refactor(channelserver): add numeric column helpers and extract protocol constants

Add readCharacterInt/adjustCharacterInt helpers for single-column integer operations on the characters table. Eliminates fmt.Sprintf SQL construction in handlers_misc.go and replaces inline queries across cafe, kouryou, and mercenary handlers. Second round of protocol constant extraction: adds constants_time.go (secsPerDay, secsPerWeek), constants_raviente.go (register IDs, semaphore constants), and named constants across 14 handler files replacing raw hex/numeric literals. Updates anti-patterns doc to mark #4 (magic numbers) as substantially fixed.
2026-03-21 23:22:34 +01:00 · 2026-02-20 21:18:40 +01:00
parent 28bf6e93fb
commit 458d8c9397
20 changed files with 182 additions and 124 deletions
--- a/docs/anti-patterns.md
+++ b/docs/anti-patterns.md
@@ -150,32 +150,16 @@ There is no repository layer, no service layer — just handlers.

 ---

-## 4. Magic Numbers Everywhere
+## 4. ~~Magic Numbers Everywhere~~ (Substantially Fixed)

-Binary protocol code is full of unexplained numeric literals with no named constants or comments:
+**Status:** Two rounds of extraction have replaced the highest-impact magic numbers with named constants:

-```go
-// handlers_cast_binary.go
-bf.WriteUint8(0x02)
-bf.WriteUint16(0x00)
-bf.Seek(4, io.SeekStart)
-```
+- **Round 1** (commit `7c444b0`): `constants_quest.go`, `handlers_guild_info.go`, `handlers_quest.go`, `handlers_rengoku.go`, `handlers_session.go`, `model_character.go`
+- **Round 2**: `constants_time.go` (shared `secsPerDay`, `secsPerWeek`), `constants_raviente.go` (register IDs, semaphore constants), plus constants in `handlers_register.go`, `handlers_semaphore.go`, `handlers_session.go`, `handlers_festa.go`, `handlers_diva.go`, `handlers_event.go`, `handlers_mercenary.go`, `handlers_misc.go`, `handlers_plate.go`, `handlers_cast_binary.go`, `handlers_commands.go`, `handlers_reward.go`, `handlers_guild_mission.go`, `sys_channel_server.go`

-```go
-// handlers_data.go
-if dataLen > 0x20000 { ... }
-```
+**Remaining:** Unknown protocol fields (e.g., `handlers_diva.go:112-115` `0x19, 0x2D, 0x02, 0x02`) are intentionally left as literals until their meaning is understood. Data tables (monster point tables, item IDs) are data, not protocol constants. Standard empty ACK payloads (`make([]byte, 4)`) are idiomatic Go.

-```go
-// Various handlers
-bf.WriteUint32(0x0A218EAD)  // What is this?
-```
-
-Packet field offsets, sizes, flags, and game constants appear as raw numbers throughout.
-
-**Impact:** New contributors can't understand what these values mean. Protocol documentation exists only in the developer's memory. Bugs from using the wrong constant are hard to catch.
-
-**Recommendation:** Define named constants in relevant packages (e.g., `const MaxDataChunkSize = 0x20000`, `const CastBinaryTypePosition = 0x02`).
+**Impact:** ~~New contributors can't understand what these values mean.~~ Most protocol-meaningful constants now have names and comments.

 ---

@@ -318,7 +302,7 @@ Database operations use raw `database/sql` with PostgreSQL-specific syntax throu
 | Severity | Anti-patterns |
 |----------|--------------|
 | **High** | ~~Missing ACK responses / softlocks (#2)~~ **Fixed**, no architectural layering (#3), tight DB coupling (#13) |
-| **Medium** | Magic numbers (#4), ~~inconsistent binary I/O (#5)~~ **Resolved**, Session god object (#6), ~~copy-paste handlers (#8)~~ **Fixed**, raw SQL duplication (#9) |
+| **Medium** | ~~Magic numbers (#4)~~ **Fixed**, ~~inconsistent binary I/O (#5)~~ **Resolved**, Session god object (#6), ~~copy-paste handlers (#8)~~ **Fixed**, raw SQL duplication (#9) |
 | **Low** | God files (#1), ~~`init()` registration (#10)~~ **Fixed**, ~~inconsistent logging (#12)~~ **Fixed**, mutex granularity (#7), ~~panic-based flow (#11)~~ **Fixed** |

 ### Root Cause
--- a/server/channelserver/constants_raviente.go
+++ b/server/channelserver/constants_raviente.go
@@ -0,0 +1,14 @@
+package channelserver
+
+// Raviente register type IDs (used in MsgSysLoadRegister / MsgSysNotifyRegister)
+const (
+	raviRegisterState   = uint32(0x40000)
+	raviRegisterSupport = uint32(0x50000)
+	raviRegisterGeneral = uint32(0x60000)
+)
+
+// Raviente semaphore constants
+const (
+	raviSemaphoreStride = 0x10000    // ID spacing between hs_l0* semaphores
+	raviSemaphoreMax    = uint16(127) // max players per Raviente semaphore
+)
--- a/server/channelserver/constants_time.go
+++ b/server/channelserver/constants_time.go
@@ -0,0 +1,7 @@
+package channelserver
+
+// Shared time duration constants (seconds)
+const (
+	secsPerDay  = 86400  // 24 hours
+	secsPerWeek = 604800 // 7 days
+)
--- a/server/channelserver/handlers_cafe.go
+++ b/server/channelserver/handlers_cafe.go
@@ -14,25 +14,23 @@ import (

