[workspace-model] Optimize memory consumption by new VirtualFileUrlManagerImpl

GitOrigin-RevId: 97900049061297e1c32feb8c79570f4a6f0f2abf

platform/workspaceModel-ide-tests/testSrc/com/intellij/workspace/jps/VirtualFileNameStoreTest.kt

@@ -29,7 +29,7 @@ class VirtualFileNameStoreTest {
     Assert.assertEquals(3, store.generateIdForName("c"))
     store.removeName("b")
     store.removeName("a")
-    Assert.assertEquals(2, store.generateIdForName("e"))
+    Assert.assertEquals(4, store.generateIdForName("e"))
-    Assert.assertEquals(1, store.generateIdForName("f"))
+    Assert.assertEquals(5, store.generateIdForName("f"))
   }
 }

platform/workspaceModel-ide/src/com/intellij/workspace/ide/IdGenerator.kt

@@ -1,18 +0,0 @@
-// Copyright 2000-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
-package com.intellij.workspace.ide
-
-import org.jetbrains.annotations.TestOnly
-import java.util.*
-
-internal class IdGenerator {
-  private val freeIdsQueue: Queue<Int> = LinkedList()
-  private var generator: Int = 0
-  fun generateId() = freeIdsQueue.poll() ?: ++generator
-  fun releaseId(id: Int) = freeIdsQueue.add(id)
-
-  @TestOnly
-  fun clear() {
-    generator = 0
-    freeIdsQueue.clear()
-  }
-}

platform/workspaceModel-ide/src/com/intellij/workspace/ide/VirtualFileNameStore.kt

@@ -1,47 +1,45 @@
 // Copyright 2000-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.intellij.workspace.ide
 
-import com.intellij.util.containers.BidirectionalMap
+import gnu.trove.THashMap
 import org.jetbrains.annotations.TestOnly
 
 internal class VirtualFileNameStore {
   private val generator = IdGenerator()
-  private val nameStore = BidirectionalMap<String, IdPerCount>()
+  private val name2IdStore = THashMap<String, IdPerCount>()
+  private val id2NameStore = THashMap<Int, String>()
 
   fun generateIdForName(name: String): Int {
-    val idPerCount = nameStore[name]
+    val idPerCount = name2IdStore[name]
     if (idPerCount != null) {
       idPerCount.usageCount++
       return idPerCount.id
     } else {
       val id = generator.generateId()
-      nameStore[name] = IdPerCount(id, 1)
+      name2IdStore[name] = IdPerCount(id, 1)
+      id2NameStore[id] = name
       return id
     }
   }
 
   fun removeName(name: String) {
-    val idPerCount = nameStore[name] ?: return
+    val idPerCount = name2IdStore[name] ?: return
     if (idPerCount.usageCount == 1L) {
-      nameStore.remove(name)
+      name2IdStore.remove(name)
-      generator.releaseId(idPerCount.id)
+      id2NameStore.remove(idPerCount.id)
     } else {
       idPerCount.usageCount--
     }
   }
 
-  fun getNameForId(id: Int): String? {
+  fun getNameForId(id: Int): String? = id2NameStore[id]
-    val list = nameStore.getKeysByValue(IdPerCount(id, 1)) ?: return null
-    if (list.isEmpty()) return null
-    assert(list.size == 1)
-    return list[0]
-  }
 
-  fun getIdForName(name: String) = nameStore[name]?.id
+  fun getIdForName(name: String) = name2IdStore[name]?.id
 
   @TestOnly
   fun clear() {
-    nameStore.clear()
+    name2IdStore.clear()
+    id2NameStore.clear()
     generator.clear()
   }
 }
@@ -58,4 +56,14 @@ private data class IdPerCount(val id: Int, var usageCount: Long) {
   }
 
   override fun hashCode() = 31 * id.hashCode()
+}
+
+internal class IdGenerator {
+  private var generator: Int = 0
+  fun generateId() = ++generator
+
+  @TestOnly
+  fun clear() {
+    generator = 0
+  }
 }

platform/workspaceModel-ide/src/com/intellij/workspace/ide/VirtualFileUrlManagerImpl.kt

