perkeep/cmd/camget/graph.go

157 lines
3.1 KiB
Go

/*
Copyright 2012 Google Inc.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package main
import (
"fmt"
"io"
"log"
"strings"
"sync"
"camlistore.org/pkg/blob"
"camlistore.org/pkg/index"
"camlistore.org/pkg/schema"
)
func check(err error) {
if err != nil {
log.Fatal(err)
}
}
type node struct {
br blob.Ref
g *graph
size int64
blob *schema.Blob
edges []blob.Ref
}
func (n *node) dotName() string {
return strings.Replace(n.br.String(), "-", "_", -1)
}
func (n *node) dotLabel() string {
name := n.displayName()
if n.blob == nil {
return fmt.Sprintf("%s\n%d bytes", name, n.size)
}
return name + "\n" + n.blob.Type()
}
func (n *node) color() string {
if n.br == n.g.root {
return "#a0ffa0"
}
if n.blob == nil {
return "#aaaaaa"
}
return "#a0a0ff"
}
func (n *node) displayName() string {
s := n.br.String()
s = s[strings.Index(s, "-")+1:]
return s[:7]
}
func (n *node) load() {
defer n.g.wg.Done()
rc, err := fetch(n.g.src, n.br)
check(err)
defer rc.Close()
sniff := index.NewBlobSniffer(n.br)
n.size, err = io.Copy(sniff, rc)
check(err)
sniff.Parse()
blob, ok := sniff.SchemaBlob()
if !ok {
return
}
n.blob = blob
for _, part := range blob.ByteParts() {
n.addEdge(part.BlobRef)
n.addEdge(part.BytesRef)
}
}
func (n *node) addEdge(dst blob.Ref) {
if !dst.Valid() {
return
}
n.g.startLoadNode(dst)
n.edges = append(n.edges, dst)
}
type graph struct {
src blob.StreamingFetcher
root blob.Ref
mu sync.Mutex // guards n
n map[string]*node
wg sync.WaitGroup
}
func (g *graph) startLoadNode(br blob.Ref) {
g.mu.Lock()
defer g.mu.Unlock()
key := br.String()
if _, ok := g.n[key]; ok {
return
}
n := &node{
g: g,
br: br,
}
g.n[key] = n
g.wg.Add(1)
go n.load()
}
func printGraph(src blob.StreamingFetcher, root blob.Ref) {
g := &graph{
src: src,
root: root,
n: make(map[string]*node),
}
g.startLoadNode(root)
g.wg.Wait()
fmt.Println("digraph G {")
fmt.Println(" node [fontsize=10,fontname=Arial]")
fmt.Println(" edge [fontsize=10,fontname=Arial]")
for _, n := range g.n {
fmt.Printf("\n %s [label=%q,style=filled,fillcolor=%q]\n", n.dotName(), n.dotLabel(), n.color())
for i, e := range n.edges {
// TODO: create an edge type.
// Also, this edgeLabel is specific to file parts. Other schema
// types might not even have a concept of ordering. This is hack.
edgeLabel := fmt.Sprintf("%d", i)
if i == 0 {
edgeLabel = "first"
} else if i == len(n.edges)-1 {
edgeLabel = "last"
}
fmt.Printf(" %s -> %s [label=%q]\n", n.dotName(), g.n[e.String()].dotName(), edgeLabel)
}
}
fmt.Printf("}\n")
}