lbcd/blockchain/chainquery.go
Brannon King 3fde64cd63 [lbry] rpc: added getchaintips RPC
remove btcjson dep in chainquery
2021-12-14 14:00:59 -08:00

124 lines
3.3 KiB
Go

package blockchain
import (
"sort"
"strings"
btcutil "github.com/lbryio/lbcutil"
)
type ChainTip struct { // duplicate of btcjson.GetChainTipsResult to avoid circular reference
Height int64
Hash string
BranchLen int64
Status string
}
// nodeHeightSorter implements sort.Interface to allow a slice of nodes to
// be sorted by height in ascending order.
type nodeHeightSorter []ChainTip
// Len returns the number of nodes in the slice. It is part of the
// sort.Interface implementation.
func (s nodeHeightSorter) Len() int {
return len(s)
}
// Swap swaps the nodes at the passed indices. It is part of the
// sort.Interface implementation.
func (s nodeHeightSorter) Swap(i, j int) {
s[i], s[j] = s[j], s[i]
}
// Less returns whether the node with index i should sort before the node with
// index j. It is part of the sort.Interface implementation.
func (s nodeHeightSorter) Less(i, j int) bool {
// To ensure stable order when the heights are the same, fall back to
// sorting based on hash.
if s[i].Height == s[j].Height {
return strings.Compare(s[i].Hash, s[j].Hash) < 0
}
return s[i].Height < s[j].Height
}
// ChainTips returns information, in JSON-RPC format, about all the currently
// known chain tips in the block index.
func (b *BlockChain) ChainTips() []ChainTip {
// we need our current tip
// we also need all of our orphans that aren't in the prevOrphans
var results []ChainTip
tip := b.bestChain.Tip()
results = append(results, ChainTip{
Height: int64(tip.height),
Hash: tip.hash.String(),
BranchLen: 0,
Status: "active",
})
b.orphanLock.RLock()
defer b.orphanLock.RUnlock()
notInBestChain := func(block *btcutil.Block) bool {
node := b.bestChain.NodeByHeight(block.Height())
if node == nil {
return false
}
return node.hash.IsEqual(block.Hash())
}
for hash, orphan := range b.orphans {
if len(b.prevOrphans[hash]) > 0 {
continue
}
fork := orphan.block
for fork != nil && notInBestChain(fork) {
fork = b.orphans[*fork.Hash()].block
}
result := ChainTip{
Height: int64(orphan.block.Height()),
Hash: hash.String(),
BranchLen: int64(orphan.block.Height() - fork.Height()),
}
// Determine the status of the chain tip.
//
// active:
// The current best chain tip.
//
// invalid:
// The block or one of its ancestors is invalid.
//
// headers-only:
// The block or one of its ancestors does not have the full block data
// available which also means the block can't be validated or
// connected.
//
// valid-fork:
// The block is fully validated which implies it was probably part of
// main chain at one point and was reorganized.
//
// valid-headers:
// The full block data is available and the header is valid, but the
// block was never validated which implies it was probably never part
// of the main chain.
tipStatus := b.index.LookupNode(&hash).status
if tipStatus.KnownInvalid() {
result.Status = "invalid"
} else if !tipStatus.HaveData() {
result.Status = "headers-only"
} else if tipStatus.KnownValid() {
result.Status = "valid-fork"
} else {
result.Status = "valid-headers"
}
results = append(results, result)
}
// Generate the results sorted by descending height.
sort.Sort(sort.Reverse(nodeHeightSorter(results)))
return results
}