { - blocks = global.blocks[idx] - if len(blocks) == 0 { - info.ackedStatus[idx].count = 0 - continue - } - rec = info.ackedStatus[idx] - if len(global.breakpoints[idx]) > 0 { - breakpoint = global.breakpoints[idx][0] - block = blocks[0] - if block.Position.Round >= breakpoint.roundID { - continue - } - rec.minHeight = block.Position.Height - rec.count = breakpoint.lastHeight - block.Position.Height + 1 - } else { - rec.minHeight = blocks[0].Position.Height - rec.count = uint64(len(blocks)) - } - } - } - return -} - -// totalOrdering represent a process unit to handle total ordering for blocks. -type totalOrdering struct { - // pendings stores blocks awaiting to be ordered. - pendings map[common.Hash]*types.Block - - // The round of config used when performing total ordering. - curRound uint64 - - // duringFlush is a flag to switch the flush mode and normal mode. - duringFlush bool - - // flushReadyChains checks if the last block of that chain arrived. Once - // last blocks from all chains in current config are arrived, we can - // perform flush. - flushReadyChains map[uint32]struct{} - - // flushed is a map of flushed blocks. - flushed map[uint32]struct{} - - // globalVector group all pending blocks by proposers and - // sort them by block height. This structure is helpful when: - // - // - build global height vector - // - picking candidates next round - globalVector *totalOrderingGlobalVector - - // candidates caches result of potential function during generating preceding - // set. - candidates []*totalOrderingCandidateInfo - - // acked stores the 'block A acked by block B' by acked[A.Hash][B.Hash] - acked map[common.Hash]map[common.Hash]struct{} - - // dirtyChainIDs stores chainIDs that is "dirty", i.e. needed updating all - // cached statuses (win record, acking status). - dirtyChainIDs []int - - // objCache caches allocated objects, like map. - objCache *totalOrderingCache - - // candidateChainMapping keeps a mapping from candidate's hash to - // their chain IDs. - candidateChainMapping map[uint32]common.Hash - - // candidateChainIDs records chain ID of all candidates. - candidateChainIDs []uint32 - - // configs keeps configuration for each round in continuous way. - configs []*totalOrderingConfig -} - -// newTotalOrdering constructs an totalOrdering instance. -func newTotalOrdering( - dMoment time.Time, round uint64, cfg *types.Config) *totalOrdering { - config := &totalOrderingConfig{} - config.fromConfig(round, cfg) - config.setRoundBeginTime(dMoment) - candidates := make([]*totalOrderingCandidateInfo, config.numChains) - to := &totalOrdering{ - pendings: make(map[common.Hash]*types.Block), - dirtyChainIDs: make([]int, 0, config.numChains), - acked: make(map[common.Hash]map[common.Hash]struct{}), - objCache: newTotalOrderingObjectCache(config.numChains), - candidateChainMapping: make(map[uint32]common.Hash), - candidates: candidates, - candidateChainIDs: make([]uint32, 0, config.numChains), - curRound: config.roundID, - globalVector: newTotalOrderingGlobalVector( - config.roundID, config.numChains), - } - to.configs = []*totalOrderingConfig{config} - return to -} - -// appendConfig add new configs for upcoming rounds. If you add a config for -// round R, next time you can only add the config for round R+1. -func (to *totalOrdering) appendConfig( - round uint64, config *types.Config) error { - - if round != uint64(len(to.configs))+to.configs[0].roundID { - return ErrRoundNotIncreasing - } - if config.PhiRatio < 0.5 || config.PhiRatio > 1.0 { - return ErrTotalOrderingPhiRatio - } - to.configs = append( - to.configs, - newTotalOrderingConfig(to.configs[len(to.configs)-1], config)) - // Resize internal structures. - to.globalVector.resize(config.NumChains) - to.objCache.resize(config.NumChains) - if int(config.NumChains) > len(to.candidates) { - newCandidates := make([]*totalOrderingCandidateInfo, config.NumChains) - copy(newCandidates, to.candidates) - to.candidates = newCandidates - } - return nil -} - -func (to *totalOrdering) switchRound() { - to.curRound++ - to.globalVector.switchRound(to.curRound) -} - -// buildBlockRelation update all its indirect acks recursively. -func (to *totalOrdering) buildBlockRelation(b *types.Block) { - var ( - curBlock, nextBlock *types.Block - ack common.Hash - acked map[common.Hash]struct{} - exists, alreadyPopulated bool - toCheck = []*types.Block{b} - ) - for len(toCheck) != 0 { - curBlock, toCheck = toCheck[len(toCheck)-1], toCheck[:len(toCheck)-1] - if curBlock.Position.Round > b.Position.Round { - // It's illegal for a block to ack some blocks in future