No more printing to stderr, add WarnHandler

We don't wanna clutter up the end users logs unless it's their choice

Author: markus-wa

README.md

@@ -35,7 +35,7 @@ func main() {
 		log.Fatal(err)
 	}
 
-	p := dem.NewParser(f)
+	p := dem.NewParser(f, dem.WarnToStdErr)
 
 	// Parse header
 	p.ParseHeader()

common/common.go

@@ -8,16 +8,14 @@
 package common
 
 import (
-	"fmt"
-	"os"
 	"strings"
 )
 
 // MapEquipment creates an EquipmentElement from the name of the weapon / equipment.
 func MapEquipment(eqName string) EquipmentElement {
 	eqName = strings.TrimPrefix(eqName, weaponPrefix)
 
-	wep := EqUnknown
+	var wep EquipmentElement
 
 	if strings.Contains(eqName, "knife") || strings.Contains(eqName, "bayonet") {
 		wep = EqKnife
@@ -191,7 +189,8 @@ func MapEquipment(eqName string) EquipmentElement {
 		case "worldspawn":
 
 		default:
-			fmt.Fprintf(os.Stderr, "WARNING: Unknown weapon / equipment %q\n", eqName)
+			// TODO: This is really bad imo but we can't access Parser.warn here :/
+			wep = EqUnknown
 		}
 	}
 	return wep

demoinfocs_test.go

@@ -32,7 +32,7 @@ func TestDemoInfoCs(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	p := dem.NewParser(f)
+	p := dem.NewParser(f, dem.WarnToStdErr)
 
 	fmt.Println("Parsing header")
 	p.RegisterEventHandler(func(e events.HeaderParsedEvent) {
@@ -89,7 +89,7 @@ func TestCancelParseToEnd(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	p := dem.NewParser(f)
+	p := dem.NewParser(f, nil)
 	err = p.ParseHeader()
 	if err != nil {
 		t.Fatal(err)
@@ -119,7 +119,7 @@ func TestConcurrent(t *testing.T) {
 		f, _ := os.Open(defaultDemPath)
 		defer f.Close()
 
-		p := dem.NewParser(f)
+		p := dem.NewParser(f, nil)
 		err := p.ParseHeader()
 		if err != nil {
 			t.Fatal(err)
@@ -166,7 +166,7 @@ func TestDemoSet(t *testing.T) {
 					}
 				}()
 
-				p := dem.NewParser(f)
+				p := dem.NewParser(f, nil)
 				err = p.ParseHeader()
 				if err != nil {
 					t.Fatal(err)
@@ -187,7 +187,7 @@ func BenchmarkDemoInfoCs(b *testing.B) {
 				b.Fatal(err)
 			}
 
-			p := dem.NewParser(f)
+			p := dem.NewParser(f, nil)
 			err = p.ParseHeader()
 			if err != nil {
 				b.Fatal(err)
@@ -219,7 +219,7 @@ func BenchmarkInMemory(b *testing.B) {
 
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		p := dem.NewParser(bytes.NewReader(d))
+		p := dem.NewParser(bytes.NewReader(d), nil)
 		err = p.ParseHeader()
 		if err != nil {
 			b.Fatal(err)

demopacket.go

@@ -66,7 +66,21 @@ func (p *Parser) parsePacket() {
 			m = new(msg.CSVCMsg_UserMessage)
 
 		default:
-			// We don't care about anything else for now
+			if p.warn != nil {
+				var name string
+				if cmd < 8 || cmd >= 100 {
+					name = msg.NET_Messages_name[int32(cmd)]
+				} else {
+					name = msg.SVC_Messages_name[int32(cmd)]
+				}
+				if name == "" {
+					// Send a warning if the command is unknown
+					// This might mean our proto files are out of date
+					p.warn(fmt.Sprintf("Unknown message command %q", cmd))
+				}
+			}
+
+			// On to the next one
 			p.bitReader.EndChunk()
 			continue
 		}

example_test.go

@@ -18,7 +18,7 @@ func TestExample(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	p := dem.NewParser(f)
+	p := dem.NewParser(f, dem.WarnToStdErr)
 
 	// Parse header
 	p.ParseHeader()

packet_handlers.go

@@ -3,7 +3,6 @@ package demoinfocs
 import (
 	"bytes"
 	"fmt"
-	"os"
 	"strconv"
 
 	r3 "github.com/golang/geo/r3"
@@ -71,6 +70,8 @@ func (p *Parser) readEnterPVS(reader *bit.BitReader, entityID int) *st.Entity {
 			r := bit.NewSmallBitReader(bytes.NewReader(p.instanceBaselines[scID]))
 			newEntity.ApplyUpdate(r)
 			r.Pool()
+			// TODO: Unregister PropertyUpdateHandlers from CollectProperties()
+			// PropertyUpdateHandlers would have to be registered as pointers for that to work
 		}
 		p.preprocessedBaselines[scID] = ppBase
 	}
@@ -473,7 +474,9 @@ func (p *Parser) handleGameEvent(ge *msg.CSVCMsg_GameEvent) {
 	case "hltv_fixed": // Dunno
 	case "cs_match_end_restart": // Yawn
 	default:
-		fmt.Fprintf(os.Stderr, "WARNING: Unknown event %q\n", d.Name)
+		if p.warn != nil {
+			p.warn(fmt.Sprintf("Unknown event %q", d.Name))
+		}
 	}
 }
 
