moby/daemon/links.go
Daniel Nephin 4f0d95fa6e Add canonical import comment
Signed-off-by: Daniel Nephin <dnephin@docker.com>
2018-02-05 16:51:57 -05:00

91 lines
2.6 KiB
Go

package daemon // import "github.com/docker/docker/daemon"
import (
"sync"
"github.com/docker/docker/container"
)
// linkIndex stores link relationships between containers, including their specified alias
// The alias is the name the parent uses to reference the child
type linkIndex struct {
// idx maps a parent->alias->child relationship
idx map[*container.Container]map[string]*container.Container
// childIdx maps child->parent->aliases
childIdx map[*container.Container]map[*container.Container]map[string]struct{}
mu sync.Mutex
}
func newLinkIndex() *linkIndex {
return &linkIndex{
idx: make(map[*container.Container]map[string]*container.Container),
childIdx: make(map[*container.Container]map[*container.Container]map[string]struct{}),
}
}
// link adds indexes for the passed in parent/child/alias relationships
func (l *linkIndex) link(parent, child *container.Container, alias string) {
l.mu.Lock()
if l.idx[parent] == nil {
l.idx[parent] = make(map[string]*container.Container)
}
l.idx[parent][alias] = child
if l.childIdx[child] == nil {
l.childIdx[child] = make(map[*container.Container]map[string]struct{})
}
if l.childIdx[child][parent] == nil {
l.childIdx[child][parent] = make(map[string]struct{})
}
l.childIdx[child][parent][alias] = struct{}{}
l.mu.Unlock()
}
// unlink removes the requested alias for the given parent/child
func (l *linkIndex) unlink(alias string, child, parent *container.Container) {
l.mu.Lock()
delete(l.idx[parent], alias)
delete(l.childIdx[child], parent)
l.mu.Unlock()
}
// children maps all the aliases-> children for the passed in parent
// aliases here are the aliases the parent uses to refer to the child
func (l *linkIndex) children(parent *container.Container) map[string]*container.Container {
l.mu.Lock()
children := l.idx[parent]
l.mu.Unlock()
return children
}
// parents maps all the aliases->parent for the passed in child
// aliases here are the aliases the parents use to refer to the child
func (l *linkIndex) parents(child *container.Container) map[string]*container.Container {
l.mu.Lock()
parents := make(map[string]*container.Container)
for parent, aliases := range l.childIdx[child] {
for alias := range aliases {
parents[alias] = parent
}
}
l.mu.Unlock()
return parents
}
// delete deletes all link relationships referencing this container
func (l *linkIndex) delete(container *container.Container) []string {
l.mu.Lock()
var aliases []string
for alias, child := range l.idx[container] {
aliases = append(aliases, alias)
delete(l.childIdx[child], container)
}
delete(l.idx, container)
delete(l.childIdx, container)
l.mu.Unlock()
return aliases
}