terraform/internal/terraform/transform.go

53 lines
1.6 KiB
Go

package terraform
import (
"log"
"github.com/hashicorp/terraform/internal/dag"
"github.com/hashicorp/terraform/internal/logging"
)
// GraphTransformer is the interface that transformers implement. This
// interface is only for transforms that need entire graph visibility.
type GraphTransformer interface {
Transform(*Graph) error
}
// GraphVertexTransformer is an interface that transforms a single
// Vertex within with graph. This is a specialization of GraphTransformer
// that makes it easy to do vertex replacement.
//
// The GraphTransformer that runs through the GraphVertexTransformers is
// VertexTransformer.
type GraphVertexTransformer interface {
Transform(dag.Vertex) (dag.Vertex, error)
}
type graphTransformerMulti struct {
Transforms []GraphTransformer
}
func (t *graphTransformerMulti) Transform(g *Graph) error {
var lastStepStr string
for _, t := range t.Transforms {
log.Printf("[TRACE] (graphTransformerMulti) Executing graph transform %T", t)
if err := t.Transform(g); err != nil {
return err
}
if thisStepStr := g.StringWithNodeTypes(); thisStepStr != lastStepStr {
log.Printf("[TRACE] (graphTransformerMulti) Completed graph transform %T with new graph:\n%s ------", t, logging.Indent(thisStepStr))
lastStepStr = thisStepStr
} else {
log.Printf("[TRACE] (graphTransformerMulti) Completed graph transform %T (no changes)", t)
}
}
return nil
}
// GraphTransformMulti combines multiple graph transformers into a single
// GraphTransformer that runs all the individual graph transformers.
func GraphTransformMulti(ts ...GraphTransformer) GraphTransformer {
return &graphTransformerMulti{Transforms: ts}
}