利用Trie结构将性能提升了10倍

借助新的并行计算工具构造了一个Trie结构，在保持APK Parser性能基本不变的情况下，将
自动适配表达式的性能提升了10倍。原先一个表达式求值需要耗费将近1秒，现在只需20ms不到。

旧的Benchmark记录

BM: Parse DexClasses takes 758 ms.
BM: Search android.support.v4.app takes 747 ms.
BM: Search com.tencent.mm.ui.contact takes 1239 ms.
BM: Search com.tencent.mm.plugin.sns.ui takes 1393 ms.
BM: Search com.tencent.mm takes 1635 ms.
BM: Search com.tencent.mm.ui.conversation takes 761 ms.
BM: Search com.tencent.mm.sdk.platformtools takes 860 ms.
BM: Search com.tencent.mm.sdk.platformtools takes 669 ms.
BM: Search com.tencent.mm.booter.notification takes 561 ms.
BM: Search com.tencent.mm.storage takes 871 ms.
BM: Search com.tencent.mm.booter.notification.queue takes 913 ms.
BM: Search com.tencent.mm.ui takes 518 ms.
BM: Search com.tencent.mm.modelsfs takes 626 ms.
BM: Search com.tencent.mm.ui.chatting takes 470 ms.
BM: Search over classes takes 4414 ms.

数据结构升级后的Benchmark记录

BM: Parse DexClasses takes 779 ms.
BM: Search android.support.v4.app takes 42 ms.
BM: Search com.tencent.mm takes 167 ms.
BM: Search com.tencent.mm.sdk.platformtools takes 5 ms.
BM: Search com.tencent.mm.booter.notification takes 1 ms.
BM: Search com.tencent.mm.booter.notification.queue takes 0 ms.
BM: Search com.tencent.mm.modelsfs takes 0 ms.
BM: Search com.tencent.mm.plugin.sns.ui takes 66 ms.
BM: Search com.tencent.mm.storage takes 1 ms.
BM: Search com.tencent.mm.ui takes 2 ms.
BM: Search com.tencent.mm.ui.chatting takes 24 ms.
BM: Search com.tencent.mm.ui.contact takes 19 ms.
BM: Search com.tencent.mm.ui.conversation takes 14 ms.
BM: Search over classes takes 558 ms.

src/main/kotlin/com/gh0u1l5/wechatmagician/spellbook/WechatGlobal.kt

@@ -6,6 +6,7 @@ import com.gh0u1l5.wechatmagician.spellbook.SpellBook.getApplicationVersion
 import com.gh0u1l5.wechatmagician.spellbook.base.Version
 import com.gh0u1l5.wechatmagician.spellbook.base.WaitChannel
 import com.gh0u1l5.wechatmagician.spellbook.parser.ApkFile
+import com.gh0u1l5.wechatmagician.spellbook.parser.ClassTrie
 import com.gh0u1l5.wechatmagician.spellbook.util.BasicUtil.tryAsynchronously
 import de.robv.android.xposed.callbacks.XC_LoadPackage
 import java.lang.ref.WeakReference
@@ -75,7 +76,7 @@ object WechatGlobal {
  * 这些类名使用的是 JVM 标准中规定的类名格式, 例如 String 的类名会被表示为 "Ljava/lang/String;"
  * Refer: https://docs.oracle.com/javase/specs/jvms/se7/html/jvms-4.html#jvms-4.3
  */
- @Volatile var wxClasses: Array<String>? = null
+ @Volatile var wxClasses: ClassTrie? = null
  get() {
  if (!wxUnitTestMode) {
  initChannel.wait(INIT_TIMEOUT)

src/main/kotlin/com/gh0u1l5/wechatmagician/spellbook/parser/ApkFile.kt

@@ -1,5 +1,7 @@
 package com.gh0u1l5.wechatmagician.spellbook.parser
 
+import com.gh0u1l5.wechatmagician.spellbook.util.ParallelUtil.parallelForEach
+
 import java.io.Closeable
 import java.io.File
 import java.nio.ByteBuffer
@@ -23,13 +25,27 @@ class ApkFile(apkFile: File) : Closeable {
  override fun close() =
  zipFile.close()
 
