add pattern cache and id sorting to resolver.

services/resolver.go

@@ -6,39 +6,29 @@ import (
 	"git.aiterp.net/lucifer3/server/device"
 	"git.aiterp.net/lucifer3/server/events"
 	"github.com/gobwas/glob"
+	"sort"
+	"strings"
 	"sync"
 )
 
 func NewResolver() *Resolver {
 	return &Resolver{
-		pointers: make([]*device.Pointer, 0, 128),
+		pointers:     make([]*device.Pointer, 0, 128),
+		patternCache: make(map[string]glob.Glob),
 	}
 }
 
 // Resolver implements both device.Resolver and lucifer3.Service. There should be only one of them as it keeps its
 // state from event-sourcery.
 type Resolver struct {
-	mu       sync.Mutex
-	pointers []*device.Pointer
-}
-
-func (r *Resolver) ensure(id string) *device.Pointer {
-	for _, ptr := range r.pointers {
-		if ptr.ID == id {
-			return ptr
-		}
-	}
-
-	r.pointers = append(r.pointers, &device.Pointer{
-		ID: id,
-	})
-
-	return r.pointers[len(r.pointers)-1]
+	mu           sync.Mutex
+	pointers     []*device.Pointer
+	patternCache map[string]glob.Glob
 }
 
 func (r *Resolver) resolve(pattern string) []*device.Pointer {
-	g, err := glob.Compile(pattern, ':')
-	if err != nil {
+	g := r.patternToGlob(pattern)
+	if g == nil {
 		return []*device.Pointer{}
 	}
 
@@ -53,14 +43,14 @@ func (r *Resolver) resolve(pattern string) []*device.Pointer {
 }
 
 func (r *Resolver) Resolve(pattern string) []device.Pointer {
-	g, err := glob.Compile(pattern, ':')
-	if err != nil {
-		return []device.Pointer{}
-	}
-
 	r.mu.Lock()
 	defer r.mu.Unlock()
 
+	g := r.patternToGlob(pattern)
+	if g == nil {
+		return []device.Pointer{}
+	}
+
 	res := make([]device.Pointer, 0, 32)
 	for _, ptr := range r.pointers {
 		if ptr.Matches(g) {
@@ -83,6 +73,7 @@ func (r *Resolver) HandleEvent(_ *lucifer3.EventBus, event lucifer3.Event) {
 		ptr := r.ensure(event.ID)
 		if event.InternalName != "" && ptr.Name() == "" {
 			ptr.AddAlias("lucifer:name:" + event.InternalName)
+			r.sortPointers()
 		}
 		r.mu.Unlock()
 	}
@@ -95,13 +86,81 @@ func (r *Resolver) HandleCommand(_ *lucifer3.EventBus, command lucifer3.Command)
 		for _, ptr := range r.resolve(command.Match) {
 			ptr.AddAlias(command.Alias)
 		}
+		if strings.HasPrefix(command.Alias, "lucifer:name:") {
+			r.sortPointers()
+		}
 		r.mu.Unlock()
 
 	case commands.RemoveAlias:
 		r.mu.Lock()
 		for _, ptr := range r.resolve(command.Match) {
-			ptr.AddAlias(command.Alias)
+			ptr.RemoveAlias(command.Alias)
+		}
+		if strings.HasPrefix(command.Alias, "lucifer:name:") {
+			r.sortPointers()
 		}
 		r.mu.Unlock()
 	}
 }
+
+func (r *Resolver) ensure(id string) *device.Pointer {
+	for _, ptr := range r.pointers {
+		if ptr.ID == id {
+			return ptr
+		}
+	}
+
+	r.pointers = append(r.pointers, &device.Pointer{
+		ID: id,
+	})
+
+	return r.pointers[len(r.pointers)-1]
+}
+
+func (r *Resolver) patternToGlob(pattern string) glob.Glob {
+	if cached, ok := r.patternCache[pattern]; ok {
+		return cached
+	}
+
+	g, err := glob.Compile(pattern, ':')
+	if err != nil {
+		return nil
+	}
+
+	// Keep this in bounds. Random cache deletions after 128 length.
+	if len(r.patternCache) > 128 {
+		i := 64
+		for k := range r.patternCache {
+			if i == 0 {
+				break
+			}
+
+			delete(r.patternCache, k)
+			i -= 1
+		}
+	}
+
+	// Cache it
+	r.patternCache[pattern] = g
+
+	return g
+}
+
+func (r *Resolver) sortPointers() {
+	sort.Slice(r.pointers, func(i, j int) bool {
+		ni := r.pointers[i].Name()
+		nj := r.pointers[j].Name()
+
+		if ni == nj {
+			return r.pointers[i].ID < r.pointers[j].ID
+		}
+		if ni == "" {
+			return false
+		}
+		if nj == "" {
+			return true
+		}
+
+		return ni < nj
+	})
+}