badger: use a different transaction for each goroutine.

This commit is contained in:
fiatjaf
2024-02-08 11:08:28 -03:00
parent bd8998deb3
commit 830d51e96d

View File

@@ -35,131 +35,119 @@ func (b BadgerBackend) QueryEvents(ctx context.Context, filter nostr.Filter) (ch
}
go func() {
err := b.View(func(txn *badger.Txn) error {
// iterate only through keys and in reverse order
opts := badger.IteratorOptions{
Reverse: true,
}
defer close(ch)
// actually iterate
iteratorClosers := make([]func(), len(queries))
for i, q := range queries {
go func(i int, q query) {
it := txn.NewIterator(opts)
iteratorClosers[i] = it.Close
// actually iterate
for _, q := range queries {
q := q
go b.View(func(txn *badger.Txn) error {
// iterate only through keys and in reverse order
opts := badger.IteratorOptions{
Reverse: true,
}
defer close(q.results)
it := txn.NewIterator(opts)
defer it.Close()
defer close(q.results)
for it.Seek(q.startingPoint); it.ValidForPrefix(q.prefix); it.Next() {
item := it.Item()
key := item.Key()
for it.Seek(q.startingPoint); it.ValidForPrefix(q.prefix); it.Next() {
item := it.Item()
key := item.Key()
idxOffset := len(key) - 4 // this is where the idx actually starts
idxOffset := len(key) - 4 // this is where the idx actually starts
// "id" indexes don't contain a timestamp
if !q.skipTimestamp {
createdAt := binary.BigEndian.Uint32(key[idxOffset-4 : idxOffset])
if createdAt < since {
break
}
// "id" indexes don't contain a timestamp
if !q.skipTimestamp {
createdAt := binary.BigEndian.Uint32(key[idxOffset-4 : idxOffset])
if createdAt < since {
break
}
idx := make([]byte, 5)
idx[0] = rawEventStorePrefix
copy(idx[1:], key[idxOffset:])
// fetch actual event
item, err := txn.Get(idx)
if err != nil {
if err == badger.ErrDiscardedTxn {
return
}
log.Printf("badger: failed to get %x based on prefix %x, index key %x from raw event store: %s\n",
idx, q.prefix, key, err)
return
}
item.Value(func(val []byte) error {
evt := &nostr.Event{}
if err := nostr_binary.Unmarshal(val, evt); err != nil {
log.Printf("badger: value read error (id %x): %s\n", val[0:32], err)
return err
}
// check if this matches the other filters that were not part of the index
if extraFilter == nil || extraFilter.Matches(evt) {
q.results <- evt
}
return nil
})
}
}(i, q)
}
// max number of events we'll return
limit := b.MaxLimit
if filter.Limit > 0 && filter.Limit < limit {
limit = filter.Limit
}
idx := make([]byte, 5)
idx[0] = rawEventStorePrefix
copy(idx[1:], key[idxOffset:])
// receive results and ensure we only return the most recent ones always
emittedEvents := 0
// fetch actual event
item, err := txn.Get(idx)
if err != nil {
if err == badger.ErrDiscardedTxn {
return err
}
log.Printf("badger: failed to get %x based on prefix %x, index key %x from raw event store: %s\n",
idx, q.prefix, key, err)
return err
}
item.Value(func(val []byte) error {
evt := &nostr.Event{}
if err := nostr_binary.Unmarshal(val, evt); err != nil {
log.Printf("badger: value read error (id %x): %s\n", val[0:32], err)
return err
}
// first pass
emitQueue := make(priorityQueue, 0, len(queries)+limit)
for _, q := range queries {
evt, ok := <-q.results
if ok {
emitQueue = append(emitQueue, &queryEvent{Event: evt, query: q.i})
// check if this matches the other filters that were not part of the index
if extraFilter == nil || extraFilter.Matches(evt) {
q.results <- evt
}
return nil
})
}
}
// now it's a good time to schedule this
defer func() {
close(ch)
for _, itclose := range iteratorClosers {
itclose()
}
}()
// queue may be empty here if we have literally nothing
if len(emitQueue) == 0 {
return nil
})
}
// max number of events we'll return
limit := b.MaxLimit
if filter.Limit > 0 && filter.Limit < limit {
limit = filter.Limit
}
// receive results and ensure we only return the most recent ones always
emittedEvents := 0
// first pass
emitQueue := make(priorityQueue, 0, len(queries)+limit)
for _, q := range queries {
evt, ok := <-q.results
if ok {
emitQueue = append(emitQueue, &queryEvent{Event: evt, query: q.i})
}
}
// queue may be empty here if we have literally nothing
if len(emitQueue) == 0 {
return
}
heap.Init(&emitQueue)
// iterate until we've emitted all events required
for {
// emit latest event in queue
latest := emitQueue[0]
ch <- latest.Event
// stop when reaching limit
emittedEvents++
if emittedEvents == limit {
break
}
heap.Init(&emitQueue)
// fetch a new one from query results and replace the previous one with it
if evt, ok := <-queries[latest.query].results; ok {
emitQueue[0].Event = evt
heap.Fix(&emitQueue, 0)
} else {
// if this query has no more events we just remove this and proceed normally
heap.Remove(&emitQueue, 0)
// iterate until we've emitted all events required
for {
// emit latest event in queue
latest := emitQueue[0]
ch <- latest.Event
// stop when reaching limit
emittedEvents++
if emittedEvents == limit {
// check if the list is empty and end
if len(emitQueue) == 0 {
break
}
// fetch a new one from query results and replace the previous one with it
if evt, ok := <-queries[latest.query].results; ok {
emitQueue[0].Event = evt
heap.Fix(&emitQueue, 0)
} else {
// if this query has no more events we just remove this and proceed normally
heap.Remove(&emitQueue, 0)
// check if the list is empty and end
if len(emitQueue) == 0 {
break
}
}
}
return nil
})
if err != nil {
log.Printf("badger: query txn error: %s\n", err)
}
}()