1package terraform 2 3import ( 4 "log" 5 6 "github.com/hashicorp/terraform/internal/dag" 7 "github.com/hashicorp/terraform/internal/logging" 8) 9 10// GraphTransformer is the interface that transformers implement. This 11// interface is only for transforms that need entire graph visibility. 12type GraphTransformer interface { 13 Transform(*Graph) error 14} 15 16// GraphVertexTransformer is an interface that transforms a single 17// Vertex within with graph. This is a specialization of GraphTransformer 18// that makes it easy to do vertex replacement. 19// 20// The GraphTransformer that runs through the GraphVertexTransformers is 21// VertexTransformer. 22type GraphVertexTransformer interface { 23 Transform(dag.Vertex) (dag.Vertex, error) 24} 25 26type graphTransformerMulti struct { 27 Transforms []GraphTransformer 28} 29 30func (t *graphTransformerMulti) Transform(g *Graph) error { 31 var lastStepStr string 32 for _, t := range t.Transforms { 33 log.Printf("[TRACE] (graphTransformerMulti) Executing graph transform %T", t) 34 if err := t.Transform(g); err != nil { 35 return err 36 } 37 if thisStepStr := g.StringWithNodeTypes(); thisStepStr != lastStepStr { 38 log.Printf("[TRACE] (graphTransformerMulti) Completed graph transform %T with new graph:\n%s ------", t, logging.Indent(thisStepStr)) 39 lastStepStr = thisStepStr 40 } else { 41 log.Printf("[TRACE] (graphTransformerMulti) Completed graph transform %T (no changes)", t) 42 } 43 } 44 45 return nil 46} 47 48// GraphTransformMulti combines multiple graph transformers into a single 49// GraphTransformer that runs all the individual graph transformers. 50func GraphTransformMulti(ts ...GraphTransformer) GraphTransformer { 51 return &graphTransformerMulti{Transforms: ts} 52} 53