45 lines
1.0 KiB
Go
45 lines
1.0 KiB
Go
package terraform
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import (
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"fmt"
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"github.com/hashicorp/terraform/dag"
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)
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// VertexTransformer is a GraphTransformer that transforms vertices
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// using the GraphVertexTransformers. The Transforms are run in sequential
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// order. If a transform replaces a vertex then the next transform will see
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// the new vertex.
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type VertexTransformer struct {
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Transforms []GraphVertexTransformer
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}
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func (t *VertexTransformer) Transform(g *Graph) error {
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for _, v := range g.Vertices() {
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for _, vt := range t.Transforms {
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newV, err := vt.Transform(v)
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if err != nil {
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return err
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}
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// If the vertex didn't change, then don't do anything more
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if newV == v {
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continue
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}
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// Vertex changed, replace it within the graph
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if ok := g.Replace(v, newV); !ok {
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// This should never happen, big problem
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return fmt.Errorf(
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"Failed to replace %s with %s!\n\nSource: %#v\n\nTarget: %#v",
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dag.VertexName(v), dag.VertexName(newV), v, newV)
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}
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// Replace v so that future transforms use the proper vertex
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v = newV
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}
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}
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return nil
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}
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