chaosd/pkg/utils/graph.go

75 lines
1.7 KiB
Go

// Copyright 2020 Chaos Mesh Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// See the License for the specific language governing permissions and
// limitations under the License.
package utils
import (
"github.com/pingcap/log"
"go.uber.org/zap"
)
// Edge represents an edge in graph
type Edge struct {
Source uint32
Target uint32
Next *Edge
}
// Graph represents a graph with link list
type Graph struct {
head map[uint32]*Edge
}
// NewGraph creates a Graph
func NewGraph() *Graph {
return &Graph{
head: make(map[uint32]*Edge),
}
}
// Insert inserts an Edge into a graph from source to target
func (g *Graph) Insert(source uint32, target uint32) {
newEdge := Edge{
Source: source,
Target: target,
Next: g.head[source],
}
g.head[source] = &newEdge
}
// IterFrom starts iterating from source node
func (g *Graph) IterFrom(source uint32) *Edge {
return g.head[source]
}
// Flatten flattens the subtree from source (without checking whether it's a tree)
func (g *Graph) Flatten(source uint32) []uint32 {
current := g.head[source]
var flatTree []uint32
for {
if current == nil {
break
}
children := g.Flatten(current.Target)
flatTree = append(flatTree, current.Target)
flatTree = append(flatTree, children...)
current = current.Next
}
log.Debug("get flatTree", zap.Uint32("source", source), zap.Uint32s("flatTree", flatTree))
return flatTree
}