refactor(channelserver): replace magic numbers with named protocol constants

Extract numeric literals into named constants across quest handling,
save data parsing, rengoku skill layout, diva event timing, guild info,
achievement trophies, RP accrual rates, and semaphore IDs. Adds
constants_quest.go for quest-related constants shared across functions.

Pure rename/extract with zero behavior change.

server/channelserver/constants_quest.go

@@ -12,8 +12,8 @@ const (
 
 // Event quest binary frame offsets
 const (
-	questFrameTimeFlagOffset  = 25
-	questFrameVariant3Offset  = 175
+	questFrameTimeFlagOffset = 25
+	questFrameVariant3Offset = 175
 )
 
 // Quest body lengths per game version

server/channelserver/handlers_guild_info.go

@@ -12,6 +12,12 @@ import (
 	"github.com/jmoiron/sqlx"
 )
 
+// Guild sentinel and cost constants
+const (
+	guildNotJoinedSentinel = uint32(0xFFFFFFFF)
+	guildRoomMaxRP         = uint32(55000)
+)
+
 func handleMsgMhfInfoGuild(s *Session, p mhfpacket.MHFPacket) {
 	pkt := p.(*mhfpacket.MsgMhfInfoGuild)
 
@@ -32,7 +38,7 @@ func handleMsgMhfInfoGuild(s *Session, p mhfpacket.MHFPacket) {
 		guildLeaderName := stringsupport.UTF8ToSJIS(guild.LeaderName)
 
 		characterGuildData, err := GetCharacterGuildData(s, s.charID)
-		characterJoinedAt := uint32(0xFFFFFFFF)
+		characterJoinedAt := guildNotJoinedSentinel
 
 		if characterGuildData != nil && characterGuildData.JoinedAt != nil {
 			characterJoinedAt = uint32(characterGuildData.JoinedAt.Unix())
@@ -123,7 +129,7 @@ func handleMsgMhfInfoGuild(s *Session, p mhfpacket.MHFPacket) {
 		}
 		bf.WriteUint8(limit)
 
-		bf.WriteUint32(55000)
+		bf.WriteUint32(guildRoomMaxRP)
 		bf.WriteUint32(uint32(guild.RoomExpiry.Unix()))
 		bf.WriteUint16(guild.RoomRP)
 		bf.WriteUint16(0) // Ignored

server/channelserver/handlers_quest.go

@@ -223,24 +223,24 @@ func loadQuestFile(s *Session, questId int) []byte {
 	fileBytes.SetLE()
 	_, _ = fileBytes.Seek(int64(fileBytes.ReadUint32()), 0)
 
-	bodyLength := 320
+	bodyLength := questBodyLenZZ
 	if s.server.erupeConfig.RealClientMode <= _config.S6 {
-		bodyLength = 160
+		bodyLength = questBodyLenS6
 	} else if s.server.erupeConfig.RealClientMode <= _config.F5 {
-		bodyLength = 168
+		bodyLength = questBodyLenF5
 	} else if s.server.erupeConfig.RealClientMode <= _config.G101 {
-		bodyLength = 192
+		bodyLength = questBodyLenG101
 	} else if s.server.erupeConfig.RealClientMode <= _config.Z1 {
-		bodyLength = 224
+		bodyLength = questBodyLenZ1
 	}
 
