From 59b02eade556f0b6d569043135be8dd09c529fa6 Mon Sep 17 00:00:00 2001
From: Reese Norris <reese.norris@gmail.com>
Date: Tue, 9 Apr 2024 15:18:18 -0700
Subject: [PATCH] switch geohash technique to 15-bit precision integer

---
 fsd_client.go  | 4 ++--
 main.go        | 2 +-
 post_office.go | 8 ++++----
 3 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/fsd_client.go b/fsd_client.go
index ced5b6a..367b06a 100644
--- a/fsd_client.go
+++ b/fsd_client.go
@@ -27,7 +27,7 @@ type FSDClient struct {
 	NetworkRating   int
 	SimulatorType   int
 	RealName        string
-	CurrentGeohash  string
+	CurrentGeohash  uint64
 	SendFastEnabled bool
 
 	Kill    chan string // Signal to disconnect this client
@@ -367,7 +367,7 @@ func HandleConnection(conn *net.TCPConn) {
 		NetworkRating:              int(claimedRating),
 		SimulatorType:              addPilotPDU.SimulatorType,
 		RealName:                   addPilotPDU.RealName,
-		CurrentGeohash:             "",
+		CurrentGeohash:             0,
 		SendFastEnabled:            false,
 		Kill:                       make(chan string, 1),
 		Mailbox:                    make(chan string, 16),
diff --git a/main.go b/main.go
index 1a2d4db..4acd5a7 100644
--- a/main.go
+++ b/main.go
@@ -114,7 +114,7 @@ func configurePostOffice() {
 	PO = &PostOffice{
 		clientRegistry:     make(map[string]*FSDClient),
 		supervisorRegistry: make(map[string]*FSDClient),
-		geohashRegistry:    make(map[string][]*FSDClient),
+		geohashRegistry:    make(map[uint64][]*FSDClient),
 	}
 }
 
diff --git a/post_office.go b/post_office.go
index a75d3b9..f28abd5 100644
--- a/post_office.go
+++ b/post_office.go
@@ -11,7 +11,7 @@ import (
 type PostOffice struct {
 	clientRegistry     map[string]*FSDClient
 	supervisorRegistry map[string]*FSDClient
-	geohashRegistry    map[string][]*FSDClient
+	geohashRegistry    map[uint64][]*FSDClient
 	lock               sync.RWMutex
 }
 
@@ -141,7 +141,7 @@ func (p *PostOffice) SendMail(messages []Mail) {
 				}
 			}
 		case MailTypeBroadcastRanged:
-			neighbors := geohash.Neighbors(msg.Source.CurrentGeohash)
+			neighbors := geohash.NeighborsInt(msg.Source.CurrentGeohash)
 			searchHashes := append(neighbors, msg.Source.CurrentGeohash)
 			for _, hash := range searchHashes {
 				clients, ok := p.geohashRegistry[hash]
@@ -186,7 +186,7 @@ func (p *PostOffice) SendMail(messages []Mail) {
 	}
 }
 
-func (p *PostOffice) removeClientFromGeohashRegistry(client *FSDClient, hash string) {
+func (p *PostOffice) removeClientFromGeohashRegistry(client *FSDClient, hash uint64) {
 	clientList, ok := p.geohashRegistry[client.CurrentGeohash]
 	if !ok {
 		return
@@ -217,7 +217,7 @@ func (p *PostOffice) removeClientFromGeohashRegistry(client *FSDClient, hash str
 // SetLocation updates the internal geohash tracking state for a client, if necessary
 func (p *PostOffice) SetLocation(client *FSDClient, lat, lng float64) {
 	// Check if the geohash has changed since we last updated
-	hash := geohash.EncodeWithPrecision(lat, lng, 3)
+	hash := geohash.EncodeIntWithPrecision(lat, lng, 15)
 	if hash == client.CurrentGeohash {
 		return
 	}