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lmdb: new querying mechanism.

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This commit is contained in:
fiatjaf
2025-08-04 15:16:38 -03:00
parent 6bda63de17
commit 2750ae3751
7 changed files with 256 additions and 399 deletions
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4
eventstore/lmdb/count.go
View File

@@ -42,7 +42,7 @@ func (b *LMDBBackend) CountEvents(filter nostr.Filter) (uint32, error) {
}
// "id" indexes don't contain a timestamp
if q.timestampSize == 4 {
if q.dbi != b.indexId {
createdAt := binary.BigEndian.Uint32(it.key[len(it.key)-4:])
if createdAt < since {
break
@@ -131,7 +131,7 @@ func (b *LMDBBackend) CountEventsHLL(filter nostr.Filter, offset int) (uint32, *
}
// "id" indexes don't contain a timestamp
if q.timestampSize == 4 {
if q.dbi != b.indexId {
createdAt := binary.BigEndian.Uint32(it.key[len(it.key)-4:])
if createdAt < since {
break

88
eventstore/lmdb/helpers.go
View File

@@ -1,6 +1,7 @@
package lmdb
import (
"bytes"
"crypto/md5"
"encoding/binary"
"encoding/hex"
@@ -14,14 +15,59 @@ import (
"github.com/PowerDNS/lmdb-go/lmdb"
)
// this iterator always goes backwards
type iterator struct {
query query
// iteration stuff
cursor *lmdb.Cursor
key []byte
valIdx []byte
err error
// this keeps track of last timestamp value pulled from this
last uint32
// if we shouldn't fetch more from this
exhausted bool
// results not yet emitted
idxs [][]byte
timestamps []uint32
}
func (it *iterator) pull(n int, since uint32) {
query := it.query
for range n {
// in the beginning we already have a k and a v and an err from the cursor setup, so check and use these
if it.err != nil ||
len(it.key) != query.keySize ||
!bytes.HasPrefix(it.key, query.prefix) {
// either iteration has errored or we reached the end of this prefix
// fmt.Println(" reached end", hex.EncodeToString(it.key), query.keySize, hex.EncodeToString(query.prefix), it.err)
it.exhausted = true
return
}
createdAt := binary.BigEndian.Uint32(it.key[len(it.key)-4:])
if createdAt < since {
// fmt.Println(" reached since", createdAt, "<", since)
it.exhausted = true
return
}
// got a key
it.idxs = append(it.idxs, it.key)
it.last = createdAt
// advance the cursor for the next call
it.next()
}
return
}
// goes backwards
func (it *iterator) seek(key []byte) {
if _, _, errsr := it.cursor.Get(key, nil, lmdb.SetRange); errsr != nil {
if operr, ok := errsr.(*lmdb.OpError); !ok || operr.Errno != lmdb.NotFound {
@@ -38,11 +84,51 @@ func (it *iterator) seek(key []byte) {
}
}
// goes backwards
func (it *iterator) next() {
// move one back (we'll look into k and v and err in the next iteration)
it.key, it.valIdx, it.err = it.cursor.Get(nil, nil, lmdb.Prev)
}
type iterators []iterator
// quickselect reorders the slice just enough to make the top k elements be arranged at the end
// i.e. [1, 700, 25, 312, 44, 28] with k=3 becomes something like [28, 25, 1, 44, 312, 700]
// in this case it's hardcoded to use the 'last' field of the iterator
func (its iterators) quickselect(left int, right int, k int) {
if right == left {
return
}
// partition
pivot := its[(right+left)/2].last
l := left
r := right
for l <= r {
for its[l].last < pivot {
l++
}
for its[r].last > pivot {
r--
}
if l >= r {
break
}
its[l].last, its[r].last = its[r].last, its[l].last
r--
l++
}
mid := r
// ~
if k > mid {
its.quickselect(mid+1, right, k)
} else {
its.quickselect(left, mid, k)
}
}
type key struct {
dbi lmdb.DBI
key []byte

451
eventstore/lmdb/query.go
View File

@@ -1,11 +1,9 @@
package lmdb
import (
"bytes"
"encoding/binary"
"fmt"
"iter"
"log"
"math"
"slices"
"fiatjaf.com/nostr"
@@ -20,6 +18,11 @@ func (b *LMDBBackend) QueryEvents(filter nostr.Filter, maxLimit int) iter.Seq[no
return
}
if filter.IDs != nil {
// do a special id query
// TODO
}
// max number of events we'll return
if tlimit := filter.GetTheoreticalLimit(); tlimit == 0 || filter.LimitZero {
return
@@ -32,368 +35,130 @@ func (b *LMDBBackend) QueryEvents(filter nostr.Filter, maxLimit int) iter.Seq[no