 	// The n bytes directly following the data pointer must go directly into the event's body, after the header and before the string pointers.
 	questBody := byteframe.NewByteFrameFromBytes(fileBytes.ReadBytes(uint(bodyLength)))
 	questBody.SetLE()
 	// Find the master quest string pointer
-	_, _ = questBody.Seek(40, 0)
+	_, _ = questBody.Seek(questStringPointerOff, 0)
 	_, _ = fileBytes.Seek(int64(questBody.ReadUint32()), 0)
-	_, _ = questBody.Seek(40, 0)
+	_, _ = questBody.Seek(questStringPointerOff, 0)
 	// Overwrite it
 	questBody.WriteUint32(uint32(bodyLength))
 	_, _ = questBody.Seek(0, 2)
@@ -248,8 +248,8 @@ func loadQuestFile(s *Session, questId int) []byte {
 	// Rewrite the quest strings and their pointers
 	var tempString []byte
 	newStrings := byteframe.NewByteFrame()
-	tempPointer := bodyLength + 32
-	for i := 0; i < 8; i++ {
+	tempPointer := bodyLength + questStringTablePadding
+	for i := 0; i < questStringCount; i++ {
 		questBody.WriteUint32(uint32(tempPointer))
 		temp := int64(fileBytes.Index())
 		_, _ = fileBytes.Seek(int64(fileBytes.ReadUint32()), 0)
@@ -284,21 +284,21 @@ func makeEventQuest(s *Session, rows *sql.Rows) ([]byte, error) {
 	bf.WriteUint32(0) // Unk
 	bf.WriteUint8(0)  // Unk
 	switch questType {
-	case 16:
+	case QuestTypeRegularRaviente:
 		bf.WriteUint8(s.server.erupeConfig.GameplayOptions.RegularRavienteMaxPlayers)
-	case 22:
+	case QuestTypeViolentRaviente:
 		bf.WriteUint8(s.server.erupeConfig.GameplayOptions.ViolentRavienteMaxPlayers)
-	case 40:
+	case QuestTypeBerserkRaviente:
 		bf.WriteUint8(s.server.erupeConfig.GameplayOptions.BerserkRavienteMaxPlayers)
-	case 50:
+	case QuestTypeExtremeRaviente:
 		bf.WriteUint8(s.server.erupeConfig.GameplayOptions.ExtremeRavienteMaxPlayers)
-	case 51:
+	case QuestTypeSmallBerserkRavi:
 		bf.WriteUint8(s.server.erupeConfig.GameplayOptions.SmallBerserkRavienteMaxPlayers)
 	default:
 		bf.WriteUint8(maxPlayers)
 	}
 	bf.WriteUint8(questType)
-	if questType == 9 {
+	if questType == QuestTypeSpecialTool {
 		bf.WriteBool(false)
 	} else {
 		bf.WriteBool(true)
@@ -314,9 +314,9 @@ func makeEventQuest(s *Session, rows *sql.Rows) ([]byte, error) {
 	// Time Flag Replacement
 	// Bitset Structure: b8 UNK, b7 Required Objective, b6 UNK, b5 Night, b4 Day, b3 Cold, b2 Warm, b1 Spring
 	// if the byte is set to 0 the game choses the quest file corresponding to whatever season the game is on
-	_, _ = bf.Seek(25, 0)
+	_, _ = bf.Seek(questFrameTimeFlagOffset, 0)
 	flagByte := bf.ReadUint8()
-	_, _ = bf.Seek(25, 0)
+	_, _ = bf.Seek(questFrameTimeFlagOffset, 0)
 	if s.server.erupeConfig.GameplayOptions.SeasonOverride {
 		bf.WriteUint8(flagByte & 0b11100000)
 	} else {
@@ -332,10 +332,10 @@ func makeEventQuest(s *Session, rows *sql.Rows) ([]byte, error) {
 	// Bitset Structure Quest Variant 2: b8 Road, b7 High Conquest, b6 Fixed Difficulty, b5 No Active Feature, b4 Timer, b3 No Cuff, b2 No Halk Pots, b1 Low Conquest
 	// Bitset Structure Quest Variant 3: b8 No Sigils, b7 UNK, b6 Interception, b5 Zenith, b4 No GP Skills, b3 No Simple Mode?, b2 GSR to GR, b1 No Reward Skills
 
-	_, _ = bf.Seek(175, 0)
+	_, _ = bf.Seek(questFrameVariant3Offset, 0)
 	questVariant3 := bf.ReadUint8()
 	questVariant3 &= 0b11011111 // disable Interception flag
-	_, _ = bf.Seek(175, 0)
+	_, _ = bf.Seek(questFrameVariant3Offset, 0)
 	bf.WriteUint8(questVariant3)
 
