prysm-pulse/beacon-chain/db/kv/utils.go
Radosław Kapka 5569a68452
Code cleanup (#9992)
* Value assigned to a variable is never read before being overwritten

* The result of append is not used anywhere

* Suspicious assignment of range-loop vars detected

* Unused method receiver detected

* Revert "Auxiliary commit to revert individual files from 54edcb445484a2e5d79612e19af8e949b8861253"

This reverts commit bbd1e1beabf7b0c5cfc4f514dcc820062ad6c063.

* Method modifies receiver

* Fix test

* Duplicate imports detected

* Incorrectly formatted error string

* Types of function parameters can be combined

* One more "Unused method receiver detected"

* Unused parameter detected in function
2021-12-07 17:52:39 +00:00

102 lines
3.4 KiB
Go

package kv
import (
"bytes"
"context"
bolt "go.etcd.io/bbolt"
"go.opencensus.io/trace"
)
// lookupValuesForIndices takes in a list of indices and looks up
// their corresponding values in the DB, returning a list of
// roots which can then be used for batch lookups of their corresponding
// objects from the DB. For example, if we are fetching
// attestations and we have an index `[]byte("5")` under the shard indices bucket,
// we might find roots `0x23` and `0x45` stored under that index. We can then
// do a batch read for attestations corresponding to those roots.
func lookupValuesForIndices(ctx context.Context, indicesByBucket map[string][]byte, tx *bolt.Tx) [][][]byte {
_, span := trace.StartSpan(ctx, "BeaconDB.lookupValuesForIndices")
defer span.End()
values := make([][][]byte, 0, len(indicesByBucket))
for k, v := range indicesByBucket {
bkt := tx.Bucket([]byte(k))
roots := bkt.Get(v)
splitRoots := make([][]byte, 0, len(roots)/32)
for i := 0; i < len(roots); i += 32 {
splitRoots = append(splitRoots, roots[i:i+32])
}
values = append(values, splitRoots)
}
return values
}
// updateValueForIndices updates the value for each index by appending it to the previous
// values stored at said index. Typically, indices are roots of data that can then
// be used for reads or batch reads from the DB.
func updateValueForIndices(ctx context.Context, indicesByBucket map[string][]byte, root []byte, tx *bolt.Tx) error {
_, span := trace.StartSpan(ctx, "BeaconDB.updateValueForIndices")
defer span.End()
for k, idx := range indicesByBucket {
bkt := tx.Bucket([]byte(k))
valuesAtIndex := bkt.Get(idx)
if valuesAtIndex == nil {
if err := bkt.Put(idx, root); err != nil {
return err
}
} else {
// Do not save duplication in indices bucket
for i := 0; i < len(valuesAtIndex); i += 32 {
if bytes.Equal(valuesAtIndex[i:i+32], root) {
return nil
}
}
if err := bkt.Put(idx, append(valuesAtIndex, root...)); err != nil {
return err
}
}
}
return nil
}
// deleteValueForIndices clears a root stored at each index.
func deleteValueForIndices(ctx context.Context, indicesByBucket map[string][]byte, root []byte, tx *bolt.Tx) error {
_, span := trace.StartSpan(ctx, "BeaconDB.deleteValueForIndices")
defer span.End()
for k, idx := range indicesByBucket {
bkt := tx.Bucket([]byte(k))
valuesAtIndex := bkt.Get(idx)
if valuesAtIndex != nil {
start := bytes.Index(valuesAtIndex, root)
// If the root was not found inside the values at index slice, we continue.
// Root must be correctly aligned to avoid matching to subsequences of adjacent values.
if start == -1 || start%len(root) != 0 {
continue
}
// We clear out the root from the values at index slice. For example,
// If we had [0x32, 0x33, 0x45] and we wanted to clear out 0x33, the code below
// updates the slice to [0x32, 0x45].
valuesStart := make([]byte, len(valuesAtIndex[:start]))
copy(valuesStart, valuesAtIndex[:start])
valuesEnd := make([]byte, len(valuesAtIndex[start+len(root):]))
copy(valuesEnd, valuesAtIndex[start+len(root):])
valuesAtIndex = append(valuesStart, valuesEnd...)
// If this removes the last value, delete the whole key/value entry.
if len(valuesAtIndex) == 0 {
if err := bkt.Delete(idx); err != nil {
return err
}
continue
}
if err := bkt.Put(idx, valuesAtIndex); err != nil {
return err
}
}
}
return nil
}