Golang schema.EdgeDirection函數代碼示例

func edgeKindLess(kind1, kind2 string) bool {
	// General ordering:
	//   anchor edge kinds before non-anchor edge kinds
	//   forward edges before reverse edges
	//   edgeOrdering[i] (and variants) before edgeOrdering[i+1:]
	//   edge variants after root edge kind (ordered lexicographically)
	//   otherwise, order lexicographically

	if kind1 == kind2 {
		return false
	} else if a1, a2 := schema.IsAnchorEdge(kind1), schema.IsAnchorEdge(kind2); a1 != a2 {
		return a1
	} else if d1, d2 := schema.EdgeDirection(kind1), schema.EdgeDirection(kind2); d1 != d2 {
		return d1 == schema.Forward
	}
	kind1, kind2 = schema.Canonicalize(kind1), schema.Canonicalize(kind2)
	for _, kind := range edgeOrdering {
		if kind1 == kind {
			return true
		} else if kind2 == kind {
			return false
		} else if v1, v2 := schema.IsEdgeVariant(kind1, kind), schema.IsEdgeVariant(kind2, kind); v1 != v2 {
			return v1
		} else if v1 {
			return kind1 < kind2
		}
	}
	return kind1 < kind2
}

func addReverseEdges(ctx context.Context, gs graphstore.Service) error {
	log.Println("Adding reverse edges")
	var (
		totalEntries int
		addedEdges   int
	)
	startTime := time.Now()
	err := gs.Scan(ctx, new(spb.ScanRequest), func(entry *spb.Entry) error {
		kind := entry.EdgeKind
		if kind != "" && schema.EdgeDirection(kind) == schema.Forward {
			if err := gs.Write(ctx, &spb.WriteRequest{
				Source: entry.Target,
				Update: []*spb.WriteRequest_Update{{
					Target:    entry.Source,
					EdgeKind:  schema.MirrorEdge(kind),
					FactName:  entry.FactName,
					FactValue: entry.FactValue,
				}},
			}); err != nil {
				return fmt.Errorf("Failed to write reverse edge: %v", err)
			}
			addedEdges++
		}
		totalEntries++
		return nil
	})
	log.Printf("Wrote %d reverse edges to GraphStore (%d total entries): %v", addedEdges, totalEntries, time.Since(startTime))
	return err
}

// EnsureReverseEdges checks if gs contains reverse edges.  If it doesn't, it
// will scan gs for all forward edges, adding a reverse for each back into the
// GraphStore.  This is necessary for a GraphStoreService to work properly.
func EnsureReverseEdges(ctx context.Context, gs graphstore.Service) error {
	var edge *spb.Entry
	if err := gs.Scan(ctx, &spb.ScanRequest{}, func(e *spb.Entry) error {
		if graphstore.IsEdge(e) {
			edge = e
			return io.EOF
		}
		return nil
	}); err != nil {
		return err
	}

	if edge == nil {
		log.Println("No edges found in GraphStore")
		return nil
	} else if schema.EdgeDirection(edge.EdgeKind) == schema.Reverse {
		return nil
	}

	var foundReverse bool
	if err := gs.Read(ctx, &spb.ReadRequest{
		Source:   edge.Target,
		EdgeKind: schema.MirrorEdge(edge.EdgeKind),
	}, func(entry *spb.Entry) error {
		foundReverse = true
		return nil
	}); err != nil {
		return fmt.Errorf("error checking for reverse edge: %v", err)
	}
	if foundReverse {
		return nil
	}
	return addReverseEdges(ctx, gs)
}

func getDecorations(ctx context.Context, es xrefs.EdgesService, anchor *xpb.NodeInfo) ([]*srvpb.FileDecorations_Decoration, error) {
	var (
		isAnchor   bool
		start, end int
		err        error
	)
	for _, f := range anchor.Fact {
		switch f.Name {
		case schema.NodeKindFact:
			if string(f.Value) == schema.AnchorKind {
				isAnchor = true
			}
		case schema.AnchorStartFact:
			start, err = strconv.Atoi(string(f.Value))
			if err != nil {
				return nil, fmt.Errorf("invalid anchor %q start offset: %q", anchor.Ticket, string(f.Value))
			}
		case schema.AnchorEndFact:
			end, err = strconv.Atoi(string(f.Value))
			if err != nil {
				return nil, fmt.Errorf("invalid anchor %q end offset: %q", anchor.Ticket, string(f.Value))
			}
		}
	}
	if !isAnchor {
		return nil, nil
	} else if start > end {
		log.Printf("Invalid anchor span %d:%d for %q", start, end, anchor.Ticket)
		return nil, nil
	}