b.lmdbEnv.View(func(txn *lmdb.Txn) error {
txn.RawRead = true
results, err := b.query(txn, filter, maxLimit)
for _, ie := range results {
if !yield(ie.Event) {
break
}
}
return err
return b.query(txn, filter, maxLimit, yield)
})
}
}
func (b *LMDBBackend) query(txn *lmdb.Txn, filter nostr.Filter, limit int) ([]internal.IterEvent, error) {
func (b *LMDBBackend) query(txn *lmdb.Txn, filter nostr.Filter, limit int, yield func(nostr.Event) bool) error {
queries, extraAuthors, extraKinds, extraTagKey, extraTagValues, since, err := b.prepareQueries(filter)
if err != nil {
return nil, err
return err
}
iterators := make([]*iterator, len(queries))
exhausted := make([]bool, len(queries)) // indicates that a query won't be used anymore
results := make([][]internal.IterEvent, len(queries))
pulledPerQuery := make([]int, len(queries))
iterators := make(iterators, len(queries))
batchSizePerQuery := internal.BatchSizePerNumberOfQueries(limit, len(queries))
// these are kept updated so we never pull from the iterator that is at further distance
// (i.e. the one that has the oldest event among all)
// we will continue to pull from it as soon as some other iterator takes the position
oldest := internal.IterEvent{Q: -1}
sndPhase := false // after we have gathered enough events we will change the way we iterate
secondBatch := make([][]internal.IterEvent, 0, len(queries)+1)
sndPhaseParticipants := make([]int, 0, len(queries)+1)
// while merging results in the second phase we will alternate between these two lists
// to avoid having to create new lists all the time
var sndPhaseResultsA []internal.IterEvent
var sndPhaseResultsB []internal.IterEvent
var sndPhaseResultsToggle bool // this is just a dummy thing we use to keep track of the alternating
var sndPhaseHasResultsPending bool
remainingUnexhausted := len(queries) // when all queries are exhausted we can finally end this thing
batchSizePerQuery := internal.BatchSizePerNumberOfQueries(limit, remainingUnexhausted)
firstPhaseTotalPulled := 0
exhaust := func(q int) {
exhausted[q] = true
remainingUnexhausted--
if q == oldest.Q {
oldest = internal.IterEvent{Q: -1}
}
}
var firstPhaseResults []internal.IterEvent
for q := range queries {
for q, query := range queries {
cursor, err := txn.OpenCursor(queries[q].dbi)
if err != nil {
return nil, err
return err
}
iterators[q] = &iterator{cursor: cursor}
iterators[q] = iterator{
query: query,
cursor: cursor,
}
defer cursor.Close()
iterators[q].seek(queries[q].startingPoint)
results[q] = make([]internal.IterEvent, 0, batchSizePerQuery*2)
}
// fmt.Println("queries", filter, len(queries))
// initial pull from all queries
for _, it := range iterators {
it.pull(batchSizePerQuery, since)
}
for c := 0; ; c++ {
batchSizePerQuery = internal.BatchSizePerNumberOfQueries(limit, remainingUnexhausted)
numberOfIteratorsToPullOnEachRound := max(1, int(math.Ceil(float64(len(iterators))/float64(14))))
totalEventsEmitted := 0
tempResults := make([]nostr.Event, 0, batchSizePerQuery*2)
// fmt.Println(" iteration", c, "remaining", remainingUnexhausted, "batchsize", batchSizePerQuery)
// we will go through all the iterators in batches until we have pulled all the required results
for q, query := range queries {
if exhausted[q] {
for len(iterators) > 0 {
// reset stuff
tempResults = tempResults[:0]
// after pulling from all iterators once we now find out what iterators are
// the ones we should keep pulling from next (i.e. which one's last emitted timestamp is the highest)
iterators.quickselect(min(numberOfIteratorsToPullOnEachRound, len(iterators)), 0, len(iterators))
// we now know what is our threshold
threshold := iterators[len(iterators)-1].last
// so we can emit all the events higher than it
for _, it := range iterators {
for t, ts := range it.timestamps {
if ts >= threshold {
idx := it.idxs[t]
// discard this regardless of what happens
internal.SwapDelete(it.timestamps, t)
internal.SwapDelete(it.idxs, t)
t--
// fetch actual event
bin, err := txn.Get(b.rawEventStore, idx)
if err != nil {
