IDEA-374699 [debugger] Avoid excessive deduplication

As was described in  137fc9538070237f44c0868d9b947bb66d514bb1, frames are never compared by value.

GitOrigin-RevId: fe8f1f11a29b39fd282dfc1acd97cd14e3dd1184

platform/xdebugger-impl/src/com/intellij/xdebugger/impl/frame/XFramesAsyncPresentationManager.kt

@@ -9,7 +9,8 @@ import com.intellij.platform.util.coroutines.childScope
 import com.intellij.ui.ColoredTextContainer
 import com.intellij.xdebugger.frame.XStackFrame
 import com.intellij.xdebugger.frame.XStackFrameUiPresentationContainer
-import fleet.multiplatform.shims.ConcurrentHashMap
+import com.intellij.xdebugger.impl.util.identityConcurrentHashMap
+import com.intellij.xdebugger.impl.util.identityWrapper
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.cancel
@@ -31,14 +32,14 @@ class XFramesAsyncPresentationManager(private val cs: CoroutineScope) {
 
 class XFramesAsyncPresentationHandler(private val framesList: XDebuggerFramesList, private val cs: CoroutineScope) {
 
-  private val cache = ConcurrentHashMap<XStackFrame, XStackFrameUiPresentationContainer>()
+  private val cache = identityConcurrentHashMap<XStackFrame, XStackFrameUiPresentationContainer>()
   private val repaintRequests = MutableSharedFlow<Unit>()
 
   fun scheduleForFrames(stackFrames: List<XStackFrame>) {
     for (stackFrame in stackFrames) {
       cs.launch(Dispatchers.Default) {
         stackFrame.customizePresentation().collectLatest { newPresentation ->
-          cache += stackFrame to newPresentation
+          cache += stackFrame.identityWrapper() to newPresentation
           repaintRequests.emit(Unit)
           withContext(Dispatchers.EDT) {
             // TODO cooldown period to reduce invocations count
@@ -52,7 +53,7 @@ class XFramesAsyncPresentationHandler(private val framesList: XDebuggerFramesLis
   fun clear(): Unit = cache.clear()
 
   fun customizePresentation(stackFrame: XStackFrame, container: ColoredTextContainer) {
-    cache[stackFrame]?.customizePresentation(container)
+    cache[stackFrame.identityWrapper()]?.customizePresentation(container)
   }
 
   fun sessionStopped() {

platform/xdebugger-impl/src/com/intellij/xdebugger/impl/rpc/models/XStackFrameModel.kt

@@ -11,6 +11,8 @@ import com.intellij.util.awaitCancellationAndInvoke
 import com.intellij.xdebugger.frame.XStackFrame
 import com.intellij.xdebugger.impl.XDebugSessionImpl
 import com.intellij.xdebugger.impl.rpc.XStackFrameId
+import com.intellij.xdebugger.impl.util.identityConcurrentHashMap
+import com.intellij.xdebugger.impl.util.identityWrapper
 import kotlinx.coroutines.CoroutineScope
 import org.jetbrains.annotations.ApiStatus
 import java.util.concurrent.ConcurrentHashMap
@@ -57,10 +59,10 @@ private class XStackFrameDeduplicator {
   }
 
   private class ScopeBoundStorage() {
-    private val storage = ConcurrentHashMap<IdentityWrapper, XStackFrameId>()
+    private val storage = identityConcurrentHashMap<XStackFrame, XStackFrameId>()
 
     fun getOrStore(stack: XStackFrame, createId: () -> XStackFrameId): XStackFrameId {
-      return storage.computeIfAbsent(IdentityWrapper(stack)) { createId() }
+      return storage.computeIfAbsent(stack.identityWrapper()) { createId() }
     }
 
     fun clear() {
@@ -68,16 +70,6 @@ private class XStackFrameDeduplicator {
     }
   }
 
-  private class IdentityWrapper(val frame: XStackFrame) {
-    override fun equals(other: Any?): Boolean {
-      return other is IdentityWrapper && frame === other.frame
-    }
-
-    override fun hashCode(): Int {
-      return System.identityHashCode(frame)
-    }
-  }
-
   companion object {
     fun getInstance(): XStackFrameDeduplicator = service()
   }

platform/xdebugger-impl/src/com/intellij/xdebugger/impl/util/IdentityConcurrentHashMap.kt

@@ -0,0 +1,17 @@
+// Copyright 2000-2025 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+package com.intellij.xdebugger.impl.util
+
+import fleet.multiplatform.shims.ConcurrentHashMap
+
+internal class IdentityWrapper<T>(val obj: T) {
+  override fun equals(other: Any?): Boolean {
+    return other is IdentityWrapper<T> && obj === other.obj
+  }
+
+  override fun hashCode(): Int {
+    return System.identityHashCode(obj)
+  }
+}
+
+internal fun <K> K.identityWrapper() = IdentityWrapper(this)
+internal fun <K, V> identityConcurrentHashMap() = ConcurrentHashMap<IdentityWrapper<K>, V>()