eventstore: replace bluge with bleve.

bluge seems to be abandoned and bleve should work better, who knows.

eventstore/bleve/lib.go

@@ -0,0 +1,61 @@
+package bleve
+
+import (
+	"errors"
+	"fmt"
+	"sync"
+
+	"fiatjaf.com/nostr"
+	"fiatjaf.com/nostr/eventstore"
+	bleve "github.com/blevesearch/bleve/v2"
+	bleveMapping "github.com/blevesearch/bleve/v2/mapping"
+)
+
+var _ eventstore.Store = (*BleveBackend)(nil)
+
+type BleveBackend struct {
+	sync.Mutex
+	// Path is where the index will be saved
+	Path string
+
+	// RawEventStore is where we'll fetch the raw events from
+	// bleve will only store ids, so the actual events must be somewhere else
+	RawEventStore eventstore.Store
+
+	index bleve.Index
+}
+
+func (b *BleveBackend) Close() {
+	if b.index != nil {
+		b.index.Close()
+	}
+}
+
+func (b *BleveBackend) Init() error {
+	if b.Path == "" {
+		return fmt.Errorf("missing Path")
+	}
+	if b.RawEventStore == nil {
+		return fmt.Errorf("missing RawEventStore")
+	}
+
+	// try to open existing index
+	index, err := bleve.Open(b.Path)
+	if err == bleve.ErrorIndexPathDoesNotExist {
+		// create new index with default mapping
+		mapping := bleveMapping.NewIndexMapping()
+		index, err = bleve.New(b.Path, mapping)
+		if err != nil {
+			return fmt.Errorf("error creating index: %w", err)
+		}
+	} else if err != nil {
+		return fmt.Errorf("error opening index: %w", err)
+	}
+
+	b.index = index
+	return nil
+}
+
+func (b *BleveBackend) CountEvents(nostr.Filter) (uint32, error) {
+	return 0, errors.New("not supported")
+}