log.Printf("lmdb: failed to get %x from raw event store: %s (query prefix=%x, index=%s)\n",
idx, err, it.query.prefix, b.dbiName(it.query.dbi))
continue
}
// check it against pubkeys without decoding the entire thing
if extraAuthors != nil && !slices.Contains(extraAuthors, betterbinary.GetPubKey(bin)) {
continue
}
// check it against kinds without decoding the entire thing
if extraKinds != nil && !slices.Contains(extraKinds, betterbinary.GetKind(bin)) {
continue
}
// decode the entire thing
event := nostr.Event{}
if err := betterbinary.Unmarshal(bin, &event); err != nil {
log.Printf("lmdb: value read error (id %x) on query prefix %x sp %x dbi %s: %s\n",
betterbinary.GetID(bin), it.query.prefix, it.query.startingPoint, b.dbiName(it.query.dbi), err)
continue
}
// fmt.Println(" event", betterbinary.GetID(bin), "kind", betterbinary.GetKind(bin).Num(), "author", betterbinary.GetPubKey(bin), "ts", betterbinary.GetCreatedAt(bin), hex.EncodeToString(it.key), it.valIdx)
// if there is still a tag to be checked, do it now
if extraTagValues != nil && !event.Tags.ContainsAny(extraTagKey, extraTagValues) {
continue
}
tempResults = append(tempResults, event)
}
}
}
// emit this stuff in order
slices.SortFunc(tempResults, nostr.CompareEvent)
for _, evt := range tempResults {
if !yield(evt) {
return nil
}
totalEventsEmitted++
if totalEventsEmitted == limit {
return nil
}
}
// now pull more events
for i := 0; i < min(len(iterators), numberOfIteratorsToPullOnEachRound); i++ {
it := iterators[i]
if it.exhausted {
if len(it.idxs) == 0 {
// eliminating this from the list of iterators
internal.SwapDelete(iterators, i)
i--
}
continue
}
if oldest.Q == q && remainingUnexhausted > 1 {
continue
}
// fmt.Println(" query", q, unsafe.Pointer(&results[q]), b.dbiName(query.dbi), hex.EncodeToString(query.prefix), hex.EncodeToString(query.startingPoint), len(results[q]))
it := iterators[q]
// fmt.Println(" ", q, unsafe.Pointer(iterators[q]), it.err)
pulledThisIteration := 0
for {
// we already have a k and a v and an err from the cursor setup, so check and use these
if it.err != nil ||
len(it.key) != query.keySize ||
!bytes.HasPrefix(it.key, query.prefix) {
// either iteration has errored or we reached the end of this prefix
// fmt.Println(" reached end", hex.EncodeToString(it.key), query.keySize, hex.EncodeToString(query.prefix), it.err)
exhaust(q)
break
}
// "id" indexes don't contain a timestamp
if query.timestampSize == 4 {
createdAt := binary.BigEndian.Uint32(it.key[len(it.key)-4:])
if createdAt < since {
// fmt.Println(" reached since", createdAt, "<", since)
exhaust(q)
break
}
}
// fetch actual event
bin, err := txn.Get(b.rawEventStore, it.valIdx)
if err != nil {
log.Printf(
"lmdb: failed to get %x based on prefix %x, index key %x from raw event store: %s\n",
it.valIdx, query.prefix, it.key, err)
return nil, fmt.Errorf("iteration error: %w", err)
}
// check it against pubkeys without decoding the entire thing
if extraAuthors != nil && !slices.Contains(extraAuthors, betterbinary.GetPubKey(bin)) {
it.next()
continue
}
// check it against kinds without decoding the entire thing
if extraKinds != nil && !slices.Contains(extraKinds, betterbinary.GetKind(bin)) {
it.next()
continue
}
// decode the entire thing
event := nostr.Event{}
if err := betterbinary.Unmarshal(bin, &event); err != nil {
log.Printf("lmdb: value read error (id %x) on query prefix %x sp %x dbi %d: %s\n", betterbinary.GetID(bin),
query.prefix, query.startingPoint, query.dbi, err)
return nil, fmt.Errorf("event read error: %w", err)
}
// fmt.Println(" event", betterbinary.GetID(bin), "kind", betterbinary.GetKind(bin).Num(), "author", betterbinary.GetPubKey(bin), "ts", betterbinary.GetCreatedAt(bin), hex.EncodeToString(it.key), it.valIdx)
// if there is still a tag to be checked, do it now
if extraTagValues != nil && !event.Tags.ContainsAny(extraTagKey, extraTagValues) {
it.next()
continue
}
// this event is good to be used
evt := internal.IterEvent{Event: event, Q: q}
//
//
if sndPhase {
// do the process described below at HIWAWVRTP.
