/*
* Extract "classes.dex" from archive file.
*
* If "quiet" is set, don't report common errors.
*/
UnzipToFileResult dexUnzipToFile(const char* zipFileName,
const char* outFileName, bool quiet)
{
UnzipToFileResult result = kUTFRSuccess;
static const char* kFileToExtract = "classes.dex";
ZipArchive archive;
ZipEntry entry;
bool unlinkOnFailure = false;
int fd = -1;
if (dexZipOpenArchive(zipFileName, &archive) != 0) {
if (!quiet) {
fprintf(stderr, "Unable to open '%s' as zip archive\n",
zipFileName);
}
result = kUTFRNotZip;
goto bail;
}
fd = open(outFileName, O_WRONLY | O_CREAT | O_EXCL, 0600);
if (fd < 0) {
fprintf(stderr, "Unable to create output file '%s': %s\n",
outFileName, strerror(errno));
result = kUTFROutputFileProblem;
goto bail;
}
unlinkOnFailure = true;
entry = dexZipFindEntry(&archive, kFileToExtract);
if (entry == NULL) {
if (!quiet) {
fprintf(stderr, "Unable to find '%s' in '%s'\n",
kFileToExtract, zipFileName);
}
result = kUTFRNoClassesDex;
goto bail;
}
if (dexZipExtractEntryToFile(&archive, entry, fd) != 0) {
fprintf(stderr, "Extract of '%s' from '%s' failed\n",
kFileToExtract, zipFileName);
result = kUTFRBadZip;
goto bail;
}
bail:
if (fd >= 0)
close(fd);
if (unlinkOnFailure && result != kUTFRSuccess)
unlink(outFileName);
dexZipCloseArchive(&archive);
return result;
}
/*
* Checks the dependencies of the dex cache file corresponding
* to the jar file at the absolute path "fileName".
*/
DexCacheStatus dvmDexCacheStatus(const char *fileName)
{
ZipArchive archive;
char* cachedName = NULL;
int fd;
DexCacheStatus result = DEX_CACHE_ERROR;
ZipEntry entry;
/* Always treat elements of the bootclasspath as up-to-date.
* The fact that interpreted code is running at all means that this
* should be true.
*/
if (dvmClassPathContains(gDvm.bootClassPath, fileName)) {
return DEX_CACHE_OK;
}
//TODO: match dvmJarFileOpen()'s logic. Not super-important
// (the odex-first logic is only necessary for dexpreopt)
// but it would be nice to be consistent.
/* Try to find the dex file inside of the archive.
*/
if (dexZipOpenArchive(fileName, &archive) != 0) {
return DEX_CACHE_BAD_ARCHIVE;
}
entry = dexZipFindEntry(&archive, kDexInJarName);
if (entry != NULL) {
bool newFile = false;
/*
* See if there's an up-to-date copy of the optimized dex
* in the cache, but don't create one if there isn't.
*/
ALOGV("dvmDexCacheStatus: Checking cache for %s", fileName);
cachedName = dexOptGenerateCacheFileName(fileName, kDexInJarName);
if (cachedName == NULL)
return DEX_CACHE_BAD_ARCHIVE;
fd = dvmOpenCachedDexFile(fileName, cachedName,
dexGetZipEntryModTime(&archive, entry),
dexGetZipEntryCrc32(&archive, entry),
/*isBootstrap=*/false, &newFile, /*createIfMissing=*/false);
ALOGV("dvmOpenCachedDexFile returned fd %d", fd);
if (fd < 0) {
result = DEX_CACHE_STALE;
goto bail;
}
/* dvmOpenCachedDexFile locks the file as a side-effect.
* Unlock and close it.
*/
if (!dvmUnlockCachedDexFile(fd)) {
/* uh oh -- this process needs to exit or we'll wedge the system */
ALOGE("Unable to unlock DEX file");
goto bail;
}
/* When createIfMissing is false, dvmOpenCachedDexFile() only
* returns a valid fd if the cache file is up-to-date.
*/
} else {
/*
* There's no dex file in the jar file. See if there's an
* optimized dex file living alongside the jar.
