From e75a77e6b8a62473d9bb4f7a197dcd57d6f46970 Mon Sep 17 00:00:00 2001
From: wish <wish@sek.ai>
Date: Sat, 28 Oct 2023 11:55:06 +1100
Subject: [PATCH] optimise grpToGR

---
 server/channelserver/handlers_character.go |   2 +-
 server/channelserver/handlers_data.go      | 179 ++++-----------------
 2 files changed, 29 insertions(+), 152 deletions(-)

diff --git a/server/channelserver/handlers_character.go b/server/channelserver/handlers_character.go
index 4c5802293..cf17693d7 100644
--- a/server/channelserver/handlers_character.go
+++ b/server/channelserver/handlers_character.go
@@ -226,7 +226,7 @@ func (save *CharacterSaveData) updateStructWithSaveData() {
 		if _config.ErupeConfig.RealClientMode >= _config.G10 {
 			save.KQF = save.decompSave[save.Pointers[pKQF] : save.Pointers[pKQF]+8]
 			if save.HRP == uint16(999) {
-				save.GR = grpToGR(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]+4])))
 			}
 		}
 	}
diff --git a/server/channelserver/handlers_data.go b/server/channelserver/handlers_data.go
index 74f6de9d0..5de1c4f65 100644
--- a/server/channelserver/handlers_data.go
+++ b/server/channelserver/handlers_data.go
@@ -73,162 +73,39 @@ func handleMsgMhfSavedata(s *Session, p mhfpacket.MHFPacket) {
 	doAckSimpleSucceed(s, pkt.AckHandle, make([]byte, 4))
 }
 
-func grpToGR(n uint32) uint16 {
-	var gr uint16
-	gr = 1
-	switch grp := int(n); {
-	case grp < 208750: // Up to 50
-		i := 0
-		for {
-			grp -= 500
-			if grp <= 500 {
-				if grp < 0 {
-					i--
+func grpToGR(n int) uint16 {
+	var gr int
+	a := []int{208750, 593400, 993400, 1400900, 2315900, 3340900, 4505900, 5850900, 7415900, 9230900, 11345900, 100000000}
+	b := []int{7850, 8000, 8150, 9150, 10250, 11650, 13450, 15650, 18150, 21150, 23950}
+	c := []int{51, 100, 150, 200, 300, 400, 500, 600, 700, 800, 900}
+
+	for i := 0; i < len(a); i++ {
+		if n < a[i] {
+			if i == 0 {
+				for {
+					n -= 500
+					if n <= 500 {
+						if n < 0 {
+							i--
+						}
+						break
+					} else {
+						i++
+						for j := 0; j < i; j++ {
+							n -= 150
+						}
+					}
 				}
-				break
+				gr = i + 2
 			} else {
-				i++
-				for j := 0; j < i; j++ {
-					grp -= 150
-				}
+				n -= a[i-1]
+				gr = c[i-1]
+				gr += n / b[i-1]
 			}
+			break
 		}
-		gr = uint16(i + 2)
-		break
-	case grp < 593400: // 51-99
-		grp -= 208750
-		i := 51
-		for {
-			if grp < 7850 {
-				break
-			}
-			i++
-			grp -= 7850
-		}
-		gr = uint16(i)
-		break
-	case grp < 993400: // 100-149
-		grp -= 593400
-		i := 100
-		for {
-			if grp < 8000 {
-				break
-			}
-			i++
-			grp -= 8000
-		}
-		gr = uint16(i)
-		break
-	case grp < 1400900: // 150-199
-		grp -= 993400
-		i := 150
-		for {
-			if grp < 8150 {
-				break
-			}
-			i++
-			grp -= 8150
-		}
-		gr = uint16(i)
-		break
-	case grp < 2315900: // 200-299
-		grp -= 1400900
-		i := 200
-		for {
-			if grp < 9150 {
-				break
-			}
-			i++
-			grp -= 9150
-		}
-		gr = uint16(i)
-		break
-	case grp < 3340900: // 300-399
-		grp -= 2315900
-		i := 300
-		for {
-			if grp < 10250 {
-				break
-			}
-			i++
-			grp -= 10250
-		}
-		gr = uint16(i)
-		break
-	case grp < 4505900: // 400-499
-		grp -= 3340900
-		i := 400
-		for {
-			if grp < 11650 {
-				break
-			}
-			i++
-			grp -= 11650
-		}
-		gr = uint16(i)
-		break
-	case grp < 5850900: // 500-599
-		grp -= 4505900
-		i := 500
-		for {
-			if grp < 13450 {
-				break
-			}
-			i++
-			grp -= 13450
-		}
-		gr = uint16(i)
-		break
-	case grp < 7415900: // 600-699
-		grp -= 5850900
-		i := 600
-		for {
-			if grp < 15650 {
-				break
-			}
-			i++
-			grp -= 15650
-		}
-		gr = uint16(i)
-		break
-	case grp < 9230900: // 700-799
-		grp -= 7415900
-		i := 700
-		for {
-			if grp < 18150 {
-				break
-			}
-			i++
-			grp -= 18150
-		}
-		gr = uint16(i)
-		break
-	case grp < 11345900: // 800-899
-		grp -= 9230900
-		i := 800
-		for {
-			if grp < 21150 {
-				break
-			}
-			i++
-			grp -= 21150
-		}
-		gr = uint16(i)
-		break
-	default: // 900+
-		grp -= 11345900
-		i := 900
-		for {
-			if grp < 23950 {
-				break
-			}
-			i++
-			grp -= 23950
-		}
-		gr = uint16(i)
-		break
 	}
-	return gr
+	return uint16(gr)
 }
 
 func dumpSaveData(s *Session, data []byte, suffix string) {