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Diffstat (limited to 'activerecord/lib/active_record/statement_cache.rb')
-rw-r--r-- | activerecord/lib/active_record/statement_cache.rb | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/statement_cache.rb b/activerecord/lib/active_record/statement_cache.rb new file mode 100644 index 0000000000..dd4ee0c4a0 --- /dev/null +++ b/activerecord/lib/active_record/statement_cache.rb @@ -0,0 +1,26 @@ +module ActiveRecord + + # Statement cache is used to cache a single statement in order to avoid creating the AST again. + # Initializing the cache is done by passing the statement in the initialization block: + # + # cache = ActiveRecord::StatementCache.new do + # Book.where(name: "my book").limit(100) + # end + # + # The cached statement is executed by using the +execute+ method: + # + # cache.execute + # + # The relation returned by the block is cached, and for each +execute+ call the cached relation gets duped. + # Database is queried when +to_a+ is called on the relation. + class StatementCache + def initialize + @relation = yield + raise ArgumentError.new("Statement cannot be nil") if @relation.nil? + end + + def execute + @relation.dup.to_a + end + end +end |