// 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
}
// 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 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
}
func (g *UndirectedMap) RemoveNode(node VertexId) {
makeError := func(err interface{}) (res erx.Error) {
res = erx.NewSequentLevel("Remove node from graph.", err, 1)
res.AddV("node id", node)
return
}
if _, ok := g.edges[node]; !ok {
panic(makeError(erx.NewError("Node doesn't exist.")))
}
g.edges[node] = nil, false
for _, connectedVertexes := range g.edges {
connectedVertexes[node] = false, false
}
return
}
// Adding arrow to graph.
func (g *DirectedMap) AddArc(from, to VertexId) {
makeError := func(err interface{}) (res erx.Error) {
res = erx.NewSequentLevel("Add arc to graph.", err, 1)
res.AddV("tail", from)
res.AddV("head", to)
return
}
g.touchNode(from)
g.touchNode(to)
if direction, ok := g.directArcs[from][to]; ok && direction {
panic(makeError(erx.NewError("Duplicate arrow.")))
}
g.directArcs[from][to] = true
g.reversedArcs[to][from] = true
g.arcsCnt++
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
}
// Adding arrow to graph.
func (g *UndirectedMap) AddEdge(from, to VertexId) {
makeError := func(err interface{}) (res erx.Error) {
res = erx.NewSequentLevel("Add edge to graph.", err, 1)
res.AddV("node 1", from)
res.AddV("node 2", to)
return
}
g.touchNode(from)
g.touchNode(to)
if direction, ok := g.edges[from][to]; ok && direction {
panic(makeError(erx.NewError("Duplicate arrow.")))
}
g.edges[from][to] = true
g.edges[to][from] = true
g.edgesCnt++
return
}
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
}
// 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
}
func (g *DirectedMap) RemoveNode(node VertexId) {
makeError := func(err interface{}) (res erx.Error) {
res = erx.NewSequentLevel("Remove node from graph.", err, 1)
res.AddV("node id", node)
return
}
_, okDirect := g.directArcs[node]
_, okReversed := g.reversedArcs[node]
if !okDirect && !okReversed {
panic(makeError(erx.NewError("Node doesn't exist.")))
}
g.directArcs[node] = nil, false
g.reversedArcs[node] = nil, false
for _, connectedVertexes := range g.directArcs {
connectedVertexes[node] = false, false
}
for _, connectedVertexes := range g.reversedArcs {
connectedVertexes[node] = false, false
}
return
}
// 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 *UndirectedMatrix) getConnectionId(node1, node2 VertexId, create bool) int {
makeError := func(err interface{}) (res erx.Error) {
res = erx.NewSequentLevel("Calculating connection id.", 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 id1, id2 int
node1Exist := false
node2Exist := false
id1, node1Exist = g.VertexIds[node1]
id2, node2Exist = g.VertexIds[node2]
// checking for errors
{
if node1 == node2 {
panic(makeError(erx.NewError("Equal nodes.")))
}
if !create {
if !node1Exist {
panic(makeError(erx.NewError("First node doesn't exist in graph")))
}
if !node2Exist {
panic(makeError(erx.NewError("Second node doesn't exist in graph")))
}
} else if !node1Exist || !node2Exist {
if node1Exist && node2Exist {
if g.size-len(g.VertexIds) < 2 {
panic(makeError(erx.NewError("Not enough space to create two new nodes.")))
}
} else {
if g.size-len(g.VertexIds) < 1 {
panic(makeError(erx.NewError("Not enough space to create new node.")))
}
}
}
}
if !node1Exist {
id1 = int(len(g.VertexIds))
g.VertexIds[node1] = id1
}
if !node2Exist {
id2 = int(len(g.VertexIds))
g.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*(g.size-1) + id2 - 1 - id1*(id1+1)/2
return connId
}