	edges, err := es.Edges(ctx, &xpb.EdgesRequest{Ticket: []string{anchor.Ticket}})
	if err != nil {
		return nil, err
	}
	if len(edges.EdgeSet) != 1 {
		return nil, fmt.Errorf("invalid number of EdgeSets returned for anchor: %d", len(edges.EdgeSet))
	}

	a := &srvpb.FileDecorations_Decoration_Anchor{
		Ticket:      anchor.Ticket,
		StartOffset: int32(start),
		EndOffset:   int32(end),
	}
	var ds []*srvpb.FileDecorations_Decoration
	for _, grp := range edges.EdgeSet[0].Group {
		if schema.EdgeDirection(grp.Kind) == schema.Forward && grp.Kind != schema.ChildOfEdge {
			for _, target := range grp.TargetTicket {
				ds = append(ds, &srvpb.FileDecorations_Decoration{
					Anchor:       a,
					Kind:         grp.Kind,
					TargetTicket: target,
				})
			}
		}
	}
	return ds, nil
}

func filterReverses(rd stream.EntryReader) stream.EntryReader {
	return func(f func(*spb.Entry) error) error {
		return rd(func(e *spb.Entry) error {
			if graphstore.IsNodeFact(e) || schema.EdgeDirection(e.EdgeKind) == schema.Forward {
				return f(e)
			}
			return nil
		})
	}
}

// ToString returns a human-readable string representation of p.
func ToString(p *ipb.Path) string {
	s := "**" + p.Pivot.NodeKind + "**"
	for _, e := range p.Edges {
		if schema.EdgeDirection(e.Kind) == schema.Forward {
			s += fmt.Sprintf(" -[%s]> %s", e.Kind, e.Target.NodeKind)
		} else {
			s += fmt.Sprintf(" <[%s]- %s", schema.MirrorEdge(e.Kind), e.Target.NodeKind)
		}
	}
	return s
}

// expandEdgeKind prefixes unrooted (not starting with "/") edge kinds with the
// standard Kythe edge prefix ("/kythe/edge/").
func expandEdgeKind(kind string) string {
	ck := schema.Canonicalize(kind)
	if strings.HasPrefix(ck, "/") {
		return kind
	}

	expansion := schema.EdgePrefix + ck
	if schema.EdgeDirection(kind) == schema.Reverse {
		return schema.MirrorEdge(expansion)
	}
	return expansion
}

// FromSource creates a set of *ipb.Paths for each of its edges as well as a
// single *ipb.Path with only its pivot set to be the source node.
func FromSource(src *ipb.Source) []*ipb.Path {
	var paths []*ipb.Path

	n := specialize(assemble.Node(src))
	paths = append(paths, &ipb.Path{Pivot: n})
	for kind, group := range src.EdgeGroups {
		if schema.EdgeDirection(kind) != schema.Forward {
			continue
		}
		for _, tgt := range group.Edges {
			paths = append(paths, &ipb.Path{
				Pivot: &ipb.Path_Node{
					Ticket: tgt.Ticket,
				},
				Edges: []*ipb.Path_Edge{{
					Kind:    schema.MirrorEdge(kind),
					Ordinal: int32(tgt.Ordinal),
					Target:  n,
				}},
			})
		}
	}
	return paths
}

// Run writes the xrefs and filetree serving tables to db based on the given
// graphstore.Service.
func Run(ctx context.Context, gs graphstore.Service, db keyvalue.DB, opts *Options) error {
	if opts == nil {
		opts = new(Options)
	}

	log.Println("Starting serving pipeline")

	out := &servingOutput{
		xs:  table.ProtoBatchParallel{&table.KVProto{DB: db}},
		idx: &table.KVInverted{DB: db},
	}
	entries := make(chan *spb.Entry, chBuf)

	var cErr error
	var wg sync.WaitGroup
	var sortedEdges disksort.Interface
	wg.Add(1)
	go func() {
		sortedEdges, cErr = combineNodesAndEdges(ctx, opts, out, entries)
		if cErr != nil {
			cErr = fmt.Errorf("error combining nodes and edges: %v", cErr)
		}
		wg.Done()
	}()

