fix: correctly deallocate info buffers

This ensures that if either of the infos was in fact built,
but the deallocate function is called before the respective
toPacket function, we release the allocated buffer.
This can happen due to exceptions or just abnormal process flow,
in any case, we make the assumption that if an info object is
deallocated, it will not be written into the channels from that
point onward, and as such, it is safe to release the buffers related
to them.

protocol/osrs-221-model/src/main/kotlin/net/rsprot/protocol/game/outgoing/info/npcinfo/NpcInfo.kt

@@ -130,6 +130,15 @@ public class NpcInfo internal constructor(
      */
     internal var exception: Exception? = null
 
+    /**
+     * Whether the buffer allocated by this NPC info object has been built
+     * into a packet message. If this returns false, but NPC info was in fact built,
+     * we have an allocated buffer that needs releasing. If the NPC info itself
+     * is released but isn't built into packet, we make sure to release it, to avoid
+     * any memory leaks.
+     */
+    private var builtIntoPacket: Boolean = false
+
     /**
      * Returns the backing byte buffer holding all the computed information.
      * @throws IllegalStateException if the buffer is null, meaning it has no yet been
@@ -152,6 +161,7 @@ public class NpcInfo internal constructor(
                 exception,
             )
         }
+        builtIntoPacket = true
         return if (this.viewDistance > MAX_SMALL_PACKET_DISTANCE) {
             NpcInfoLarge(backingBuffer())
         } else {
@@ -167,6 +177,7 @@ public class NpcInfo internal constructor(
         // Acquire a new buffer with each cycle, in case the previous one isn't fully written out yet
         val buffer = allocator.buffer(BUF_CAPACITY, BUF_CAPACITY)
         this.buffer = buffer
+        this.builtIntoPacket = false
         return buffer
     }
 
@@ -505,9 +516,11 @@ public class NpcInfo internal constructor(
     }
 
     override fun onDealloc() {
-        val buffer = this.buffer
-        if (buffer != null && buffer.refCnt() > 0) {
-            buffer.release(buffer.refCnt())
+        if (!builtIntoPacket) {
+            val buffer = this.buffer
+            if (buffer != null && buffer.refCnt() > 0) {
+                buffer.release(buffer.refCnt())
+            }
         }
         this.buffer = null
     }

protocol/osrs-221-model/src/main/kotlin/net/rsprot/protocol/game/outgoing/info/playerinfo/PlayerInfo.kt

@@ -150,6 +150,15 @@ public class PlayerInfo internal constructor(
      */
     internal var exception: Exception? = null
 
+    /**
+     * Whether the buffer allocated by this player info object has been built
+     * into a packet message. If this returns false, but player info was in fact built,
+     * we have an allocated buffer that needs releasing. If the NPC info itself
+     * is released but isn't built into packet, we make sure to release it, to avoid
+     * any memory leaks.
+     */
+    private var builtIntoPacket: Boolean = false
+
     /**
      * Returns the backing buffer for this cycle.
      * @throws IllegalStateException if the buffer has not been allocated yet.
@@ -175,6 +184,7 @@ public class PlayerInfo internal constructor(
                 exception,
             )
         }
+        this.builtIntoPacket = true
         return PlayerInfoPacket(backingBuffer())
     }
 
@@ -584,6 +594,7 @@ public class PlayerInfo internal constructor(
         // Acquire a new buffer with each cycle, in case the previous one isn't fully written out yet
         val buffer = allocator.buffer(BUF_CAPACITY, BUF_CAPACITY)
         this.buffer = buffer
+        this.builtIntoPacket = false
         return buffer
     }
 
@@ -642,9 +653,14 @@ public class PlayerInfo internal constructor(
      * to stick around for extended periods of time. Any primitive properties will remain untouched.
      */
     override fun onDealloc() {
-        val buffer = this.buffer
-        if (buffer != null && buffer.refCnt() > 0) {
-            buffer.release(buffer.refCnt())
+        // If player info was constructed, but it was not built into a packet object
+        // it implies the packet is never being written to Netty, which means
+        // a memory leak is occurring - if that is the case, release the buffer here
+        if (!builtIntoPacket) {
+            val buffer = this.buffer
+            if (buffer != null && buffer.refCnt() > 0) {
+                buffer.release(buffer.refCnt())
+            }
         }
         this.buffer = null
         avatar.extendedInfo.reset()