round. - panic(ErrForwardAck) - } - for _, ack = range curBlock.Acks { - if acked, exists = to.acked[ack]; !exists { - acked = to.objCache.getAckedVector() - to.acked[ack] = acked - } - // Check if the block is handled. - if _, alreadyPopulated = acked[b.Hash]; alreadyPopulated { - continue - } - acked[b.Hash] = struct{}{} - // See if we need to do this recursively. - if nextBlock, exists = to.pendings[ack]; exists { - toCheck = append(toCheck, nextBlock) - } - } - } -} - -// clean a block from working set. This behaviour would prevent -// our memory usage growing infinity. -func (to *totalOrdering) clean(b *types.Block) { - var ( - h = b.Hash - chainID = b.Position.ChainID - ) - to.objCache.putAckedVector(to.acked[h]) - delete(to.acked, h) - delete(to.pendings, h) - to.candidates[chainID].recycle(to.objCache) - to.candidates[chainID] = nil - delete(to.candidateChainMapping, chainID) - // Remove this candidate from candidate IDs. - to.candidateChainIDs = - removeFromSortedUint32Slice(to.candidateChainIDs, chainID) - // Clear records of this candidate from other candidates. - for _, idx := range to.candidateChainIDs { - to.candidates[idx].clean(chainID) - } -} - -// updateVectors is a helper function to update all cached vectors. -func (to *totalOrdering) updateVectors( - b *types.Block) (isOldest bool, err error) { - var ( - candidateHash common.Hash - chainID uint32 - acked bool - pending bool - ) - // Update global height vector - if isOldest, pending, err = to.globalVector.addBlock(b); err != nil { - return - } - if to.duringFlush { - // It makes no sense to calculate potential functions of total ordering - // when flushing would be happened. - return - } - if pending { - // The chain of this block contains breakpoints, which means their - // height are not continuous. This implementation of DEXON total - // ordering algorithm assumes the height of blocks in working set should - // be continuous. - // - // To workaround this issue, when block arrived after breakpoints, - // their information would not be contributed to current working set. - // This mechanism works because we switch rounds by flushing and - // reset the whole working set. - // This works because forward acking blocks are rejected. - return - } - // Update candidates' acking status. - for chainID, candidateHash = range to.candidateChainMapping { - if _, acked = to.acked[candidateHash][b.Hash]; !acked { - continue - } - if err = to.candidates[chainID].addBlock(b); err != nil { - return - } - } - return -} - -// prepareCandidate builds totalOrderingCandidateInfo for a new candidate. -func (to *totalOrdering) prepareCandidate(b *types.Block) { - var ( - info = newTotalOrderingCandidateInfo(b.Hash, to.objCache) - chainID = b.Position.ChainID - ) - to.candidates[chainID] = info - to.candidateChainMapping[chainID] = b.Hash - // Add index to slot to allocated list, make sure the modified list is sorted. - to.candidateChainIDs = append(to.candidateChainIDs, chainID) - sort.Slice(to.candidateChainIDs, func(i, j int) bool { - return to.candidateChainIDs[i] < to.candidateChainIDs[j] - }) - to.globalVector.prepareHeightRecord(b, info, to.acked[b.Hash]) - return -} - -// isCandidate checks if a block only contains acks to delivered blocks. -func (to *totalOrdering) isCandidate(b *types.Block) bool { - for _, ack := range b.Acks { - if _, exists := to.pendings[ack]; exists { - return false - } - } - return true -} - -// output finishes the delivery of preceding set. -func (to *totalOrdering) output( - precedings map[common.Hash]struct{}, - numChains uint32) (ret []*types.Block) { - - for p := range precedings { - // Remove the first element from corresponding blockVector. - b := to.pendings[p] - chainID := b.Position.ChainID - // TODO(mission): frequent reallocation here. - to.globalVector.blocks[chainID] = to.globalVector.blocks[chainID][1:] - ret = append(ret, b) - // Remove block relations. - to.clean(b) - to.dirtyChainIDs = append(to.dirtyChainIDs, int(chainID)) - } - sort.Sort(types.ByHash(ret)) - // Find new candidates from global vector's tips. - // The complexity here is O(N^2logN). - // TODO(mission): only tips which acking some blocks in the devliered set - // should be checked. This improvement related to the latency introduced by K. - for chainID, blocks := range to.globalVector.blocks[:numChains] { - if len(blocks) == 0 { - continue - } - if _, picked := to.candidateChainMapping[uint32(chainID)]; picked { - continue - } - if !to.isCandidate(blocks[0]) { - continue - } - // Build totalOrderingCandidateInfo for new