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package participant
import (
"context"
"slices"
"strings"
"sync"
)
type Index[T any] struct {
mu sync.Mutex
items map[string]T
changed chan struct{}
}
func NewIndex[T any]() *Index[T] {
return &Index[T]{items: map[string]T{}, changed: make(chan struct{})}
}
func (x *Index[T]) Put(name string, value T) {
x.mu.Lock()
x.items[name] = value
x.notifyLocked()
x.mu.Unlock()
}
func (x *Index[T]) Remove(name string) {
x.mu.Lock()
if _, ok := x.items[name]; ok {
delete(x.items, name)
x.notifyLocked()
}
x.mu.Unlock()
}
func (x *Index[T]) Get(name string) (T, bool) {
x.mu.Lock()
defer x.mu.Unlock()
value, ok := x.items[name]
return value, ok
}
func (x *Index[T]) List() []T {
x.mu.Lock()
names := make([]string, 0, len(x.items))
for name := range x.items {
names = append(names, name)
}
slices.SortFunc(names, strings.Compare)
out := make([]T, 0, len(names))
for _, name := range names {
out = append(out, x.items[name])
}
x.mu.Unlock()
return out
}
func (x *Index[T]) Find(match func(T) bool) (T, bool) {
for _, value := range x.List() {
if match(value) {
return value, true
}
}
var zero T
return zero, false
}
func (x *Index[T]) Filter(match func(T) bool) []T {
var out []T
for _, value := range x.List() {
if match(value) {
out = append(out, value)
}
}
return out
}
func (x *Index[T]) Await(ctx context.Context, done func() bool) error {
for {
x.mu.Lock()
changed := x.changed
x.mu.Unlock()
if done() {
return nil
}
select {
case <-ctx.Done():
return ctx.Err()
case <-changed:
}
}
}
func (x *Index[T]) notifyLocked() {
close(x.changed)
x.changed = make(chan struct{})
}
