// Init initializes the enabled indexes. This is called during chain
// initialization and primarily consists of catching up all indexes to the
// current best chain tip. This is necessary since each index can be disabled
// and re-enabled at any time and attempting to catch-up indexes at the same
// time new blocks are being downloaded would lead to an overall longer time to
// catch up due to the I/O contention.
//
// This is part of the blockchain.IndexManager interface.
func (m *Manager) Init(chain *blockchain.BlockChain) error {
// Nothing to do when no indexes are enabled.
if len(m.enabledIndexes) == 0 {
return nil
}
// Finish and drops that were previously interrupted.
if err := m.maybeFinishDrops(); err != nil {
return err
}
// Create the initial state for the indexes as needed.
err := m.db.Update(func(dbTx database.Tx) error {
// Create the bucket for the current tips as needed.
meta := dbTx.Metadata()
_, err := meta.CreateBucketIfNotExists(indexTipsBucketName)
if err != nil {
return err
}
return m.maybeCreateIndexes(dbTx)
})
if err != nil {
return err
}
// Initialize each of the enabled indexes.
for _, indexer := range m.enabledIndexes {
if err := indexer.Init(); err != nil {
return err
}
}
// Rollback indexes to the main chain if their tip is an orphaned fork.
// This is fairly unlikely, but it can happen if the chain is
// reorganized while the index is disabled. This has to be done in
// reverse order because later indexes can depend on earlier ones.
var cachedBlock *dcrutil.Block
for i := len(m.enabledIndexes); i > 0; i-- {
indexer := m.enabledIndexes[i-1]
// Fetch the current tip for the index.
var height uint32
var hash *chainhash.Hash
err := m.db.View(func(dbTx database.Tx) error {
idxKey := indexer.Key()
hash, height, err = dbFetchIndexerTip(dbTx, idxKey)
if err != nil {
return err
}
return nil
})
if err != nil {
return err
}
// Nothing to do if the index does not have any entries yet.
if height == 0 {
continue
}
// Loop until the tip is a block that exists in the main chain.
initialHeight := height
err = m.db.Update(func(dbTx database.Tx) error {
for {
if blockchain.DBMainChainHasBlock(dbTx, hash) {
break
}
// Get the block, unless it's already cached.
var block *dcrutil.Block
if cachedBlock == nil && height > 0 {
block, err = blockchain.DBFetchBlockByHeight(dbTx,
int64(height))
if err != nil {
return err
}
} else {
block = cachedBlock
}
// Load the parent block for the height since it is
// required to remove it.
parent, err := blockchain.DBFetchBlockByHeight(dbTx,
int64(height)-1)
if err != nil {
return err
}
cachedBlock = parent
// When the index requires all of the referenced
// txouts they need to be retrieved from the
// transaction index.
var view *blockchain.UtxoViewpoint
if indexNeedsInputs(indexer) {
var err error
view, err = makeUtxoView(dbTx, block, parent)
if err != nil {
return err
}
}
// Remove all of the index entries associated
// with the block and update the indexer tip.
err = dbIndexDisconnectBlock(dbTx, indexer,
block, parent, view)
if err != nil {
return err
}
// Update the tip to the previous block.
hash = &block.MsgBlock().Header.PrevBlock
height--
}
return nil
})
if err != nil {
return err
}
if initialHeight != height {
log.Infof("Removed %d orphaned blocks from %s "+
"(heights %d to %d)", initialHeight-height,
indexer.Name(), height+1, initialHeight)
}
}
// Fetch the current tip heights for each index along with tracking the
// lowest one so the catchup code only needs to start at the earliest
// block and is able to skip connecting the block for the indexes that
// don't need it.
bestHeight := chain.BestSnapshot().Height
lowestHeight := bestHeight
indexerHeights := make([]uint32, len(m.enabledIndexes))
err = m.db.View(func(dbTx database.Tx) error {
for i, indexer := range m.enabledIndexes {
idxKey := indexer.Key()
hash, height, err := dbFetchIndexerTip(dbTx, idxKey)
if err != nil {
return err
}
log.Debugf("Current %s tip (height %d, hash %v)",
indexer.Name(), height, hash)
indexerHeights[i] = height
if height < uint32(lowestHeight) {
lowestHeight = int64(height)
}
}
return nil
})
if err != nil {
return err
}
// Nothing to index if all of the indexes are caught up.
if lowestHeight == bestHeight {
return nil
}
// Create a progress logger for the indexing process below.
progressLogger := progresslog.NewBlockProgressLogger("Indexed", log)
// At this point, one or more indexes are behind the current best chain
// tip and need to be caught up, so log the details and loop through
// each block that needs to be indexed.
log.Infof("Catching up indexes from height %d to %d", lowestHeight,
bestHeight)
var cachedParent *dcrutil.Block
for height := lowestHeight + 1; height <= bestHeight; height++ {
var block, parent *dcrutil.Block
err = m.db.Update(func(dbTx database.Tx) error {
// Get the parent of the block, unless it's already cached.
if cachedParent == nil && height > 0 {
parent, err = blockchain.DBFetchBlockByHeight(dbTx, height-1)
if err != nil {
return err
}
} else {
parent = cachedParent
}
// Load the block for the height since it is required to index
// it.
block, err = blockchain.DBFetchBlockByHeight(dbTx, height)
if err != nil {
return err
}
cachedParent = block
// Connect the block for all indexes that need it.
var view *blockchain.UtxoViewpoint
for i, indexer := range m.enabledIndexes {
// Skip indexes that don't need to be updated with this
// block.
if indexerHeights[i] >= uint32(height) {
continue
}
// When the index requires all of the referenced
// txouts and they haven't been loaded yet, they
// need to be retrieved from the transaction
// index.
if view == nil && indexNeedsInputs(indexer) {
var errMakeView error
view, errMakeView = makeUtxoView(dbTx, block, parent)
if errMakeView != nil {
return errMakeView
}
}
errLocal := dbIndexConnectBlock(dbTx, indexer, block,
parent, view)
if errLocal != nil {
return errLocal
}
indexerHeights[i] = uint32(height)
}
return nil
})
if err != nil {
return err
}
progressLogger.LogBlockHeight(block, parent)
}
log.Infof("Indexes caught up to height %d", bestHeight)
return nil
}