candidate. - to.prepareCandidate(blocks[0]) - } - return -} - -// generateDeliverSet generates preceding set and checks if the preceding set -// is deliverable by potential function. -func (to *totalOrdering) generateDeliverSet() ( - delivered map[common.Hash]struct{}, mode uint32) { - - var ( - chainID, otherChainID uint32 - info, otherInfo *totalOrderingCandidateInfo - precedings = make(map[uint32]struct{}) - cfg = to.getCurrentConfig() - ) - mode = TotalOrderingModeNormal - to.globalVector.updateCandidateInfo(to.dirtyChainIDs, to.objCache) - globalInfo := to.globalVector.cachedCandidateInfo - for _, chainID = range to.candidateChainIDs { - to.candidates[chainID].updateAckingHeightVector( - globalInfo, cfg.k, to.dirtyChainIDs, to.objCache) - } - // Update winning records for each candidate. - // TODO(mission): It's not reasonable to request one routine for each - // candidate, the context switch rate would be high. - var wg sync.WaitGroup - wg.Add(len(to.candidateChainIDs)) - for _, chainID := range to.candidateChainIDs { - info = to.candidates[chainID] - go func(can uint32, canInfo *totalOrderingCandidateInfo) { - defer wg.Done() - for _, otherChainID := range to.candidateChainIDs { - if can == otherChainID { - continue - } - canInfo.updateWinRecord( - otherChainID, - to.candidates[otherChainID], - to.dirtyChainIDs, - to.objCache, - cfg.numChains) - } - }(chainID, info) - } - wg.Wait() - // Reset dirty chains. - to.dirtyChainIDs = to.dirtyChainIDs[:0] - globalAnsLength := globalInfo.getAckingNodeSetLength( - globalInfo, cfg.k, cfg.numChains) -CheckNextCandidateLoop: - for _, chainID = range to.candidateChainIDs { - info = to.candidates[chainID] - for _, otherChainID = range to.candidateChainIDs { - if chainID == otherChainID { - continue - } - otherInfo = to.candidates[otherChainID] - // TODO(mission): grade should be bounded by current numChains. - if otherInfo.winRecords[chainID].grade( - cfg.numChains, cfg.phi, globalAnsLength) != 0 { - continue CheckNextCandidateLoop - } - } - precedings[chainID] = struct{}{} - } - if len(precedings) == 0 { - return - } - // internal is a helper function to verify internal stability. - internal := func() bool { - var ( - isPreceding, beaten bool - p uint32 - ) - for _, chainID = range to.candidateChainIDs { - if _, isPreceding = precedings[chainID]; isPreceding { - continue - } - beaten = false - for p = range precedings { - // TODO(mission): grade should be bound by current numChains. - if beaten = to.candidates[p].winRecords[chainID].grade( - cfg.numChains, cfg.phi, globalAnsLength) == 1; beaten { - break - } - } - if !beaten { - return false - } - } - return true - } - // checkAHV is a helper function to verify external stability. - // It would make sure some preceding block is strong enough - // to lead the whole preceding set. - checkAHV := func() bool { - var ( - height, count uint64 - p uint32 - ) - for p = range precedings { - count = 0 - info = to.candidates[p] - for _, height = range info.cachedHeightVector { - if height != infinity { - count++ - if count > cfg.phi { - return true - } - } - } - } - return false - } - // checkANS is a helper function to verify external stability. - // It would make sure all preceding blocks are strong enough - // to be delivered. - checkANS := func() bool { - var chainAnsLength uint64 - for p := range precedings { - chainAnsLength = to.candidates[p].getAckingNodeSetLength( - globalInfo, cfg.k, cfg.numChains) - if uint64(chainAnsLength) < uint64(cfg.numChains)-cfg.phi { - return false - } - } - return true - } - // If all chains propose enough blocks, we should force - // to deliver since the whole picture of the DAG is revealed. - if globalAnsLength != uint64(cfg.numChains) { - // Check internal stability first. - if !internal() { - return - } - - // The whole picture is not ready, we need to check if - // exteranl stability is met, and we can deliver earlier. - if checkAHV() && checkANS() { - mode = TotalOrderingModeEarly - } else { - return - } - } - delivered = make(map[common.Hash]struct{}) - for p := range precedings { - delivered[to.candidates[p].hash] = struct{}{} - } - return -} - -// flushBlocks flushes blocks. -func (to *totalOrdering) flushBlocks() ( - flushed []*types.Block, mode uint32, err error) { - mode = TotalOrderingModeFlush - cfg := to.getCurrentConfig() - - // Flush blocks until last blocks from all chains appeared. - if len(to.flushReadyChains) < int(cfg.numChains) { - return - } - if len(to.flushReadyChains) > int(cfg.numChains) { - // This case should never be occured. - err = ErrFutureRoundDelivered - return - } - // Dump