add ParserConfig.IgnorePacketEntitiesPanic flag for POV demo workaround

Author: markus-wa

pkg/demoinfocs/events/events.go

@@ -605,6 +605,7 @@ const (
 	WarnTypeUnknownEquipmentIndex
 	WarnTypeMissingItemDefinitionIndex
 	WarnTypeStringTableParsingFailure // Should happen only with CS2 POV demos
+	WarnTypePacketEntitiesPanic
 )
 
 // ParserWarn signals that a non-fatal problem occurred during parsing.

pkg/demoinfocs/parser.go

@@ -84,6 +84,7 @@ type parser struct {
 	errLock                         sync.Mutex       // Used to sync up error mutations between parsing & handling go-routines
 	decryptionKey                   []byte           // Stored in `match730_*.dem.info` see MatchInfoDecryptionKey().
 	source2FallbackGameEventListBin []byte           // sv_hibernate_when_empty bug workaround
+	ignorePacketEntitiesPanic       bool             // Used to ignore PacketEntities parsing panics (some POV demos seem to have broken rare broken PacketEntities)
 	/**
 	 * Set to the client slot of the recording player.
 	 * Always -1 for GOTV demos.
@@ -361,6 +362,10 @@ type ParserConfig struct {
 	// It's used when the game event list is not found in the demo file.
 	// This can happen due to a CS2 bug with sv_hibernate_when_empty.
 	Source2FallbackGameEventListBin []byte
+
+	// IgnorePacketEntitiesPanic tells the parser to ignore PacketEntities parsing panics.
+	// This is required as a workaround for some POV demos that seem to contain rare PacketEntities parsing issues.
+	IgnorePacketEntitiesPanic bool
 }
 
 // DefaultParserConfig is the default Parser configuration used by NewParser().
@@ -399,6 +404,8 @@ func NewParserWithConfig(demostream io.Reader, config ParserConfig) Parser {
 		p.source2FallbackGameEventListBin = defaultSource2FallbackGameEventListBin
 	}
 
+	p.ignorePacketEntitiesPanic = config.IgnorePacketEntitiesPanic
+
 	dispatcherCfg := dp.Config{
 		PanicHandler: func(v any) {
 			p.setError(fmt.Errorf("%v\nstacktrace:\n%s", v, debug.Stack()))

pkg/demoinfocs/parsing.go

@@ -71,7 +71,18 @@ func (p *parser) ParseHeader() (common.DemoHeader, error) {
 	case "PBDEMS2":
 		p.bitReader.Skip(8 << 3) // skip 8 bytes
 
-		p.stParser = sendtables2.NewParser()
+		var warnFunc func(error)
+
+		if p.ignorePacketEntitiesPanic {
+			warnFunc = func(err error) {
+				p.eventDispatcher.Dispatch(events.ParserWarn{
+					Type:    events.WarnTypePacketEntitiesPanic,
+					Message: fmt.Sprintf("encountered PacketEntities panic: %v", err),
+				})
+			}
+		}
+
+		p.stParser = sendtables2.NewParser(warnFunc)
 
 		p.stParser.OnEntity(p.onEntity)
 

pkg/demoinfocs/sendtables2/entity.go

@@ -2,6 +2,7 @@ package sendtables2
 
 import (
 	"fmt"
+	"os"
 	"strings"
 
 	"github.com/golang/geo/r3"
@@ -252,6 +253,8 @@ func (e *Entity) OnDestroy(delegate func()) {
 }
 
 func (e *Entity) Destroy() {
+	e.active = false
+
 	for _, delegate := range e.onDestroy {
 		delegate()
 	}
@@ -467,6 +470,17 @@ func (e *Entity) readFields(r *reader, paths *[]*fieldPath) {
 
 // Internal Callback for OnCSVCMsg_PacketEntities.
 func (p *Parser) OnPacketEntities(m *msgs2.CSVCMsg_PacketEntities) error {
+	defer func() {
+		if p.packetEntitiesPanicWarnFunc == nil {
+			return
+		}
+
+		r := recover()
+		if r != nil {
+			fmt.Fprintf(os.Stderr, "error in OnPacketEntities: %v\n", r)
+		}
+	}()
+
 	r := newReader(m.GetEntityData())
 
 	var (
@@ -481,6 +495,7 @@ func (p *Parser) OnPacketEntities(m *msgs2.CSVCMsg_PacketEntities) error {
 		if p.entityFullPackets > 0 {
 			return nil
 		}
+
 		p.entityFullPackets++
 	}
 