 func handleMsgMhfAcquireCafeItem(s *Session, p mhfpacket.MHFPacket) {
 	pkt := p.(*mhfpacket.MsgMhfAcquireCafeItem)
-	var netcafePoints uint32
-	err := s.server.db.QueryRow("UPDATE characters SET netcafe_points = netcafe_points - $1 WHERE id = $2 RETURNING netcafe_points", pkt.PointCost, s.charID).Scan(&netcafePoints)
+	netcafePoints, err := adjustCharacterInt(s, "netcafe_points", -int(pkt.PointCost))
 	if err != nil {
-		s.logger.Error("Failed to get netcafe points from db", zap.Error(err))
+		s.logger.Error("Failed to deduct netcafe points", zap.Error(err))
 	}
 	resp := byteframe.NewByteFrame()
-	resp.WriteUint32(netcafePoints)
+	resp.WriteUint32(uint32(netcafePoints))
 	doAckSimpleSucceed(s, pkt.AckHandle, resp.Data())
 }

 func handleMsgMhfUpdateCafepoint(s *Session, p mhfpacket.MHFPacket) {
 	pkt := p.(*mhfpacket.MsgMhfUpdateCafepoint)
-	var netcafePoints uint32
-	err := s.server.db.QueryRow("SELECT COALESCE(netcafe_points, 0) FROM characters WHERE id = $1", s.charID).Scan(&netcafePoints)
+	netcafePoints, err := readCharacterInt(s, "netcafe_points")
 	if err != nil {
-		s.logger.Error("Failed to get netcate points from db", zap.Error(err))
+		s.logger.Error("Failed to get netcafe points", zap.Error(err))
 	}
 	resp := byteframe.NewByteFrame()
-	resp.WriteUint32(netcafePoints)
+	resp.WriteUint32(uint32(netcafePoints))
 	doAckSimpleSucceed(s, pkt.AckHandle, resp.Data())
 }

@@ -93,17 +91,16 @@ func handleMsgMhfGetCafeDuration(s *Session, p mhfpacket.MHFPacket) {
 		}
 	}

-	var cafeTime uint32
-	err = s.server.db.QueryRow("SELECT cafe_time FROM characters WHERE id = $1", s.charID).Scan(&cafeTime)
+	cafeTime, err := readCharacterInt(s, "cafe_time")
 	if err != nil {
 		s.logger.Error("Failed to get cafe time", zap.Error(err))
 		doAckBufFail(s, pkt.AckHandle, make([]byte, 4))
 		return
 	}
 	if mhfcourse.CourseExists(30, s.courses) {
-		cafeTime = uint32(TimeAdjusted().Unix()) - uint32(s.sessionStart) + cafeTime
+		cafeTime = int(TimeAdjusted().Unix()) - int(s.sessionStart) + cafeTime
 	}
-	bf.WriteUint32(cafeTime)
+	bf.WriteUint32(uint32(cafeTime))
 	if s.server.erupeConfig.RealClientMode >= _config.ZZ {
 		bf.WriteUint16(0)
 		ps.Uint16(bf, fmt.Sprintf(s.server.i18n.cafe.reset, int(cafeReset.Month()), cafeReset.Day()), true)
@@ -218,16 +215,11 @@ func handleMsgMhfPostCafeDurationBonusReceived(s *Session, p mhfpacket.MHFPacket
 }

 func addPointNetcafe(s *Session, p int) error {
-	var points int
-	err := s.server.db.QueryRow("SELECT netcafe_points FROM characters WHERE id = $1", s.charID).Scan(&points)
+	points, err := readCharacterInt(s, "netcafe_points")
 	if err != nil {
 		return err
 	}
-	if points+p > s.server.erupeConfig.GameplayOptions.MaximumNP {
-		points = s.server.erupeConfig.GameplayOptions.MaximumNP
-	} else {
-		points += p
-	}
+	points = min(points+p, s.server.erupeConfig.GameplayOptions.MaximumNP)
 	if _, err := s.server.db.Exec("UPDATE characters SET netcafe_points=$1 WHERE id=$2", points, s.charID); err != nil {
 		s.logger.Error("Failed to update netcafe points", zap.Error(err))
 	}
--- a/server/channelserver/handlers_cast_binary.go
+++ b/server/channelserver/handlers_cast_binary.go
@@ -34,8 +34,13 @@ func handleMsgSysCastBinary(s *Session, p mhfpacket.MHFPacket) {
 	pkt := p.(*mhfpacket.MsgSysCastBinary)
 	tmp := byteframe.NewByteFrameFromBytes(pkt.RawDataPayload)

-	if pkt.BroadcastType == BroadcastTypeStage && pkt.MessageType == BinaryMessageTypeData && len(pkt.RawDataPayload) == 0x10 {
-		if tmp.ReadUint16() == 0x0002 && tmp.ReadUint8() == 0x18 {
+	const (
+		timerPayloadSize = 0x10         // expected payload length for timer packets
+		timerSubtype     = uint16(0x0002) // timer data subtype identifier
+		timerFlag        = uint8(0x18)   // timer flag byte
+	)
+	if pkt.BroadcastType == BroadcastTypeStage && pkt.MessageType == BinaryMessageTypeData && len(pkt.RawDataPayload) == timerPayloadSize {
+		if tmp.ReadUint16() == timerSubtype && tmp.ReadUint8() == timerFlag {
 			var timer bool
 			if err := s.server.db.QueryRow(`SELECT COALESCE(timer, false) FROM users WHERE id=$1`, s.userID).Scan(&timer); err != nil {
 				s.logger.Error("Failed to get timer setting", zap.Error(err))
--- a/server/channelserver/handlers_commands.go
+++ b/server/channelserver/handlers_commands.go
@@ -44,6 +44,8 @@ func sendDisabledCommandMessage(s *Session, cmd _config.Command) {
 	sendServerChatMessage(s, fmt.Sprintf(s.server.i18n.commands.disabled, cmd.Name))
 }