// if we've reached here this means we've already passed the `since` check.
// now we have to eliminate the event currently at the `since` threshold.
nextThreshold := firstPhaseResults[len(firstPhaseResults)-2]
if oldest.Event.ID == nostr.ZeroID {
// fmt.Println(" b1", evt.ID[0:8])
// BRANCH WHEN WE DON'T HAVE THE OLDEST EVENT (BWWDHTOE)
// when we don't have the oldest set, we will keep the results
// and not change the cutting point -- it's bad, but hopefully not that bad.
results[q] = append(results[q], evt)
sndPhaseHasResultsPending = true
} else if nextThreshold.CreatedAt > oldest.CreatedAt {
// fmt.Println(" b2", nextThreshold.CreatedAt, ">", oldest.CreatedAt, evt.ID[0:8])
// one of the events we have stored is the actual next threshold
// eliminate last, update since with oldest
firstPhaseResults = firstPhaseResults[0 : len(firstPhaseResults)-1]
since = uint32(oldest.CreatedAt)
// fmt.Println(" new since", since, evt.ID[0:8])
// we null the oldest Event as we can't rely on it anymore
// (we'll fall under BWWDHTOE above) until we have a new oldest set.
oldest = internal.IterEvent{Q: -1}
// anything we got that would be above this won't trigger an update to
// the oldest anyway, because it will be discarded as being after the limit.
//
// finally
// add this to the results to be merged later
results[q] = append(results[q], evt)
sndPhaseHasResultsPending = true
} else if nextThreshold.CreatedAt < evt.CreatedAt {
// the next last event in the firstPhaseResults is the next threshold
// fmt.Println(" b3", nextThreshold.CreatedAt, "<", oldest.CreatedAt, evt.ID[0:8])
// eliminate last, update since with the antelast
firstPhaseResults = firstPhaseResults[0 : len(firstPhaseResults)-1]
since = uint32(nextThreshold.CreatedAt)
// fmt.Println(" new since", since)
// add this to the results to be merged later
results[q] = append(results[q], evt)
sndPhaseHasResultsPending = true
// update the oldest event
if evt.CreatedAt < oldest.CreatedAt {
oldest = evt
}
} else {
// fmt.Println(" b4", evt.ID[0:8])
// oops, _we_ are the next `since` threshold
firstPhaseResults[len(firstPhaseResults)-1] = evt
since = uint32(evt.CreatedAt)
// fmt.Println(" new since", since)
// do not add us to the results to be merged later
// as we're already inhabiting the firstPhaseResults slice
}
} else {
results[q] = append(results[q], evt)
firstPhaseTotalPulled++
// update the oldest event
if oldest.Event.ID == nostr.ZeroID || evt.CreatedAt < oldest.CreatedAt {
oldest = evt
}
}
pulledPerQuery[q]++
pulledThisIteration++
if pulledThisIteration > batchSizePerQuery {
// batch filled
it.next()
// fmt.Println(" filled", hex.EncodeToString(it.key), it.valIdx)
break
}
if pulledPerQuery[q] >= limit {
// batch filled + reached limit for this query (which is the global limit)
exhaust(q)
it.next()
break
}
it.next()
}
}
// we will do this check if we don't accumulated the requested number of events yet
// fmt.Println("oldest", oldest.Event, "from iter", oldest.Q)
if sndPhase && sndPhaseHasResultsPending && (oldest.Event.ID == nostr.ZeroID || remainingUnexhausted == 0) {
// fmt.Println("second phase aggregation!")
