该系列文章分析基于 Tinker1.7.6 版本
Tinker项目地址：https://github.com/Tencent/tinker
Tinker接入及源码分析（一）：简单介绍以及如何接入
Tinker接入及源码分析（二）：加载补丁源码分析
Tinker接入及源码分析（三）：合成补丁源码分析
上篇文章分析了加载补丁的源码，本篇文章会继续分析tinker初始化过程以及合成补丁的过程。
之前也说过，使用Tinker之前必须通过如下代码初始化Tinker：
public static class Builder { PRivate final Context context; private final boolean mainProcess; private final boolean patchProcess; private int status = -1; private LoadReporter loadReporter; private PatchReporter patchReporter; private PatchListener listener; private File patchDirectory; private File patchInfoFile; private File patchInfoLockFile; private Boolean tinkerLoadVerifyFlag; /** * Start building a new {@link Tinker} instance. */ public Builder(Context context) { if (context == null) { throw new TinkerRuntimeException("Context must not be null."); } this.context = context; this.mainProcess = TinkerServiceInternals.isInMainProcess(context); this.patchProcess = TinkerServiceInternals.isInTinkerPatchServiceProcess(context); this.patchDirectory = SharePatchFileUtil.getPatchDirectory(context); if (this.patchDirectory == null) { TinkerLog.e(TAG, "patchDirectory is null!"); return; } this.patchInfoFile = SharePatchFileUtil.getPatchInfoFile(patchDirectory.getAbsolutePath()); this.patchInfoLockFile = SharePatchFileUtil.getPatchInfoLockFile(patchDirectory.getAbsolutePath()); TinkerLog.w(TAG, "tinker patch directory: %s", patchDirectory); } //省略了set方法 public Tinker build() { if (status == -1) { status = ShareConstants.TINKER_ENABLE_ALL; } if (loadReporter == null) { loadReporter = new DefaultLoadReporter(context); } if (patchReporter == null) { patchReporter = new DefaultPatchReporter(context); } if (listener == null) { listener = new DefaultPatchListener(context); } if (tinkerLoadVerifyFlag == null) { tinkerLoadVerifyFlag = false; } return new Tinker(context, status, loadReporter, patchReporter, listener, patchDirectory, patchInfoFile, patchInfoLockFile, mainProcess, patchProcess, tinkerLoadVerifyFlag); } }上面代码省略了set方法，我们只关注默认设置。其中mainProcess，patchProcess判断当前是否是应用进程和补丁合成进程。loadReporter，patchReporter 顾名思义是一些过程的回调。PatchListener 是我们关注的重点，也是补丁合成的入口，它的默认实现是DefaultPatchListener，下面分析会用到。
patchDirectory，patchInfoFile，patchInfoLockFile分别是：
/data/data/package_name/tinker/ /data/data/package_name/tinker/patch.info/data/data/package_name/tinker/info.locktinkerLoadVerifyFlag是新建application时传进去的参数，用于判断是否每次加载都做md5校验。
初始化好Tinker之后再调用Tinker.create(tinker);
/** * create custom tinker by {@link Tinker.Builder} * please do it when very first your app start. * * @param tinker */ public static void create(Tinker tinker) { if (sInstance != null) { throw new TinkerRuntimeException("Tinker instance is already set."); } sInstance = tinker; }sInstance是静态变量，保证Tinker是单例的，并且只初始化一次。
最后调用tinker.install(applicationLike.getTinkerResultIntent())；
public void install(Intent intentResult) { install(intentResult, DefaultTinkerResultService.class, new UpgradePatch());} /** * you must install tinker first!! * * @param intentResult * @param serviceClass * @param upgradePatch */ public void install(Intent intentResult, Class<? extends AbstractResultService> serviceClass, AbstractPatch upgradePatch) { sInstalled = true; TinkerPatchService.setPatchProcessor(upgradePatch, serviceClass); if (!isTinkerEnabled()) { TinkerLog.e(TAG, "tinker is disabled"); return; } if (intentResult == null) { throw new TinkerRuntimeException("intentResult must not be null."); } tinkerLoadResult = new TinkerLoadResult(); tinkerLoadResult.parseTinkerResult(getContext(), intentResult); //after load code set loadReporter.onLoadResult(patchDirectory, tinkerLoadResult.loadCode, tinkerLoadResult.costTime); if (!loaded) { TinkerLog.w(TAG, "tinker load fail!"); }}这里值得注意的是install方法的后面两个参数，serviceClass 是用于补丁合成成功后启动的Service来处理合成结果，upgradePatch 是真正合成补丁的类，分别提供了默认实现DefaultTinkerResultService和UpgradePatch，这两个参数也支持自定义。