+const chatFlagServer = 0x80 // marks a message as server-originated
+
 func sendServerChatMessage(s *Session, message string) {
 	// Make the inside of the casted binary
 	bf := byteframe.NewByteFrame()
@@ -51,7 +53,7 @@ func sendServerChatMessage(s *Session, message string) {
 	msgBinChat := &binpacket.MsgBinChat{
 		Unk0:       0,
 		Type:       5,
-		Flags:      0x80,
+		Flags:      chatFlagServer,
 		Message:    message,
 		SenderName: "Erupe",
 	}
--- a/server/channelserver/handlers_diva.go
+++ b/server/channelserver/handlers_diva.go
@@ -15,7 +15,7 @@ import (
 const (
 	divaPhaseDuration = 601200  // 6d 23h = first song phase
 	divaInterlude     = 3900    // 65 min = gap between phases
-	divaWeekDuration  = 604800  // 7 days = subsequent phase length
+	divaWeekDuration  = secsPerWeek // 7 days = subsequent phase length
 	divaTotalLifespan = 2977200 // ~34.5 days = full event window
 )

@@ -76,7 +76,8 @@ func handleMsgMhfGetUdSchedule(s *Session, p mhfpacket.MHFPacket) {
 	pkt := p.(*mhfpacket.MsgMhfGetUdSchedule)
 	bf := byteframe.NewByteFrame()

-	id, start := uint32(0xCAFEBEEF), uint32(0)
+	const divaIDSentinel = uint32(0xCAFEBEEF)
+	id, start := divaIDSentinel, uint32(0)
 	rows, err := s.server.db.Queryx("SELECT id, (EXTRACT(epoch FROM start_time)::int) as start_time FROM events WHERE event_type='diva'")
 	if err != nil {
 		s.logger.Error("Failed to query diva schedule", zap.Error(err))
--- a/server/channelserver/handlers_event.go
+++ b/server/channelserver/handlers_event.go
@@ -175,7 +175,7 @@ func handleMsgMhfGetKeepLoginBoostStatus(s *Session, p mhfpacket.MHFPacket) {
 			}
 		}

-		boost.WeekCount = uint8((TimeAdjusted().Unix()-boost.Expiration.Unix())/604800 + 1)
+		boost.WeekCount = uint8((TimeAdjusted().Unix()-boost.Expiration.Unix())/secsPerWeek + 1)

 		if boost.WeekCount >= boost.WeekReq {
 			boost.Active = true
--- a/server/channelserver/handlers_festa.go
+++ b/server/channelserver/handlers_festa.go
@@ -103,6 +103,13 @@ func cleanupFesta(s *Session) {
 	}
 }

+// Festa timing constants (all values in seconds)
+const (
+	festaVotingDuration = 9000    // 150 min voting window
+	festaRewardDuration = 1240200 // ~14.35 days reward period
+	festaEventLifespan  = 2977200 // ~34.5 days total event window
+)
+
 func generateFestaTimestamps(s *Session, start uint32, debug bool) []uint32 {
 	timestamps := make([]uint32, 5)
 	midnight := TimeMidnight()
@@ -111,26 +118,26 @@ func generateFestaTimestamps(s *Session, start uint32, debug bool) []uint32 {
 		switch start {
 		case 1:
 			timestamps[0] = midnight
-			timestamps[1] = timestamps[0] + 604800
-			timestamps[2] = timestamps[1] + 604800
-			timestamps[3] = timestamps[2] + 9000
-			timestamps[4] = timestamps[3] + 1240200
+			timestamps[1] = timestamps[0] + secsPerWeek
+			timestamps[2] = timestamps[1] + secsPerWeek
+			timestamps[3] = timestamps[2] + festaVotingDuration
+			timestamps[4] = timestamps[3] + festaRewardDuration
 		case 2:
-			timestamps[0] = midnight - 604800
+			timestamps[0] = midnight - secsPerWeek
 			timestamps[1] = midnight
-			timestamps[2] = timestamps[1] + 604800
-			timestamps[3] = timestamps[2] + 9000
-			timestamps[4] = timestamps[3] + 1240200
+			timestamps[2] = timestamps[1] + secsPerWeek
+			timestamps[3] = timestamps[2] + festaVotingDuration
+			timestamps[4] = timestamps[3] + festaRewardDuration
 		case 3:
-			timestamps[0] = midnight - 1209600
-			timestamps[1] = midnight - 604800
+			timestamps[0] = midnight - 2*secsPerWeek
+			timestamps[1] = midnight - secsPerWeek
 			timestamps[2] = midnight
-			timestamps[3] = timestamps[2] + 9000
-			timestamps[4] = timestamps[3] + 1240200
+			timestamps[3] = timestamps[2] + festaVotingDuration
+			timestamps[4] = timestamps[3] + festaRewardDuration
 		}
 		return timestamps
 	}
-	if start == 0 || TimeAdjusted().Unix() > int64(start)+2977200 {
+	if start == 0 || TimeAdjusted().Unix() > int64(start)+festaEventLifespan {
 		cleanupFesta(s)
 		// Generate a new festa, starting midnight tomorrow
 		start = uint32(midnight.Add(24 * time.Hour).Unix())
@@ -139,10 +146,10 @@ func generateFestaTimestamps(s *Session, start uint32, debug bool) []uint32 {
 		}
 	}
 	timestamps[0] = start
-	timestamps[1] = timestamps[0] + 604800
-	timestamps[2] = timestamps[1] + 604800
-	timestamps[3] = timestamps[2] + 9000
-	timestamps[4] = timestamps[3] + 1240200
+	timestamps[1] = timestamps[0] + secsPerWeek
+	timestamps[2] = timestamps[1] + secsPerWeek
+	timestamps[3] = timestamps[2] + festaVotingDuration
+	timestamps[4] = timestamps[3] + festaRewardDuration
 	return timestamps
 }