// when we are in the second phase we will aggressively aggregate results on every iteration
//
secondBatch = secondBatch[:0]
for s := 0; s < len(sndPhaseParticipants); s++ {
q := sndPhaseParticipants[s]
if len(results[q]) > 0 {
secondBatch = append(secondBatch, results[q])
}
if exhausted[q] {
sndPhaseParticipants = internal.SwapDelete(sndPhaseParticipants, s)
s--
}
}
// every time we get here we will alternate between these A and B lists
// combining everything we have into a new partial results list.
// after we've done that we can again set the oldest.
// fmt.Println(" xxx", sndPhaseResultsToggle)
if sndPhaseResultsToggle {
secondBatch = append(secondBatch, sndPhaseResultsB)
sndPhaseResultsA = internal.MergeSortMultiple(secondBatch, limit, sndPhaseResultsA)
oldest = sndPhaseResultsA[len(sndPhaseResultsA)-1]
// fmt.Println(" new aggregated a", len(sndPhaseResultsB))
} else {
secondBatch = append(secondBatch, sndPhaseResultsA)
sndPhaseResultsB = internal.MergeSortMultiple(secondBatch, limit, sndPhaseResultsB)
oldest = sndPhaseResultsB[len(sndPhaseResultsB)-1]
// fmt.Println(" new aggregated b", len(sndPhaseResultsB))
}
sndPhaseResultsToggle = !sndPhaseResultsToggle
since = uint32(oldest.CreatedAt)
// fmt.Println(" new since", since)
// reset the `results` list so we can keep using it
results = results[:len(queries)]
for _, q := range sndPhaseParticipants {
results[q] = results[q][:0]
}
} else if !sndPhase && firstPhaseTotalPulled >= limit && remainingUnexhausted > 0 {
// fmt.Println("have enough!", firstPhaseTotalPulled, "/", limit, "remaining", remainingUnexhausted)
// we will exclude this oldest number as it is not relevant anymore
// (we now want to keep track only of the oldest among the remaining iterators)
oldest = internal.IterEvent{Q: -1}
// HOW IT WORKS AFTER WE'VE REACHED THIS POINT (HIWAWVRTP)
// now we can combine the results we have and check what is our current oldest event.
// we also discard anything that is after the current cutting point (`limit`).
// so if we have [1,2,3], [10, 15, 20] and [7, 21, 49] but we only want 6 total
// we can just keep [1,2,3,7,10,15] and discard [20, 21, 49],
// and also adjust our `since` parameter to `15`, discarding anything we get after it
// and immediately declaring that iterator exhausted.
// also every time we get result that is more recent than this updated `since` we can
// keep it but also discard the previous since, moving the needle one back -- for example,
// if we get an `8` we can keep it and move the `since` parameter to `10`, discarding `15`
// in the process.
all := make([][]internal.IterEvent, len(results))
copy(all, results) // we have to use this otherwise internal.MergeSortMultiple will scramble our results slice
firstPhaseResults = internal.MergeSortMultiple(all, limit, nil)
oldest = firstPhaseResults[limit-1]
since = uint32(oldest.CreatedAt)
// fmt.Println("new since", since)
for q := range queries {
if exhausted[q] {
continue
}
// we also automatically exhaust any of the iterators that have already passed the
// cutting point (`since`)
if results[q][len(results[q])-1].CreatedAt < oldest.CreatedAt {
exhausted[q] = true
remainingUnexhausted--
continue
}
// for all the remaining iterators,
// since we have merged all the events in this `firstPhaseResults` slice, we can empty the
// current `results` slices and reuse them.
