Golang CoreGraph.PredecessorsWith方法代码示例

func (spec specUnixDomainListener) Resolve(g system.CoreGraph, mid uint64, src system.VertexTuple) (e system.StdEdge, success bool) {
	// check for existing edge; this one is quite straightforward
	re := g.OutWith(src.ID, q.Qbe(system.EType("listening"), "type", "unix", "path", spec.Path))
	if len(re) == 1 {
		return re[0], true
	}

	e = system.StdEdge{
		Source: src.ID,
		Props:  ps.NewMap(),
		EType:  "listening",
	}

	e.Props = e.Props.Set("path", system.Property{MsgSrc: mid, Value: spec.Path})

	envid, _, hasenv := findEnv(g, src)
	if hasenv {
		rv := g.PredecessorsWith(envid, q.Qbv(system.VType("comm"), "type", "unix", "path", spec.Path))
		if len(rv) == 1 {
			success = true
			e.Target = rv[0].ID
		}
	}

	return
}

func findDataset(g system.CoreGraph, envid uint64, name []string) (id uint64, success bool) {
	// first time through use the parent type
	vtype := system.VType("parent-dataset")
	id = envid

	var n string
	for len(name) > 0 {
		n, name = name[0], name[1:]
		rv := g.PredecessorsWith(id, q.Qbv(vtype, "name", n))
		vtype = "dataset"

		if len(rv) != 1 {
			return 0, false
		}

		id = rv[0].ID
	}

	return id, true
}

func (spec DataLink) Resolve(g system.CoreGraph, mid uint64, src system.VertexTuple) (e system.StdEdge, success bool) {
	e = system.StdEdge{
		Source: src.ID,
		Props:  ps.NewMap(),
		EType:  "datalink",
	}

	// DataLinks have a 'name' field that is expected to be unique for the source, if present
	if spec.Name != "" {
		// TODO 'name' is a traditional unique key; a change in it inherently denotes a new edge. how to handle this?
		// FIXME this approach just always updates the mid, which is weird?
		e.Props = e.Props.Set("name", system.Property{MsgSrc: mid, Value: spec.Name})

		re := g.OutWith(src.ID, q.Qbe(system.EType("datalink"), "name", spec.Name))
		if len(re) == 1 {
			success = true
			e = re[0]
		}
	}

	if spec.Type != "" {
		e.Props = e.Props.Set("type", system.Property{MsgSrc: mid, Value: spec.Type})
	}
	if spec.Subset != "" {
		e.Props = e.Props.Set("subset", system.Property{MsgSrc: mid, Value: spec.Subset})
	}
	if spec.Interaction != "" {
		e.Props = e.Props.Set("interaction", system.Property{MsgSrc: mid, Value: spec.Interaction})
	}

	// Special bits: if we have ConnUnix data, eliminate ConnNet data, and vice-versa.
	var isLocal bool
	if spec.ConnUnix.Path != "" {
		isLocal = true
		e.Props = e.Props.Set("path", system.Property{MsgSrc: mid, Value: spec.ConnUnix.Path})
		e.Props = e.Props.Delete("hostname")
		e.Props = e.Props.Delete("ipv4")
		e.Props = e.Props.Delete("ipv6")
		e.Props = e.Props.Delete("port")
		e.Props = e.Props.Delete("proto")
	} else {
		e.Props = e.Props.Set("port", system.Property{MsgSrc: mid, Value: spec.ConnNet.Port})
		e.Props = e.Props.Set("proto", system.Property{MsgSrc: mid, Value: spec.ConnNet.Proto})

		// can only be one of hostname, ipv4 or ipv6
		if spec.ConnNet.Hostname != "" {
			e.Props = e.Props.Set("hostname", system.Property{MsgSrc: mid, Value: spec.ConnNet.Hostname})
		} else if spec.ConnNet.Ipv4 != "" {
			e.Props = e.Props.Set("ipv4", system.Property{MsgSrc: mid, Value: spec.ConnNet.Ipv4})
		} else {
			e.Props = e.Props.Set("ipv6", system.Property{MsgSrc: mid, Value: spec.ConnNet.Ipv6})
		}
	}

	if success {
		return
	}

	var sock system.VertexTuple
	var rv system.VertexTupleVector // just for reuse
	// If net, must scan; if local, a bit easier.
	if !isLocal {
		// First, find the environment vertex
		rv = g.VerticesWith(q.Qbv(system.VType("environment")))
		var envid uint64
		for _, vt := range rv {
			if maputil.AnyMatch(e.Props, vt.Vertex.Properties, "hostname", "ipv4", "ipv6") {
				envid = vt.ID
				break
			}
		}

		// No matching env found, bail out
		if envid == 0 {
			return
		}

		// Now, walk the environment's edges to find the vertex representing the port
		rv = g.PredecessorsWith(envid, q.Qbv(system.VType("comm"), "type", "port", "port", spec.ConnNet.Port).And(q.Qbe(system.EType("envlink"))))

		if len(rv) != 1 {
			return
		}
		sock = rv[0]

		// With sock in hand, now find its proc
		rv = g.PredecessorsWith(sock.ID, q.Qbe(system.EType("listening"), "proto", spec.ConnNet.Proto).And(q.Qbv(system.VType("process"))))
		if len(rv) != 1 {
			// TODO could/will we ever allow >1?
			return
		}
	} else {
		envid, _, exists := findEnv(g, src)

		if !exists {
			// this is would be a pretty weird case
			return
		}

		// Walk the graph to find the vertex representing the unix socket
//.........这里部分代码省略.........