Merge pull request #13938 from marcandre/sized_enumerator

Sized enumerator

2 files changed, 13 insertions, 6 deletions

diff --git a/activerecord/lib/active_record/relation/batches.rb b/activerecord/lib/active_record/relation/batches.rb
index 666cef80a9..29fc150b3d 100644
--- a/activerecord/lib/active_record/relation/batches.rb
+++ b/activerecord/lib/active_record/relation/batches.rb
@@ -52,7 +52,9 @@ module ActiveRecord
           records.each { |record| yield record }
         end
       else
-        enum_for :find_each, options
+        enum_for :find_each, options do
+          options[:start] ? where(table[primary_key].gteq(options[:start])).size : size
+        end
       end
     end
 
@@ -96,17 +98,22 @@ module ActiveRecord
     # the batch sizes.
     def find_in_batches(options = {})
       options.assert_valid_keys(:start, :batch_size)
-      return to_enum(:find_in_batches, options) unless block_given?
 
       relation = self
+      start = options[:start]
+      batch_size = options[:batch_size] || 1000
+
+      unless block_given?
+        return to_enum(:find_in_batches, options) do
+          total = start ? where(table[primary_key].gteq(start)).size : size
+          (total - 1).div(batch_size) + 1
+        end
+      end
 
       if logger && (arel.orders.present? || arel.taken.present?)
         logger.warn("Scoped order and limit are ignored, it's forced to be batch order and batch size")
       end
 
-      start = options[:start]
-      batch_size = options[:batch_size] || 1000
-
       relation = relation.reorder(batch_order).limit(batch_size)
       records = start ? relation.where(table[primary_key].gteq(start)).to_a : relation.to_a
 
diff --git a/activerecord/lib/active_record/result.rb b/activerecord/lib/active_record/result.rb
index 469451e2f4..228b2aa60f 100644
--- a/activerecord/lib/active_record/result.rb
+++ b/activerecord/lib/active_record/result.rb
@@ -54,7 +54,7 @@ module ActiveRecord
       if block_given?
         hash_rows.each { |row| yield row }
       else
-        hash_rows.to_enum
+        hash_rows.to_enum { @rows.size }
       end
     end