pagination optimization

pkg/mongo/repository.go

@@ -26,6 +26,8 @@ type Pagination struct {
 	Cursor    string `json:"cursor"`    // Base64 encoded cursor for cursor-based pagination
 	SortField string `json:"sortField"` // Field to sort by (default: "_id")
 	SortOrder int    `json:"sortOrder"` // Sort order: 1 for ascending, -1 for descending
+	// Projection limits fields returned from Find (e.g. exclude large blobs on list endpoints).
+	Projection bson.M `json:"projection,omitempty"`
 }
 
 // PaginatedResult represents a paginated result set
@@ -138,6 +140,10 @@ func (r *repository[T]) FindAll(ctx context.Context, filter bson.M, pagination P
 		SetSort(sort).
 		SetLimit(int64(pagination.Limit + 1)) // +1 to check if there are more documents
 
+	if len(pagination.Projection) > 0 {
+		findOptions.SetProjection(pagination.Projection)
+	}
+
 	// Handle cursor-based pagination
 	if pagination.Cursor != "" {
 		cursorFilter, err := r.buildCursorFilter(pagination.Cursor, pagination.SortField, pagination.SortOrder)
@@ -181,13 +187,14 @@ func (r *repository[T]) FindAll(ctx context.Context, filter bson.M, pagination P
 		items = items[:pagination.Limit] // Remove the extra item
 	}
 
-	// Get total count
-	totalCount, err := r.Count(ctx, filter)
-	if err != nil {
+	// Get total count for pagination metadata
+	var totalCount int64
+	var countErr error
+	totalCount, countErr = r.Count(ctx, filter)
+	if countErr != nil {
 		r.logger.Error("Failed to get total count", map[string]interface{}{
-			"error": err.Error(),
+			"error": countErr.Error(),
 		})
-		// Don't fail the entire query, just set count to 0
 		totalCount = 0
 	}
 

pkg/mongo/utils.go

@@ -7,8 +7,8 @@ import (
 
 // Index represents a MongoDB index
 type Index struct {
-	Name    string                `json:"name"`
-	Keys    bson.D                `json:"keys"`
+	Name    string                       `json:"name"`
+	Keys    bson.D                       `json:"keys"`
 	Options *options.IndexOptionsBuilder `json:"options"`
 }
 
@@ -33,7 +33,6 @@ func (i *Index) WithSparse(sparse bool) *Index {
 	return i
 }
 
-
 // WithExpireAfterSeconds sets the TTL for the index
 func (i *Index) WithExpireAfterSeconds(seconds int32) *Index {
 	i.Options.SetExpireAfterSeconds(seconds)
@@ -294,6 +293,12 @@ func (pb *PaginationBuilder) SortDesc(field string) *PaginationBuilder {
 	return pb.SortBy(field, "desc")
 }
 
+// Projection sets optional MongoDB field projection for Find (e.g. exclude large fields).
+func (pb *PaginationBuilder) Projection(projection bson.M) *PaginationBuilder {
+	pb.pagination.Projection = projection
+	return pb
+}
+
 // Build returns the final pagination options
 func (pb *PaginationBuilder) Build() Pagination {
 	return pb.pagination