Release/0.9.1

CHANGELOG

@@ -1,3 +1,7 @@
+Version 0.9.1 (2026-02-18)
+--------------------------
+Avoid off-heap memory growth from JDK direct buffer caching (#186)
+
 Version 0.9.0 (2026-02-06)
 --------------------------
 Extract ASN fields from ISP database (#183)

README.md

@@ -19,12 +19,12 @@ can also configure an LRU (Least Recently Used) cache of variable size
 
 ## Installation
 
-The latest version of scala-maxmind-iplookups is **0.9.0** and is compatible with Scala 2.13.
+The latest version of scala-maxmind-iplookups is **0.9.1** and is compatible with Scala 2.13.
 
 Add this to your SBT config:
 
 ```scala
-val maxmindIpLookups = "com.snowplowanalytics" %% "scala-maxmind-iplookups" % "0.9.0"
+val maxmindIpLookups = "com.snowplowanalytics" %% "scala-maxmind-iplookups" % "0.9.1"
 ```
 
 Retrieve the `GeoLite2-City.mmdb` file from the [MaxMind downloads page][maxmind-downloads]
@@ -295,7 +295,7 @@ As such we recommend upgrading to version 0.4.0 as soon as possible
 
 ## Copyright and license
 
-Copyright 2012-2022 Snowplow Analytics Ltd.
+Copyright 2012-2026 Snowplow Analytics Ltd.
 
 Licensed under the [Apache License, Version 2.0][license] (the "License");
 you may not use this software except in compliance with the License.

src/main/scala/com.snowplowanalytics.maxmind.iplookups/IpLookups.scala

@@ -12,7 +12,7 @@
  */
 package com.snowplowanalytics.maxmind.iplookups
 
-import java.io.File
+import java.io.{File, FileInputStream}
 import java.net.InetAddress
 
 import cats.{Eval, Id, Monad}
@@ -21,7 +21,6 @@ import cats.syntax.flatMap._
 import cats.syntax.functor._
 import cats.syntax.option._
 import com.maxmind.db.CHMCache
-import com.maxmind.db.Reader.FileMode
 import com.maxmind.geoip2.DatabaseReader
 import com.snowplowanalytics.lrumap.{CreateLruMap, LruMap}
 
@@ -226,18 +225,25 @@ class IpLookups[F[_]: Monad] private[iplookups] (
   /**
    * Get a LookupService from a database file
    *
-   * Note: In MEMORY mode, .build() performs blocking I/O by reading the entire database from disk into memory.
+   * Opens the file as a FileInputStream and passes it to DatabaseReader's InputStream-based
+   * constructor. This avoids the File-based constructor which uses FileChannel.read into a heap
+   * ByteBuffer, causing the JDK to allocate and cache temporary direct ByteBuffers in
+   * thread-local storage (sun.nio.ch.Util.BufferCache), leading to off-heap memory growth.
    *
    * @param serviceFile The database file
    * @return LookupService
    */
   private def getService(serviceFile: Option[File]): Option[DatabaseReader] =
     serviceFile.map { f =>
-      val builder = new DatabaseReader.Builder(f).fileMode(FileMode.MEMORY)
-      (
-        if (memCache) builder.withCache(new CHMCache())
-        else builder
-      ).build()
+      val stream = new FileInputStream(f)
+      try {
+        val builder = new DatabaseReader.Builder(stream)
+        (
+          if (memCache) builder.withCache(new CHMCache())
+          else builder
+        ).build()
+      } finally
+        stream.close()
     }
 
   /**