func (g *MixedMap) CheckEdgeType(tail VertexId, head VertexId) MixedConnectionType {
defer func() {
if e := recover(); e != nil {
err := erx.NewSequent("Check edge type in mixed graph.", e)
err.AddV("tail", tail)
err.AddV("head", head)
panic(err)
}
}()
connectedVertexes, ok := g.connections[tail]
if !ok {
panic(erx.NewError("Fist node doesn't exist."))
}
if _, ok = g.connections[head]; !ok {
panic(erx.NewError("Second node doesn't exist."))
}
direction, ok := connectedVertexes[head]
if !ok {
direction = CT_NONE
}
return direction
}
func (gr *MixedMatrix) getConnectionId(node1, node2 VertexId, create bool) int {
defer func() {
if e := recover(); e != nil {
err := erx.NewSequent("Calculating connection id.", e)
err.AddV("node 1", node1)
err.AddV("node 2", node2)
panic(err)
}
}()
var id1, id2 int
node1Exist := false
node2Exist := false
id1, node1Exist = gr.VertexIds[node1]
id2, node2Exist = gr.VertexIds[node2]
// checking for errors
{
if node1 == node2 {
panic(erx.NewError("Equal nodes."))
}
if !create {
if !node1Exist {
panic(erx.NewError("First node doesn't exist in graph"))
}
if !node2Exist {
panic(erx.NewError("Second node doesn't exist in graph"))
}
} else if !node1Exist || !node2Exist {
if node1Exist && node2Exist {
if gr.size-len(gr.VertexIds) < 2 {
panic(erx.NewError("Not enough space to create two new nodes."))
}
} else {
if gr.size-len(gr.VertexIds) < 1 {
panic(erx.NewError("Not enough space to create new node."))
}
}
}
}
if !node1Exist {
id1 = int(len(gr.VertexIds))
gr.VertexIds[node1] = id1
}
if !node2Exist {
id2 = int(len(gr.VertexIds))
gr.VertexIds[node2] = id2
}
// switching id1, id2 in order to id1 < id2
if id1 > id2 {
id1, id2 = id2, id1
}
// id from upper triangle matrix, stored in vector
connId := id1*(gr.size-1) + id2 - 1 - id1*(id1+1)/2
return connId
}
// Removing arrow 'from' and 'to' nodes
func (g *MixedMap) RemoveArc(from, to VertexId) {
defer func() {
if e := recover(); e != nil {
err := erx.NewSequent("Remove arc from graph.", e)
err.AddV("tail", from)
err.AddV("head", to)
panic(err)
}
}()
if _, ok := g.connections[from]; ok {
panic(erx.NewError("Tail node doesn't exist."))
}
if _, ok := g.connections[to]; ok {
panic(erx.NewError("Head node doesn't exist."))
}
if dir, ok := g.connections[from][to]; !ok || dir != CT_DIRECTED {
panic(erx.NewError("Arc doesn't exist."))
}
g.connections[from][to] = CT_NONE, false
g.connections[to][from] = CT_NONE, false
g.arcsCnt--
return
}
// Adding edge to graph.
func (g *MixedMap) AddEdge(from, to VertexId) {
defer func() {
if e := recover(); e != nil {
err := erx.NewSequent("Add edge to graph.", e)
err.AddV("node 1", from)
err.AddV("node 2", to)
panic(err)
}
}()
g.touchNode(from)
g.touchNode(to)
if direction, ok := g.connections[from][to]; ok {
err := erx.NewError("Duplicate connection.")
err.AddV("connection type", direction)
panic(err)
}
g.connections[from][to] = CT_UNDIRECTED
g.connections[to][from] = CT_UNDIRECTED
g.edgesCnt++
return
}
// Getting node predecessors
func (g *MixedMap) GetPredecessors(node VertexId) VertexesIterable {
iterator := func() <-chan VertexId {
ch := make(chan VertexId)
go func() {
defer func() {
if e := recover(); e != nil {
err := erx.NewSequent("Getting node predecessors.", e)
err.AddV("node id", node)
panic(err)
}
}()
accessorsMap, ok := g.connections[node]
if !ok {
panic(erx.NewError("Node doesn't exists."))
