Evaluate path predicates incrementally from cached directory paths

internal/filter/apply.go

@@ -43,13 +43,20 @@ func Apply(ctx context.Context, t *inventory.Tree, q *Query, m inventory.SizeMod
 	r := &Result{Query: q, Mode: m, Sizes: make([]int64, n), Matched: make([]bool, n)}
 	covered := make([]bool, n)
 	c := &Ctx{Tree: t, Now: time.Now().UnixNano()}
+	if q.UsesPath {
+		c.dirPaths = map[inventory.NodeID]string{}
+	}
 	for i := range n {
 		if i&0xffff == 0 && ctx.Err() != nil {
 			return nil, ctx.Err()
 		}
 		id := inventory.NodeID(i)
 		nd := t.Node(id)
-		c.ID, c.Node = id, nd
+		c.ID, c.Node, c.path = id, nd, ""
+		if c.dirPaths != nil && nd.IsDir() {
+			c.path = c.lowerPath()
+			c.dirPaths[id] = c.path
+		}
 		if i > 0 && q.Match(c) {
 			r.Matched[i] = true
 			covered[i] = true

internal/filter/eval.go

@@ -16,6 +16,9 @@ type Ctx struct {
 	Node *inventory.Node
 	Now  int64 // unix nanoseconds
 	path string
+	// dirPaths caches lower-cased directory paths during Apply, which visits
+	// parents before children, so a node's path is one concatenation.
+	dirPaths map[inventory.NodeID]string
 }
 
 func (c *Ctx) str(f Field) string {
@@ -25,7 +28,7 @@ func (c *Ctx) str(f Field) string {
 		return strings.ToLower(n.Name)
 	case FPath:
 		if c.path == "" {
-			c.path = strings.ToLower(c.Tree.Path(c.ID))
+			c.path = c.lowerPath()
 		}
 		return c.path
 	case FExt:
@@ -62,6 +65,22 @@ func (c *Ctx) num(f Field) int64 {
 	return 0
 }
 
+func (c *Ctx) lowerPath() string {
+	if c.dirPaths != nil {
+		if p, ok := c.dirPaths[c.ID]; ok {
+			return p
+		}
+		if pp, ok := c.dirPaths[c.Node.Parent]; ok {
+			sep := string(filepath.Separator)
+			if strings.HasSuffix(pp, sep) {
+				sep = ""
+			}
+			return pp + sep + strings.ToLower(c.Node.Name)
+		}
+	}
+	return strings.ToLower(c.Tree.Path(c.ID))
+}
+
 type node interface{ eval(*Ctx) bool }
 
 type andNode struct{ l, r node }
@@ -154,7 +173,4 @@ func (n numNode) eval(c *Ctx) bool {
 }
 
 // Match evaluates the query against one node.
-func (q *Query) Match(c *Ctx) bool {
-	c.path = ""
-	return q.root.eval(c)
-}
+func (q *Query) Match(c *Ctx) bool { return q.root.eval(c) }