vendor/github.com/hashicorp/terraform/terraform/transform_vertex.go

   1 package terraform
   2
   3 import (
   4         "fmt"
   5
   6         "github.com/hashicorp/terraform/dag"
   7 )
   8
   9 // VertexTransformer is a GraphTransformer that transforms vertices
  10 // using the GraphVertexTransformers. The Transforms are run in sequential
  11 // order. If a transform replaces a vertex then the next transform will see
  12 // the new vertex.
  13 type VertexTransformer struct {
  14         Transforms []GraphVertexTransformer
  15 }
  16
  17 func (t *VertexTransformer) Transform(g *Graph) error {
  18         for _, v := range g.Vertices() {
  19                 for _, vt := range t.Transforms {
  20                         newV, err := vt.Transform(v)
  21                         if err != nil {
  22                                 return err
  23                         }
  24
  25                         // If the vertex didn't change, then don't do anything more
  26                         if newV == v {
  27                                 continue
  28                         }
  29
  30                         // Vertex changed, replace it within the graph
  31                         if ok := g.Replace(v, newV); !ok {
  32                                 // This should never happen, big problem
  33                                 return fmt.Errorf(
  34                                         "Failed to replace %s with %s!\n\nSource: %#v\n\nTarget: %#v",
  35                                         dag.VertexName(v), dag.VertexName(newV), v, newV)
  36                         }
  37
  38                         // Replace v so that future transforms use the proper vertex
  39                         v = newV
  40                 }
  41         }
  42
  43         return nil
  44 }