 	_, _ = bf.Seek(0, 2)
@@ -400,7 +400,7 @@ func handleMsgMhfEnumerateQuest(s *Session, p mhfpacket.MHFPacket) {
 				s.logger.Error("Failed to make event quest", zap.Error(err))
 				continue
 			} else {
-				if len(data) > 896 || len(data) < 352 {
+				if len(data) > questDataMaxLen || len(data) < questDataMinLen {
 					s.logger.Error("Invalid quest data length", zap.Int("len", len(data)))
 					continue
 				} else {
@@ -601,25 +601,25 @@ func handleMsgMhfEnumerateQuest(s *Session, p mhfpacket.MHFPacket) {
 	}
 	tuneValues = temp
 
-	tuneLimit := 770
+	tuneLimit := tuneLimitZZ
 	if s.server.erupeConfig.RealClientMode <= _config.G1 {
-		tuneLimit = 256
+		tuneLimit = tuneLimitG1
 	} else if s.server.erupeConfig.RealClientMode <= _config.G3 {
-		tuneLimit = 283
+		tuneLimit = tuneLimitG3
 	} else if s.server.erupeConfig.RealClientMode <= _config.GG {
-		tuneLimit = 315
+		tuneLimit = tuneLimitGG
 	} else if s.server.erupeConfig.RealClientMode <= _config.G61 {
-		tuneLimit = 332
+		tuneLimit = tuneLimitG61
 	} else if s.server.erupeConfig.RealClientMode <= _config.G7 {
-		tuneLimit = 339
+		tuneLimit = tuneLimitG7
 	} else if s.server.erupeConfig.RealClientMode <= _config.G81 {
-		tuneLimit = 396
+		tuneLimit = tuneLimitG81
 	} else if s.server.erupeConfig.RealClientMode <= _config.G91 {
-		tuneLimit = 694
+		tuneLimit = tuneLimitG91
 	} else if s.server.erupeConfig.RealClientMode <= _config.G101 {
-		tuneLimit = 704
+		tuneLimit = tuneLimitG101
 	} else if s.server.erupeConfig.RealClientMode <= _config.Z2 {
-		tuneLimit = 750
+		tuneLimit = tuneLimitZ2
 	}
 	if len(tuneValues) > tuneLimit {
 		tuneValues = tuneValues[:tuneLimit]

server/channelserver/handlers_rengoku.go

@@ -14,18 +14,31 @@ import (
 	"go.uber.org/zap"
 )
 
+// Rengoku save blob layout offsets
+const (
+	rengokuSkillSlotsStart  = 0x1B
+	rengokuSkillSlotsEnd    = 0x21
+	rengokuSkillValuesStart = 0x2E
+	rengokuSkillValuesEnd   = 0x3A
+	rengokuPointsStart      = 0x3B
+	rengokuPointsEnd        = 0x47
+	rengokuMaxStageMpOffset = 71
+	rengokuMinPayloadSize   = 91
+	rengokuMaxPayloadSize   = 4096
+)
+
 // rengokuSkillsZeroed checks if the skill slot IDs (offsets 0x1B-0x20) and
 // equipped skill values (offsets 0x2E-0x39) are all zero in a rengoku save blob.
 func rengokuSkillsZeroed(data []byte) bool {
-	if len(data) < 0x3A {
+	if len(data) < rengokuSkillValuesEnd {
 		return true
 	}
-	for _, b := range data[0x1B:0x21] {
+	for _, b := range data[rengokuSkillSlotsStart:rengokuSkillSlotsEnd] {
 		if b != 0 {
 			return false
 		}
 	}
-	for _, b := range data[0x2E:0x3A] {
+	for _, b := range data[rengokuSkillValuesStart:rengokuSkillValuesEnd] {
 		if b != 0 {
 			return false
 		}
@@ -35,10 +48,10 @@ func rengokuSkillsZeroed(data []byte) bool {
 