@@ -496,12 +511,7 @@ func (p *Parser) OnPacketEntities(m *msgs2.CSVCMsg_PacketEntities) error {
 		index = next
 
 		cmd = r.readBits(2)
-		if cmd == 0 && m.GetHasPvsVisBits() > 0 {
-			cmd = r.readBits(2) << 3
-			if cmd&0x08 == 8 {
-				continue
-			}
-		}
+
 		if cmd&0x01 == 0 {
 			if cmd&0x02 != 0 {
 				classID = int32(r.readBits(p.classIdSize))
@@ -537,7 +547,12 @@ func (p *Parser) OnPacketEntities(m *msgs2.CSVCMsg_PacketEntities) error {
 
 				op = st.EntityOpCreated | st.EntityOpEntered
 			} else {
-				if e = p.entities[index]; e == nil {
+				if m.GetHasPvsVisBits() > 0 && r.readBits(2)&0x01 != 0 {
+					continue
+				}
+
+				e = p.entities[index]
+				if e == nil {
 					_panicf("unable to find existing entity %d", index)
 				}
 
@@ -552,21 +567,18 @@ func (p *Parser) OnPacketEntities(m *msgs2.CSVCMsg_PacketEntities) error {
 		} else {
 			e = p.entities[index]
 			if e == nil {
-				continue
 				_panicf("unable to find existing entity %d", index)
 			}
 
 			if !e.active {
-				_panicf("entity %d (%s) ordered to leave, already inactive", e.class.classId, e.class.name)
+				continue // entity has already been destroyed
 			}
 
 			op = st.EntityOpLeft
 			if cmd&0x02 != 0 {
 				op |= st.EntityOpDeleted
 
 				e.Destroy()
-
-				delete(p.entities, index)
 			}
 		}
 

pkg/demoinfocs/sendtables2/parser.go

@@ -57,16 +57,17 @@ type tuple struct {
 }
 
 type Parser struct {
-	serializers       map[string]*serializer
-	classIdSize       uint32
-	classBaselines    map[int32][]byte
-	classesById       map[int32]*class
-	classesByName     map[string]*class
-	entityFullPackets int
-	entities          map[int32]*Entity
-	entityHandlers    []st.EntityHandler
-	pathCache         []*fieldPath
-	tuplesCache       []tuple
+	serializers                 map[string]*serializer
+	classIdSize                 uint32
+	classBaselines              map[int32][]byte
+	classesById                 map[int32]*class
+	classesByName               map[string]*class
+	entityFullPackets           int
+	entities                    map[int32]*Entity
+	entityHandlers              []st.EntityHandler
+	pathCache                   []*fieldPath
+	tuplesCache                 []tuple
+	packetEntitiesPanicWarnFunc func(error)
 }
 
 func (p *Parser) ReadEnterPVS(r *bit.BitReader, index int, entities map[int]st.Entity, slot int) st.Entity {
@@ -106,13 +107,14 @@ func (p *Parser) ServerClasses() st.ServerClasses {
 	return (*serverClasses)(p)
 }
 
-func NewParser() *Parser {
+func NewParser(packetEntitiesPanicWarnFunc func(error)) *Parser {
 	return &Parser{
-		serializers:    make(map[string]*serializer),
-		classBaselines: make(map[int32][]byte),
-		classesById:    make(map[int32]*class),
-		classesByName:  make(map[string]*class),
-		entities:       make(map[int32]*Entity),
+		serializers:                 make(map[string]*serializer),
+		classBaselines:              make(map[int32][]byte),
+		classesById:                 make(map[int32]*class),
+		classesByName:               make(map[string]*class),
+		entities:                    make(map[int32]*Entity),
+		packetEntitiesPanicWarnFunc: packetEntitiesPanicWarnFunc,
 	}
 }