}
for VertexId, connType := range accessorsMap {
if connType == CT_DIRECTED_REVERSED {
ch <- VertexId
}
}
close(ch)
}()
return ch
}
return VertexesIterable(&nodesIterableLambdaHelper{iterFunc: iterator})
}
// Getting node predecessors
func (g *DirectedMap) GetPredecessors(node VertexId) VertexesIterable {
iterator := func() <-chan VertexId {
ch := make(chan VertexId)
go func() {
defer func() {
if e := recover(); e != nil {
err := erx.NewSequent("Get node accessors in mixed graph.", e)
err.AddV("node", node)
panic(err)
}
}()
accessorsMap, ok := g.reversedArcs[node]
if !ok {
panic(erx.NewError("Node doesn't exists."))
}
for VertexId, _ := range accessorsMap {
ch <- VertexId
}
close(ch)
}()
return ch
}
return VertexesIterable(&nodesIterableLambdaHelper{iterFunc: iterator})
}
// Getting all nodes, connected to given one
func (g *UndirectedMatrix) GetNeighbours(node VertexId) VertexesIterable {
iterator := func() <-chan VertexId {
ch := make(chan VertexId)
go func() {
if _, ok := g.VertexIds[node]; !ok {
panic(erx.NewError("Unknown node."))
}
var connId int
for aNode, _ := range g.VertexIds {
if aNode == node {
continue
}
connId = g.getConnectionId(node, aNode, false)
if g.nodes[connId] {
ch <- aNode
}
}
close(ch)
}()
return ch
}
return VertexesIterable(&nodesIterableLambdaHelper{iterFunc: iterator})
}
// Removing edge, connecting node1 and node2
func (g *UndirectedMatrix) RemoveEdge(node1, node2 VertexId) {
makeError := func(err interface{}) (res erx.Error) {
res = erx.NewSequentLevel("Remove edge from graph.", err, 1)
res.AddV("node 1", node1)
res.AddV("node 2", node2)
return
}
defer func() {
// warning! such code generates wrong file/line info about error!
// see http://groups.google.com/group/golang-nuts/browse_thread/thread/66bd57dcdac63aa
// for details
if err := recover(); err != nil {
panic(makeError(err))
}
}()
conn := g.getConnectionId(node1, node2, false)
if !g.nodes[conn] {
panic(erx.NewError("Edge doesn't exist."))
}
g.nodes[conn] = false
g.edgesCnt--
return
}
// Getting node predecessors
func (g *MixedMap) GetNeighbours(node VertexId) VertexesIterable {
iterator := func() <-chan VertexId {
ch := make(chan VertexId)
go func() {
defer func() {
if e := recover(); e != nil {
err := erx.NewSequent("Get node neighbours.", e)
err.AddV("node id", node)
panic(err)
}
}()
if connectedMap, ok := g.connections[node]; ok {
for VertexId, connType := range connectedMap {
if connType == CT_UNDIRECTED {
ch <- VertexId
}
}
} else {
panic(erx.NewError("Node doesn't exists."))
}
close(ch)
}()
return ch
}
return VertexesIterable(&nodesIterableLambdaHelper{iterFunc: iterator})
}
func (gr *MixedMatrix) TypedConnectionsIter() <-chan TypedConnection {
ch := make(chan TypedConnection)
go func() {
for from, _ := range gr.VertexIds {
for to, _ := range gr.VertexIds {
if from >= to {
continue
}
conn := gr.getConnectionId(from, to, false)
switch gr.nodes[conn] {
case CT_NONE:
case CT_UNDIRECTED:
ch <- TypedConnection{Connection: Connection{Tail: from, Head: to}, Type: CT_UNDIRECTED}
case CT_DIRECTED:
ch <- TypedConnection{Connection: Connection{Tail: from, Head: to}, Type: CT_DIRECTED}
case CT_DIRECTED_REVERSED:
ch <- TypedConnection{Connection: Connection{Tail: to, Head: from}, Type: CT_DIRECTED}
default:
err := erx.NewError("Internal error: wrong connection type in mixed graph matrix")
err.AddV("connection type", gr.nodes[conn])
err.AddV("connection id", conn)
err.AddV("tail node", from)
err.AddV("head node", to)
panic(err)
}
}
}
close(ch)
}()
return ch
}
func topologicalSortHelper(gr DirectedGraphReader, curNode VertexId, nodes []VertexId, status map[VertexId]bool) (pos int, hasCycles bool) {
if isBlack, ok := status[curNode]; ok {
err := erx.NewError("Internal error in topological sort: node already in status map")
err.AddV("node id", curNode)
err.AddV("status in map", isBlack)
panic(err)
}
hasCycles = false
status[curNode] = false
pos = len(nodes)
for accessor := range gr.GetAccessors(curNode).VertexesIter() {
if isBlack, ok := status[accessor]; ok {
if !isBlack {
// cycle detected!
