From 50151dacb3414eb05e610feb8dc23b64ef6e4eaa Mon Sep 17 00:00:00 2001
From: bemusementpark <bemusementpark>
Date: Wed, 9 Oct 2024 15:42:39 +1030
Subject: [PATCH] Use std lib binarySearch

---
 .../thoughtcrime/securesms/util/IP2Country.kt | 27 +++----------------
 1 file changed, 3 insertions(+), 24 deletions(-)

diff --git a/app/src/main/java/org/thoughtcrime/securesms/util/IP2Country.kt b/app/src/main/java/org/thoughtcrime/securesms/util/IP2Country.kt
index 7ec2de4e4c..d6b71b3151 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/util/IP2Country.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/util/IP2Country.kt
@@ -12,6 +12,7 @@ import org.session.libsignal.utilities.ThreadUtils
 import java.io.DataInputStream
 import java.io.InputStream
 import java.io.InputStreamReader
+import kotlin.math.absoluteValue
 
 private fun ipv4Int(ip: String): UInt =
     ip.split(".", "/", ",").take(4).fold(0U) { acc, s -> acc shl 8 or s.toUInt() }
@@ -91,8 +92,8 @@ class IP2Country internal constructor(
         countryNamesCache[ip]?.let { return it }
 
         val ipInt = ipv4Int(ip)
-        val index = ips.fuzzyBinarySearch(ipInt)
-        val code = index?.let { codes[it] }
+        val index = ips.binarySearch(ipInt).let { it.takeIf { it >= 0 } ?: (it.absoluteValue - 2) }
+        val code = codes.getOrNull(index)
         val bestMatchCountry = countryToNames[code]
 
         if (bestMatchCountry != null) countryNamesCache[ip] = bestMatchCountry
@@ -115,25 +116,3 @@ class IP2Country internal constructor(
     }
     // endregion
 }
-
-@OptIn(ExperimentalUnsignedTypes::class)
-private fun UIntArray.fuzzyBinarySearch(target: UInt): Int? {
-    if (isEmpty()) return null
-
-    var low = 0
-    var high = size - 1
-
-    while (low <= high) {
-        val mid = (low + high) / 2
-        val midValue = this[mid]
-
-        when {
-            midValue == target -> return mid // Exact match found
-            midValue < target -> low = mid + 1 // Search in the right half
-            else -> high = mid - 1 // Search in the left half
-        }
-    }
-
-    // If no exact match, return the largest index with value <= target
-    return if (high >= 0) high else null
-}