79 lines
2.1 KiB
Go
79 lines
2.1 KiB
Go
package mmm
|
|
|
|
import (
|
|
"context"
|
|
"encoding/binary"
|
|
"encoding/hex"
|
|
"fmt"
|
|
"slices"
|
|
|
|
"github.com/PowerDNS/lmdb-go/lmdb"
|
|
"github.com/nbd-wtf/go-nostr"
|
|
)
|
|
|
|
func (il *IndexingLayer) DeleteEvent(ctx context.Context, evt *nostr.Event) error {
|
|
return il.mmmm.lmdbEnv.Update(func(mmmtxn *lmdb.Txn) error {
|
|
return il.lmdbEnv.Update(func(iltxn *lmdb.Txn) error {
|
|
return il.delete(mmmtxn, iltxn, evt)
|
|
})
|
|
})
|
|
}
|
|
|
|
func (il *IndexingLayer) delete(mmmtxn *lmdb.Txn, iltxn *lmdb.Txn, evt *nostr.Event) error {
|
|
zeroRefs := false
|
|
b := il.mmmm
|
|
|
|
b.Logger.Debug().Str("layer", il.name).Uint16("il", il.id).Msg("deleting")
|
|
|
|
// first in the mmmm txn we check if we have the event still
|
|
idPrefix8, _ := hex.DecodeString(evt.ID[0 : 8*2])
|
|
val, err := mmmtxn.Get(b.indexId, idPrefix8)
|
|
if err != nil {
|
|
if lmdb.IsNotFound(err) {
|
|
// we already do not have this anywhere
|
|
return nil
|
|
}
|
|
return fmt.Errorf("failed to check if we have the event %x: %w", idPrefix8, err)
|
|
}
|
|
|
|
// we have this, but do we have it in the current layer?
|
|
// val is [posb][il_idx][il_idx...]
|
|
pos := positionFromBytes(val[0:12])
|
|
|
|
// check references
|
|
currentLayer := binary.BigEndian.AppendUint16(nil, il.id)
|
|
for i := 12; i < len(val); i += 2 {
|
|
if slices.Equal(val[i:i+2], currentLayer) {
|
|
// we will remove the current layer if it's found
|
|
nextval := make([]byte, len(val)-2)
|
|
copy(nextval, val[0:i])
|
|
copy(nextval[i:], val[i+2:])
|
|
|
|
if err := mmmtxn.Put(b.indexId, idPrefix8, nextval, 0); err != nil {
|
|
return fmt.Errorf("failed to update references for %x: %w", idPrefix8, err)
|
|
}
|
|
|
|
// if there are no more layers we will delete everything later
|
|
zeroRefs = len(nextval) == 12
|
|
|
|
break
|
|
}
|
|
}
|
|
|
|
// calculate all index keys we have for this event and delete them
|
|
for k := range il.getIndexKeysForEvent(evt) {
|
|
if err := iltxn.Del(k.dbi, k.key, val[0:12]); err != nil && !lmdb.IsNotFound(err) {
|
|
return fmt.Errorf("index entry %v/%x deletion failed: %w", k.dbi, k.key, err)
|
|
}
|
|
}
|
|
|
|
// if there are no more refs we delete the event from the id index and mmap
|
|
if zeroRefs {
|
|
if err := b.purge(mmmtxn, idPrefix8, pos); err != nil {
|
|
panic(err)
|
|
}
|
|
}
|
|
|
|
return nil
|
|
}
|