@@ -174,7 +181,8 @@ func handleMsgMhfInfoFesta(s *Session, p mhfpacket.MHFPacket) {
 	pkt := p.(*mhfpacket.MsgMhfInfoFesta)
 	bf := byteframe.NewByteFrame()

-	id, start := uint32(0xDEADBEEF), uint32(0)
+	const festaIDSentinel = uint32(0xDEADBEEF)
+	id, start := festaIDSentinel, uint32(0)
 	rows, err := s.server.db.Queryx("SELECT id, (EXTRACT(epoch FROM start_time)::int) as start_time FROM events WHERE event_type='festa'")
 	if err != nil {
 		s.logger.Error("Failed to query festa schedule", zap.Error(err))
@@ -342,7 +350,7 @@ func handleMsgMhfInfoFesta(s *Session, p mhfpacket.MHFPacket) {
 		var guildID uint32
 		var guildName string
 		var guildTeam = FestivalColorNone
-		offset := 86400 * uint32(i)
+		offset := secsPerDay * uint32(i)
 		if err := s.server.db.QueryRow(`
 				SELECT fs.guild_id, g.name, fr.team, SUM(fs.souls) as _
 				FROM festa_submissions fs
@@ -351,7 +359,7 @@ func handleMsgMhfInfoFesta(s *Session, p mhfpacket.MHFPacket) {
 				WHERE EXTRACT(EPOCH FROM fs.timestamp)::int > $1 AND EXTRACT(EPOCH FROM fs.timestamp)::int < $2
 				GROUP BY fs.guild_id, g.name, fr.team
 				ORDER BY _ DESC LIMIT 1
-			`, timestamps[1]+offset, timestamps[1]+offset+86400).Scan(&guildID, &guildName, &guildTeam, &temp); err != nil && !errors.Is(err, sql.ErrNoRows) {
+			`, timestamps[1]+offset, timestamps[1]+offset+secsPerDay).Scan(&guildID, &guildName, &guildTeam, &temp); err != nil && !errors.Is(err, sql.ErrNoRows) {
 			s.logger.Error("Failed to get festa daily ranking", zap.Error(err))
 		}
 		bf.WriteUint32(guildID)
--- a/server/channelserver/handlers_guild_mission.go
+++ b/server/channelserver/handlers_guild_mission.go
@@ -56,8 +56,9 @@ func handleMsgMhfGetGuildMissionList(s *Session, p mhfpacket.MHFPacket) {
 func handleMsgMhfGetGuildMissionRecord(s *Session, p mhfpacket.MHFPacket) {
 	pkt := p.(*mhfpacket.MsgMhfGetGuildMissionRecord)

-	// No guild mission records = 0x190 empty bytes
-	doAckBufSucceed(s, pkt.AckHandle, make([]byte, 0x190))
+	const guildMissionRecordSize = 0x190
+	// No guild mission records = empty buffer
+	doAckBufSucceed(s, pkt.AckHandle, make([]byte, guildMissionRecordSize))
 }

 func handleMsgMhfAddGuildMissionCount(s *Session, p mhfpacket.MHFPacket) {
--- a/server/channelserver/handlers_helpers.go
+++ b/server/channelserver/handlers_helpers.go
@@ -96,6 +96,22 @@ func saveCharacterData(s *Session, ackHandle uint32, column string, data []byte,
 	doAckSimpleSucceed(s, ackHandle, make([]byte, 4))
 }

+// readCharacterInt reads a single integer column from the characters table.
+// Returns 0 for NULL columns via COALESCE.
+func readCharacterInt(s *Session, column string) (int, error) {
+	var value int
+	err := s.server.db.QueryRow("SELECT COALESCE("+column+", 0) FROM characters WHERE id=$1", s.charID).Scan(&value)
+	return value, err
+}
+
+// adjustCharacterInt atomically adds delta to an integer column and returns the new value.
+// Handles NULL columns via COALESCE (NULL + delta = delta).
+func adjustCharacterInt(s *Session, column string, delta int) (int, error) {
+	var value int
+	err := s.server.db.QueryRow("UPDATE characters SET "+column+"=COALESCE("+column+", 0)+$1 WHERE id=$2 RETURNING "+column, delta, s.charID).Scan(&value)
+	return value, err
+}
+
 func updateRights(s *Session) {
 	rightsInt := uint32(2)
 	_ = s.server.db.QueryRow("SELECT rights FROM users WHERE id=$1", s.userID).Scan(&rightsInt)
--- a/server/channelserver/handlers_kouryou.go
+++ b/server/channelserver/handlers_kouryou.go
@@ -17,8 +17,7 @@ func handleMsgMhfAddKouryouPoint(s *Session, p mhfpacket.MHFPacket) {
 		zap.Uint32("points_to_add", pkt.KouryouPoints),
 	)