hasCycles = true
return
} else {
// we have already visited this node
continue
}
}
pos, hasCycles = topologicalSortHelper(gr, accessor, nodes[0:pos], status)
if hasCycles {
return
}
}
status[curNode] = true
pos--
nodes[pos] = curNode
return
}
// Adding new edge to graph
func (g *UndirectedMatrix) AddEdge(node1, node2 VertexId) {
makeError := func(err interface{}) (res erx.Error) {
res = erx.NewSequentLevel("Add edge to graph.", err, 1)
res.AddV("node 1", node1)
res.AddV("node 2", node2)
return
}
defer func() {
// warning! such code generates wrong file/line info about error!
// see http://groups.google.com/group/golang-nuts/browse_thread/thread/66bd57dcdac63aa
// for details
if err := recover(); err != nil {
panic(makeError(err))
}
}()
var conn int
conn = g.getConnectionId(node1, node2, true)
if g.nodes[conn] {
err := erx.NewError("Duplicate edge.")
err.AddV("connection id", conn)
panic(makeError(err))
}
g.nodes[conn] = true
g.edgesCnt++
return
}
// Adding directed arc to graph
func (gr *MixedMatrix) AddArc(tail, head VertexId) {
defer func() {
if e := recover(); e != nil {
err := erx.NewSequent("Add arc to mixed graph.", e)
err.AddV("tail", tail)
err.AddV("head", head)
panic(err)
}
}()
conn := gr.getConnectionId(tail, head, true)
if gr.nodes[conn] != CT_NONE {
err := erx.NewError("Duplicate edge.")
err.AddV("connection id", conn)
err.AddV("type", gr.nodes[conn])
panic(err)
}
if tail < head {
gr.nodes[conn] = CT_DIRECTED
} else {
gr.nodes[conn] = CT_DIRECTED_REVERSED
}
gr.arcsCnt++
}
// Removding directed arc
func (gr *MixedMatrix) RemoveArc(tail, head VertexId) {
defer func() {
if e := recover(); e != nil {
err := erx.NewSequent("Remove arc from mixed graph.", e)
err.AddV("tail", tail)
err.AddV("head", head)
panic(err)
}
}()
conn := gr.getConnectionId(tail, head, true)
expectedType := CT_NONE
if tail < head {
expectedType = CT_DIRECTED
} else {
expectedType = CT_DIRECTED_REVERSED
}
if gr.nodes[conn] != expectedType {
err := erx.NewError("Arc doesn't exists.")
err.AddV("connection id", conn)
err.AddV("type", gr.nodes[conn])
panic(err)
}
gr.nodes[conn] = CT_NONE
gr.arcsCnt--
}
func (g *MixedMap) TypedConnectionsIter() <-chan TypedConnection {
ch := make(chan TypedConnection)
go func() {
for from, connectedVertexes := range g.connections {
for to, connType := range connectedVertexes {
switch connType {
case CT_NONE:
case CT_UNDIRECTED:
if from < to {
ch <- TypedConnection{Connection: Connection{Tail: from, Head: to}, Type: CT_UNDIRECTED}
}
case CT_DIRECTED:
ch <- TypedConnection{Connection: Connection{Tail: from, Head: to}, Type: CT_DIRECTED}
case CT_DIRECTED_REVERSED:
default:
err := erx.NewError("Internal error: wrong connection type in mixed graph matrix")
err.AddV("connection type", connType)
err.AddV("tail node", from)
err.AddV("head node", to)
panic(err)
}
}
}
close(ch)
}()
return ch
}
// Generic function to check if graph contain specific path.
//
// First argument gr is an interface with two functions to check node existance and
// connection existance between two nodes in graph.
//
// unexistNodePanic flag is used to point wether or not to panic if we figure out that
// one of the nodes in path doesn't exist in graph. If unexistNodePanic is false, then
// result of the function will be false.
func ContainPath(gr NodeAndConnectionChecker, path []VertexId, unexistNodePanic bool) bool {
defer func() {
if e := recover(); e != nil {
err := erx.NewSequent("Checking if graph contain path", e)
err.AddV("path", path)
err.AddV("panic if node doesn't exist in graph", unexistNodePanic)
panic(err)
}
}()
if len(path) == 0 {
// emty path always exists
return true
}
prev := path[0]
if !gr.CheckNode(prev) {
if unexistNodePanic {
err := erx.NewError("Node doesn't exist in graph.")