@@ -4,16 +4,18 @@ package com.intellij.workspace.ide
 import com.intellij.openapi.components.service
 import com.intellij.openapi.project.Project
 import com.intellij.openapi.util.io.FileUtil
+import com.intellij.util.SmartList
 import com.intellij.workspace.api.VirtualFileUrl
 import com.intellij.workspace.api.VirtualFileUrlManager
+import gnu.trove.THashMap
 import kotlin.collections.set
 
 class VirtualFileUrlManagerImpl: VirtualFileUrlManager() {
   private val idGenerator= IdGenerator()
   private val EMPTY_URL = VirtualFileUrl(0, this)
   private val fileNameStore = VirtualFileNameStore()
-  private val id2NodeMapping = HashMap<Int, FilePathNode>()
+  private val id2NodeMapping = THashMap<Int, FilePathNode>()
-  private var segmentId2RootNodeMapping = mutableMapOf<Int, FilePathNode>()
+  private var segmentId2RootNodeMapping = THashMap<Int, FilePathNode>()
 
   companion object {
     fun getInstance(project: Project): VirtualFileUrlManager = project.service<VirtualFileUrlManagerImpl>()
@@ -82,12 +84,12 @@ class VirtualFileUrlManagerImpl: VirtualFileUrlManager() {
         }
       }
 
-      val node = latestNode.children.find { it.contentId == nameId }
+      val node = latestNode.findChild(nameId)
       if (node == null) {
         val nodeId = idGenerator.generateId()
         val newNode = FilePathNode(nodeId, nameId, latestNode)
         id2NodeMapping[nodeId] = newNode
-        latestNode.children.add(newNode)
+        latestNode.addChild(newNode)
         latestNode = newNode
         // If it's the latest name of folder or files, save entity Id as node value
         if (index == latestElement) return VirtualFileUrl(nodeId, this)
@@ -106,27 +108,25 @@ class VirtualFileUrlManagerImpl: VirtualFileUrlManager() {
       println("File not found")
       return
     }
-    if (node.children.isNotEmpty()) return
+    if (!node.isEmpty()) return
 
     var currentNode: FilePathNode = node
     do {
       val parent = currentNode.parent
       if (parent == null) {
-        if (currentNode === findRootNode(currentNode.contentId) && currentNode.children.isEmpty()) {
+        if (currentNode === findRootNode(currentNode.contentId) && currentNode.isEmpty()) {
           removeNameUsage(currentNode.contentId)
-          idGenerator.releaseId(currentNode.nodeId)
           id2NodeMapping.remove(currentNode.nodeId)
           segmentId2RootNodeMapping.remove(currentNode.contentId)
         }
         return
       }
 
-      parent.children.remove(currentNode)
+      parent.removeChild(currentNode)
       removeNameUsage(currentNode.contentId)
-      idGenerator.releaseId(currentNode.nodeId)
       id2NodeMapping.remove(currentNode.nodeId)
       currentNode = parent
-    } while (currentNode.children.isEmpty())
+    } while (currentNode.isEmpty())
   }
 
   internal fun update(oldPath: String, newPath: String) {
@@ -157,7 +157,7 @@ class VirtualFileUrlManagerImpl: VirtualFileUrlManager() {
         }
       }
 
-      latestNode.children.find { it.contentId == nameId }?.let {
+      latestNode.findChild(nameId)?.let {
         if (index == latestElement) return it
         latestNode = it
       } ?: return null
@@ -202,7 +202,28 @@ class VirtualFileUrlManagerImpl: VirtualFileUrlManager() {
   }
 
   private inner class FilePathNode(val nodeId: Int, val contentId: Int, val parent: FilePathNode? = null) {
-    val children: MutableSet<FilePathNode> = mutableSetOf()
+    private var children: MutableList<FilePathNode>? = null
+
+    internal fun findChild(nameId: Int): FilePathNode? {
+      // If search of child node will be slow, replace SmartList to THashSet
+      // For now SmartList reduce 500Kb memory on IDEA project
+      return children?.find { it.contentId == nameId }
+    }
+
+    internal fun addChild(newNode: FilePathNode) {
+      createChildrenList()
+      children!!.add(newNode)
+    }
+
+    internal fun removeChild(node: FilePathNode) {
+      children?.remove(node)
+    }
+
+    internal fun isEmpty() = children == null || children!!.isEmpty()
+
+    private fun createChildrenList() {
+      if (children == null) children = SmartList()
+    }
 
     override fun toString(): String {
       val buffer = StringBuilder()
@@ -213,7 +234,7 @@ class VirtualFileUrlManagerImpl: VirtualFileUrlManager() {
     private fun print(buffer: StringBuilder, prefix: String, childrenPrefix: String) {
       val name = this@VirtualFileUrlManagerImpl.fileNameStore.getNameForId(contentId)
       buffer.append("$prefix $name\n")
-      val iterator = children.iterator()
+      val iterator = children?.iterator() ?: return
       while (iterator.hasNext()) {
         val next = iterator.next()
         if (iterator.hasNext()) {
@@ -225,5 +246,4 @@ class VirtualFileUrlManagerImpl: VirtualFileUrlManager() {
       }
     }
   }
-
 }