- val classTypes: Array<String> by lazy {
- var ret = emptyArray<String>()
- for (i in 1 until 1000) {
- val path = if (i == 1) DEX_FILE else String.format(DEX_ADDITIONAL, i)
- val entry = zipFile.getEntry(path) ?: break
- val buffer = ByteBuffer.wrap(readEntry(entry))
- ret += DexParser(buffer).parseClassTypes()
+ private fun getDexFilePath(idx: Int) =
+ if (idx == 1) DEX_FILE else String.format(DEX_ADDITIONAL, idx)
+
+ private fun isDexFileExist(idx: Int): Boolean {
+ val path = getDexFilePath(idx)
+ return zipFile.getEntry(path) != null
+ }
+
+ val classTypes: ClassTrie by lazy {
+ var last = 2
+ while (isDexFileExist(last)) last++
+
+ val ret = ClassTrie()
+ (1..last).parallelForEach { idx ->
+ val path = getDexFilePath(idx)
+ val entry = zipFile.getEntry(path)
+ val data = readEntry(entry)
+ val buffer = ByteBuffer.wrap(data)
+ DexParser(buffer).parseClassTypes().forEach { type ->
+ ret += type
+ }
  }
  return@lazy ret
  }

src/main/kotlin/com/gh0u1l5/wechatmagician/spellbook/parser/ClassTrie.kt

@@ -0,0 +1,71 @@
+package com.gh0u1l5.wechatmagician.spellbook.parser
+
+import com.gh0u1l5.wechatmagician.spellbook.util.ParallelUtil.parallelForEach
+import java.util.concurrent.ConcurrentHashMap
+
+class ClassTrie {
+ companion object {
+ private fun convertJVMTypeToClassName(type: String) =
+ type.substring(1, type.length - 1).replace('/', '.')
+ }
+
+ private val head: TrieNode = TrieNode()
+
+ operator fun plusAssign(type: String) {
+ head.add(convertJVMTypeToClassName(type))
+ }
+
+ operator fun plusAssign(types: Array<String>) {
+ types.asList().parallelForEach { this += it }
+ }
+
+ fun search(packageName: String, depth: Int): List<String> {
+ return head.search(packageName, depth)
+ }
+
+ private class TrieNode {
+ val classes: MutableList<String> = ArrayList(50)
+
+ val children: MutableMap<String, TrieNode> = ConcurrentHashMap()
+
+ fun add(className: String) {
+ add(className, 0)
+ }
+
+ private fun add(className: String, pos: Int) {
+ val delimiterAt = className.indexOf('.', pos)
+ if (delimiterAt == -1) {
+ synchronized(this) {
+ classes.add(className)
+ }
+ return
+ }
+ val pkg = className.substring(pos, delimiterAt)
+ if (pkg !in children) {
+ children[pkg] = TrieNode()
+ }
+ children[pkg]!!.add(className, delimiterAt + 1)
+ }
+
+ fun get(depth: Int = 0): List<String> {
+ if (depth == 0) {
+ return classes
+ }
+ return children.flatMap { it.value.get(depth - 1) }
+ }
+
+ fun search(packageName: String, depth: Int): List<String> {
+ return search(packageName, depth, 0)
+ }
+
+ private fun search(packageName: String, depth: Int, pos: Int): List<String> {
+ val delimiterAt = packageName.indexOf('.', pos)
+ if (delimiterAt == -1) {
+ val pkg = packageName.substring(pos)
+ return children[pkg]?.get(depth) ?: emptyList()
+ }
+ val pkg = packageName.substring(pos, delimiterAt)
+ return children[pkg]?.search(packageName, depth, delimiterAt + 1) ?: emptyList()
+ }
+ }
+}

src/main/kotlin/com/gh0u1l5/wechatmagician/spellbook/util/MirrorUtil.kt

@@ -1,7 +1,6 @@
 package com.gh0u1l5.wechatmagician.spellbook.util
 
 import com.gh0u1l5.wechatmagician.spellbook.WechatGlobal
-import com.gh0u1l5.wechatmagician.spellbook.util.ParallelUtil.parallelMap
 