*/
fd = openAlternateSuffix(fileName, "odex", O_RDONLY, &cachedName);
if (fd < 0) {
ALOGI("Zip is good, but no %s inside, and no .odex "
"file in the same directory", kDexInJarName);
result = DEX_CACHE_BAD_ARCHIVE;
goto bail;
}
ALOGV("Using alternate file (odex) for %s ...", fileName);
if (!dvmCheckOptHeaderAndDependencies(fd, false, 0, 0, true, true)) {
ALOGE("%s odex has stale dependencies", fileName);
ALOGE("odex source not available -- failing");
result = DEX_CACHE_STALE_ODEX;
goto bail;
} else {
ALOGV("%s odex has good dependencies", fileName);
}
}
result = DEX_CACHE_OK;
bail:
dexZipCloseArchive(&archive);
free(cachedName);
if (fd >= 0) {
close(fd);
}
return result;
}
/*
* Open a Jar file. It's okay if it's just a Zip archive without all of
* the Jar trimmings, but we do insist on finding "classes.dex" inside
* or an appropriately-named ".odex" file alongside.
*
* If "isBootstrap" is not set, the optimizer/verifier regards this DEX as
* being part of a different class loader.
*/
int dvmJarFileOpen(const char* fileName, const char* odexOutputName,
JarFile** ppJarFile, bool isBootstrap)
{
/*
* TODO: This function has been duplicated and modified to become
* dvmRawDexFileOpen() in RawDexFile.c. This should be refactored.
*/
ZipArchive archive;
DvmDex* pDvmDex = NULL;
char* cachedName = NULL;
bool archiveOpen = false;
bool locked = false;
int fd = -1;
int result = -1;
/* Even if we're not going to look at the archive, we need to
* open it so we can stuff it into ppJarFile.
*/
if (dexZipOpenArchive(fileName, &archive) != 0)
goto bail;
archiveOpen = true;
/* If we fork/exec into dexopt, don't let it inherit the archive's fd.
*/
dvmSetCloseOnExec(dexZipGetArchiveFd(&archive));
/* First, look for a ".odex" alongside the jar file. It will
* have the same name/path except for the extension.
*/
fd = openAlternateSuffix(fileName, "odex", O_RDONLY, &cachedName);
if (fd >= 0) {
ALOGV("Using alternate file (odex) for %s ...", fileName);
if (!dvmCheckOptHeaderAndDependencies(fd, false, 0, 0, true, true)) {
ALOGE("%s odex has stale dependencies", fileName);
free(cachedName);
cachedName = NULL;
close(fd);
fd = -1;
goto tryArchive;
} else {
ALOGV("%s odex has good dependencies", fileName);
//TODO: make sure that the .odex actually corresponds
// to the classes.dex inside the archive (if present).
// For typical use there will be no classes.dex.
}
} else {
ZipEntry entry;
tryArchive:
/*
* Pre-created .odex absent or stale. Look inside the jar for a
* "classes.dex".
*/
entry = dexZipFindEntry(&archive, kDexInJarName);
if (entry != NULL) {
bool newFile = false;
/*
* We've found the one we want. See if there's an up-to-date copy
* in the cache.
*
* On return, "fd" will be seeked just past the "opt" header.
*
* If a stale .odex file is present and classes.dex exists in
* the archive, this will *not* return an fd pointing to the
* .odex file; the fd will point into dalvik-cache like any
* other jar.
*/
if (odexOutputName == NULL) {
cachedName = dexOptGenerateCacheFileName(fileName,
kDexInJarName);
if (cachedName == NULL)
goto bail;
} else {
cachedName = strdup(odexOutputName);
}
ALOGV("dvmJarFileOpen: Checking cache for %s (%s)",
fileName, cachedName);
fd = dvmOpenCachedDexFile(fileName, cachedName,
dexGetZipEntryModTime(&archive, entry),
dexGetZipEntryCrc32(&archive, entry),
isBootstrap, &newFile, /*createIfMissing=*/true);
if (fd < 0) {
ALOGI("Unable to open or create cache for %s (%s)",
fileName, cachedName);
goto bail;
}
locked = true;
/*
* If fd points to a new file (because there was no cached version,
* or the cached version was stale), generate the optimized DEX.