err.AddV("node", prev)
panic(err)
}
return false
}
if len(path) == 1 {
return true
}
for i := 1; i < len(path); i++ {
cur := path[i]
if !gr.CheckNode(cur) {
if unexistNodePanic {
err := erx.NewError("Node doesn't exist in graph.")
err.AddV("node", cur)
panic(err)
}
return false
}
if !gr.CheckConnection(prev, cur) {
return false
}
prev = cur
}
return true
}
func NewMixedMatrix(size int) *MixedMatrix {
if size <= 0 {
panic(erx.NewError("Trying to create mixed matrix graph with zero size"))
}
g := new(MixedMatrix)
g.nodes = make([]MixedConnectionType, size*(size-1)/2)
g.size = size
g.VertexIds = make(map[VertexId]int)
return g
}
// Adding single node to graph
func (gr *MixedMatrix) AddNode(node VertexId) {
defer func() {
if e := recover(); e != nil {
err := erx.NewSequent("Add node to graph.", e)
err.AddV("node id", node)
panic(err)
}
}()
if _, ok := gr.VertexIds[node]; ok {
panic(erx.NewError("Node already exists."))
}
if len(gr.VertexIds) == gr.size {
panic(erx.NewError("Not enough space to add new node"))
}
gr.VertexIds[node] = len(gr.VertexIds)
}
func (g *UndirectedMap) CheckEdge(from, to VertexId) (isExist bool) {
makeError := func(err interface{}) (res erx.Error) {
res = erx.NewSequentLevel("Check edge existance in graph.", err, 1)
res.AddV("node 1", from)
res.AddV("node 2", to)
return
}
connectedVertexes, ok := g.edges[from]
if !ok {
panic(makeError(erx.NewError("Fist node doesn't exist.")))
}
if _, ok = g.edges[to]; !ok {
panic(makeError(erx.NewError("Second node doesn't exist.")))
}
_, isExist = connectedVertexes[to]
return
}
func (g *DirectedMap) CheckArc(from, to VertexId) (isExist bool) {
makeError := func(err interface{}) (res erx.Error) {
res = erx.NewSequentLevel("Checking arc existance in graph.", err, 1)
res.AddV("tail", from)
res.AddV("head", to)
return
}
connectedVertexes, ok := g.directArcs[from]
if !ok {
panic(makeError(erx.NewError("From node doesn't exist.")))
}
if _, ok = g.reversedArcs[to]; !ok {
panic(makeError(erx.NewError("To node doesn't exist.")))
}
_, isExist = connectedVertexes[to]
return
}
// Removing arrow 'from' and 'to' nodes
func (g *UndirectedMap) RemoveEdge(from, to VertexId) {
makeError := func(err interface{}) (res erx.Error) {
res = erx.NewSequentLevel("Remove edge from graph.", err, 1)
res.AddV("node 1", from)
res.AddV("node 2", to)
return
}
connectedVertexes, ok := g.edges[from]
if !ok {
panic(makeError(erx.NewError("First node doesn't exists")))
}
if _, ok = connectedVertexes[to]; ok {
panic(makeError(erx.NewError("Second node doesn't exists")))
}
g.edges[from][to] = false, false
g.edges[to][from] = false, false
g.edgesCnt--
return
}
// Copy all connections from iterator to mixed graph
//
// todo: merge with CopyDirectedGraph
func CopyMixedGraph(from TypedConnectionsIterable, to MixedGraphWriter) {
for conn := range from.TypedConnectionsIter() {
switch conn.Type {
case CT_UNDIRECTED:
to.AddEdge(conn.Tail, conn.Head)
case CT_DIRECTED:
to.AddArc(conn.Tail, conn.Head)
default:
err := erx.NewError("Internal error: unknown connection type")
panic(err)
}
}
}
// Removing arrow 'from' and 'to' nodes
func (g *DirectedMap) RemoveArc(from, to VertexId) {
makeError := func(err interface{}) (res erx.Error) {
res = erx.NewSequentLevel("Remove arc from graph.", err, 1)
res.AddV("tail", from)
res.AddV("head", to)
return
}
connectedVertexes, ok := g.directArcs[from]
if !ok {
panic(makeError(erx.NewError("Tail node doesn't exist.")))
}
if _, ok = connectedVertexes[to]; ok {
panic(makeError(erx.NewError("Head node doesn't exist.")))
