optimize sieve

Sieve/Services/SieveProcessor.cs

@@ -412,6 +412,15 @@ namespace Sieve.Services
             return result;
         }
         public int ResultCountBeForeApplyPagination = 0;
+        public void CaculateSkipAndTake( TSieveModel model, ref int skip, ref int take)
+        {
+            var page = model?.Page ?? 1;
+            var pageSize = model?.PageSize ?? _options.Value.DefaultPageSize;
+            var maxPageSize = _options.Value.MaxPageSize > 0 ? _options.Value.MaxPageSize : pageSize;
+            skip = (page - 1) * pageSize;
+            take = Math.Min(pageSize, maxPageSize);
+        }
+
         private IQueryable<TEntity> ApplyPagination<TEntity>(
             TSieveModel model,
             IQueryable<TEntity> result)