optimise field path cache

Author: markus-wa

pkg/demoinfocs/sendtables2/entity.go

@@ -424,9 +424,9 @@ func (p *Parser) FilterEntity(fb func(*Entity) bool) []*Entity {
 }
 
 func (e *Entity) readFields(r *reader, paths *[]*fieldPath) {
-	readFieldPaths(r, paths)
+	n := readFieldPaths(r, paths)
 
-	for _, fp := range *paths {
+	for _, fp := range (*paths)[:n] {
 		f := e.class.serializer.getFieldForFieldPath(fp, 0)
 		name := e.class.getNameForFieldPath(fp)
 		decoder, base := e.class.serializer.getDecoderForFieldPath2(fp, 0)
@@ -462,8 +462,6 @@ func (e *Entity) readFields(r *reader, paths *[]*fieldPath) {
 				S2:        true,
 			})
 		}
-
-		fp.release()
 	}
 }
 
@@ -491,10 +489,7 @@ func (p *Parser) OnPacketEntities(m *msgs2.CSVCMsg_PacketEntities) error {
 		op  st.EntityOp
 	}
 
-	var (
-		tuples []tuple
-		paths  = make([]*fieldPath, 0)
-	)
+	var tuples []tuple
 
 	for ; updates > 0; updates-- {
 		var (
@@ -530,12 +525,10 @@ func (p *Parser) OnPacketEntities(m *msgs2.CSVCMsg_PacketEntities) error {
 
 				if baseline != nil {
 					// POV demos are missing some baselines?
-					e.readFields(newReader(baseline), &paths)
-					paths = paths[:0]
+					e.readFields(newReader(baseline), &p.pathCache)
 				}
 
-				e.readFields(r, &paths)
-				paths = paths[:0]
+				e.readFields(r, &p.pathCache)
 
 				// Fire created-handlers so update-handlers can be registered
 				for _, h := range class.createdHandlers {
@@ -559,8 +552,7 @@ func (p *Parser) OnPacketEntities(m *msgs2.CSVCMsg_PacketEntities) error {
 					op |= st.EntityOpEntered
 				}
 
-				e.readFields(r, &paths)
-				paths = paths[:0]
+				e.readFields(r, &p.pathCache)
 			}
 		} else {
 			e = p.entities[index]

pkg/demoinfocs/sendtables2/field_path.go

@@ -306,10 +306,10 @@ func (fp *fieldPath) release() {
 }
 
 // readFieldPaths reads a new slice of fieldPath values from the given reader
-func readFieldPaths(r *reader, paths *[]*fieldPath) {
+func readFieldPaths(r *reader, paths *[]*fieldPath) int {
 	fp := newFieldPath()
-
 	node := huffTree
+	i := 0
 
 	for !fp.done {
 		var next huffmanTree
@@ -326,14 +326,26 @@ func readFieldPaths(r *reader, paths *[]*fieldPath) {
 			fieldPathTable[next.Value()].fn(r, fp)
 
 			if !fp.done {
-				*paths = append(*paths, fp.copy())
+				if len(*paths) <= i {
+					*paths = append(*paths, fp.copy())
+				} else {
+					x := (*paths)[i]
+					x.last = fp.last
+					x.done = fp.done
+
+					copy(x.path, fp.path)
+				}
+
+				i++
 			}
 		} else {
 			node = next
 		}
 	}
 
 	fp.release()
+
+	return i
 }
 
 // newHuffmanTree creates a new huffmanTree from the field path table

pkg/demoinfocs/sendtables2/parser.go

@@ -60,6 +60,7 @@ type Parser struct {
 	entityFullPackets int
 	entities          map[int32]*Entity
 	entityHandlers    []st.EntityHandler
+	pathCache         []*fieldPath
 }
 
 func (p *Parser) ReadEnterPVS(r *bit.BitReader, index int, entities map[int]st.Entity, slot int) st.Entity {