@@ -618,8 +621,9 @@ func (p *Parser) handleUserMessage(um *msg.CSVCMsg_UserMessage) {
 	case msg.ECstrike15UserMessages_CS_UM_SayText:
 		st := new(msg.CCSUsrMsg_SayText)
 		err := st.Unmarshal(um.MsgData)
-		if err != nil {
-			panic(fmt.Sprintf("Failed to decode SayText message: %s", err.Error()))
+		if err != nil && p.warn != nil {
+			// Just send a warning, chat messages aren't that important
+			p.warn(fmt.Sprintf("Failed to decode SayText message: %s", err.Error()))
 		}
 
 		p.eventDispatcher.Dispatch(events.SayTextEvent{
@@ -632,8 +636,8 @@ func (p *Parser) handleUserMessage(um *msg.CSVCMsg_UserMessage) {
 	case msg.ECstrike15UserMessages_CS_UM_SayText2:
 		st := new(msg.CCSUsrMsg_SayText2)
 		err := st.Unmarshal(um.MsgData)
-		if err != nil {
-			panic(fmt.Sprintf("Failed to decode SayText2 message: %s", err.Error()))
+		if err != nil && p.warn != nil {
+			p.warn(fmt.Sprintf("Failed to decode SayText2 message: %s", err.Error()))
 		}
 
 		sender := p.players[int(st.EntIdx)]
@@ -654,7 +658,11 @@ func (p *Parser) handleUserMessage(um *msg.CSVCMsg_UserMessage) {
 				Text:      st.Params[1],
 				IsChatAll: st.Textallchat,
 			})
+
 		default:
+			if p.warn != nil {
+				p.warn(fmt.Sprintf("Skipped sending ChatMessageEvent for SayText2 with unknown MsgName %q", st.MsgName))
+			}
 		}
 
 	default:

parser.go

@@ -1,7 +1,9 @@
 package demoinfocs
 
 import (
+	"fmt"
 	"io"
+	"os"
 
 	dp "github.com/markus-wa/godispatch"
 
@@ -45,6 +47,7 @@ type Parser struct {
 	gehDescriptors        map[int32]*msg.CSVCMsg_GameEventListDescriptorT
 	stringTables          []*msg.CSVCMsg_CreateStringTable
 	cancelChan            chan struct{}
+	warn                  WarnHandler
 }
 
 // Map returns the map name. E.g. de_dust2 or de_inferno.
@@ -159,9 +162,19 @@ func (ts TeamState) Flag() string {
 	return ts.flag
 }
 
+// WarnHandler is a function that handles warnings of a Parser.
+type WarnHandler func(string)
+
+// WarnToStdErr is a WarnHandler that prints all warnings to standard error output.
+func WarnToStdErr(warning string) {
+	fmt.Fprintln(os.Stderr, warning)
+}
+
 // NewParser creates a new Parser on the basis of an io.Reader
 // - like os.File or bytes.Reader - that reads demo data.
-func NewParser(demostream io.Reader) *Parser {
+// Any warnings that don't stop the Parser from doing it's job
+// will be passed to the warnHandler if it's not nil.
+func NewParser(demostream io.Reader, warnHandler WarnHandler) *Parser {
 	var p Parser
 	// Init parser
 	p.bitReader = bit.NewLargeBitReader(demostream)
@@ -173,6 +186,7 @@ func NewParser(demostream io.Reader) *Parser {
 	p.connectedPlayers = make(map[int]*common.Player)
 	p.entities = make(map[int]*st.Entity)
 	p.cancelChan = make(chan struct{}, 1)
+	p.warn = warnHandler
 
 	// Attach proto msg handlers
 	p.msgDispatcher.RegisterHandler(p.handlePacketEntities)

parsing.go

@@ -3,7 +3,6 @@ package demoinfocs
 import (
 	"errors"
 	"fmt"
-	"os"
 
 	common "github.com/markus-wa/demoinfocs-golang/common"
 	events "github.com/markus-wa/demoinfocs-golang/events"
@@ -153,7 +152,8 @@ func (p *Parser) parseFrame() bool {
 		p.parsePacket()
 
 	case dcCustomData:
-		fmt.Fprintf(os.Stderr, "WARNING: Found CustomData but not handled\n")
+		// Might as well panic since we'll be way off if we dont skip the whole thing
+		panic("Found CustomData but not handled")
 
 	default:
 		panic(fmt.Sprintf("Canny handle it anymoe (command %v unknown)", cmd))