Low-latency AT Protocol interaction indexer.
getBackLinkDids: add cursor pagination
Aly Raffauf
(Jul 2, 2026, 10:47 PM EDT)
4079f2d0
2d9bc36e
+26
-5
+21
-2
internal/api/dids.go
+21
-2
internal/api/dids.go
···
1
1
package api
2
2
3
3
import (
4
+
"encoding/base64"
4
5
"encoding/json"
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6
"log"
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7
"net/http"
···
10
11
type backlinkDidsResponse struct {
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12
Total uint64 `json:"total"`
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13
LinkingDids []string `json:"linking_dids"`
14
+
Cursor *string `json:"cursor"`
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15
}
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func (s *Server) GetBacklinkDids(w http.ResponseWriter, r *http.Request) {
···
21
23
http.Error(w, err.Error(), http.StatusBadRequest)
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return
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25
}
26
+
24
27
25
28
limit := uint64(100)
26
29
if raw := r.URL.Query().Get("limit"); raw != "" {
···
32
35
limit = parsed
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}
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-
total, dids, err := s.Store.DistinctBacklinkDids(r.Context(), subject, collection, path, limit)
38
+
after := ""
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+
if raw := r.URL.Query().Get("cursor"); raw != "" {
40
+
decoded, err := base64.StdEncoding.DecodeString(raw)
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+
if err != nil {
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+
http.Error(w, "invalid cursor", http.StatusBadRequest)
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+
return
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+
}
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+
after = string(decoded)
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+
}
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+
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+
total, dids, err := s.Store.DistinctBacklinkDids(r.Context(), subject, collection, path, after, limit)
36
49
if err != nil {
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50
log.Println("distinct backlink dids:", err)
38
51
http.Error(w, "internal error", http.StatusInternalServerError)
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52
return
40
53
}
41
54
55
+
var cursor *string
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+
if uint64(len(dids)) == limit {
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+
encoded := base64.StdEncoding.EncodeToString([]byte(dids[len(dids)-1]))
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+
cursor = &encoded
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+
}
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+
42
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w.Header().Set("Content-Type", "application/json")
43
-
json.NewEncoder(w).Encode(backlinkDidsResponse{Total: total, LinkingDids: dids})
62
+
json.NewEncoder(w).Encode(backlinkDidsResponse{Total: total, LinkingDids: dids, Cursor: cursor})
44
63
}
+5
-3
internal/store/query.go
+5
-3
internal/store/query.go
···
19
19
return total, nil
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20
}
21
21
22
-
func (s *Store) DistinctBacklinkDids(ctx context.Context, target, collection, fieldPath string, limit uint64) (total uint64, dids []string, err error) {
22
+
func (s *Store) DistinctBacklinkDids(ctx context.Context, target, collection, fieldPath string, after string, limit uint64) (total uint64, dids []string, err error) {
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23
err = s.db.QueryRowContext(ctx,
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`SELECT COUNT(DISTINCT actor_did) FROM links WHERE target = ? AND collection = ? AND field_path = ?`,
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25
target, collection, fieldPath,
···
29
29
}
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rows, err := s.db.QueryContext(ctx,
32
-
`SELECT DISTINCT actor_did FROM links WHERE target = ? AND collection = ? AND field_path = ? LIMIT ?`,
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-
target, collection, fieldPath, limit,
32
+
`SELECT DISTINCT actor_did FROM links
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+
WHERE target = ? AND collection = ? AND field_path = ? AND actor_did > ?
34
+
ORDER BY actor_did LIMIT ?`,
35
+
target, collection, fieldPath, after, limit,
34
36
)
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if err != nil {
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38
return 0, nil, fmt.Errorf("query distinct dids: %w", err)