-	var points int
-	err := s.server.db.QueryRow("UPDATE characters SET kouryou_point=COALESCE(kouryou_point + $1, $1) WHERE id=$2 RETURNING kouryou_point", pkt.KouryouPoints, s.charID).Scan(&points)
+	points, err := adjustCharacterInt(s, "kouryou_point", int(pkt.KouryouPoints))
 	if err != nil {
 		s.logger.Error("Failed to update KouryouPoint in db",
 			zap.Error(err),
@@ -42,8 +41,7 @@ func handleMsgMhfAddKouryouPoint(s *Session, p mhfpacket.MHFPacket) {

 func handleMsgMhfGetKouryouPoint(s *Session, p mhfpacket.MHFPacket) {
 	pkt := p.(*mhfpacket.MsgMhfGetKouryouPoint)
-	var points int
-	err := s.server.db.QueryRow("SELECT COALESCE(kouryou_point, 0) FROM characters WHERE id = $1", s.charID).Scan(&points)
+	points, err := readCharacterInt(s, "kouryou_point")
 	if err != nil {
 		s.logger.Error("Failed to get kouryou_point from db",
 			zap.Error(err),
@@ -70,8 +68,7 @@ func handleMsgMhfExchangeKouryouPoint(s *Session, p mhfpacket.MHFPacket) {
 		zap.Uint32("points_to_spend", pkt.KouryouPoints),
 	)

-	var points int
-	err := s.server.db.QueryRow("UPDATE characters SET kouryou_point=kouryou_point - $1 WHERE id=$2 RETURNING kouryou_point", pkt.KouryouPoints, s.charID).Scan(&points)
+	points, err := adjustCharacterInt(s, "kouryou_point", -int(pkt.KouryouPoints))
 	if err != nil {
 		s.logger.Error("Failed to exchange Koryo points",
 			zap.Error(err),
--- a/server/channelserver/handlers_mercenary.go
+++ b/server/channelserver/handlers_mercenary.go
@@ -41,11 +41,17 @@ func handleMsgMhfLoadLegendDispatch(s *Session, p mhfpacket.MHFPacket) {
 	doAckBufSucceed(s, pkt.AckHandle, bf.Data())
 }

+// Hunter Navi buffer sizes per game version
+const (
+	hunterNaviSizeG8 = 552 // G8+ navi buffer size
+	hunterNaviSizeG7 = 280 // G7 and older navi buffer size
+)
+
 func handleMsgMhfLoadHunterNavi(s *Session, p mhfpacket.MHFPacket) {
 	pkt := p.(*mhfpacket.MsgMhfLoadHunterNavi)
-	naviLength := 552
+	naviLength := hunterNaviSizeG8
 	if s.server.erupeConfig.RealClientMode <= _config.G7 {
-		naviLength = 280
+		naviLength = hunterNaviSizeG7
 	}
 	loadCharacterData(s, pkt.AckHandle, "hunternavi", make([]byte, naviLength))
 }
@@ -67,9 +73,9 @@ func handleMsgMhfSaveHunterNavi(s *Session, p mhfpacket.MHFPacket) {

 	var dataSize int
 	if pkt.IsDataDiff {
-		naviLength := 552
+		naviLength := hunterNaviSizeG8
 		if s.server.erupeConfig.RealClientMode <= _config.G7 {
-			naviLength = 280
+			naviLength = hunterNaviSizeG7
 		}
 		var data []byte
 		// Load existing save
@@ -203,13 +209,13 @@ func handleMsgMhfReadMercenaryW(s *Session, p mhfpacket.MHFPacket) {
 	pkt := p.(*mhfpacket.MsgMhfReadMercenaryW)
 	bf := byteframe.NewByteFrame()

-	var pactID, cid uint32
+	var cid uint32
 	var name string
-	_ = s.server.db.QueryRow("SELECT pact_id FROM characters WHERE id=$1", s.charID).Scan(&pactID)
+	pactID, _ := readCharacterInt(s, "pact_id")
 	if pactID > 0 {
 		_ = s.server.db.QueryRow("SELECT name, id FROM characters WHERE rasta_id = $1", pactID).Scan(&name, &cid)
 		bf.WriteUint8(1) // numLends
-		bf.WriteUint32(pactID)
+		bf.WriteUint32(uint32(pactID))
 		bf.WriteUint32(cid)
 		bf.WriteBool(true) // Escort enabled
 		bf.WriteUint32(uint32(TimeAdjusted().Unix()))
@@ -232,7 +238,7 @@ func handleMsgMhfReadMercenaryW(s *Session, p mhfpacket.MHFPacket) {
 					continue
 				}
 				loans++
-				temp.WriteUint32(pactID)
+				temp.WriteUint32(uint32(pactID))
 				temp.WriteUint32(cid)
 				temp.WriteUint32(uint32(TimeAdjusted().Unix()))
 				temp.WriteUint32(uint32(TimeAdjusted().Add(time.Hour * 24 * 7).Unix()))
@@ -244,9 +250,8 @@ func handleMsgMhfReadMercenaryW(s *Session, p mhfpacket.MHFPacket) {

