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| 1 | +package lib |
| 2 | + |
| 3 | +import ( |
| 4 | + "context" |
| 5 | + "fmt" |
| 6 | + "sync" |
| 7 | + "time" |
| 8 | + |
| 9 | + "github.com/filecoin-project/dagstore/indexbs" |
| 10 | + "github.com/filecoin-project/dagstore/shard" |
| 11 | + "github.com/filecoin-project/go-fil-markets/piecestore" |
| 12 | + "github.com/filecoin-project/go-fil-markets/retrievalmarket" |
| 13 | + "github.com/filecoin-project/go-state-types/abi" |
| 14 | + lru "github.com/hnlq715/golang-lru" |
| 15 | + "github.com/ipfs/go-cid" |
| 16 | + logging "github.com/ipfs/go-log/v2" |
| 17 | +) |
| 18 | + |
| 19 | +var sslog = logging.Logger("shardselect") |
| 20 | + |
| 21 | +// ShardSelector is used by the dagstore's index-backed blockstore to select |
| 22 | +// the best shard from which to retrieve a particular cid. |
| 23 | +// It chooses the first shard that is unsealed and free (zero cost). |
| 24 | +// It caches the results per-shard. |
| 25 | +type ShardSelector struct { |
| 26 | + ctx context.Context |
| 27 | + ps piecestore.PieceStore |
| 28 | + sa retrievalmarket.SectorAccessor |
| 29 | + rp retrievalmarket.RetrievalProvider |
| 30 | + |
| 31 | + // The striped lock protects against multiple threads doing a lookup |
| 32 | + // against the sealing subsystem / retrieval ask for the same shard |
| 33 | + stripedLock [256]sync.Mutex |
| 34 | + cache *lru.Cache |
| 35 | +} |
| 36 | + |
| 37 | +func NewShardSelector(ctx context.Context, ps piecestore.PieceStore, sa retrievalmarket.SectorAccessor, rp retrievalmarket.RetrievalProvider) (*ShardSelector, error) { |
| 38 | + cache, err := lru.New(2048) |
| 39 | + if err != nil { |
| 40 | + return nil, fmt.Errorf("creating shard selector cache: %w", err) |
| 41 | + } |
| 42 | + return &ShardSelector{ctx: ctx, ps: ps, sa: sa, rp: rp, cache: cache}, nil |
| 43 | +} |
| 44 | + |
| 45 | +var selectorCacheDuration = 10 * time.Minute |
| 46 | +var selectorCacheErrorDuration = time.Minute |
| 47 | + |
| 48 | +type shardSelectResult struct { |
| 49 | + available bool |
| 50 | + err error |
| 51 | +} |
| 52 | + |
| 53 | +// ShardSelectorF chooses the first shard that is unsealed and free (zero cost) |
| 54 | +func (s *ShardSelector) ShardSelectorF(c cid.Cid, shards []shard.Key) (shard.Key, error) { |
| 55 | + // If no shards are selected, return ErrNoShardSelected |
| 56 | + lastErr := indexbs.ErrNoShardSelected |
| 57 | + |
| 58 | + sslog.Debugw("shard selection", "shards", shards) |
| 59 | + for _, sk := range shards { |
| 60 | + lkidx := s.stripedLockIndex(sk) |
| 61 | + s.stripedLock[lkidx].Lock() |
| 62 | + available, err := s.isAvailable(sk) |
| 63 | + s.stripedLock[lkidx].Unlock() |
| 64 | + |
| 65 | + if available { |
| 66 | + // We found an available shard, return it |
| 67 | + sslog.Debugw("shard selected", "shard", sk) |
| 68 | + return sk, nil |
| 69 | + } |
| 70 | + if err != nil { |
| 71 | + sslog.Debugw("shard error", "shard", sk, "err", err) |
| 72 | + lastErr = err |
| 73 | + } |
| 74 | + } |
| 75 | + |
| 76 | + // None of the shards are available |
| 77 | + sslog.Debugw("no shard selected", "shards", shards, "err", lastErr) |
| 78 | + return shard.Key{}, lastErr |
| 79 | +} |
| 80 | + |
| 81 | +func (s *ShardSelector) isAvailable(sk shard.Key) (bool, error) { |
| 82 | + // Check if the shard key is in the cache |
| 83 | + var res *shardSelectResult |
| 84 | + resi, cached := s.cache.Get(sk) |
| 85 | + if cached { |
| 86 | + res = resi.(*shardSelectResult) |
| 87 | + sslog.Debugw("shard cache hit", "shard", sk) |
| 88 | + return res.available, res.err |
| 89 | + } |
| 90 | + sslog.Debugw("shard cache miss", "shard", sk) |
| 91 | + |
| 92 | + // Check if the shard is available |
| 93 | + res = &shardSelectResult{} |