 // rengokuHasPoints checks if any skill point allocation (offsets 0x3B-0x46) is nonzero.
 func rengokuHasPoints(data []byte) bool {
-	if len(data) < 0x47 {
+	if len(data) < rengokuPointsEnd {
 		return false
 	}
-	for _, b := range data[0x3B:0x47] {
+	for _, b := range data[rengokuPointsStart:rengokuPointsEnd] {
 		if b != 0 {
 			return true
 		}
@@ -51,15 +64,15 @@ func rengokuHasPoints(data []byte) bool {
 // preserving the skills that the client failed to populate due to a race
 // condition during area transitions (see issue #85).
 func rengokuMergeSkills(dst, src []byte) {
-	copy(dst[0x1B:0x21], src[0x1B:0x21])
-	copy(dst[0x2E:0x3A], src[0x2E:0x3A])
+	copy(dst[rengokuSkillSlotsStart:rengokuSkillSlotsEnd], src[rengokuSkillSlotsStart:rengokuSkillSlotsEnd])
+	copy(dst[rengokuSkillValuesStart:rengokuSkillValuesEnd], src[rengokuSkillValuesStart:rengokuSkillValuesEnd])
 }
 
 func handleMsgMhfSaveRengokuData(s *Session, p mhfpacket.MHFPacket) {
 	// Saved every floor on road, holds values such as floors progressed, points etc.
 	// Can be safely handled by the client.
 	pkt := p.(*mhfpacket.MsgMhfSaveRengokuData)
-	if len(pkt.RawDataPayload) < 91 || len(pkt.RawDataPayload) > 4096 {
+	if len(pkt.RawDataPayload) < rengokuMinPayloadSize || len(pkt.RawDataPayload) > rengokuMaxPayloadSize {
 		s.logger.Warn("Rengoku payload size out of range", zap.Int("len", len(pkt.RawDataPayload)))
 		doAckSimpleSucceed(s, pkt.AckHandle, make([]byte, 4))
 		return
@@ -72,10 +85,10 @@ func handleMsgMhfSaveRengokuData(s *Session, p mhfpacket.MHFPacket) {
 	// path triggers a rengoku save BEFORE the load response has been parsed into
 	// the character data area. This produces a save with zeroed skill fields but
 	// preserved point totals. Detect this pattern and merge existing skill data.
-	if len(saveData) >= 0x47 && rengokuSkillsZeroed(saveData) && rengokuHasPoints(saveData) {
+	if len(saveData) >= rengokuPointsEnd && rengokuSkillsZeroed(saveData) && rengokuHasPoints(saveData) {
 		var existing []byte
 		if err := s.server.db.QueryRow("SELECT rengokudata FROM characters WHERE id=$1", s.charID).Scan(&existing); err == nil {
-			if len(existing) >= 0x47 && !rengokuSkillsZeroed(existing) {
+			if len(existing) >= rengokuPointsEnd && !rengokuSkillsZeroed(existing) {
 				s.logger.Info("Rengoku save has zeroed skills with invested points, preserving existing skills",
 					zap.Uint32("charID", s.charID))
 				merged := make([]byte, len(saveData))
@@ -106,7 +119,7 @@ func handleMsgMhfSaveRengokuData(s *Session, p mhfpacket.MHFPacket) {
 		return
 	}
 	bf := byteframe.NewByteFrameFromBytes(saveData)
-	_, _ = bf.Seek(71, 0)
+	_, _ = bf.Seek(rengokuMaxStageMpOffset, 0)
 	maxStageMp := bf.ReadUint32()
 	maxScoreMp := bf.ReadUint32()
 	_, _ = bf.Seek(4, 1)

server/channelserver/handlers_session.go

@@ -500,12 +500,12 @@ func handleMsgMhfTransitMessage(s *Session, p mhfpacket.MHFPacket) {
 	case 1, 2, 3: // usersearchidx, usersearchname, lobbysearchname
 		// Snapshot matching sessions under lock, then build response outside locks.
 		type sessionResult struct {
-			charID    uint32
-			name      []byte
-			stageID   []byte
-			ip        net.IP
-			port      uint16
-			userBin3  []byte
+			charID   uint32
+			name     []byte
+			stageID  []byte
+			ip       net.IP
+			port     uint16
+			userBin3 []byte
 		}
 		var results []sessionResult
 