 		if pkt.Op != 1 && pkt.Op != 4 {
 			var data []byte
-			var gcp uint32
 			_ = s.server.db.QueryRow("SELECT savemercenary FROM characters WHERE id=$1", s.charID).Scan(&data)
-			_ = s.server.db.QueryRow("SELECT COALESCE(gcp, 0) FROM characters WHERE id=$1", s.charID).Scan(&gcp)
+			gcp, _ := readCharacterInt(s, "gcp")

 			if len(data) == 0 {
 				bf.WriteBool(false)
@@ -254,7 +259,7 @@ func handleMsgMhfReadMercenaryW(s *Session, p mhfpacket.MHFPacket) {
 				bf.WriteBool(true)
 				bf.WriteBytes(data)
 			}
-			bf.WriteUint32(gcp)
+			bf.WriteUint32(uint32(gcp))
 		}
 	}

--- a/server/channelserver/handlers_misc.go
+++ b/server/channelserver/handlers_misc.go
@@ -4,7 +4,6 @@ import (
 	"erupe-ce/common/byteframe"
 	_config "erupe-ce/config"
 	"erupe-ce/network/mhfpacket"
-	"fmt"
 	"math/bits"
 	"time"

@@ -23,7 +22,9 @@ func handleMsgMhfGetEtcPoints(s *Session, p mhfpacket.MHFPacket) {
 	}

 	var bonusQuests, dailyQuests, promoPoints uint32
-	_ = s.server.db.QueryRow(`SELECT bonus_quests, daily_quests, promo_points FROM characters WHERE id = $1`, s.charID).Scan(&bonusQuests, &dailyQuests, &promoPoints)
+	if err := s.server.db.QueryRow(`SELECT bonus_quests, daily_quests, promo_points FROM characters WHERE id = $1`, s.charID).Scan(&bonusQuests, &dailyQuests, &promoPoints); err != nil {
+		s.logger.Error("Failed to get etc points", zap.Error(err))
+	}
 	resp := byteframe.NewByteFrame()
 	resp.WriteUint8(3) // Maybe a count of uint32(s)?
 	resp.WriteUint32(bonusQuests)
@@ -48,17 +49,11 @@ func handleMsgMhfUpdateEtcPoint(s *Session, p mhfpacket.MHFPacket) {
 		return
 	}

-	var value int16
-	err := s.server.db.QueryRow(fmt.Sprintf(`SELECT %s FROM characters WHERE id = $1`, column), s.charID).Scan(&value)
+	value, err := readCharacterInt(s, column)
 	if err == nil {
-		if value+pkt.Delta < 0 {
-			if _, err := s.server.db.Exec(fmt.Sprintf(`UPDATE characters SET %s = 0 WHERE id = $1`, column), s.charID); err != nil {
-				s.logger.Error("Failed to reset etc point", zap.Error(err))
-			}
-		} else {
-			if _, err := s.server.db.Exec(fmt.Sprintf(`UPDATE characters SET %s = %s + $1 WHERE id = $2`, column, column), pkt.Delta, s.charID); err != nil {
-				s.logger.Error("Failed to update etc point", zap.Error(err))
-			}
+		newVal := max(value+int(pkt.Delta), 0)
+		if _, err := s.server.db.Exec("UPDATE characters SET "+column+"=$1 WHERE id=$2", newVal, s.charID); err != nil {
+			s.logger.Error("Failed to update etc point", zap.Error(err))
 		}
 	}
 	doAckSimpleSucceed(s, pkt.AckHandle, make([]byte, 4))
@@ -156,13 +151,20 @@ func handleMsgMhfGetDailyMissionPersonal(s *Session, p mhfpacket.MHFPacket) {}

 func handleMsgMhfSetDailyMissionPersonal(s *Session, p mhfpacket.MHFPacket) {}

+// Equip skin history buffer sizes per game version
+const (
+	skinHistSizeZZ = 3200 // ZZ and newer
+	skinHistSizeZ2 = 2560 // Z2 and older
+	skinHistSizeZ1 = 1280 // Z1 and older
+)
+
 func equipSkinHistSize(mode _config.Mode) int {
-	size := 3200
+	size := skinHistSizeZZ
 	if mode <= _config.Z2 {
-		size = 2560
+		size = skinHistSizeZ2
 	}
 	if mode <= _config.Z1 {
-		size = 1280
+		size = skinHistSizeZ1
 	}
 	return size
 }
@@ -245,7 +247,8 @@ func handleMsgMhfGetLobbyCrowd(s *Session, p mhfpacket.MHFPacket) {
 	// It can be worried about later if we ever get to the point where there are
 	// full servers to actually need to migrate people from and empty ones to
 	pkt := p.(*mhfpacket.MsgMhfGetLobbyCrowd)
-	doAckBufSucceed(s, pkt.AckHandle, make([]byte, 0x320))
+	const lobbyCrowdResponseSize = 0x320
+	doAckBufSucceed(s, pkt.AckHandle, make([]byte, lobbyCrowdResponseSize))
 }

 // TrendWeapon represents trending weapon usage data.
--- a/server/channelserver/handlers_plate.go
+++ b/server/channelserver/handlers_plate.go
@@ -34,9 +34,19 @@ func handleMsgMhfLoadPlateData(s *Session, p mhfpacket.MHFPacket) {
 	loadCharacterData(s, pkt.AckHandle, "platedata", nil)
 }

