[javadoc] Add a cache for javadoc fragment ids

#IDEA-376337 GitOrigin-RevId: 5eefe6cfb1ba5e04fe8cba24592ca7ea1d6c9a9c
2026-09-18 09:34:34 +07:00 · 2025-09-17 19:25:18 +00:00
parent cf0b1ecfab
commit 1a9c32c51b
2 changed files with 117 additions and 0 deletions
@@ -0,0 +1,67 @@
+// 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.codeInsight.javadoc.index
+
+import com.intellij.openapi.components.Service
+import com.intellij.openapi.components.service
+import com.intellij.openapi.project.Project
+import com.intellij.psi.JavaPsiFacade
+import com.intellij.psi.javadoc.PsiDocComment
+import com.intellij.psi.search.GlobalSearchScope
+import com.intellij.util.indexing.ID
+import java.util.concurrent.ConcurrentHashMap
+import java.util.regex.Pattern
+
+@JvmField
+val NAME: ID<String, LinkedHashSet<JavaDocFragmentData>> = ID.create("java.javadoc.fragment.anchors")
+
+data class JavaDocFragmentData(val name: String, val offset: Int)
+
+@Service(Service.Level.PROJECT)
+private class JavaDocFragmentCacheService {
+  private data class Entry(val stamp: Long, val data: LinkedHashSet<JavaDocFragmentData>)
+  private val cache: ConcurrentHashMap<String, Entry> = ConcurrentHashMap()
+
+  // Matches any HTML opening tag with an id attribute
+  private val ID_PATTERN: Pattern = Pattern.compile("<[a-zA-Z0-9\\-]*[^>] id=[\"']?([^\"'> ]+)[\"']?[^>]*>", Pattern.CASE_INSENSITIVE)
+
+  fun getAnchors(project: Project, fqn: String): LinkedHashSet<JavaDocFragmentData> {
+    val entry = cache[fqn]
+    val psiClass = JavaPsiFacade.getInstance(project).findClass(fqn, GlobalSearchScope.projectScope(project))
+    val file = psiClass?.containingFile ?: return LinkedHashSet()
+    if (entry != null && file.modificationStamp == entry.stamp) return entry.data
+
+    val result = LinkedHashSet<JavaDocFragmentData>().apply {
+      addAll(findIdsFromComment(psiClass.docComment))
+      for (method in psiClass.methods) addAll(findIdsFromComment(method.docComment))
+      for (field in psiClass.fields) addAll(findIdsFromComment(field.docComment))
+    }
+
+    cache[fqn] = Entry(file.modificationStamp, result)
+    return result
+  }
+
+  private fun findIdsFromComment(docComment: PsiDocComment?): List<JavaDocFragmentData> {
+    val text = docComment?.text ?: return listOf()
+    if (" id=" !in text && " ID=" !in text) return listOf()
+    val offset = docComment.textOffset
+    return findIdsFromText(text)
+      .map { JavaDocFragmentData(it.name, it.offset + offset) }
+  }
+
+  private fun findIdsFromText(docText: String): List<JavaDocFragmentData> {
+    return ID_PATTERN.matcher(docText).results()
+      .map { result ->
+        val id = result.group(1)
+        when (id != null && !id.isBlank()) {
+          true -> JavaDocFragmentData(id, result.start(1))
+          false -> null
+        }
+      }
+      .toList()
+      .filterNotNull()
+  }
+}
+
+fun getAnchors(project: Project, fqnOrPackage: String): LinkedHashSet<JavaDocFragmentData> {
+  return project.service<JavaDocFragmentCacheService>().getAnchors(project, fqnOrPackage)
+}