perf(core.loader): 插件ClassLoader白名单采用前缀树进行匹配

改善规则较多时的字符串匹配性能。

projects/sdk/core/loader/src/main/kotlin/com/tencent/shadow/core/loader/classloaders/PluginClassLoader.kt

@@ -20,6 +20,7 @@ package com.tencent.shadow.core.loader.classloaders
 
 import android.os.Build
 import dalvik.system.BaseDexClassLoader
+import org.jetbrains.annotations.TestOnly
 import java.io.File
 
 
@@ -48,18 +49,22 @@ class PluginClassLoader(
      * 宿主的白名单包名
      * 在白名单包里面的宿主类，插件才可以访问
      */
-    private val allHostWhiteList: Array<String>
+    private val allHostWhiteTrie = PackageNameTrie()
 
     private val loaderClassLoader = PluginClassLoader::class.java.classLoader!!
 
     init {
-        val defaultWhiteList = arrayOf(
-                               "org.apache.commons.logging"//org.apache.commons.logging是非常特殊的的包,由系统放到App的PathClassLoader中.
-        )
-        if (hostWhiteList != null) {
-            allHostWhiteList = defaultWhiteList.plus(hostWhiteList)
-        }else {
-            allHostWhiteList = defaultWhiteList
+        hostWhiteList?.forEach {
+            allHostWhiteTrie.insert(it)
+        }
+
+        //org.apache.commons.logging是非常特殊的的包,由系统放到App的PathClassLoader中.
+        allHostWhiteTrie.insert("org.apache.commons.logging")
+
+        //Android 9.0以下的系统里面带有http包，走系统的不走本地的
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.P) {
+            allHostWhiteTrie.insert("org.apache.http")
+            allHostWhiteTrie.insert("org.apache.http.**")
         }
     }
 
@@ -79,11 +84,7 @@ class PluginClassLoader(
             }
 
             //包名在白名单中的类按双亲委派逻辑，从宿主中加载
-            if (className.inPackage(allHostWhiteList)
-                //Android 9.0以下的系统里面带有http包，走系统的不走本地的
-                || (Build.VERSION.SDK_INT < Build.VERSION_CODES.P
-                        && className.startsWith("org.apache.http"))
-            ) {
+            if (className.inPackage(allHostWhiteTrie)) {
                 return super.loadClass(className, resolve)
             }
 
@@ -114,33 +115,75 @@ class PluginClassLoader(
 
 private fun String.subStringBeforeDot() = substringBeforeLast('.', "")
 
+@Deprecated("use PackageNameTrie instead.")
+@TestOnly
 internal fun String.inPackage(packageNames: Array<String>): Boolean {
+    val trie = PackageNameTrie()
+    packageNames.forEach {
+        trie.insert(it)
+    }
+    return inPackage(trie)
+}
+
+private fun String.inPackage(packageNames: PackageNameTrie): Boolean {
     val packageName = subStringBeforeDot()
+    return packageNames.isMatch(packageName)
+}
 
-    return packageNames.any {
-        return@any when {
-            it == "" -> false
-            it == ".*" -> false
-            it == ".**" -> false
-            it.endsWith(".*") -> {//只允许一级子包
-                val sub = packageName.subStringBeforeDot()
-                if (sub.isEmpty()) {
-                    false
-                } else {
-                    sub == it.subStringBeforeDot()
-                }
+/**
+ * 基于Trie算法对包名进行前缀匹配
+ */
+private class PackageNameTrie {
+    private class Node {
+        val subNodes = mutableMapOf<String, Node>()
+        var isLastPackageOfARule = false
+    }
+
+    private val root = Node()
+
+    fun insert(packageNameRule: String) {
+        var node = root
+        packageNameRule.split('.').forEach {
+            if (it.isEmpty()) return //"",".*",".**"这种无包名情况不允许设置
+
+            var subNode = node.subNodes[it]
+            if (subNode == null) {
+                subNode = Node()
+                node.subNodes[it] = subNode
+            }
+            node = subNode
+        }
+        node.isLastPackageOfARule = true
+    }
+
+    fun isMatch(packageName: String): Boolean {
+        var node = root
+
+        val split = packageName.split('.')
+        val lastIndex = split.size - 1
+        for ((index, name) in split.withIndex()) {
+            // 只要下级包名规则中有**，就完成了匹配
+            val twoStars = node.subNodes["**"]
+            if (twoStars != null) {
+                return true
             }
-            it.endsWith(".**") -> {//允许所有子包
-                val sub = packageName.subStringBeforeDot()
-                if (sub.isEmpty()) {
-                    false
-                } else {
-                    "$sub.".startsWith(it.subStringBeforeDot() + '.')
+
+            // 剩最后一级包名时，如果规则是*则完成比配
+            if (index == lastIndex) {
+                val oneStar = node.subNodes["*"]
+                if (oneStar != null) {
+                    return true
                 }
             }
-            else -> packageName == it
+
+            // 找不到下级包名时即匹配失败
+            val subNode = node.subNodes[name]
+            if (subNode == null) {
+                return false
+            } else {
+                node = subNode
+            }
         }
+        return node.isLastPackageOfARule
     }
 }
-
-