}
g.directArcs[from][to] = false, false
g.reversedArcs[to][from] = false, false
g.arcsCnt--
return
}
func (g *MixedMap) CheckArc(from, to VertexId) (isExist bool) {
defer func() {
if e := recover(); e != nil {
err := erx.NewSequent("Checking arc existance in graph.", e)
err.AddV("tail", from)
err.AddV("head", to)
panic(err)
}
}()
connectedVertexes, ok := g.connections[from]
if !ok {
panic(erx.NewError("Tail node doesn't exist."))
}
if _, ok = g.connections[to]; !ok {
panic(erx.NewError("Head node doesn't exist."))
}
connType, ok := connectedVertexes[to]
return ok && connType == CT_DIRECTED
}
func (g *MixedMap) CheckEdge(from, to VertexId) bool {
defer func() {
if e := recover(); e != nil {
err := erx.NewSequent("Check edge existance in graph.", e)
err.AddV("node 1", from)
err.AddV("node 2", to)
panic(err)
}
}()
connectedVertexes, ok := g.connections[from]
if !ok {
panic(erx.NewError("Fist node doesn't exist."))
}
if _, ok = g.connections[to]; !ok {
panic(erx.NewError("Second node doesn't exist."))
}
direction, ok := connectedVertexes[to]
return ok && direction == CT_UNDIRECTED
}
// Create new simple nodes priority queue
//
// size is maximum number of nodes, which queue can store simultaneously
func newPriorityQueueSimple(initialSize int) *nodesPriorityQueueSimple {
if initialSize <= 0 {
err := erx.NewError("Can't create priority queue with non-positive size.")
err.AddV("size", initialSize)
panic(err)
}
q := &nodesPriorityQueueSimple{
data: make(nodesPriority, initialSize),
nodesIndex: make(map[VertexId]int),
size: 0,
}
return q
}
// Retrieving path from path marks.
func PathFromMarks(marks PathMarks, destination VertexId) Vertexes {
defer func() {
if e := recover(); e != nil {
err := erx.NewSequent("Retrieving path from path marks.", e)
err.AddV("marks", marks)
err.AddV("destination", destination)
panic(err)
}
}()
destInfo, ok := marks[destination]
if !ok || destInfo.Weight == math.MaxFloat64 {
// no path from any source to destination
return nil
}
curVertexInfo := destInfo
path := make(Vertexes, 10)
curPathPos := 0
path[curPathPos] = destination
curPathPos++
for curVertexInfo.Weight > 0.0 {
if len(path) == curPathPos {
// reallocate memory for path
tmp := make(Vertexes, 2*curPathPos)
copy(tmp, path)
path = tmp
}
path[curPathPos] = curVertexInfo.PrevVertex
curPathPos++
var ok bool
curVertexInfo, ok = marks[curVertexInfo.PrevVertex]
if !ok {
err := erx.NewError("Can't find path mark info for vertex in path.")
err.AddV("vertex", curVertexInfo.PrevVertex)
err.AddV("cur path", path)
panic(err)
}
}
path = path[0:curPathPos]
// reversing path
pathLen := len(path)
for i := 0; i < pathLen/2; i++ {
path[i], path[pathLen-i-1] = path[pathLen-i-1], path[i]
}
return path
}
// Removing arrow 'from' and 'to' nodes
func (g *MixedMap) RemoveEdge(from, to VertexId) {
defer func() {
if e := recover(); e != nil {
err := erx.NewSequent("Removing edge from graph.", e)
err.AddV("node 1", from)
err.AddV("node 2", to)
panic(err)
}
}()
if _, ok := g.connections[from]; !ok {
panic(erx.NewError("First node doesn't exists"))
}
if _, ok := g.connections[to]; !ok {
panic(erx.NewError("Second node doesn't exists"))
}
g.connections[from][to] = CT_NONE, false
g.connections[to][from] = CT_NONE, false
g.edgesCnt--
return
}
// Adding single node to graph
func (g *UndirectedMap) AddNode(node VertexId) {
makeError := func(err interface{}) (res erx.Error) {
res = erx.NewSequentLevel("Add node to graph.", err, 1)
res.AddV("node id", node)
return
}
if _, ok := g.edges[node]; ok {
panic(makeError(erx.NewError("Node already exists.")))
}
g.edges[node] = make(map[VertexId]bool)
return
}
// Adding single node to graph
func (g *MixedMap) AddNode(node VertexId) {
defer func() {
if e := recover(); e != nil {
err := erx.NewSequent("Add node to graph.", e)
err.AddV("node id", node)
panic(err)
}
}()
if _, ok := g.connections[node]; ok {
panic(erx.NewError("Node already exists."))
}
g.connections[node] = make(map[VertexId]MixedConnectionType)
return
}