73 lines
1.6 KiB
Go
73 lines
1.6 KiB
Go
package badger
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import (
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"context"
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"encoding/hex"
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"log"
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"github.com/dgraph-io/badger/v4"
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"github.com/nbd-wtf/go-nostr"
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)
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var serialDelete uint32 = 0
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func (b *BadgerBackend) DeleteEvent(ctx context.Context, evt *nostr.Event) error {
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deletionHappened := false
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err := b.Update(func(txn *badger.Txn) error {
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var err error
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deletionHappened, err = b.delete(txn, evt)
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return err
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})
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if err != nil {
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return err
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}
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// after deleting, run garbage collector (sometimes)
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if deletionHappened {
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serialDelete = (serialDelete + 1) % 256
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if serialDelete == 0 {
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if err := b.RunValueLogGC(0.8); err != nil && err != badger.ErrNoRewrite {
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log.Println("badger gc errored:" + err.Error())
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}
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}
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}
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return nil
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}
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func (b *BadgerBackend) delete(txn *badger.Txn, evt *nostr.Event) (bool, error) {
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idx := make([]byte, 1, 5)
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idx[0] = rawEventStorePrefix
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// query event by id to get its idx
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idPrefix8, _ := hex.DecodeString(evt.ID[0 : 8*2])
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prefix := make([]byte, 1+8)
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prefix[0] = indexIdPrefix
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copy(prefix[1:], idPrefix8)
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opts := badger.IteratorOptions{
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PrefetchValues: false,
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}
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it := txn.NewIterator(opts)
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it.Seek(prefix)
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if it.ValidForPrefix(prefix) {
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idx = append(idx, it.Item().Key()[1+8:]...)
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}
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it.Close()
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// if no idx was found, end here, this event doesn't exist
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if len(idx) == 1 {
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return false, nil
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}
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// calculate all index keys we have for this event and delete them
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for k := range b.getIndexKeysForEvent(evt, idx[1:]) {
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if err := txn.Delete(k); err != nil {
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return false, err
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}
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}
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// delete the raw event
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return true, txn.Delete(idx)
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}
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