openide/java/java-tests/testSrc/com/intellij/util/indexing/CountingFileBasedIndexExtension.kt

// 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.util.indexing

import com.intellij.openapi.extensions.InternalIgnoreDependencyViolation
import com.intellij.openapi.vfs.VirtualFile
import com.intellij.util.io.EnumeratorIntegerDescriptor
import com.intellij.util.io.KeyDescriptor
import java.util.concurrent.atomic.AtomicInteger

@InternalIgnoreDependencyViolation
internal class CountingFileBasedIndexExtension : ScalarIndexExtension<Int>() {
  override fun getIndexer(): DataIndexer<Int, Void, FileContent> {
    return DataIndexer {
      COUNTER.incrementAndGet()
      mapOf(1 to null)
    }
  }

  override fun getName(): ID<Int, Void> = INDEX_ID
  override fun getKeyDescriptor(): KeyDescriptor<Int> = EnumeratorIntegerDescriptor.INSTANCE
  override fun getVersion(): Int = 0
  override fun getInputFilter(): FileBasedIndex.InputFilter = FileBasedIndex.InputFilter { f: VirtualFile -> f.name.contains("Foo") }
  override fun dependsOnFileContent(): Boolean = true

  companion object {
    @JvmStatic
    val INDEX_ID = ID.create<Int, Void>("counting.file.based.index")
    @JvmStatic
    val COUNTER = AtomicInteger()
  }
}