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  1. package blockchain
  2. import (
  3. "fmt"
  4. "sync"
  5. cmn "github.com/tendermint/tmlibs/common"
  6. dbm "github.com/tendermint/tmlibs/db"
  7. "github.com/tendermint/tendermint/types"
  8. )
  9. /*
  10. BlockStore is a simple low level store for blocks.
  11. There are three types of information stored:
  12. - BlockMeta: Meta information about each block
  13. - Block part: Parts of each block, aggregated w/ PartSet
  14. - Commit: The commit part of each block, for gossiping precommit votes
  15. Currently the precommit signatures are duplicated in the Block parts as
  16. well as the Commit. In the future this may change, perhaps by moving
  17. the Commit data outside the Block. (TODO)
  18. // NOTE: BlockStore methods will panic if they encounter errors
  19. // deserializing loaded data, indicating probable corruption on disk.
  20. */
  21. type BlockStore struct {
  22. db dbm.DB
  23. mtx sync.RWMutex
  24. height int64
  25. }
  26. // NewBlockStore returns a new BlockStore with the given DB,
  27. // initialized to the last height that was committed to the DB.
  28. func NewBlockStore(db dbm.DB) *BlockStore {
  29. bsjson := LoadBlockStoreStateJSON(db)
  30. return &BlockStore{
  31. height: bsjson.Height,
  32. db: db,
  33. }
  34. }
  35. // Height returns the last known contiguous block height.
  36. func (bs *BlockStore) Height() int64 {
  37. bs.mtx.RLock()
  38. defer bs.mtx.RUnlock()
  39. return bs.height
  40. }
  41. // LoadBlock returns the block with the given height.
  42. // If no block is found for that height, it returns nil.
  43. func (bs *BlockStore) LoadBlock(height int64) *types.Block {
  44. var blockMeta = bs.LoadBlockMeta(height)
  45. if blockMeta == nil {
  46. return nil
  47. }
  48. var block = new(types.Block)
  49. buf := []byte{}
  50. for i := 0; i < blockMeta.BlockID.PartsHeader.Total; i++ {
  51. part := bs.LoadBlockPart(height, i)
  52. buf = append(buf, part.Bytes...)
  53. }
  54. err := cdc.UnmarshalBinary(buf, block)
  55. if err != nil {
  56. // NOTE: The existence of meta should imply the existence of the
  57. // block. So, make sure meta is only saved after blocks are saved.
  58. panic(cmn.ErrorWrap(err, "Error reading block"))
  59. }
  60. return block
  61. }
  62. // LoadBlockPart returns the Part at the given index
  63. // from the block at the given height.
  64. // If no part is found for the given height and index, it returns nil.
  65. func (bs *BlockStore) LoadBlockPart(height int64, index int) *types.Part {
  66. var part = new(types.Part)
  67. bz := bs.db.Get(calcBlockPartKey(height, index))
  68. if len(bz) == 0 {
  69. return nil
  70. }
  71. err := cdc.UnmarshalBinaryBare(bz, part)
  72. if err != nil {
  73. panic(cmn.ErrorWrap(err, "Error reading block part"))
  74. }
  75. return part
  76. }
  77. // LoadBlockMeta returns the BlockMeta for the given height.
  78. // If no block is found for the given height, it returns nil.
  79. func (bs *BlockStore) LoadBlockMeta(height int64) *types.BlockMeta {
  80. var blockMeta = new(types.BlockMeta)
  81. bz := bs.db.Get(calcBlockMetaKey(height))
  82. if len(bz) == 0 {
  83. return nil
  84. }
  85. err := cdc.UnmarshalBinaryBare(bz, blockMeta)
  86. if err != nil {
  87. panic(cmn.ErrorWrap(err, "Error reading block meta"))
  88. }
  89. return blockMeta
  90. }
  91. // LoadBlockCommit returns the Commit for the given height.
  92. // This commit consists of the +2/3 and other Precommit-votes for block at `height`,
  93. // and it comes from the block.LastCommit for `height+1`.
  94. // If no commit is found for the given height, it returns nil.
  95. func (bs *BlockStore) LoadBlockCommit(height int64) *types.Commit {
  96. var commit = new(types.Commit)
  97. bz := bs.db.Get(calcBlockCommitKey(height))
  98. if len(bz) == 0 {
  99. return nil
  100. }
  101. err := cdc.UnmarshalBinaryBare(bz, commit)
  102. if err != nil {
  103. panic(cmn.ErrorWrap(err, "Error reading block commit"))
  104. }
  105. return commit
  106. }
  107. // LoadSeenCommit returns the locally seen Commit for the given height.
  108. // This is useful when we've seen a commit, but there has not yet been
  109. // a new block at `height + 1` that includes this commit in its block.LastCommit.
