diff options
Diffstat (limited to 'activerecord/lib/active_record/collection_cache_key.rb')
-rw-r--r-- | activerecord/lib/active_record/collection_cache_key.rb | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/collection_cache_key.rb b/activerecord/lib/active_record/collection_cache_key.rb new file mode 100644 index 0000000000..43784b70e3 --- /dev/null +++ b/activerecord/lib/active_record/collection_cache_key.rb @@ -0,0 +1,39 @@ +module ActiveRecord + module CollectionCacheKey + def collection_cache_key(collection = all, timestamp_column = :updated_at) # :nodoc: + query_signature = Digest::MD5.hexdigest(collection.to_sql) + key = "#{collection.model_name.cache_key}/query-#{query_signature}" + + if collection.loaded? + size = collection.size + if size > 0 + timestamp = collection.max_by(×tamp_column).public_send(timestamp_column) + end + else + column_type = type_for_attribute(timestamp_column.to_s) + column = "#{connection.quote_table_name(collection.table_name)}.#{connection.quote_column_name(timestamp_column)}" + + query = collection + .unscope(:select) + .select("COUNT(*) AS #{connection.quote_column_name("size")}", "MAX(#{column}) AS timestamp") + .unscope(:order) + result = connection.select_one(query) + + if result.blank? + size = 0 + timestamp = nil + else + size = result["size"] + timestamp = column_type.deserialize(result["timestamp"]) + end + + end + + if timestamp + "#{key}-#{size}-#{timestamp.utc.to_s(cache_timestamp_format)}" + else + "#{key}-#{size}" + end + end + end +end |