forked from cayleygraph/cayley
/
stream.go
393 lines (358 loc) · 8.74 KB
/
stream.go
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package gephi
import (
"bytes"
"encoding/json"
"fmt"
"io"
"math/rand"
"net/http"
"strconv"
"strings"
"github.com/julienschmidt/httprouter"
"golang.org/x/net/context"
"github.com/cayleygraph/cayley/clog"
"github.com/cayleygraph/cayley/graph"
"github.com/cayleygraph/cayley/graph/iterator"
"github.com/cayleygraph/cayley/graph/path"
"github.com/cayleygraph/cayley/quad"
"github.com/cayleygraph/cayley/voc/rdf"
"github.com/cayleygraph/cayley/voc/rdfs"
"github.com/cayleygraph/cayley/voc/schema"
)
const (
defaultLimit = 10000
defaultSize = 20
limitCoord = 500
)
const (
iriInlinePred = quad.IRI("gephi:inline")
iriPosX = quad.IRI("gephi:x")
iriPosY = quad.IRI("gephi:y")
)
var defaultInline = []quad.IRI{
iriPosX, iriPosY,
rdf.Type,
rdfs.Label,
schema.Name,
schema.UrlProp,
}
type GraphStreamHandler struct {
QS graph.QuadStore
}
type valHash [quad.HashSize]byte
type GraphStream struct {
seen map[valHash]int
buf *bytes.Buffer
w io.Writer
}
func printNodeID(id int) string {
return strconv.FormatInt(int64(id), 16)
}
func NewGraphStream(w io.Writer) *GraphStream {
return &GraphStream{
w: w,
seen: make(map[valHash]int),
buf: bytes.NewBuffer(nil),
}
}
func toNodeLabel(v quad.Value) string {
if v == nil {
return ""
}
return fmt.Sprint(v.Native())
}
func randCoord() float64 {
return (rand.Float64() - 0.5) * limitCoord * 2
}
func randPos() (x float64, y float64) {
x = randCoord()
x2 := x * x
for y = randCoord(); x2+y*y > limitCoord*limitCoord; y = randCoord() {
}
return
}
func setStringProp(v *string, props map[quad.Value]quad.Value, name quad.IRI) {
if p, ok := props[name]; ok {
if s, ok := p.Native().(string); ok {
*v = s
}
}
}
func (gs *GraphStream) makeOneNode(id string, v quad.Value, props map[quad.Value]quad.Value) map[string]streamNode {
x, y := randPos()
var xok, yok bool
if p, ok := props[iriPosX]; ok {
xok = true
switch p := p.(type) {
case quad.Int:
x = float64(p)
case quad.Float:
x = float64(p)
default:
xok = false
}
}
if p, ok := props[iriPosY]; ok {
yok = true
switch p := p.(type) {
case quad.Int:
y = float64(p)
case quad.Float:
y = float64(p)
default:
yok = false
}
}
var slabel string
setStringProp(&slabel, props, rdfs.Label)
setStringProp(&slabel, props, schema.Name)
var label interface{}
if slabel != "" {
label = slabel
} else {
label = v.Native()
}
node := streamNode{
"label": label,
"size": defaultSize, "x": x, "y": y,
}
for k, v := range props {
if k == nil || v == nil ||
(k == iriPosX && xok) ||
(k == iriPosY && yok) {
continue
}
node[toNodeLabel(k)] = toNodeLabel(v)
}
return map[string]streamNode{id: node}
}
func (gs *GraphStream) AddNode(v quad.Value, props map[quad.Value]quad.Value) string {
var h valHash
quad.HashTo(v, h[:])
return gs.addNode(v, h, props)
}
func (gs *GraphStream) encode(o interface{}) {
data, _ := json.Marshal(o)
gs.buf.Write(data)
// Gephi requires \r character at the end of each line
gs.buf.WriteString("\r\n")
}
func (gs *GraphStream) addNode(v quad.Value, h valHash, props map[quad.Value]quad.Value) string {
id, ok := gs.seen[h]
if ok {
return printNodeID(id)
} else if v == nil {
return ""
}
id = len(gs.seen)
gs.seen[h] = id
sid := printNodeID(id)
m := gs.makeOneNode(sid, v, props)
gs.encode(graphStreamEvent{AddNodes: m})
return sid
}
func (gs *GraphStream) ChangeNode(v quad.Value, sid string, props map[quad.Value]quad.Value) {
m := gs.makeOneNode(sid, v, props)
gs.encode(graphStreamEvent{ChangeNodes: m})
}
func (gs *GraphStream) AddEdge(i int, s, o string, p quad.Value) {
id := "q" + strconv.FormatInt(int64(i), 16)
ps := toNodeLabel(p)
gs.encode(graphStreamEvent{
AddEdges: map[string]streamEdge{id: {
Subject: s,
Predicate: ps, Label: ps,
Object: o,
}},
})
}
func (gs *GraphStream) Flush() error {
if gs.buf.Len() == 0 {
return nil
}
_, err := gs.buf.WriteTo(gs.w)
if err == nil {
gs.buf.Reset()
}
return err
}
type streamNode map[string]interface{}
type streamEdge struct {
Subject string `json:"source"`
Label string `json:"label"`
Predicate string `json:"pred"`
Object string `json:"target"`
}
type graphStreamEvent struct {
AddNodes map[string]streamNode `json:"an,omitempty"`
ChangeNodes map[string]streamNode `json:"cn,omitempty"`
DelNodes map[string]streamNode `json:"dn,omitempty"`
AddEdges map[string]streamEdge `json:"ae,omitempty"`
ChangeEdges map[string]streamEdge `json:"ce,omitempty"`
DelEdges map[string]streamEdge `json:"de,omitempty"`
}
func (s *GraphStreamHandler) serveRawQuads(ctx context.Context, gs *GraphStream, sub, pred, obj, label []quad.Value, limit int) {
var it graph.Iterator
if len(sub)+len(pred)+len(obj)+len(label) == 0 {
it = s.QS.QuadsAllIterator()
} else {
var subIt []graph.Iterator
linksTo := func(d quad.Direction, vals []quad.Value) {
if len(vals) == 0 {
return
}
fixed := s.QS.FixedIterator()
for _, v := range vals {
fixed.Add(s.QS.ValueOf(v))
}
subIt = append(subIt, iterator.NewLinksTo(s.QS, fixed, d))
}
linksTo(quad.Subject, sub)
linksTo(quad.Predicate, pred)
linksTo(quad.Object, obj)
linksTo(quad.Label, label)
it = iterator.NewAnd(s.QS, subIt...)