+// Plate data size constants
+const (
+	plateDataMaxPayload  = 262144 // max compressed platedata size
+	plateDataEmptySize   = 140000 // empty platedata buffer
+	plateBoxMaxPayload   = 32768  // max compressed platebox size
+	plateBoxEmptySize    = 4800   // empty platebox buffer
+	plateMysetDefaultLen = 1920   // default platemyset buffer
+	plateMysetMaxPayload = 4096   // max platemyset payload size
+)
+
 func handleMsgMhfSavePlateData(s *Session, p mhfpacket.MHFPacket) {
 	pkt := p.(*mhfpacket.MsgMhfSavePlateData)
-	if len(pkt.RawDataPayload) > 262144 {
+	if len(pkt.RawDataPayload) > plateDataMaxPayload {
 		s.logger.Warn("PlateData payload too large", zap.Int("len", len(pkt.RawDataPayload)))
 		doAckSimpleSucceed(s, pkt.AckHandle, make([]byte, 4))
 		return
@@ -78,7 +88,7 @@ func handleMsgMhfSavePlateData(s *Session, p mhfpacket.MHFPacket) {
 			}
 		} else {
 			// create empty save if absent
-			data = make([]byte, 140000)
+			data = make([]byte, plateDataEmptySize)
 		}

 		// Perform diff and compress it to write back to db
@@ -144,7 +154,7 @@ func handleMsgMhfLoadPlateBox(s *Session, p mhfpacket.MHFPacket) {

 func handleMsgMhfSavePlateBox(s *Session, p mhfpacket.MHFPacket) {
 	pkt := p.(*mhfpacket.MsgMhfSavePlateBox)
-	if len(pkt.RawDataPayload) > 32768 {
+	if len(pkt.RawDataPayload) > plateBoxMaxPayload {
 		s.logger.Warn("PlateBox payload too large", zap.Int("len", len(pkt.RawDataPayload)))
 		doAckSimpleSucceed(s, pkt.AckHandle, make([]byte, 4))
 		return
@@ -173,7 +183,7 @@ func handleMsgMhfSavePlateBox(s *Session, p mhfpacket.MHFPacket) {
 			}
 		} else {
 			// create empty save if absent
-			data = make([]byte, 4800)
+			data = make([]byte, plateBoxEmptySize)
 		}

 		// Perform diff and compress it to write back to db
@@ -213,12 +223,12 @@ func handleMsgMhfSavePlateBox(s *Session, p mhfpacket.MHFPacket) {

 func handleMsgMhfLoadPlateMyset(s *Session, p mhfpacket.MHFPacket) {
 	pkt := p.(*mhfpacket.MsgMhfLoadPlateMyset)
-	loadCharacterData(s, pkt.AckHandle, "platemyset", make([]byte, 1920))
+	loadCharacterData(s, pkt.AckHandle, "platemyset", make([]byte, plateMysetDefaultLen))
 }

 func handleMsgMhfSavePlateMyset(s *Session, p mhfpacket.MHFPacket) {
 	pkt := p.(*mhfpacket.MsgMhfSavePlateMyset)
-	if len(pkt.RawDataPayload) > 4096 {
+	if len(pkt.RawDataPayload) > plateMysetMaxPayload {
 		s.logger.Warn("PlateMyset payload too large", zap.Int("len", len(pkt.RawDataPayload)))
 		doAckSimpleSucceed(s, pkt.AckHandle, make([]byte, 4))
 		return
--- a/server/channelserver/handlers_register.go
+++ b/server/channelserver/handlers_register.go
@@ -19,6 +19,9 @@ func handleMsgMhfRegisterEvent(s *Session, p mhfpacket.MHFPacket) {
 	doAckSimpleSucceed(s, pkt.AckHandle, bf.Data())
 }

+// ACK error codes from the MHF client
+const ackEFailed = uint8(0x41) // _ACK_EFAILED = 65
+
 func handleMsgMhfReleaseEvent(s *Session, p mhfpacket.MHFPacket) {
 	pkt := p.(*mhfpacket.MsgMhfReleaseEvent)

