compose/local/dependencies.go

114 lines
2.5 KiB
Go

// +build local
/*
Copyright 2020 Docker Compose CLI 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,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package local
import (
"context"
"github.com/compose-spec/compose-go/types"
"golang.org/x/sync/errgroup"
)
func inDependencyOrder(ctx context.Context, project *types.Project, fn func(context.Context, types.ServiceConfig) error) error {
graph := buildDependencyGraph(project.Services)
eg, ctx := errgroup.WithContext(ctx)
results := make(chan string)
errors := make(chan error)
for len(graph) > 0 {
for _, n := range graph.independents() {
service := n.service
eg.Go(func() error {
err := fn(ctx, service)
if err != nil {
errors <- err
return err
}
results <- service.Name
return nil
})
}
select {
case result := <-results:
graph.resolved(result)
case err := <-errors:
return err
}
}
return eg.Wait()
}
type dependencyGraph map[string]node
type node struct {
service types.ServiceConfig
dependencies []string
dependent []string
}
func (d dependencyGraph) independents() []node {
var nodes []node
for _, node := range d {
if len(node.dependencies) == 0 {
nodes = append(nodes, node)
}
}
return nodes
}
func (graph dependencyGraph) resolved(result string) {
for _, parent := range graph[result].dependent {
node := graph[parent]
node.dependencies = remove(node.dependencies, result)
graph[parent] = node
}
delete(graph, result)
}
func buildDependencyGraph(services types.Services) dependencyGraph {
graph := dependencyGraph{}
for _, s := range services {
graph[s.Name] = node{
service: s,
}
}
for _, s := range services {
node := graph[s.Name]
for _, name := range s.GetDependencies() {
dependency := graph[name]
node.dependencies = append(node.dependencies, name)
dependency.dependent = append(dependency.dependent, s.Name)
graph[name] = dependency
}
graph[s.Name] = node
}
return graph
}
func remove(slice []string, item string) []string {
var s []string
for _, i := range slice {
if i != item {
s = append(s, i)
}
}
return s
}