| 94 | + res.available, res.err = s.checkIsAvailable(sk) |
| 95 | + expireIn := selectorCacheDuration |
| 96 | + if res.err != nil { |
| 97 | + // If there's an error, cache for a short duration so that we |
| 98 | + // don't wait too long to try again. |
| 99 | + expireIn = selectorCacheErrorDuration |
| 100 | + res.available = false |
| 101 | + res.err = fmt.Errorf("running shard selection for shard %s: %w", sk, res.err) |
| 102 | + sslog.Warnw("checking shard availability", "shard", sk, "err", res.err) |
| 103 | + } |
| 104 | + // Add the result to the cache |
| 105 | + s.cache.AddEx(sk, res, expireIn) |
| 106 | + |
| 107 | + return res.available, res.err |
| 108 | +} |
| 109 | + |
| 110 | +func (s *ShardSelector) checkIsAvailable(sk shard.Key) (bool, error) { |
| 111 | + // Parse piece CID |
| 112 | + pieceCid, err := cid.Parse(sk.String()) |
| 113 | + if err != nil { |
| 114 | + return false, fmt.Errorf("parsing shard key as cid: %w", err) |
| 115 | + } |
| 116 | + |
| 117 | + // Read piece info from piece store |
| 118 | + sslog.Debugw("getting piece info", "shard", sk) |
| 119 | + pieceInfo, err := s.ps.GetPieceInfo(pieceCid) |
| 120 | + if err != nil { |
| 121 | + return false, fmt.Errorf("get piece info: %w", err) |
| 122 | + } |
| 123 | + |
| 124 | + // Filter for deals that are unsealed |
| 125 | + sslog.Debugw("filtering for unsealed deals", "shard", sk, "deals", len(pieceInfo.Deals)) |
| 126 | + unsealedDeals := make([]piecestore.DealInfo, 0, len(pieceInfo.Deals)) |
| 127 | + var lastErr error |
| 128 | + for _, di := range pieceInfo.Deals { |
| 129 | + isUnsealed, err := s.sa.IsUnsealed(s.ctx, di.SectorID, di.Offset.Unpadded(), di.Length.Unpadded()) |
| 130 | + if err != nil { |
| 131 | + sslog.Warnf("checking if sector is unsealed", "shard", "sector", di.SectorID, sk, "err", err) |
| 132 | + lastErr = err |
| 133 | + continue |
| 134 | + } |
| 135 | + |
| 136 | + if isUnsealed { |
| 137 | + sslog.Debugw("sector is unsealed", "shard", "sector", di.SectorID) |
| 138 | + unsealedDeals = append(unsealedDeals, di) |
| 139 | + } else { |
| 140 | + sslog.Debugw("sector is sealed", "shard", "sector", di.SectorID) |
| 141 | + } |
| 142 | + } |
| 143 | + |
| 144 | + if len(unsealedDeals) == 0 { |
| 145 | + // It wasn't possible to find an unsealed sector |
| 146 | + sslog.Debugw("no unsealed deals found", "shard", sk) |
| 147 | + return false, lastErr |
| 148 | + } |
| 149 | + |
| 150 | + // Check if the piece is available for free (zero-cost) retrieval |
| 151 | + input := retrievalmarket.PricingInput{ |
| 152 | + // Piece from which the payload will be retrieved |
| 153 | + PieceCID: pieceInfo.PieceCID, |
| 154 | + Unsealed: true, |
| 155 | + } |
| 156 | + |
| 157 | + var dealsIds []abi.DealID |
| 158 | + for _, d := range unsealedDeals { |
| 159 | + dealsIds = append(dealsIds, d.DealID) |
| 160 | + } |
| 161 | + |
| 162 | + sslog.Debugw("getting dynamic asking price for unsealed deals", "shard", sk, "deals", len(unsealedDeals)) |
| 163 | + ask, err := s.rp.GetDynamicAsk(s.ctx, input, dealsIds) |
| 164 | + if err != nil { |
| 165 | + return false, fmt.Errorf("getting retrieval ask: %w", err) |
| 166 | + } |
| 167 | + |
| 168 | + // The piece is available for free retrieval |
| 169 | + if ask.PricePerByte.NilOrZero() { |
| 170 | + sslog.Debugw("asking price for unsealed deals is zero", "shard", sk) |
| 171 | + return true, nil |
| 172 | + } |
| 173 | + |
| 174 | + sslog.Debugw("asking price-per-byte for unsealed deals is non-zero", "shard", sk, "price", ask.PricePerByte.String()) |
| 175 | + return false, nil |
| 176 | +} |
| 177 | + |
| 178 | +func (s *ShardSelector) stripedLockIndex(sk shard.Key) int { |
| 179 | + skstr := sk.String() |
| 180 | + return int(skstr[len(skstr)-1]) |
| 181 | +} |
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