Tinker源码分析(二):加载补丁流程

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本系列 Tinker 源码解析基于 Tinker v1.9.12

前一篇讲到了利用反射执行的是 TinkerLoader.tryLoad 方法

tryLoad

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@Override
public Intent tryLoad(TinkerApplication app) {
    Intent resultIntent = new Intent();

    long begin = SystemClock.elapsedRealtime();
    tryLoadPatchFilesInternal(app, resultIntent);
    long cost = SystemClock.elapsedRealtime() - begin;
    ShareIntentUtil.setIntentPatchCostTime(resultIntent, cost);
    return resultIntent;
}

加载的流程主要在 tryLoadPatchFilesInternal 里面。tryLoadPatchFilesInternal 方法很长，我们需要分段来看。

tryLoadPatchFilesInternal

一开始是各种校验

检查 tinker 是否开启

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final int tinkerFlag = app.getTinkerFlags();
// 检查 tinker 是否开启
if (!ShareTinkerInternals.isTinkerEnabled(tinkerFlag)) {
    Log.w(TAG, "tryLoadPatchFiles: tinker is disable, just return");
    ShareIntentUtil.setIntentReturnCode(resultIntent, ShareConstants.ERROR_LOAD_DISABLE);
    return;
}

检查当前的进程

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// 检查当前的进程，确保不是 :patch 进程
if (ShareTinkerInternals.isInPatchProcess(app)) {
    Log.w(TAG, "tryLoadPatchFiles: we don't load patch with :patch process itself, just return");
    ShareIntentUtil.setIntentReturnCode(resultIntent, ShareConstants.ERROR_LOAD_DISABLE);
    return;
}

获取 tinker 目录，检查目录是否存在

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// tinker 获取 tinker 目录，/data/data/tinker.sample.android/tinker
File patchDirectoryFile = SharePatchFileUtil.getPatchDirectory(app);
if (patchDirectoryFile == null) {
    Log.w(TAG, "tryLoadPatchFiles:getPatchDirectory == null");
    //treat as not exist
    ShareIntentUtil.setIntentReturnCode(resultIntent, ShareConstants.ERROR_LOAD_PATCH_DIRECTORY_NOT_EXIST);
    return;
}
String patchDirectoryPath = patchDirectoryFile.getAbsolutePath();
// 检查 tinker 目录是否存在
//check patch directory whether exist
if (!patchDirectoryFile.exists()) {
    Log.w(TAG, "tryLoadPatchFiles:patch dir not exist:" + patchDirectoryPath);
    ShareIntentUtil.setIntentReturnCode(resultIntent, ShareConstants.ERROR_LOAD_PATCH_DIRECTORY_NOT_EXIST);
    return;
}

检查 patch.info 文件是否存在, patch.info 是补丁信息文件，里面记录着新旧两个补丁版本的 md5 值

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// 文件目录 /data/data/tinker.sample.android/tinker/patch.info
File patchInfoFile = SharePatchFileUtil.getPatchInfoFile(patchDirectoryPath);

// 检查 patch.info 补丁信息文件是否存在
//check patch info file whether exist
if (!patchInfoFile.exists()) {
    Log.w(TAG, "tryLoadPatchFiles:patch info not exist:" + patchInfoFile.getAbsolutePath());
    ShareIntentUtil.setIntentReturnCode(resultIntent, ShareConstants.ERROR_LOAD_PATCH_INFO_NOT_EXIST);
    return;
}

读取 patch.info 文件，并包装成一个 SharePatchInfo ，并检查 patchInfo 是否为空 (先加锁 file lock 再解锁)

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//old = 641e634c5b8f1649c75caf73794acbdf
//new = 2c150d8560334966952678930ba67fa8
// tinker/info.lock
File patchInfoLockFile = SharePatchFileUtil.getPatchInfoLockFile(patchDirectoryPath);

// 检查 patch info 文件中的补丁版本信息
patchInfo = SharePatchInfo.readAndCheckPropertyWithLock(patchInfoFile, patchInfoLockFile);
if (patchInfo == null) {
    ShareIntentUtil.setIntentReturnCode(resultIntent, ShareConstants.ERROR_LOAD_PATCH_INFO_CORRUPTED);
    return;
}

检查读取出来的 patchInfo 补丁版本信息

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String oldVersion = patchInfo.oldVersion;
String newVersion = patchInfo.newVersion;
String oatDex = patchInfo.oatDir;

if (oldVersion == null || newVersion == null || oatDex == null) {
    //it is nice to clean patch
    Log.w(TAG, "tryLoadPatchFiles:onPatchInfoCorrupted");
    ShareIntentUtil.setIntentReturnCode(resultIntent, ShareConstants.ERROR_LOAD_PATCH_INFO_CORRUPTED);
    return;
}