	err := gs.Scan(ctx, &spb.ScanRequest{}, func(e *spb.Entry) error {
		if graphstore.IsNodeFact(e) || schema.EdgeDirection(e.EdgeKind) == schema.Forward {
			entries <- e
		}
		return nil
	})
	close(entries)
	if err != nil {
		return fmt.Errorf("error scanning GraphStore: %v", err)
	}

	wg.Wait()
	if cErr != nil {
		return cErr
	}

	pesIn, dIn := make(chan *srvpb.Edge, chBuf), make(chan *srvpb.Edge, chBuf)
	var pErr, fErr error
	wg.Add(2)
	go func() {
		defer wg.Done()
		if err := writePagedEdges(ctx, pesIn, out.xs, opts); err != nil {
			pErr = fmt.Errorf("error writing paged edge sets: %v", err)
		}
	}()
	go func() {
		defer wg.Done()
		if err := writeDecorAndRefs(ctx, opts, dIn, out); err != nil {
			fErr = fmt.Errorf("error writing file decorations: %v", err)
		}
	}()

	err = sortedEdges.Read(func(x interface{}) error {
		e := x.(*srvpb.Edge)
		pesIn <- e
		dIn <- e
		return nil
	})
	close(pesIn)
	close(dIn)
	if err != nil {
		return fmt.Errorf("error reading edges table: %v", err)
	}

	wg.Wait()
	if pErr != nil {
		return pErr
	}
	return fErr
}

//.........這裏部分代碼省略.........
		children, err := getEdges(ctx, g.gs, fileVName, func(e *spb.Entry) bool {
			return e.EdgeKind == revChildOfEdgeKind
		})
		if err != nil {
			return nil, fmt.Errorf("failed to retrieve file children: %v", err)
		}

		targetSet := stringset.New()
		for _, edge := range children {
			anchor := edge.Target
			ticket := kytheuri.ToString(anchor)
			anchorNodeReply, err := g.Nodes(ctx, &xpb.NodesRequest{
				Ticket: []string{ticket},
			})
			if err != nil {
				return nil, fmt.Errorf("failure getting reference source node: %v", err)
			} else if len(anchorNodeReply.Nodes) != 1 {
				return nil, fmt.Errorf("found %d nodes for {%+v}", len(anchorNodeReply.Nodes), anchor)
			}

			node, ok := xrefs.NodesMap(anchorNodeReply.Nodes)[ticket]
			if !ok {
				return nil, fmt.Errorf("failed to find info for node %q", ticket)
			} else if string(node[schema.NodeKindFact]) != schema.AnchorKind {
				// Skip child if it isn't an anchor node
				continue
			}

			anchorStart, err := strconv.Atoi(string(node[schema.AnchorStartFact]))
			if err != nil {
				log.Printf("Invalid anchor start offset %q for node %q: %v", node[schema.AnchorStartFact], ticket, err)
				continue
			}
			anchorEnd, err := strconv.Atoi(string(node[schema.AnchorEndFact]))
			if err != nil {
				log.Printf("Invalid anchor end offset %q for node %q: %v", node[schema.AnchorEndFact], ticket, err)
				continue
			}

			if loc.Kind == xpb.Location_SPAN {
				// Check if anchor fits within/around requested source text window
				if !xrefs.InSpanBounds(req.SpanKind, int32(anchorStart), int32(anchorEnd), loc.Start.ByteOffset, loc.End.ByteOffset) {
					continue
				} else if anchorStart > anchorEnd {
					log.Printf("Invalid anchor offset span %d:%d", anchorStart, anchorEnd)
					continue
				}
			}

			targets, err := getEdges(ctx, g.gs, anchor, func(e *spb.Entry) bool {
				return schema.EdgeDirection(e.EdgeKind) == schema.Forward && e.EdgeKind != schema.ChildOfEdge
			})
			if err != nil {
				return nil, fmt.Errorf("failed to retrieve targets of anchor %v: %v", anchor, err)
			}
			if len(targets) == 0 {
				log.Printf("Anchor missing forward edges: {%+v}", anchor)
				continue
			}

			if node := filterNode(patterns, anchorNodeReply.Nodes[ticket]); node != nil {
				reply.Nodes[ticket] = node
			}
			for _, edge := range targets {
				targetTicket := kytheuri.ToString(edge.Target)
				targetSet.Add(targetTicket)
				reply.Reference = append(reply.Reference, &xpb.DecorationsReply_Reference{
					SourceTicket: ticket,
					Kind:         edge.Kind,
					TargetTicket: targetTicket,
					AnchorStart:  norm.ByteOffset(int32(anchorStart)),
					AnchorEnd:    norm.ByteOffset(int32(anchorEnd)),
				})
			}
		}
		sort.Sort(bySpan(reply.Reference))

