diff options
Diffstat (limited to 'activerecord/lib/active_record/statement_cache.rb')
-rw-r--r-- | activerecord/lib/active_record/statement_cache.rb | 61 |
1 files changed, 56 insertions, 5 deletions
diff --git a/activerecord/lib/active_record/statement_cache.rb b/activerecord/lib/active_record/statement_cache.rb index dd4ee0c4a0..8372d54c15 100644 --- a/activerecord/lib/active_record/statement_cache.rb +++ b/activerecord/lib/active_record/statement_cache.rb @@ -14,13 +14,64 @@ module ActiveRecord # 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? + Substitute = Struct.new :name + + class Params + def [](name); Substitute.new name; end + end + + class BindMap + def initialize(bind_values) + @value_map = {} + @bind_values = bind_values + + bind_values.each_with_index do |(column, value), i| + if Substitute === value + @value_map[value.name] = i + end + end + end + + def bind(values) + bvs = @bind_values.map { |pair| pair.dup } + values.each { |k,v| bvs[@value_map[k]][1] = v } + bvs + end + end + + def initialize(block = Proc.new) + @mutex = Mutex.new + @relation = nil + @sql = nil + @binds = nil + @block = block + @params = Params.new + end + + def execute(params) + rel = relation @params + + arel = rel.arel + klass = rel.klass + bv = binds rel + + klass.find_by_sql sql(klass, arel, bv), bv.bind(params) + end + alias :call :execute + + private + def binds(rel) + @binds || @mutex.synchronize { @binds ||= BindMap.new rel.bind_values } + end + + def sql(klass, arel, bv) + @sql || @mutex.synchronize { + @sql ||= klass.connection.to_sql arel, bv + } end - def execute - @relation.dup.to_a + def relation(values) + @relation || @mutex.synchronize { @relation ||= @block.call(values) } end end end |