opentofu/addrs/output_value.go
Alisdair McDiarmid a43b035a51 core: Reduce string allocations for addrs Equal
Generating strings and comparing them to implement Equal is a quick and
easy solution. Unfortunately when this code is in the hot path, it
becomes very expensive, so this commit changes some of those instances
to compare the values directly.

Combined with using addr.Equal instead of checking for string equality,
this makes Terraform dramatically faster for some operations, such as
generating large JSON plans.
2021-03-05 13:23:32 -05:00

80 lines
2.3 KiB
Go

package addrs
import (
"fmt"
)
// OutputValue is the address of an output value, in the context of the module
// that is defining it.
//
// This is related to but separate from ModuleCallOutput, which represents
// a module output from the perspective of its parent module. Since output
// values cannot be represented from the module where they are defined,
// OutputValue is not Referenceable, while ModuleCallOutput is.
type OutputValue struct {
Name string
}
func (v OutputValue) String() string {
return "output." + v.Name
}
// Absolute converts the receiver into an absolute address within the given
// module instance.
func (v OutputValue) Absolute(m ModuleInstance) AbsOutputValue {
return AbsOutputValue{
Module: m,
OutputValue: v,
}
}
// AbsOutputValue is the absolute address of an output value within a module instance.
//
// This represents an output globally within the namespace of a particular
// configuration. It is related to but separate from ModuleCallOutput, which
// represents a module output from the perspective of its parent module.
type AbsOutputValue struct {
Module ModuleInstance
OutputValue OutputValue
}
// OutputValue returns the absolute address of an output value of the given
// name within the receiving module instance.
func (m ModuleInstance) OutputValue(name string) AbsOutputValue {
return AbsOutputValue{
Module: m,
OutputValue: OutputValue{
Name: name,
},
}
}
func (v AbsOutputValue) String() string {
if v.Module.IsRoot() {
return v.OutputValue.String()
}
return fmt.Sprintf("%s.%s", v.Module.String(), v.OutputValue.String())
}
func (v AbsOutputValue) Equal(o AbsOutputValue) bool {
return v.OutputValue == o.OutputValue && v.Module.Equal(o.Module)
}
// ModuleCallOutput converts an AbsModuleOutput into a ModuleCallOutput,
// returning also the module instance that the ModuleCallOutput is relative
// to.
//
// The root module does not have a call, and so this method cannot be used
// with outputs in the root module, and will panic in that case.
func (v AbsOutputValue) ModuleCallOutput() (ModuleInstance, AbsModuleCallOutput) {
if v.Module.IsRoot() {
panic("ReferenceFromCall used with root module output")
}
caller, call := v.Module.CallInstance()
return caller, AbsModuleCallOutput{
Call: call,
Name: v.OutputValue.Name,
}
}