7 "github.com/bytom/errors"
9 "github.com/bytom/protocol/bc/legacy"
10 "github.com/bytom/protocol/state"
11 "github.com/bytom/protocol/validation"
14 // maxBlockTxs limits the number of transactions
15 // included in each block.
16 const maxBlockTxs = 10000
18 // saveSnapshotFrequency stores how often to save a state
19 // snapshot to the Store.
20 const saveSnapshotFrequency = time.Hour
23 // ErrBadBlock is returned when a block is invalid.
24 ErrBadBlock = errors.New("invalid block")
26 // ErrStaleState is returned when the Chain does not have a current
28 ErrStaleState = errors.New("stale blockchain state")
30 // ErrBadStateRoot is returned when the computed assets merkle root
31 // disagrees with the one declared in a block header.
32 ErrBadStateRoot = errors.New("invalid state merkle root")
35 // GetBlock returns the block at the given height, if there is one,
36 // otherwise it returns an error.
37 func (c *Chain) GetBlock(height uint64) (*legacy.Block, error) {
38 return c.store.GetBlock(height)
41 // ValidateBlock validates an incoming block in advance of applying it
42 // to a snapshot (with ApplyValidBlock) and committing it to the
43 // blockchain (with CommitAppliedBlock).
44 func (c *Chain) ValidateBlock(block, prev *legacy.Block) error {
45 blockEnts := legacy.MapBlock(block)
46 prevEnts := legacy.MapBlock(prev)
47 err := validation.ValidateBlock(blockEnts, prevEnts)
49 return errors.Sub(ErrBadBlock, err)
51 return errors.Sub(ErrBadBlock, err)
54 // ApplyValidBlock creates an updated snapshot without validating the
56 func (c *Chain) ApplyValidBlock(block *legacy.Block) (*state.Snapshot, error) {
57 _, curSnapshot := c.State()
58 newSnapshot := state.Copy(curSnapshot)
59 err := newSnapshot.ApplyBlock(legacy.MapBlock(block))
63 //fmt.Printf("want %v, ger %v \n", block.BlockHeader.AssetsMerkleRoot, newSnapshot.Tree.RootHash())
64 if block.AssetsMerkleRoot != newSnapshot.Tree.RootHash() {
65 return nil, ErrBadStateRoot
67 return newSnapshot, nil
70 // CommitBlock commits a block to the blockchain. The block
71 // must already have been applied with ApplyValidBlock or
72 // ApplyNewBlock, which will have produced the new snapshot that's
75 // This function saves the block to the store and sometimes (not more
76 // often than saveSnapshotFrequency) saves the state tree to the
77 // store. New-block callbacks (via asynchronous block-processor pins)
80 // TODO(bobg): rename to CommitAppliedBlock for clarity (deferred from https://github.com/chain/chain/pull/788)
81 func (c *Chain) CommitAppliedBlock(ctx context.Context, block *legacy.Block, snapshot *state.Snapshot) error {
82 // SaveBlock is the linearization point. Once the block is committed
83 // to persistent storage, the block has been applied and everything
84 // else can be derived from that block.
85 err := c.store.SaveBlock(block)
87 return errors.Wrap(err, "storing block")
89 if block.Time().After(c.lastQueuedSnapshot.Add(saveSnapshotFrequency)) {
90 c.queueSnapshot(ctx, block.Height, block.Time(), snapshot)
93 err = c.store.FinalizeBlock(ctx, block.Height)
95 return errors.Wrap(err, "finalizing block")
98 // c.setState will update the local blockchain state and height.
99 // When c.store is a txdb.Store, and c has been initialized with a
100 // channel from txdb.ListenBlocks, then the above call to
101 // c.store.FinalizeBlock will have done a postgresql NOTIFY and
102 // that will wake up the goroutine in NewChain, which also calls
103 // setHeight. But duplicate calls with the same blockheight are
104 // harmless; and the following call is required in the cases where
105 // it's not redundant.
106 c.setState(block, snapshot)
111 func (c *Chain) AddBlock(ctx context.Context, block *legacy.Block) error {
112 currentBlock, _ := c.State()
113 if err := c.ValidateBlock(block, currentBlock); err != nil {
117 newSnap, err := c.ApplyValidBlock(block)
122 if err := c.CommitAppliedBlock(ctx, block, newSnap); err != nil {
126 for _, tx := range block.Transactions {
127 c.txPool.RemoveTransaction(&tx.Tx.ID)
132 func (c *Chain) queueSnapshot(ctx context.Context, height uint64, timestamp time.Time, s *state.Snapshot) {
133 // Non-blockingly queue the snapshot for storage.
134 ps := pendingSnapshot{height: height, snapshot: s}
136 case c.pendingSnapshots <- ps:
137 c.lastQueuedSnapshot = timestamp
139 // Skip it; saving snapshots is taking longer than the snapshotting period.
140 log.Printf(ctx, "snapshot storage is taking too long; last queued at %s",
141 c.lastQueuedSnapshot)
145 func (c *Chain) setHeight(h uint64) {
146 // We call setHeight from two places independently:
147 // CommitBlock and the Postgres LISTEN goroutine.
148 // This means we can get here twice for each block,
149 // and any of them might be arbitrarily delayed,
150 // which means h might be from the past.
151 // Detect and discard these duplicate calls.
153 c.state.cond.L.Lock()
154 defer c.state.cond.L.Unlock()
156 if h <= c.state.height {
160 c.state.cond.Broadcast()