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 }