@@ -656,15 +656,15 @@ func handleMsgMhfTransitMessage(s *Session, p mhfpacket.MHFPacket) {
 		}
 		// Snapshot matching stages under lock, then build response outside locks.
 		type stageResult struct {
-			ip           net.IP
-			port         uint16
-			clientCount  int
-			reserved     int
-			maxPlayers   uint16
-			stageID      string
-			stageData    []int16
-			rawBinData0  []byte
-			rawBinData1  []byte
+			ip          net.IP
+			port        uint16
+			clientCount int
+			reserved    int
+			maxPlayers  uint16
+			stageID     string
+			stageData   []int16
+			rawBinData0 []byte
+			rawBinData1 []byte
 		}
 		var stageResults []stageResult
 

server/channelserver/model_character.go

@@ -13,20 +13,20 @@ import (
 type SavePointer int
 
 const (
-	pGender        = iota // +1
-	pRP                   // +2
-	pHouseTier            // +5
-	pHouseData            // +195
-	pBookshelfData        // +lBookshelfData
-	pGalleryData          // +1748
-	pToreData             // +240
-	pGardenData           // +68
-	pPlaytime             // +4
-	pWeaponType           // +1
-	pWeaponID             // +2
-	pHR                   // +2
-	pGRP                  // +4
-	pKQF                  // +8
+	pGender = iota
+	pRP
+	pHouseTier
+	pHouseData
+	pBookshelfData
+	pGalleryData
+	pToreData
+	pGardenData
+	pPlaytime
+	pWeaponType
+	pWeaponID
+	pHR
+	pGRP
+	pKQF
 	lBookshelfData
 )
 
@@ -146,16 +146,33 @@ func (save *CharacterSaveData) updateSaveDataWithStruct() {
 	rpBytes := make([]byte, 2)
 	binary.LittleEndian.PutUint16(rpBytes, save.RP)
 	if save.Mode >= _config.F4 {
-		copy(save.decompSave[save.Pointers[pRP]:save.Pointers[pRP]+2], rpBytes)
+		copy(save.decompSave[save.Pointers[pRP]:save.Pointers[pRP]+saveFieldRP], rpBytes)
 	}
 	if save.Mode >= _config.G10 {
-		copy(save.decompSave[save.Pointers[pKQF]:save.Pointers[pKQF]+8], save.KQF)
+		copy(save.decompSave[save.Pointers[pKQF]:save.Pointers[pKQF]+saveFieldKQF], save.KQF)
 	}
 }
 