如果发现 patchInfo 中的 isRemoveNewVersion 为 true 并且在主进程中运行的话，就代表需要清除补丁了

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boolean mainProcess = ShareTinkerInternals.isInMainProcess(app);
boolean isRemoveNewVersion = patchInfo.isRemoveNewVersion;

// So far new version is not loaded in main process and other processes.
// We can remove new version directory safely.
if (mainProcess && isRemoveNewVersion) {
    Log.w(TAG, "found clean patch mark and we are in main process, delete patch file now.");
    // 获取新的补丁文件夹，例如 patch-2c150d85
    String patchName = SharePatchFileUtil.getPatchVersionDirectory(newVersion);
    if (patchName != null) {
	     // 删除新的补丁文件夹   
        String patchVersionDirFullPath = patchDirectoryPath + "/" + patchName;
        SharePatchFileUtil.deleteDir(patchVersionDirFullPath);
        // 如果旧版本和新版本一致，就把 oldVersion 和 newVersion 设置为空来清除补丁
        if (oldVersion.equals(newVersion)) {
            // !oldVersion.equals(newVersion) means new patch is applied, just fall back to old one in that case.
            // Or we will set oldVersion and newVersion to empty string to clean patch.
            oldVersion = "";
        }
        // 如果 !oldVersion.equals(newVersion) 意味着新补丁已经应用了，需要回退到原来的旧版本
        newVersion = oldVersion;
        patchInfo.oldVersion = oldVersion;
        patchInfo.newVersion = newVersion;
        // 把数据重新写入 patchInfo 文件中
        SharePatchInfo.rewritePatchInfoFileWithLock(patchInfoFile, patchInfo, patchInfoLockFile);
        // 杀掉主进程以外的所有进程
        ShareTinkerInternals.killProcessExceptMain(app);
    }
}

resultIntent.putExtra(ShareIntentUtil.INTENT_PATCH_OLD_VERSION, oldVersion);
resultIntent.putExtra(ShareIntentUtil.INTENT_PATCH_NEW_VERSION, newVersion);

根据版本变化和是否是主进程的条件决定是否允许加载最新的补丁

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boolean versionChanged = !(oldVersion.equals(newVersion));
boolean oatModeChanged = oatDex.equals(ShareConstants.CHANING_DEX_OPTIMIZE_PATH);
oatDex = ShareTinkerInternals.getCurrentOatMode(app, oatDex);
resultIntent.putExtra(ShareIntentUtil.INTENT_PATCH_OAT_DIR, oatDex);

String version = oldVersion;

// 根据版本变化和是否是主进程的条件决定是否允许加载最新的补丁
if (versionChanged && mainProcess) {
    version = newVersion;
}
if (ShareTinkerInternals.isNullOrNil(version)) {
    Log.w(TAG, "tryLoadPatchFiles:version is blank, wait main process to restart");
    ShareIntentUtil.setIntentReturnCode(resultIntent, ShareConstants.ERROR_LOAD_PATCH_INFO_BLANK);
    return;
}

检查当前新版本补丁文件夹是否存在

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//patch-641e634c
String patchName = SharePatchFileUtil.getPatchVersionDirectory(version);
if (patchName == null) {
    Log.w(TAG, "tryLoadPatchFiles:patchName is null");
    //we may delete patch info file
    ShareIntentUtil.setIntentReturnCode(resultIntent, ShareConstants.ERROR_LOAD_PATCH_VERSION_DIRECTORY_NOT_EXIST);
    return;
}
//tinker/patch.info/patch-641e634c
String patchVersionDirectory = patchDirectoryPath + "/" + patchName;

File patchVersionDirectoryFile = new File(patchVersionDirectory);

if (!patchVersionDirectoryFile.exists()) {
    Log.w(TAG, "tryLoadPatchFiles:onPatchVersionDirectoryNotFound");
    //we may delete patch info file
    ShareIntentUtil.setIntentReturnCode(resultIntent, ShareConstants.ERROR_LOAD_PATCH_VERSION_DIRECTORY_NOT_EXIST);
    return;
}

检查补丁文件是否存在并且可读

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//tinker/patch.info/patch-641e634c/patch-641e634c.apk
final String patchVersionFileRelPath = SharePatchFileUtil.getPatchVersionFile(version);
File patchVersionFile = (patchVersionFileRelPath != null ? new File(patchVersionDirectoryFile.getAbsolutePath(), patchVersionFileRelPath) : null);

if (!SharePatchFileUtil.isLegalFile(patchVersionFile)) {
    Log.w(TAG, "tryLoadPatchFiles:onPatchVersionFileNotFound");
    //we may delete patch info file
    ShareIntentUtil.setIntentReturnCode(resultIntent, ShareConstants.ERROR_LOAD_PATCH_VERSION_FILE_NOT_EXIST);
    return;
}