在install方法中会调用TinkerPatchService.setPatchProcessor(upgradePatch, serviceClass); 将这两个参数通过静态方法设置给TinkerPatchService类，TinkerPatchService类是合成补丁的Service，并且运行在新的进程中。
这样就完成了Tinker的初始化。
第一篇文章介绍过使用以下方法来加载补丁：
TinkerInstaller.onReceiveUpgradePatch(context, patchLocation)看一下具体实现：
/** * new patch file to install, try install them with :patch process * * @param context * @param patchLocation */ public static void onReceiveUpgradePatch(Context context, String patchLocation) { Tinker.with(context).getPatchListener().onPatchReceived(patchLocation); }这里会调用PatchListener,还记得之前这个参数的默认实现吗？
我们来看一下DefaultPatchListener的onPatchReceived方法：
public int onPatchReceived(String path) { int returnCode = patchCheck(path); if (returnCode == ShareConstants.ERROR_PATCH_OK) { TinkerPatchService.runPatchService(context, path); } else { Tinker.with(context).getLoadReporter().onLoadPatchListenerReceiveFail(new File(path), returnCode); } return returnCode;}patchCheck(patch)方法会判断是否开启了Tinker，以及补丁文件是否存在。然后会启动TinkerPatchService：TinkerPatchService.runPatchService(context, path);
TinkerPatchService是继承于IntentService，IntentService与普通Service的区别这里就不说了，看它的onHandleIntent方法，继承IntentService必须实现该方法，并且可以进行耗时操作：
@Override protected void onHandleIntent(Intent intent) { final Context context = getApplicationContext(); Tinker tinker = Tinker.with(context); tinker.getPatchReporter().onPatchServiceStart(intent); if (intent == null) { TinkerLog.e(TAG, "TinkerPatchService received a null intent, ignoring."); return; } String path = getPatchPathExtra(intent); if (path == null) { TinkerLog.e(TAG, "TinkerPatchService can't get the path extra, ignoring."); return; } File patchFile = new File(path); long begin = SystemClock.elapsedRealtime(); boolean result; long cost; Throwable e = null; increasingPriority(); PatchResult patchResult = new PatchResult(); try { if (upgradePatchProcessor == null) { throw new TinkerRuntimeException("upgradePatchProcessor is null."); } result = upgradePatchProcessor.tryPatch(context, path, patchResult); } catch (Throwable throwable) { e = throwable; result = false; tinker.getPatchReporter().onPatchException(patchFile, e); } cost = SystemClock.elapsedRealtime() - begin; tinker.getPatchReporter(). onPatchResult(patchFile, result, cost); patchResult.isSuccess = result; patchResult.rawPatchFilePath = path; patchResult.costTime = cost; patchResult.e = e; AbstractResultService.runResultService(context, patchResult, getPatchResultExtra(intent)); }先进行了参数校验，increasingPriority()，这个方法用于提高进程优先级，防止被回收：
private void increasingPriority() {// if (Build.VERSION.SDK_INT > 24) {// TinkerLog.i(TAG, "for Android 7.1, we just ignore increasingPriority job");// return;// } TinkerLog.i(TAG, "try to increase patch process priority"); try { Notification notification = new Notification(); if (Build.VERSION.SDK_INT < 18) { startForeground(notificationId, notification); } else { startForeground(notificationId, notification); // start InnerService startService(new Intent(this, InnerService.class)); } } catch (Throwable e) { TinkerLog.i(TAG, "try to increase patch process priority error:" + e); } }然后调用result = upgradePatchProcessor.tryPatch(context, path, patchResult);进行合成补丁，返回一个结果码，这里下面再详细说，先继续往下看， 最后会启动另一个Service：