  110. func (bs *BlockStore) LoadSeenCommit(height int64) *types.Commit {
  111. var commit = new(types.Commit)
  112. bz := bs.db.Get(calcSeenCommitKey(height))
  113. if len(bz) == 0 {
  114. return nil
  115. }
  116. err := cdc.UnmarshalBinaryBare(bz, commit)
  117. if err != nil {
  118. panic(cmn.ErrorWrap(err, "Error reading block seen commit"))
  119. }
  120. return commit
  121. }
  122. // SaveBlock persists the given block, blockParts, and seenCommit to the underlying db.
  123. // blockParts: Must be parts of the block
  124. // seenCommit: The +2/3 precommits that were seen which committed at height.
  125. // If all the nodes restart after committing a block,
  126. // we need this to reload the precommits to catch-up nodes to the
  127. // most recent height. Otherwise they'd stall at H-1.
  128. func (bs *BlockStore) SaveBlock(block *types.Block, blockParts *types.PartSet, seenCommit *types.Commit) {
  129. if block == nil {
  130. cmn.PanicSanity("BlockStore can only save a non-nil block")
  131. }
  132. height := block.Height
  133. if g, w := height, bs.Height()+1; g != w {
  134. cmn.PanicSanity(cmn.Fmt("BlockStore can only save contiguous blocks. Wanted %v, got %v", w, g))
  135. }
  136. if !blockParts.IsComplete() {
  137. cmn.PanicSanity(cmn.Fmt("BlockStore can only save complete block part sets"))
  138. }
  139. // Save block meta
  140. blockMeta := types.NewBlockMeta(block, blockParts)
  141. metaBytes := cdc.MustMarshalBinaryBare(blockMeta)
  142. bs.db.Set(calcBlockMetaKey(height), metaBytes)
  143. // Save block parts
  144. for i := 0; i < blockParts.Total(); i++ {
  145. part := blockParts.GetPart(i)
  146. bs.saveBlockPart(height, i, part)
  147. }
  148. // Save block commit (duplicate and separate from the Block)
  149. blockCommitBytes := cdc.MustMarshalBinaryBare(block.LastCommit)
  150. bs.db.Set(calcBlockCommitKey(height-1), blockCommitBytes)
  151. // Save seen commit (seen +2/3 precommits for block)
  152. // NOTE: we can delete this at a later height
  153. seenCommitBytes := cdc.MustMarshalBinaryBare(seenCommit)
  154. bs.db.Set(calcSeenCommitKey(height), seenCommitBytes)
  155. // Save new BlockStoreStateJSON descriptor
  156. BlockStoreStateJSON{Height: height}.Save(bs.db)
  157. // Done!
  158. bs.mtx.Lock()
  159. bs.height = height
  160. bs.mtx.Unlock()
  161. // Flush
  162. bs.db.SetSync(nil, nil)
  163. }
  164. func (bs *BlockStore) saveBlockPart(height int64, index int, part *types.Part) {
  165. if height != bs.Height()+1 {
  166. cmn.PanicSanity(cmn.Fmt("BlockStore can only save contiguous blocks. Wanted %v, got %v", bs.Height()+1, height))
  167. }
  168. partBytes := cdc.MustMarshalBinaryBare(part)
  169. bs.db.Set(calcBlockPartKey(height, index), partBytes)
  170. }
  171. //-----------------------------------------------------------------------------
  172. func calcBlockMetaKey(height int64) []byte {
  173. return []byte(fmt.Sprintf("H:%v", height))
  174. }
  175. func calcBlockPartKey(height int64, partIndex int) []byte {
  176. return []byte(fmt.Sprintf("P:%v:%v", height, partIndex))
  177. }
  178. func calcBlockCommitKey(height int64) []byte {
  179. return []byte(fmt.Sprintf("C:%v", height))
  180. }
  181. func calcSeenCommitKey(height int64) []byte {
  182. return []byte(fmt.Sprintf("SC:%v", height))
  183. }
  184. //-----------------------------------------------------------------------------
  185. var blockStoreKey = []byte("blockStore")
  186. type BlockStoreStateJSON struct {
  187. Height int64 `json:"height"`
  188. }
  189. // Save persists the blockStore state to the database as JSON.
  190. func (bsj BlockStoreStateJSON) Save(db dbm.DB) {
  191. bytes, err := cdc.MarshalJSON(bsj)
  192. if err != nil {
  193. cmn.PanicSanity(cmn.Fmt("Could not marshal state bytes: %v", err))
  194. }
  195. db.SetSync(blockStoreKey, bytes)
  196. }
  197. // LoadBlockStoreStateJSON returns the BlockStoreStateJSON as loaded from disk.
  198. // If no BlockStoreStateJSON was previously persisted, it returns the zero value.
  199. func LoadBlockStoreStateJSON(db dbm.DB) BlockStoreStateJSON {
  200. bytes := db.Get(blockStoreKey)
  201. if len(bytes) == 0 {
  202. return BlockStoreStateJSON{
  203. Height: 0,
  204. }
  205. }
  206. bsj := BlockStoreStateJSON{}
  207. err := cdc.UnmarshalJSON(bytes, &bsj)
  208. if err != nil {
  209. panic(fmt.Sprintf("Could not unmarshal bytes: %X", bytes))
  210. }
  211. return bsj
  212. }