@@ -43,7 +46,7 @@ func handleMsgMhfReleaseEvent(s *Session, p mhfpacket.MHFPacket) {
 	s.QueueSendMHF(&mhfpacket.MsgSysAck{
 		AckHandle:        pkt.AckHandle,
 		IsBufferResponse: false,
-		ErrorCode:        0x41,
+		ErrorCode:        ackEFailed,
 		AckData:          []byte{0x00, 0x00, 0x00, 0x00},
 	})
 }
@@ -104,11 +107,11 @@ func handleMsgSysLoadRegister(s *Session, p mhfpacket.MHFPacket) {
 	bf.WriteUint8(pkt.Values)
 	for i := uint8(0); i < pkt.Values; i++ {
 		switch pkt.RegisterID {
-		case 0x40000:
+		case raviRegisterState:
 			bf.WriteUint32(s.server.raviente.state[i])
-		case 0x50000:
+		case raviRegisterSupport:
 			bf.WriteUint32(s.server.raviente.support[i])
-		case 0x60000:
+		case raviRegisterGeneral:
 			bf.WriteUint32(s.server.raviente.register[i])
 		}
 	}
@@ -122,13 +125,13 @@ func (s *Session) notifyRavi() {
 	}
 	var temp mhfpacket.MHFPacket
 	raviNotif := byteframe.NewByteFrame()
-	temp = &mhfpacket.MsgSysNotifyRegister{RegisterID: 0x40000}
+	temp = &mhfpacket.MsgSysNotifyRegister{RegisterID: raviRegisterState}
 	raviNotif.WriteUint16(uint16(temp.Opcode()))
 	_ = temp.Build(raviNotif, s.clientContext)
-	temp = &mhfpacket.MsgSysNotifyRegister{RegisterID: 0x50000}
+	temp = &mhfpacket.MsgSysNotifyRegister{RegisterID: raviRegisterSupport}
 	raviNotif.WriteUint16(uint16(temp.Opcode()))
 	_ = temp.Build(raviNotif, s.clientContext)
-	temp = &mhfpacket.MsgSysNotifyRegister{RegisterID: 0x60000}
+	temp = &mhfpacket.MsgSysNotifyRegister{RegisterID: raviRegisterGeneral}
 	raviNotif.WriteUint16(uint16(temp.Opcode()))
 	_ = temp.Build(raviNotif, s.clientContext)
 	raviNotif.WriteUint16(0x0010) // End it.
--- a/server/channelserver/handlers_reward.go
+++ b/server/channelserver/handlers_reward.go
@@ -12,7 +12,8 @@ func handleMsgMhfGetAdditionalBeatReward(s *Session, p mhfpacket.MHFPacket) {
 	// Actual response in packet captures are all just giant batches of null bytes
 	// I'm assuming this is because it used to be tied to an actual event and
 	// they never bothered killing off the packet when they made it static
-	doAckBufSucceed(s, pkt.AckHandle, make([]byte, 0x104))
+	const beatRewardResponseSize = 0x104
+	doAckBufSucceed(s, pkt.AckHandle, make([]byte, beatRewardResponseSize))
 }

 func handleMsgMhfGetUdRankingRewardList(s *Session, p mhfpacket.MHFPacket) {
--- a/server/channelserver/handlers_semaphore.go
+++ b/server/channelserver/handlers_semaphore.go
@@ -79,9 +79,9 @@ func handleMsgSysCreateAcquireSemaphore(s *Session, p mhfpacket.MHFPacket) {
 			suffix, _ := strconv.Atoi(pkt.SemaphoreID[len(pkt.SemaphoreID)-1:])
 			s.server.semaphore[SemaphoreID] = &Semaphore{
 				name:       pkt.SemaphoreID,
-				id:         uint32((suffix + 1) * 0x10000),
+				id:         uint32((suffix + 1) * raviSemaphoreStride),
 				clients:    make(map[*Session]uint32),
-				maxPlayers: 127,
+				maxPlayers: raviSemaphoreMax,
 			}
 		} else {
 			s.server.semaphore[SemaphoreID] = NewSemaphore(s, SemaphoreID, 1)
--- a/server/channelserver/handlers_session.go
+++ b/server/channelserver/handlers_session.go
@@ -394,6 +394,8 @@ func handleMsgSysIssueLogkey(s *Session, p mhfpacket.MHFPacket) {
 	doAckBufSucceed(s, pkt.AckHandle, resp.Data())
 }

+const localhostAddrLE = uint32(0x0100007F) // 127.0.0.1 in little-endian
+
 // Kill log binary layout constants
 const (
 	killLogHeaderSize   = 32  // bytes before monster kill count array
@@ -557,7 +559,7 @@ func handleMsgMhfTransitMessage(s *Session, p mhfpacket.MHFPacket) {
 			if !local {
 				resp.WriteUint32(binary.LittleEndian.Uint32(r.ip))
 			} else {
-				resp.WriteUint32(0x0100007F)
+				resp.WriteUint32(localhostAddrLE)
 			}
 			resp.WriteUint16(r.port)
 			resp.WriteUint32(r.charID)
@@ -757,7 +759,7 @@ func handleMsgMhfTransitMessage(s *Session, p mhfpacket.MHFPacket) {
 			if !local {
 				resp.WriteUint32(binary.LittleEndian.Uint32(sr.ip))
 			} else {
-				resp.WriteUint32(0x0100007F)
+				resp.WriteUint32(localhostAddrLE)
 			}
 			resp.WriteUint16(sr.port)

--- a/server/channelserver/sys_channel_server.go
+++ b/server/channelserver/sys_channel_server.go
@@ -312,7 +312,7 @@ func (s *Server) BroadcastChatMessage(message string) {
 	msgBinChat := &binpacket.MsgBinChat{
 		Unk0:       0,
 		Type:       5,
-		Flags:      0x80,
+		Flags:      chatFlagServer,
 		Message:    message,
 		SenderName: s.name,
 	}
@@ -420,8 +420,15 @@ func (s *Server) HasSemaphore(ses *Session) bool {
 	return false
 }

+// Server ID arithmetic constants
+const (
+	serverIDHighMask = uint16(0xFF00)
+	serverIDBase     = 0x1000 // first server ID offset
+	serverIDStride   = 0x100  // spacing between server IDs
+)
+
 // Season returns the current in-game season (0-2) based on server ID and time.
 func (s *Server) Season() uint8 {
-	sid := int64(((s.ID & 0xFF00) - 4096) / 256)
-	return uint8(((TimeAdjusted().Unix() / 86400) + sid) % 3)
+	sid := int64(((s.ID & serverIDHighMask) - serverIDBase) / serverIDStride)
+	return uint8(((TimeAdjusted().Unix() / secsPerDay) + sid) % 3)
 }