AbstractResultService.runResultService(context, patchResult, getPatchResultExtra(intent));这个Service就是之前传进来的DefaultTinkerResultService，并且将合成结果带给它回调onPatchResult方法：
public class DefaultTinkerResultService extends AbstractResultService { private static final String TAG = "Tinker.DefaultTinkerResultService"; /** * we may want to use the new patch just now!! * * @param result */ @Override public void onPatchResult(PatchResult result) { if (result == null) { TinkerLog.e(TAG, "DefaultTinkerResultService received null result!!!!"); return; } TinkerLog.i(TAG, "DefaultTinkerResultService received a result:%s ", result.toString()); //first, we want to kill the recover process TinkerServiceInternals.killTinkerPatchServiceProcess(getApplicationContext()); // if success and newPatch, it is nice to delete the raw file, and restart at once // only main process can load an upgrade patch! if (result.isSuccess) { File rawFile = new File(result.rawPatchFilePath); if (rawFile.exists()) { TinkerLog.i(TAG, "save delete raw patch file"); SharePatchFileUtil.safeDeleteFile(rawFile); } if (checkIfNeedKill(result)) { android.os.Process.killProcess(android.os.Process.myPid()); } else { TinkerLog.i(TAG, "I have already install the newly patch version!"); } } } public boolean checkIfNeedKill(PatchResult result) { Tinker tinker = Tinker.with(getApplicationContext()); if (tinker.isTinkerLoaded()) { TinkerLoadResult tinkerLoadResult = tinker.getTinkerLoadResultIfPresent(); if (tinkerLoadResult != null) { String currentVersion = tinkerLoadResult.currentVersion; if (result.patchVersion != null && result.patchVersion.equals(currentVersion)) { return false; } } } return true; }}在onPatchResult方法中会杀死补丁合成的进程，如果补丁合成成功，会将原始数据删掉，并且杀死当前进程。当然用户也可以自定义这个类，实现更好的逻辑，比如不直接杀死当前进程，而是当用户退出应用，切到后台，或者关闭屏幕的时候杀死应用，达到重启的目的，具体实现可以参考Simple中的实现。这样整个补丁的合成过程就结束了。目前为止大致Tinker初始化以及补丁合成流程已经讲完了，有兴趣的继续往下看真正合成补丁的调用
result = upgradePatchProcessor.tryPatch(context, path, patchResult);还记得之前初始化的方法吗：
public void install(Intent intentResult) { install(intentResult, DefaultTinkerResultService.class, new UpgradePatch());}这里的UpgradePatch对象便会赋值给upgradePatchProcessor，合成补丁的时候调用它的tryPatch方法：
@Override public boolean tryPatch(Context context, String tempPatchPath, PatchResult patchResult) { Tinker manager = Tinker.with(context); final File patchFile = new File(tempPatchPath); //check the signature, we should create a new checker ShareSecurityCheck signatureCheck = new ShareSecurityCheck(context); int returnCode = ShareTinkerInternals.checkTinkerPackage(context, manager.getTinkerFlags(), patchFile, signatureCheck); //it is a new patch, so we should not find a exist SharePatchInfo oldInfo = manager.getTinkerLoadResultIfPresent().patchInfo; String patchMd5 = SharePatchFileUtil.getMD5(patchFile); //use md5 as version patchResult.patchVersion = patchMd5; SharePatchInfo newInfo; //already have patch if (oldInfo != null) { newInfo = new SharePatchInfo(oldInfo.oldVersion, patchMd5, Build.FINGERPRINT); } else { newInfo = new SharePatchInfo("", patchMd5, Build.FINGERPRINT); } //check ok, we can real recover a new patch final String patchDirectory = manager.getPatchDirectory().getAbsolutePath(); final String patchName = SharePatchFileUtil.getPatchVersionDirectory(patchMd5); final