results[q] = results[q][:0]
// build this index of indexes with everybody who remains
sndPhaseParticipants = append(sndPhaseParticipants, q)
}
// we create these two lists and alternate between them so we don't have to create a
// a new one every time
sndPhaseResultsA = make([]internal.IterEvent, 0, limit*2)
sndPhaseResultsB = make([]internal.IterEvent, 0, limit*2)
// from now on we won't run this block anymore
sndPhase = true
}
// fmt.Println("remaining", remainingUnexhausted)
if remainingUnexhausted == 0 {
break
it.pull(batchSizePerQuery, since)
}
}
// fmt.Println("is sndPhase?", sndPhase)
var combinedResults []internal.IterEvent
if sndPhase {
// fmt.Println("ending second phase")
// when we reach this point either sndPhaseResultsA or sndPhaseResultsB will be full of stuff,
// the other will be empty
var sndPhaseResults []internal.IterEvent
// fmt.Println("xxx", sndPhaseResultsToggle, len(sndPhaseResultsA), len(sndPhaseResultsB))
if sndPhaseResultsToggle {
sndPhaseResults = sndPhaseResultsB
combinedResults = sndPhaseResultsA[0:limit] // reuse this
// fmt.Println(" using b", len(sndPhaseResultsA))
} else {
sndPhaseResults = sndPhaseResultsA
combinedResults = sndPhaseResultsB[0:limit] // reuse this
// fmt.Println(" using a", len(sndPhaseResultsA))
}
all := [][]internal.IterEvent{firstPhaseResults, sndPhaseResults}
combinedResults = internal.MergeSortMultiple(all, limit, combinedResults)
// fmt.Println("final combinedResults", len(combinedResults), cap(combinedResults), limit)
} else {
combinedResults = make([]internal.IterEvent, limit)
combinedResults = internal.MergeSortMultiple(results, limit, combinedResults)
}
return combinedResults, nil
return nil
}

37
eventstore/lmdb/query_planner.go
View File

@@ -14,9 +14,7 @@ type query struct {
i int
dbi lmdb.DBI
prefix []byte
results chan *nostr.Event
keySize int
timestampSize int
startingPoint []byte
}
@@ -46,20 +44,19 @@ func (b *LMDBBackend) prepareQueries(filter nostr.Filter) (
sp = sp[0:len(q.prefix)]
copy(sp, q.prefix)
queries[i].startingPoint = binary.BigEndian.AppendUint32(sp, uint32(until))
queries[i].results = make(chan *nostr.Event, 12)
}
}()
if filter.IDs != nil {
// when there are ids we ignore everything else
queries = make([]query, len(filter.IDs))
for i, id := range filter.IDs {
prefix := make([]byte, 8)
copy(prefix[0:8], id[0:8])
queries[i] = query{i: i, dbi: b.indexId, prefix: prefix[0:8], keySize: 8, timestampSize: 0}
}
return queries, nil, nil, "", nil, 0, nil
}
// if filter.IDs != nil {
// // when there are ids we ignore everything else
// queries = make([]query, len(filter.IDs))
// for i, id := range filter.IDs {
// prefix := make([]byte, 8)
// copy(prefix[0:8], id[0:8])
// queries[i] = query{i: i, dbi: b.indexId, prefix: prefix[0:8], keySize: 8}
// }
// return queries, nil, nil, "", nil, 0, nil
// }
// this is where we'll end the iteration
if filter.Since != 0 {
@@ -94,7 +91,7 @@ func (b *LMDBBackend) prepareQueries(filter nostr.Filter) (
return nil, nil, nil, "", nil, 0, fmt.Errorf("invalid 'p' tag '%s'", value)
}
binary.BigEndian.PutUint16(k[8:8+2], uint16(kind))
queries[i] = query{i: i, dbi: b.indexPTagKind, prefix: k[0 : 8+2], keySize: 8 + 2 + 4, timestampSize: 4}
queries[i] = query{i: i, dbi: b.indexPTagKind, prefix: k[0 : 8+2], keySize: 8 + 2 + 4}
i++
}
}
@@ -110,7 +107,7 @@ func (b *LMDBBackend) prepareQueries(filter nostr.Filter) (
if _, err := hex.Decode(k[0:8], []byte(value[0:8*2])); err != nil {
return nil, nil, nil, "", nil, 0, fmt.Errorf("invalid 'p' tag '%s'", value)
}
queries[i] = query{i: i, dbi: b.indexPTagKind, prefix: k[0:8], keySize: 8 + 2 + 4, timestampSize: 4}
queries[i] = query{i: i, dbi: b.indexPTagKind, prefix: k[0:8], keySize: 8 + 2 + 4}
}
}
} else {