 /**
  * 封装了一批用于检查“自动适配表达式”的函数
@@ -57,7 +56,7 @@ object MirrorUtil {
  * WARN: 仅供单元测试使用
  */
  fun generateReportWithForceEval(instances: List<Any>): List<Pair<String, String>> {
- return instances.parallelMap { instance ->
+ return instances.map { instance ->
  collectFields(instance).map {
  val value = it.second
  if (value is Lazy<*>) {
@@ -67,6 +66,6 @@ object MirrorUtil {
  }
  "${instance::class.java.canonicalName}.${it.first}" to it.second.toString()
  }
- }.flatten()
+ }.flatten() // 为了 Benchmark 的准确性, 不对结果进行排序
  }
 }

src/main/kotlin/com/gh0u1l5/wechatmagician/spellbook/util/ReflectionUtil.kt

@@ -3,6 +3,7 @@ package com.gh0u1l5.wechatmagician.spellbook.util
 import com.gh0u1l5.wechatmagician.spellbook.WechatGlobal
 import com.gh0u1l5.wechatmagician.spellbook.base.Classes
 import com.gh0u1l5.wechatmagician.spellbook.parser.ApkFile
+import com.gh0u1l5.wechatmagician.spellbook.parser.ClassTrie
 import de.robv.android.xposed.XC_MethodHook
 import de.robv.android.xposed.XposedBridge.hookMethod
 import java.lang.reflect.Field
@@ -66,40 +67,21 @@ object ReflectionUtil {
  * 里面其他包拥有的类.
  *
  * @param loader 用于取出 [Class] 对象的加载器
- * @param classes 所有已知的类名, 由于 Java 的 [ClassLoader] 对象不支持读取所有类名, 我们必须先通过其他手段
- * 获取一个类名列表, 详情请参见 [ApkFile] 和 [WechatGlobal]
+ * @param trie 整个 APK 的包结构, 由于 Java 的 [ClassLoader] 对象不支持读取所有类名, 我们必须先通过其他手段
+ * 解析 APK 结构, 然后才能检索某个包内的所有类, 详情请参见 [ApkFile] 和 [WechatGlobal]
  * @param packageName 包名
  * @param depth 深度
  */
- @JvmStatic fun findClassesFromPackage(loader: ClassLoader, classes: Array<String>, packageName: String, depth: Int = 0): Classes {
+ @JvmStatic fun findClassesFromPackage(loader: ClassLoader, trie: ClassTrie, packageName: String, depth: Int = 0): Classes {
  val key = "$depth-$packageName"
  val cached = classCache[key]
  if (cached != null) {
  return cached
  }
-
- val packageLength = packageName.count { it == '.' } + 1
- val packageDescriptor = "L${packageName.replace('.', '/')}"
- val result = Classes(classes.filter { clazz ->
- val currentPackageLength = clazz.count { it == '/' }
- if (currentPackageLength < packageLength) {
- return@filter false
- }
- // Check depth
- val currentDepth = currentPackageLength - packageLength
- if (depth != -1 && depth != currentDepth) {
- return@filter false
- }
- // Check prefix
- if (!clazz.startsWith(packageDescriptor)) {
- return@filter false
- }
- return@filter true
- }.mapNotNull {
- findClassIfExists(it.substring(1, it.length - 1).replace('/', '.'), loader)
+ val classes = Classes(trie.search(packageName, depth).mapNotNull { name ->
+ findClassIfExists(name, loader)
  })
-
- return result.also { classCache[key] = result }
+ return classes.also { classCache[key] = classes }
  }
 
  /**