String patchVersionDirectory = patchDirectory + "/" + patchName; //it is a new patch, we first delete if there is any files //don't delete dir for faster retry// SharePatchFileUtil.deleteDir(patchVersionDirectory); //copy file File destPatchFile = new File(patchVersionDirectory + "/" + SharePatchFileUtil.getPatchVersionFile(patchMd5)); try { SharePatchFileUtil.copyFileUsingStream(patchFile, destPatchFile); TinkerLog.w(TAG, "UpgradePatch after %s size:%d, %s size:%d", patchFile.getAbsolutePath(), patchFile.length(), destPatchFile.getAbsolutePath(), destPatchFile.length()); } catch (IOException e) {// e.printStackTrace(); TinkerLog.e(TAG, "UpgradePatch tryPatch:copy patch file fail from %s to %s", patchFile.getPath(), destPatchFile.getPath()); manager.getPatchReporter().onPatchTypeExtractFail(patchFile, destPatchFile, patchFile.getName(), ShareConstants.TYPE_PATCH_FILE); return false; } //we use destPatchFile instead of patchFile, because patchFile may be deleted during the patch process if (!DexDiffPatchInternal.tryRecoverDexFiles(manager, signatureCheck, context, patchVersionDirectory, destPatchFile)) { TinkerLog.e(TAG, "UpgradePatch tryPatch:new patch recover, try patch dex failed"); return false; } final File patchInfoFile = manager.getPatchInfoFile(); if (!SharePatchInfo.rewritePatchInfoFileWithLock(patchInfoFile, newInfo, SharePatchFileUtil.getPatchInfoLockFile(patchDirectory))) { TinkerLog.e(TAG, "UpgradePatch tryPatch:new patch recover, rewrite patch info failed"); manager.getPatchReporter().onPatchInfoCorrupted(patchFile, newInfo.oldVersion, newInfo.newVersion); return false; } TinkerLog.w(TAG, "UpgradePatch tryPatch: done, it is ok"); return true; }这个方法比较长，删除了一些校验的代码以及合成资源文件等方法，主要看dex文件的合成过程。开始是初始化一些目录，再将补丁文件拷贝到目标目录中：
SharePatchFileUtil.copyFileUsingStream(patchFile, destPatchFile);再调用以下方法：
DexDiffPatchInternal.tryRecoverDexFiles(manager, signatureCheck, context, patchVersionDirectory, destPatchFile)看具体实现：
protected static boolean tryRecoverDexFiles(Tinker manager, ShareSecurityCheck checker, Context context, String patchVersionDirectory, File patchFile) { if (!manager.isEnabledForDex()) { TinkerLog.w(TAG, "patch recover, dex is not enabled"); return true; } String dexMeta = checker.getMetaContentMap().get(DEX_META_FILE); if (dexMeta == null) { TinkerLog.w(TAG, "patch recover, dex is not contained"); return true; } long begin = SystemClock.elapsedRealtime(); boolean result = patchDexExtractViaDexDiff(context, patchVersionDirectory, dexMeta, patchFile); long cost = SystemClock.elapsedRealtime() - begin; TinkerLog.i(TAG, "recover dex result:%b, cost:%d", result, cost); return result; }主要就是计算耗时，最终方法是patchDexExtractViaDexDiff：
private static boolean patchDexExtractViaDexDiff(Context context, String patchVersionDirectory, String meta, final File patchFile) { String dir = patchVersionDirectory + "/" + DEX_PATH + "/"; if (!extractDexDiffInternals(context, dir, meta, patchFile, TYPE_DEX)) { TinkerLog.w(TAG, "patch recover, extractDiffInternals fail"); return false; } final Tinker manager = Tinker.with(context); File dexFiles = new File(dir); File[] files = dexFiles.listFiles(); if (files != null) { final String optimizeDexDirectory = patchVersionDirectory + "/" + DEX_OPTIMIZE_PATH + "/"; File optimizeDexDirectoryFile = new File(optimizeDexDirectory); if (!optimizeDexDirectoryFile.exists() && !optimizeDexDirectoryFile.mkdirs()) { TinkerLog.w(TAG, "patch