检查补丁文件签名以及补丁文件中的 tinker id 和基准包的 tinker id 是否一致。

注意，这里补丁文件的 tinker id 是当前补丁基准包的 tinker id ，也就是有 bug 的基准包 tinker id 。另外一个 new tinker id 是补丁加载完成后的 tinker id ，就是 bug 修复后的 tinker id 。

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ShareSecurityCheck securityCheck = new ShareSecurityCheck(app);
// 1. 检查补丁包 apk 的签名
// 2. 检查基准包的 tinker id 与补丁包中是否一致
// 3. 检查 tinker 设置与补丁包中的类型是否符合
int returnCode = ShareTinkerInternals.checkTinkerPackage(app, tinkerFlag, patchVersionFile, securityCheck);
if (returnCode != ShareConstants.ERROR_PACKAGE_CHECK_OK) {
    Log.w(TAG, "tryLoadPatchFiles:checkTinkerPackage");
    resultIntent.putExtra(ShareIntentUtil.INTENT_PATCH_PACKAGE_PATCH_CHECK, returnCode);
    ShareIntentUtil.setIntentReturnCode(resultIntent, ShareConstants.ERROR_LOAD_PATCH_PACKAGE_CHECK_FAIL);
    return;
}

resultIntent.putExtra(ShareIntentUtil.INTENT_PATCH_PACKAGE_CONFIG, securityCheck.getPackagePropertiesIfPresent());

下面是 checkTinkerPackage 方法的具体代码

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public static int checkTinkerPackage(Context context, int tinkerFlag, File patchFile, ShareSecurityCheck securityCheck) {
    // 检查补丁文件签名和 tinker id 是否一致
    // 这里为了快速校验,就只检验补丁包内部以meta.txt结尾的文件的签名，而其他的文件的合法性则通过meta.txt文件内部记录的补丁文件Md5值来校验
    int returnCode = checkSignatureAndTinkerID(context, patchFile, securityCheck);
    if (returnCode == ShareConstants.ERROR_PACKAGE_CHECK_OK) {
        // 检查配置的 tinker flag 和 meta.txt 是否匹配
        // 如果不匹配的话，中断接下来的流程
        returnCode = checkPackageAndTinkerFlag(securityCheck, tinkerFlag);
    }
    return returnCode;
}

根据不同的情况,最多有四个文件是以meta.txt结尾的:

  • package_meta.txt 补丁包的基本信息
  • dex_meta.txt dex补丁的信息
  • so_meta.txt so补丁的信息
  • res_meta.txt 资源补丁的信息

如果开启了支持 dex 热修复，检查 dex_meta.txt 文件中记录的dex文件信息对应的dex文件是否存在

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final boolean isEnabledForDex = ShareTinkerInternals.isTinkerEnabledForDex(tinkerFlag);

if (isEnabledForDex) {
    //tinker/patch.info/patch-641e634c/dex
    // 检查下发的meta文件中记录的dex信息中对应的dex文件是否存在
    boolean dexCheck = TinkerDexLoader.checkComplete(patchVersionDirectory, securityCheck, oatDex, resultIntent);
    if (!dexCheck) {
        //file not found, do not load patch
        Log.w(TAG, "tryLoadPatchFiles:dex check fail");
        return;
    }
}

如果开启了支持 so 热修复，检查 so_meta.txt 文件中记录的so文件信息对应的so文件是否存在

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final boolean isEnabledForNativeLib = ShareTinkerInternals.isTinkerEnabledForNativeLib(tinkerFlag);

if (isEnabledForNativeLib) {
    //tinker/patch.info/patch-641e634c/lib
    boolean libCheck = TinkerSoLoader.checkComplete(patchVersionDirectory, securityCheck, resultIntent);
    if (!libCheck) {
        //file not found, do not load patch
        Log.w(TAG, "tryLoadPatchFiles:native lib check fail");
        return;
    }
}

如果开启了支持 res 热修复，检查 res_meta.txt 文件中记录的res文件信息对应的res文件是否存在

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//check resource
final boolean isEnabledForResource = ShareTinkerInternals.isTinkerEnabledForResource(tinkerFlag);
Log.w(TAG, "tryLoadPatchFiles:isEnabledForResource:" + isEnabledForResource);
if (isEnabledForResource) {
    boolean resourceCheck = TinkerResourceLoader.checkComplete(app, patchVersionDirectory, securityCheck, resultIntent);
    if (!resourceCheck) {
        //file not found, do not load patch
        Log.w(TAG, "tryLoadPatchFiles:resource check fail");
        return;
    }
}

符合条件的话就更新版本信息,并将最新的patch info更新入文件.在v1.7.5的版本开始有了isSystemOTA判断,

只要用户是ART环境并且做了OTA升级，则在加载dex补丁的时候就会先把最近一次的补丁全部DexFile.loadDex一遍重新生成odex，再加载dex补丁。否则会报错