}
defer it.Close()
var sh, oh valHash
for i := 0; (limit < 0 || i < limit) && it.Next(); i++ {
qv := it.Result()
if qv == nil {
continue
}
q := s.QS.Quad(qv)
quad.HashTo(q.Subject, sh[:])
quad.HashTo(q.Object, oh[:])
s, o := gs.addNode(q.Subject, sh, nil), gs.addNode(q.Object, oh, nil)
if s == "" || o == "" {
continue
}
gs.AddEdge(i, s, o, q.Predicate)
if err := gs.Flush(); err != nil {
return
}
}
}
func shouldInline(v quad.Value) bool {
switch v.(type) {
case quad.Bool, quad.Int, quad.Float:
return true
}
return false
}
func (s *GraphStreamHandler) serveNodesWithProps(ctx context.Context, gs *GraphStream, limit int) {
propsPath := path.NewPath(s.QS).Has(iriInlinePred, quad.Bool(true))
// list of predicates marked as inline properties for gephi
inline := make(map[quad.Value]struct{})
err := propsPath.Iterate(ctx).EachValue(s.QS, func(v quad.Value) {
inline[v] = struct{}{}
})
if err != nil {
clog.Errorf("cannot iterate over properties: %v", err)
return
}
// inline some well-known predicates
for _, iri := range defaultInline {
inline[iri] = struct{}{}
inline[iri.Full()] = struct{}{}
}
ignore := make(map[quad.Value]struct{})
nodes := iterator.NewNot(propsPath.BuildIterator(), s.QS.NodesAllIterator())
defer nodes.Close()
ictx, cancel := context.WithCancel(ctx)
defer cancel()
itc := graph.Iterate(ictx, nodes).On(s.QS).Limit(limit)
qi := 0
_ = itc.EachValuePair(s.QS, func(v graph.Value, nv quad.Value) {
if _, skip := ignore[nv]; skip {
return
}
// list of inline properties
props := make(map[quad.Value]quad.Value)
var (
sid string
h, oh valHash
)
quad.HashTo(nv, h[:])
predIt := s.QS.QuadIterator(quad.Subject, nodes.Result())
defer predIt.Close()
for predIt.Next() {
// this check helps us ignore nodes with no links
if sid == "" {
sid = gs.addNode(nv, h, props)
}
q := s.QS.Quad(predIt.Result())
if _, ok := inline[q.Predicate]; ok {
props[q.Predicate] = q.Object
ignore[q.Object] = struct{}{}
} else if shouldInline(q.Object) {
props[q.Predicate] = q.Object
} else {
quad.HashTo(q.Object, oh[:])
o := gs.addNode(q.Object, oh, nil)
if o == "" {
continue
}
gs.AddEdge(qi, sid, o, q.Predicate)
qi++
if err := gs.Flush(); err != nil {
cancel()
return
}
}
}
if err := predIt.Err(); err != nil {
cancel()
return
} else if sid == "" {
return
}
if len(props) != 0 {
gs.ChangeNode(nv, sid, props)
}
if err := gs.Flush(); err != nil {
cancel()
return
}
})
}
func valuesFromString(s string) []quad.Value {
if s == "" {
return nil
}
arr := strings.Split(s, ",")
out := make([]quad.Value, 0, len(arr))
for _, s := range arr {
out = append(out, quad.StringToValue(s))
}
return out
}
func (s *GraphStreamHandler) ServeHTTP(w http.ResponseWriter, r *http.Request, params httprouter.Params) {
ctx := context.TODO()
var limit int
if s := r.FormValue("limit"); s != "" {
limit, _ = strconv.Atoi(s)
}
if limit == 0 {
limit = defaultLimit
}
mode := "raw"
if s := r.FormValue("mode"); s != "" {
mode = s
}
w.Header().Set("Content-Type", "application/stream+json")
gs := NewGraphStream(w)
switch mode {
case "nodes":
s.serveNodesWithProps(ctx, gs, limit)
case "raw":
sub := valuesFromString(r.FormValue("sub"))
pred := valuesFromString(r.FormValue("pred"))
obj := valuesFromString(r.FormValue("obj"))
label := valuesFromString(r.FormValue("label"))
s.serveRawQuads(ctx, gs, sub, pred, obj, label, limit)
default:
w.WriteHeader(http.StatusBadRequest)
return
}
}