		// Only request Nodes when there are fact filters given.
		if len(req.Filter) > 0 {
			// Ensure returned nodes are not duplicated.
			for ticket := range reply.Nodes {
				targetSet.Remove(ticket)
			}

			// Batch request all Reference target nodes
			nodesReply, err := g.Nodes(ctx, &xpb.NodesRequest{
				Ticket: targetSet.Slice(),
				Filter: req.Filter,
			})
			if err != nil {
				return nil, fmt.Errorf("failure getting reference target nodes: %v", err)
			}
			for ticket, node := range nodesReply.Nodes {
				reply.Nodes[ticket] = node
			}
		}
	}

	return reply, nil
}

func displayEdgeGraph(reply *xpb.EdgesReply) error {
	nodes := xrefs.NodesMap(reply.Nodes)
	edges := make(map[string]map[string]stringset.Set)

	for source, es := range reply.EdgeSets {
		for gKind, g := range es.Groups {
			for _, edge := range g.Edge {
				tgt := edge.TargetTicket
				src, kind := source, gKind
				if schema.EdgeDirection(kind) == schema.Reverse {
					src, kind, tgt = tgt, schema.MirrorEdge(kind), src
				}
				groups, ok := edges[src]
				if !ok {
					groups = make(map[string]stringset.Set)
					edges[src] = groups
				}
				targets, ok := groups[kind]
				if !ok {
					targets = stringset.New()
					groups[kind] = targets
				}
				targets.Add(tgt)
			}
		}
	}
	if _, err := fmt.Println("digraph kythe {"); err != nil {
		return err
	}
	for ticket, node := range nodes {
		if _, err := fmt.Printf(`	%q [label=<<table><tr><td colspan="2">%s</td></tr>`, ticket, html.EscapeString(ticket)); err != nil {
			return err
		}
		var facts []string
		for fact := range node {
			facts = append(facts, fact)
		}
		sort.Strings(facts)
		for _, fact := range facts {
			if _, err := fmt.Printf("<tr><td>%s</td><td>%s</td></tr>", html.EscapeString(fact), html.EscapeString(string(node[fact]))); err != nil {
				return err
			}
		}
		if _, err := fmt.Println("</table>> shape=plaintext];"); err != nil {
			return err
		}
	}
	if _, err := fmt.Println(); err != nil {
		return err
	}

	for src, groups := range edges {
		for kind, targets := range groups {
			for tgt := range targets {
				if _, err := fmt.Printf("\t%q -> %q [label=%q];\n", src, tgt, kind); err != nil {
					return err
				}
			}
		}
	}
	if _, err := fmt.Println("}"); err != nil {
		return err
	}
	return nil
}

func main() {
	flag.Parse()

	if len(flag.Args()) > 2 || (gs != nil && len(flag.Args()) > 1) {
		fmt.Fprintf(os.Stderr, "ERROR: too many arguments %v\n", flag.Args())
		flag.Usage()
		os.Exit(1)
	}

	if gs != nil {
		defer gsutil.LogClose(context.Background(), gs)
	}

	var in io.ReadCloser = os.Stdin
	if gs == nil && len(flag.Args()) > 0 {
		file, err := vfs.Open(context.Background(), flag.Arg(0))
		if err != nil {
			log.Fatalf("Failed to open input file %q: %v", flag.Arg(0), err)
		}
		defer file.Close()
		in = file
	}

	outIdx := 1
	if gs != nil {
		outIdx = 0
	}

	var out io.WriteCloser = os.Stdout
	if len(flag.Args()) > outIdx {
		file, err := vfs.Create(context.Background(), flag.Arg(outIdx))
		if err != nil {
			log.Fatalf("Failed to create output file %q: %v", flag.Arg(outIdx), err)
		}
		defer file.Close()
		out = file
	}

	var (
		entries      <-chan *spb.Entry
		reverseEdges int
		triples      int
	)