 // This will update the save struct with the values stored in the character save
+// Save data field sizes
+const (
+	saveFieldRP         = 2
+	saveFieldHouseTier  = 5
+	saveFieldHouseData  = 195
+	saveFieldGallery    = 1748
+	saveFieldTore       = 240
+	saveFieldGarden     = 68
+	saveFieldPlaytime   = 4
+	saveFieldWeaponID   = 2
+	saveFieldHR         = 2
+	saveFieldGRP        = 4
+	saveFieldKQF        = 8
+	saveFieldNameOffset = 88
+	saveFieldNameLen    = 12
+)
+
 func (save *CharacterSaveData) updateStructWithSaveData() {
-	save.Name, _ = stringsupport.SJISToUTF8(bfutil.UpToNull(save.decompSave[88:100]))
+	save.Name, _ = stringsupport.SJISToUTF8(bfutil.UpToNull(save.decompSave[saveFieldNameOffset : saveFieldNameOffset+saveFieldNameLen]))
 	if save.decompSave[save.Pointers[pGender]] == 1 {
 		save.Gender = true
 	} else {
@@ -163,24 +180,24 @@ func (save *CharacterSaveData) updateStructWithSaveData() {
 	}
 	if !save.IsNewCharacter {
 		if save.Mode >= _config.S6 {
-			save.RP = binary.LittleEndian.Uint16(save.decompSave[save.Pointers[pRP] : save.Pointers[pRP]+2])
-			save.HouseTier = save.decompSave[save.Pointers[pHouseTier] : save.Pointers[pHouseTier]+5]
-			save.HouseData = save.decompSave[save.Pointers[pHouseData] : save.Pointers[pHouseData]+195]
+			save.RP = binary.LittleEndian.Uint16(save.decompSave[save.Pointers[pRP] : save.Pointers[pRP]+saveFieldRP])
+			save.HouseTier = save.decompSave[save.Pointers[pHouseTier] : save.Pointers[pHouseTier]+saveFieldHouseTier]
+			save.HouseData = save.decompSave[save.Pointers[pHouseData] : save.Pointers[pHouseData]+saveFieldHouseData]
 			save.BookshelfData = save.decompSave[save.Pointers[pBookshelfData] : save.Pointers[pBookshelfData]+save.Pointers[lBookshelfData]]
-			save.GalleryData = save.decompSave[save.Pointers[pGalleryData] : save.Pointers[pGalleryData]+1748]
-			save.ToreData = save.decompSave[save.Pointers[pToreData] : save.Pointers[pToreData]+240]
-			save.GardenData = save.decompSave[save.Pointers[pGardenData] : save.Pointers[pGardenData]+68]
-			save.Playtime = binary.LittleEndian.Uint32(save.decompSave[save.Pointers[pPlaytime] : save.Pointers[pPlaytime]+4])
+			save.GalleryData = save.decompSave[save.Pointers[pGalleryData] : save.Pointers[pGalleryData]+saveFieldGallery]
+			save.ToreData = save.decompSave[save.Pointers[pToreData] : save.Pointers[pToreData]+saveFieldTore]
+			save.GardenData = save.decompSave[save.Pointers[pGardenData] : save.Pointers[pGardenData]+saveFieldGarden]
+			save.Playtime = binary.LittleEndian.Uint32(save.decompSave[save.Pointers[pPlaytime] : save.Pointers[pPlaytime]+saveFieldPlaytime])
 			save.WeaponType = save.decompSave[save.Pointers[pWeaponType]]
-			save.WeaponID = binary.LittleEndian.Uint16(save.decompSave[save.Pointers[pWeaponID] : save.Pointers[pWeaponID]+2])
-			save.HR = binary.LittleEndian.Uint16(save.decompSave[save.Pointers[pHR] : save.Pointers[pHR]+2])
+			save.WeaponID = binary.LittleEndian.Uint16(save.decompSave[save.Pointers[pWeaponID] : save.Pointers[pWeaponID]+saveFieldWeaponID])
+			save.HR = binary.LittleEndian.Uint16(save.decompSave[save.Pointers[pHR] : save.Pointers[pHR]+saveFieldHR])
 			if save.Mode >= _config.G1 {
 				if save.HR == uint16(999) {
-					save.GR = grpToGR(int(binary.LittleEndian.Uint32(save.decompSave[save.Pointers[pGRP] : save.Pointers[pGRP]+4])))
+					save.GR = grpToGR(int(binary.LittleEndian.Uint32(save.decompSave[save.Pointers[pGRP] : save.Pointers[pGRP]+saveFieldGRP])))
 				}
 			}
 			if save.Mode >= _config.G10 {
-				save.KQF = save.decompSave[save.Pointers[pKQF] : save.Pointers[pKQF]+8]
+				save.KQF = save.decompSave[save.Pointers[pKQF] : save.Pointers[pKQF]+saveFieldKQF]
 			}
 		}
 	}