dot.go

Documentation: edge-infra.dev/pkg/lib/text/drawing

     1  package drawing
     2  
     3  import (
     4  	"bytes"
     5  	"fmt"
     6  	"io"
     7  	"os"
     8  )
     9  
    10  type Digraph struct {
    11  	Title     string
    12  	Subgraphs []Subgraph
    13  }
    14  
    15  type Subgraph interface {
    16  	Print()
    17  	Fprint(w io.Writer)
    18  }
    19  
    20  type DotNode struct {
    21  	Data       string
    22  	Children   []*DotNode
    23  	Attributes map[string]string
    24  }
    25  
    26  type DotTree struct {
    27  	Root       *DotNode
    28  	Nodes      map[string]*DotNode
    29  	Attributes map[string]string
    30  }
    31  
    32  func (d *Digraph) String() string {
    33  	buf := &bytes.Buffer{}
    34  	d.Fprint(buf)
    35  	return buf.String()
    36  }
    37  
    38  func (d *Digraph) Print() {
    39  	d.Fprint(os.Stdout)
    40  }
    41  
    42  func (d *Digraph) Fprint(w io.Writer) {
    43  	fmt.Fprintf(w, "strict digraph \"%v\" {\n", d.Title)
    44  
    45  	for _, sub := range d.Subgraphs {
    46  		sub.Fprint(w)
    47  	}
    48  
    49  	fmt.Fprintln(w, "}")
    50  }
    51  
    52  func (t *DotTree) Print() {
    53  	t.Fprint(os.Stdout)
    54  }
    55  
    56  func (t *DotTree) Fprint(w io.Writer) {
    57  	fmt.Fprintf(w, "subgraph \"cluster_%v\" {\n", t.Root.Data)
    58  	for attr, val := range t.Attributes {
    59  		fmt.Fprintf(w, `%s%s=%s%s`, "\t", attr, val, "\n")
    60  	}
    61  	t.Root.print(w)
    62  	fmt.Fprintln(w, "}")
    63  }
    64  
    65  func (node *DotNode) print(w io.Writer) {
    66  	// for edges from node N to child C
    67  	for _, child := range node.Children {
    68  		// write N
    69  		nodeAttrs := ""
    70  		if len(node.Attributes) > 0 {
    71  			nodeAttrs += " ["
    72  			for attr, val := range node.Attributes {
    73  				nodeAttrs += fmt.Sprintf(`%s=%s `, attr, val)
    74  			}
    75  			nodeAttrs += "]"
    76  		}
    77  		fmt.Fprintf(w, `"%s"%s%s`, node.Data, nodeAttrs, "\n")
    78  
    79  		// write C
    80  		childAttrs := ""
    81  		if len(child.Attributes) > 0 {
    82  			childAttrs += " ["
    83  			for attr, val := range child.Attributes {
    84  				childAttrs += fmt.Sprintf(`%s=%s `, attr, val)
    85  			}
    86  			childAttrs += "]"
    87  		}
    88  		fmt.Fprintf(w, `"%s"%s%s`, child.Data, childAttrs, "\n")
    89  
    90  		// write N->C
    91  		fmt.Fprintf(w, `"%s" -> "%s"%s`, node.Data, child.Data, "\n")
    92  
    93  		// repeat for children of C
    94  		child.print(w)
    95  	}
    96  }
    97
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