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//only work for art platform oat，because of interpret, refuse 4.4 art oat
//android o use quicken default, we don't need to use interpret mode
boolean isSystemOTA = ShareTinkerInternals.isVmArt()
    && ShareTinkerInternals.isSystemOTA(patchInfo.fingerPrint)
    && Build.VERSION.SDK_INT >= 21 && !ShareTinkerInternals.isAfterAndroidO();

resultIntent.putExtra(ShareIntentUtil.INTENT_PATCH_SYSTEM_OTA, isSystemOTA);

//we should first try rewrite patch info file, if there is a error, we can't load jar
// 把patch.info的旧版本的值更新为新版本的值，写入 patch.info 中
if (mainProcess && (versionChanged || oatModeChanged)) {
    patchInfo.oldVersion = version;
    patchInfo.oatDir = oatDex;

    //update old version to new
    if (!SharePatchInfo.rewritePatchInfoFileWithLock(patchInfoFile, patchInfo, patchInfoLockFile)) {
        ShareIntentUtil.setIntentReturnCode(resultIntent, ShareConstants.ERROR_LOAD_PATCH_REWRITE_PATCH_INFO_FAIL);
        Log.w(TAG, "tryLoadPatchFiles:onReWritePatchInfoCorrupted");
        return;
    }

    Log.i(TAG, "tryLoadPatchFiles:success to rewrite patch info, kill other process.");
    ShareTinkerInternals.killProcessExceptMain(app);

    if (oatModeChanged) {
        // delete interpret odex
        // for android o, directory change. Fortunately, we don't need to support android o interpret mode any more
        Log.i(TAG, "tryLoadPatchFiles:oatModeChanged, try to delete interpret optimize files");
        SharePatchFileUtil.deleteDir(patchVersionDirectory + "/" + ShareConstants.INTERPRET_DEX_OPTIMIZE_PATH);
    }
}

加载补丁的安全次数最多三次

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if (!checkSafeModeCount(app)) {
    resultIntent.putExtra(ShareIntentUtil.INTENT_PATCH_EXCEPTION, new TinkerRuntimeException("checkSafeModeCount fail"));
    ShareIntentUtil.setIntentReturnCode(resultIntent, ShareConstants.ERROR_LOAD_PATCH_UNCAUGHT_EXCEPTION);
    Log.w(TAG, "tryLoadPatchFiles:checkSafeModeCount fail");
    return;
}

加载补丁 jar ，这一部分的代码我们后面会详细展开

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//now we can load patch jar
if (isEnabledForDex) {
    boolean loadTinkerJars = TinkerDexLoader.loadTinkerJars(app, patchVersionDirectory, oatDex, resultIntent, isSystemOTA);
    // 如果是 ota 的话，更新 oat 的文件夹路径
    if (isSystemOTA) {
        // update fingerprint after load success
        patchInfo.fingerPrint = Build.FINGERPRINT;
        patchInfo.oatDir = loadTinkerJars ? ShareConstants.INTERPRET_DEX_OPTIMIZE_PATH : ShareConstants.DEFAULT_DEX_OPTIMIZE_PATH;
        // reset to false
        oatModeChanged = false;

        if (!SharePatchInfo.rewritePatchInfoFileWithLock(patchInfoFile, patchInfo, patchInfoLockFile)) {
            ShareIntentUtil.setIntentReturnCode(resultIntent, ShareConstants.ERROR_LOAD_PATCH_REWRITE_PATCH_INFO_FAIL);
            Log.w(TAG, "tryLoadPatchFiles:onReWritePatchInfoCorrupted");
            return;
        }
        // update oat dir
        resultIntent.putExtra(ShareIntentUtil.INTENT_PATCH_OAT_DIR, patchInfo.oatDir);
    }
    if (!loadTinkerJars) {
        Log.w(TAG, "tryLoadPatchFiles:onPatchLoadDexesFail");
        return;
    }
}

加载补丁资源，这一部分的代码我们后面会详细展开

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//now we can load patch resource
if (isEnabledForResource) {
    boolean loadTinkerResources = TinkerResourceLoader.loadTinkerResources(app, patchVersionDirectory, resultIntent);
    if (!loadTinkerResources) {
        Log.w(TAG, "tryLoadPatchFiles:onPatchLoadResourcesFail");
        return;
    }
}

补丁加载流程结束

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// Init component hotplug support.
if (isEnabledForDex && isEnabledForResource) {
    ComponentHotplug.install(app, securityCheck);
}

//all is ok!
ShareIntentUtil.setIntentReturnCode(resultIntent, ShareConstants.ERROR_LOAD_OK);
Log.i(TAG, "tryLoadPatchFiles: load end, ok!");
return;
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