recover, make optimizeDexDirectoryFile fail"); return false; } TinkerLog.w(TAG, "patch recover, try to optimize dex file count:%d", files.length); boolean isSuccess = TinkerParallelDexOptimizer.optimizeAll( files, optimizeDexDirectoryFile, new TinkerParallelDexOptimizer.ResultCallback() { long startTime; @Override public void onStart(File dexFile, File optimizedDir) { startTime = System.currentTimeMillis(); TinkerLog.i(TAG, "start to optimize dex %s", dexFile.getPath()); } @Override public void onSuccess(File dexFile, File optimizedDir) { // Do nothing. TinkerLog.i(TAG, "success to optimize dex %s use time %d", dexFile.getPath(), (System.currentTimeMillis() - startTime)); } @Override public void onFailed(File dexFile, File optimizedDir, Throwable thr) { TinkerLog.i(TAG, "fail to optimize dex %s use time %d", dexFile.getPath(), (System.currentTimeMillis() - startTime)); SharePatchFileUtil.safeDeleteFile(dexFile); manager.getPatchReporter().onPatchDexOptFail(patchFile, dexFile, optimizeDexDirectory, dexFile.getName(), thr); } } ); //list again if (isSuccess) { for (File file : files) { try { if (!SharePatchFileUtil.isLegalFile(file)) { TinkerLog.e(TAG, "single dex optimizer file %s is not exist, just return false", file); return false; } String outputPathName = SharePatchFileUtil.optimizedPathFor(file, optimizeDexDirectoryFile); File outputFile = new File(outputPathName); if (!SharePatchFileUtil.isLegalFile(outputFile)) { TinkerLog.e(TAG, "parallel dex optimizer file %s fail, optimize again", outputPathName); long start = System.currentTimeMillis(); DexFile.loadDex(file.getAbsolutePath(), outputPathName, 0); TinkerLog.i(TAG, "success single dex optimize file, path: %s, use time: %d", file.getPath(), (System.currentTimeMillis() - start)); if (!SharePatchFileUtil.isLegalFile(outputFile)) { manager.getPatchReporter() .onPatchDexOptFail(patchFile, file, optimizeDexDirectory, file.getName(), new TinkerRuntimeException("dexOpt file:" + outputPathName + " is not exist")); return false; } } } catch (Throwable e) { TinkerLog.e(TAG, "dex optimize or load failed, path:" + file.getPath()); //delete file SharePatchFileUtil.safeDeleteFile(file); manager.getPatchReporter().onPatchDexOptFail(patchFile, file, optimizeDexDirectory, file.getName(), e); return false; } } } return isSuccess; } return true; }首先extractDexDiffInternals(context, dir, meta, patchFile, TYPE_DEX)是合成全量补丁，后面是通过DexFile.loadDex生成优化后的dex文件，这个过程貌似做了两遍。主要看extractDexDiffInternals，哎，不贴代码了，代码好多，自己看吧。这个方法中会拿到两个文件，一个原始包文件，一个是补丁文件：
apk = new ZipFile(apkPath);patch = new ZipFile(patchFile);安全性校验完了之后会分别调用extractDexFile(zipFile, entryFile,extractTo, dexInfo) 或者 patchDexFile(baseApk, patchPkg, oldDexEntry, patchFileEntry, patchInfo, patchedDexFile)；这里分了三种情况，
第一种情况是直接将补丁包中的dex文件拷贝到了目标文件夹下，这种情况应该是下发的补丁包就是全量包；
第二种情况是直接拷贝原apk包的dex文件，有这么一段注释：
// Small patched dex generating strategy was disabled, we copy full original dex directly now.
为什么要把原始Apk包里的dex文件复制过去呢？我也想不明白，问了一下张绍文老大，他的回答是：
因为内联以及地址错乱的问题
对，就是这个原因（因回答过于简洁，还是不太明白）。有知道的小伙伴欢迎留言告知，说的稍微详细一点。
这两种情况调用的是extractDexFile，不同的是传进去的包不一样，一个是补丁包，一个是原始包。
第三种情况是将原始dex与补丁dex合成全量dex,调用patchDexFile，最终调用如下方法合成补丁：
new DexPatchApplier(zis, (int) entry.getSize(), patchFileStream).executeAndSaveTo(zos);继续往下看DexPatchApplier类，这个可是合成dex文件的核心所在
额。。。不看了，看不下去了，有点想吐，晕代码。。。
等不晕的时候再来看吧，分析Tinker源码的文章就暂时告一段落了，对这系列文章有疑问的，或者发现写的有错误的欢迎在下方留言；如果接入遇到问题的也可以留言。
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