	if gs == nil {
		entries = stream.ReadEntries(in)
	} else {
		ch := make(chan *spb.Entry)
		entries = ch
		go func() {
			defer close(ch)
			if err := gs.Scan(context.Background(), &spb.ScanRequest{}, func(e *spb.Entry) error {
				ch <- e
				return nil
			}); err != nil {
				log.Fatalf("Error scanning graphstore: %v", err)
			}
		}()
	}

	for entry := range entries {
		if schema.EdgeDirection(entry.EdgeKind) == schema.Reverse && !*keepReverseEdges {
			reverseEdges++
			continue
		}

		t, err := toTriple(entry)
		if err != nil {
			log.Fatal(err)
		}
		fmt.Fprintln(out, t)
		triples++
	}

	if !*quiet {
		if !*keepReverseEdges {
			log.Printf("Skipped %d reverse edges", reverseEdges)
		}
		log.Printf("Wrote %d triples", triples)
	}
}

//.........這裏部分代碼省略.........
	var subkind, textEncoding *string
	var text *[]byte
	var startOffset, endOffset, snippetStart, snippetEnd *int64
	for e := range entries {
		if graphstore.IsNodeFact(e) {
			ticket := kytheuri.ToString(e.Source)
			if node.Ticket != "" && node.Ticket != ticket {
				nodeTicket := node.Ticket
				node.Ticket = ""
				var rec []byte
				if len(node.Fact) > 0 {
					rec, err = proto.Marshal(&node)
					if err != nil {
						return fmt.Errorf("error marshaling facts: %v", err)
					}
				}
				if text != nil && textEncoding == nil {
					textEncoding = proto.String(schema.DefaultTextEncoding)
				}
				if _, err := copyNode.Exec(
					nodeTicket,
					nodeKind,
					subkind,
					text,
					textEncoding,
					startOffset,
					endOffset,
					snippetStart,
					snippetEnd,
					len(node.Fact),
					rec,
				); err != nil {
					return fmt.Errorf("error copying node: %v", err)
				}
				node.Fact, text = node.Fact[0:0], nil
				nodeKind = ""
				subkind, textEncoding = nil, nil
				startOffset, endOffset, snippetStart, snippetEnd = nil, nil, nil, nil
			}
			if node.Ticket == "" {
				node.Ticket = ticket
			}
			switch e.FactName {
			case schema.NodeKindFact:
				nodeKind = string(e.FactValue)
			case schema.SubkindFact:
				subkind = proto.String(string(e.FactValue))
			case schema.TextFact:
				text = &e.FactValue
			case schema.TextEncodingFact:
				textEncoding = proto.String(string(e.FactValue))
			case schema.AnchorStartFact:
				n, err := strconv.ParseInt(string(e.FactValue), 10, 64)
				if err == nil {
					startOffset = proto.Int64(n)
				}
			case schema.AnchorEndFact:
				n, err := strconv.ParseInt(string(e.FactValue), 10, 64)
				if err == nil {
					endOffset = proto.Int64(n)
				}
			case schema.SnippetStartFact:
				n, err := strconv.ParseInt(string(e.FactValue), 10, 64)
				if err == nil {
					snippetStart = proto.Int64(n)
				}
			case schema.SnippetEndFact:
				n, err := strconv.ParseInt(string(e.FactValue), 10, 64)
				if err == nil {
					snippetEnd = proto.Int64(n)
				}
			default:
				node.Fact = append(node.Fact, &cpb.Fact{
					Name:  e.FactName,
					Value: e.FactValue,
				})
			}
		} else if schema.EdgeDirection(e.EdgeKind) == schema.Forward {
			kind, ordinal, _ := schema.ParseOrdinal(e.EdgeKind)
			ticket := kytheuri.ToString(e.Source)
			if _, err := copyEdge.Exec(ticket, kind, kytheuri.ToString(e.Target), ordinal); err != nil {
				return fmt.Errorf("error copying edge: %v", err)
			}
		}
	}

	if _, err := copyNode.Exec(); err != nil {
		return fmt.Errorf("error flushing nodes: %v", err)
	} else if _, err := copyEdge.Exec(); err != nil {
		return fmt.Errorf("error flushing edges: %v", err)
	}

	if err := nodesTx.Commit(); err != nil {
		return fmt.Errorf("error committing Nodes transaction: %v", err)
	} else if err := edgesTx.Commit(); err != nil {
		return fmt.Errorf("error committing Edges transaction: %v", err)
	}

	return nil
}