@@ -121,7 +118,7 @@ func (b *LMDBBackend) prepareQueries(filter nostr.Filter) (
dbi, k, offset := b.getTagIndexPrefix(tagKey, value)
// remove the last parts part to get just the prefix we want here
prefix := k[0:offset]
queries[i] = query{i: i, dbi: dbi, prefix: prefix, keySize: len(prefix) + 4, timestampSize: 4}
queries[i] = query{i: i, dbi: dbi, prefix: prefix, keySize: len(prefix) + 4}
}
// add an extra kind filter if available (only do this on plain tag index, not on ptag-kind index)
@@ -156,7 +153,7 @@ pubkeyMatching:
// will use pubkey index
queries = make([]query, len(filter.Authors))
for i, pk := range filter.Authors {
queries[i] = query{i: i, dbi: b.indexPubkey, prefix: pk[0:8], keySize: 8 + 4, timestampSize: 4}
queries[i] = query{i: i, dbi: b.indexPubkey, prefix: pk[0:8], keySize: 8 + 4}
}
} else {
// will use pubkeyKind index
@@ -167,7 +164,7 @@ pubkeyMatching:
prefix := make([]byte, 8+2)
copy(prefix[0:8], pk[0:8])
binary.BigEndian.PutUint16(prefix[8:8+2], uint16(kind))
queries[i] = query{i: i, dbi: b.indexPubkeyKind, prefix: prefix[0 : 8+2], keySize: 10 + 4, timestampSize: 4}
queries[i] = query{i: i, dbi: b.indexPubkeyKind, prefix: prefix[0 : 8+2], keySize: 10 + 4}
i++
}
}
@@ -184,7 +181,7 @@ pubkeyMatching:
for i, kind := range filter.Kinds {
prefix := make([]byte, 2)
binary.BigEndian.PutUint16(prefix[0:2], uint16(kind))
queries[i] = query{i: i, dbi: b.indexKind, prefix: prefix[0:2], keySize: 2 + 4, timestampSize: 4}
queries[i] = query{i: i, dbi: b.indexKind, prefix: prefix[0:2], keySize: 2 + 4}
}
// potentially with an extra useless tag filtering
@@ -195,6 +192,6 @@ pubkeyMatching:
// if we got here our query will have nothing to filter with
queries = make([]query, 1)
prefix := make([]byte, 0)
queries[0] = query{i: 0, dbi: b.indexCreatedAt, prefix: prefix, keySize: 0 + 4, timestampSize: 4}
queries[0] = query{i: 0, dbi: b.indexCreatedAt, prefix: prefix, keySize: 0 + 4}
return queries, nil, nil, "", nil, since, nil
}

15
eventstore/lmdb/replace.go
View File

@@ -2,6 +2,7 @@ package lmdb
import (
"fmt"
"iter"
"math"
"fiatjaf.com/nostr"
@@ -23,16 +24,20 @@ func (b *LMDBBackend) ReplaceEvent(evt nostr.Event) error {
}
// now we fetch the past events, whatever they are, delete them and then save the new
results, err := b.query(txn, filter, 10) // in theory limit could be just 1 and this should work
var yield_ func(nostr.Event) bool
var results iter.Seq[nostr.Event] = func(yield func(nostr.Event) bool) {
yield_ = yield
}
err := b.query(txn, filter, 10 /* in theory limit could be just 1 and this should work */, yield_)
if err != nil {
return fmt.Errorf("failed to query past events with %s: %w", filter, err)
}
shouldStore := true
for _, previous := range results {
if internal.IsOlder(previous.Event, evt) {
if err := b.delete(txn, previous.Event.ID); err != nil {
return fmt.Errorf("failed to delete event %s for replacing: %w", previous.Event.ID, err)
for previous := range results {
if internal.IsOlder(previous, evt) {
if err := b.delete(txn, previous.ID); err != nil {
return fmt.Errorf("failed to delete event %s for replacing: %w", previous.ID, err)
}
} else {
// there is a newer event already stored, so we won't store this

27
eventstore/lmdb/utils_test.go Normal file
View File

@@ -0,0 +1,27 @@
package lmdb
import (
"testing"
"github.com/stretchr/testify/require"
)
func TestQuickselect(t *testing.T) {
its := iterators{
{last: 781},
{last: 900},
{last: 1},
{last: 81},
{last: 325},
{last: 781},
{last: 562},
{last: 81},
{last: 444},
}
its.quickselect(3, 0, len(its))
require.ElementsMatch(t, its[len(its)-3:], iterators{{last: 900}, {last: 781}, {last: 781}})
its.quickselect(4, 0, len(its))
require.ElementsMatch(t, its[len(its)-4:], iterators{{last: 562}, {last: 900}, {last: 781}, {last: 781}})
}