graph

Documentation

Overview

Package graph provides an implement of cfn.Graph and can be used to graph dependencies between elements of a CloudFormation template

Example (Get)

package main

import (
	"fmt"

	"github.com/aws-cloudformation/rain/cfn/graph"
)

func main() {
	g := graph.New()
	g.Add("foo", "bar", "baz")
	g.Add("bar", "quux")
	g.Add("baz", "foo") // Circular dependencies are fine

	fmt.Println(g.Get("foo"))
	fmt.Println(g.Get("bar"))
	fmt.Println(g.Get("baz"))
}

Output:

[bar baz]
[quux]
[foo]

Example (GetReverse)

package main

import (
	"fmt"

	"github.com/aws-cloudformation/rain/cfn/graph"
)

func main() {
	g := graph.New()
	g.Add("foo", "bar", "baz")
	g.Add("bar", "quux", "baz")
	g.Add("baz", "foo") // Circular dependencies are fine

	fmt.Println(g.GetReverse("foo"))
	fmt.Println(g.GetReverse("bar"))
	fmt.Println(g.GetReverse("baz"))
}

Output:

[baz]
[foo]
[bar foo]

Example (Nodes)

package main

import (
	"fmt"

	"github.com/aws-cloudformation/rain/cfn/graph"
)

func main() {
	g := graph.New()
	g.Add("Cake", "Eggs", "Butter")
	g.Add("Eggs", "Chicken")
	g.Add("Dinner", "Chicken", "Cake")

	fmt.Println(g.Nodes())
}

Output:

[Butter Chicken Eggs Cake Dinner]

Index

• type Graph
  • func New() Graph
  • func (g *Graph) Add(item interface{}, links ...interface{})
  • func (g Graph) Get(item interface{}) []interface{}
  • func (g Graph) GetReverse(item interface{}) []interface{}
  • func (g Graph) Nodes() []interface{}
  • func (g *Graph) String() string

Examples

• Package (Get)
• Package (GetReverse)
• Package (Nodes)

Types

type Graph

type Graph struct {
	// contains filtered or unexported fields
}

Graph represents a directed, acyclic graph with ordered nodes

func New

func New() Graph

New returns a new Graph

func (*Graph) Add

func (g *Graph) Add(item interface{}, links ...interface{})

Add creates a link between two nodes in the graph

func (Graph) Get

func (g Graph) Get(item interface{}) []interface{}

Get returns all nodes that are connected to the item that you pass in.

func (Graph) GetReverse

func (g Graph) GetReverse(item interface{}) []interface{}

GetReverse returns all nodes that connect to the item that you pass in.

func (Graph) Nodes

func (g Graph) Nodes() []interface{}

Nodes returns all nodes of the graph, in order of their dependencies. Nodes with the fewest dependencies are at the beginning of the slice.

func (*Graph) String

func (g *Graph) String() string