all blocks in this round. - for len(to.flushed) != int(cfg.numChains) { - // Dump all candidates without checking potential function. - flushedHashes := make(map[common.Hash]struct{}) - for _, chainID := range to.candidateChainIDs { - candidateBlock := to.pendings[to.candidates[chainID].hash] - if candidateBlock.Position.Round > to.curRound { - continue - } - flushedHashes[candidateBlock.Hash] = struct{}{} - } - if len(flushedHashes) == 0 { - err = ErrTotalOrderingHangs - return - } - flushedBlocks := to.output(flushedHashes, cfg.numChains) - for _, b := range flushedBlocks { - if cfg.isLastBlock(b) { - to.flushed[b.Position.ChainID] = struct{}{} - } - } - flushed = append(flushed, flushedBlocks...) - } - // Switch back to non-flushing mode. - to.duringFlush = false - to.flushed = make(map[uint32]struct{}) - to.flushReadyChains = make(map[uint32]struct{}) - // Clean all cached intermediate stats. - for idx := range to.candidates { - if to.candidates[idx] == nil { - continue - } - to.candidates[idx].recycle(to.objCache) - to.candidates[idx] = nil - } - to.dirtyChainIDs = nil - to.candidateChainMapping = make(map[uint32]common.Hash) - to.candidateChainIDs = nil - to.globalVector.cachedCandidateInfo = nil - to.switchRound() - // Force picking new candidates. - numChains := to.getCurrentConfig().numChains - to.output(map[common.Hash]struct{}{}, numChains) - return -} - -// deliverBlocks delivers blocks by DEXON total ordering algorithm. -func (to *totalOrdering) deliverBlocks() ( - delivered []*types.Block, mode uint32, err error) { - - hashes, mode := to.generateDeliverSet() - cfg := to.getCurrentConfig() - // Output precedings. - delivered = to.output(hashes, cfg.numChains) - // Check if any block in delivered set is the last block in this round, if - // there is, perform flush or round-switch. - for _, b := range delivered { - if b.Position.Round > to.curRound { - err = ErrFutureRoundDelivered - return - } - if !cfg.isLastBlock(b) { - continue - } - // Code reaches here if a last block is processed. This triggers - // "duringFlush" mode if config changes. - if cfg.isFlushRequired { - // Switch to flush mode. - to.duringFlush = true - to.flushReadyChains = make(map[uint32]struct{}) - to.flushed = make(map[uint32]struct{}) - } else { - // Switch round directly. - to.switchRound() - } - break - } - if to.duringFlush { - // Collect last blocks until all last blocks appears and function - // flushBlocks will be called. - for _, b := range delivered { - if cfg.isLastBlock(b) { - to.flushed[b.Position.ChainID] = struct{}{} - } - } - // Some last blocks for the round to be flushed might not be delivered - // yet. - for _, tip := range to.globalVector.tips[:cfg.numChains] { - if tip.Position.Round > to.curRound || cfg.isLastBlock(tip) { - to.flushReadyChains[tip.Position.ChainID] = struct{}{} - } - } - } - return -} - -func (to *totalOrdering) getCurrentConfig() *totalOrderingConfig { - cfgIdx := to.curRound - to.configs[0].roundID - if cfgIdx >= uint64(len(to.configs)) { - panic(fmt.Errorf("total ordering config is not ready: %v, %v, %v", - to.curRound, to.configs[0].roundID, len(to.configs))) - } - return to.configs[cfgIdx] -} - -// addBlock adds a block to the working set of total ordering module. -func (to *totalOrdering) addBlock(b *types.Block) error { - // NOTE: Block b is assumed to be in topologically sorted, i.e., all its - // acking blocks are during or after total ordering stage. - cfg := to.getCurrentConfig() - to.pendings[b.Hash] = b - to.buildBlockRelation(b) - isOldest, err := to.updateVectors(b) - if err != nil { - return err - } - // Mark the proposer of incoming block as dirty. - if b.Position.ChainID < cfg.numChains { - to.dirtyChainIDs = append(to.dirtyChainIDs, int(b.Position.ChainID)) - _, exists := to.candidateChainMapping[b.Position.ChainID] - if isOldest && !exists && to.isCandidate(b) { - // isOldest means b is the oldest block in global vector, and isCandidate - // is still needed here due to round change. For example: - // o o o <- genesis block for round change, isCandidate returns true - // | | but isOldest is false - // o o - // | | - // o o o <- isOldest is true but isCandidate returns false - // | | / - // o o - to.prepareCandidate(b) - } - } - if to.duringFlush && cfg.isLastBlock(b) { - to.flushReadyChains[b.Position.ChainID] = struct{}{} - } - return nil -} - -// extractBlocks check if there is any deliverable set. -func (to *totalOrdering) extractBlocks() ([]*types.Block, uint32, error) { - if to.duringFlush { - return to.flushBlocks() - } - return to.deliverBlocks() -} |