* The file descriptor returned is still locked, and is positioned
* just past the optimization header.
*/
if (newFile) {
u8 startWhen, extractWhen, endWhen;
bool result;
off_t dexOffset;
dexOffset = lseek(fd, 0, SEEK_CUR);
result = (dexOffset > 0);
if (result) {
startWhen = dvmGetRelativeTimeUsec();
result = dexZipExtractEntryToFile(&archive, entry, fd) == 0;
extractWhen = dvmGetRelativeTimeUsec();
}
if (result) {
result = dvmOptimizeDexFile(fd, dexOffset,
dexGetZipEntryUncompLen(&archive, entry),
fileName,
dexGetZipEntryModTime(&archive, entry),
dexGetZipEntryCrc32(&archive, entry),
isBootstrap);
}
if (!result) {
ALOGE("Unable to extract+optimize DEX from '%s'",
fileName);
goto bail;
}
endWhen = dvmGetRelativeTimeUsec();
ALOGD("DEX prep '%s': unzip in %dms, rewrite %dms",
fileName,
(int) (extractWhen - startWhen) / 1000,
(int) (endWhen - extractWhen) / 1000);
}
} else {
ALOGI("Zip is good, but no %s inside, and no valid .odex "
"file in the same directory", kDexInJarName);
goto bail;
}
}
/*
* Map the cached version. This immediately rewinds the fd, so it
* doesn't have to be seeked anywhere in particular.
*/
if (dvmDexFileOpenFromFd(fd, &pDvmDex) != 0) {
ALOGI("Unable to map %s in %s", kDexInJarName, fileName);
goto bail;
}
if (locked) {
/* unlock the fd */
if (!dvmUnlockCachedDexFile(fd)) {
/* uh oh -- this process needs to exit or we'll wedge the system */
ALOGE("Unable to unlock DEX file");
goto bail;
}
locked = false;
}
ALOGV("Successfully opened '%s' in '%s'", kDexInJarName, fileName);
*ppJarFile = (JarFile*) calloc(1, sizeof(JarFile));
(*ppJarFile)->archive = archive;
(*ppJarFile)->cacheFileName = cachedName;
(*ppJarFile)->pDvmDex = pDvmDex;
cachedName = NULL; // don't free it below
result = 0;
bail:
/* clean up, closing the open file */
if (archiveOpen && result != 0)
dexZipCloseArchive(&archive);
free(cachedName);
if (fd >= 0) {
if (locked)
(void) dvmUnlockCachedDexFile(fd);
close(fd);
}
return result;
}
/*
* Extract "classes.dex" from zipFd into "cacheFd", leaving a little space
* up front for the DEX optimization header.
*/
static int extractAndProcessZip(int zipFd, int cacheFd,
const char* debugFileName, bool isBootstrap, const char* bootClassPath,
const char* dexoptFlagStr)
{
ZipArchive zippy; // 用于描述ZIP压缩文件的数据结构
ZipEntry zipEntry; // 用于表示一个ZIP入口
size_t uncompLen;
long modWhen, crc32;
off_t dexOffset; // 用于表示在Odex文件中，原Dex文件的起始地址
int err;
int result = -1;
int dexoptFlags = 0; /* bit flags, from enum DexoptFlags */
// 设置默认的优化模式
DexClassVerifyMode verifyMode = VERIFY_MODE_ALL;
DexOptimizerMode dexOptMode = OPTIMIZE_MODE_VERIFIED;
memset(&zippy, 0, sizeof(zippy));
/* make sure we're still at the start of an empty file */
if (lseek(cacheFd, 0, SEEK_END) != 0) {
ALOGE("DexOptZ: new cache file '%s' is not empty", debugFileName);
goto bail;
}
/*
* Write a skeletal DEX optimization header. We want the classes.dex
* to come just after it.
*/
err = dexOptCreateEmptyHeader(cacheFd);
if (err != 0)
goto bail;
/* record the file position so we can get back here later */
// 取得Odex文件中原Dex文件的起始位置，实际就是一个Odex文件头部的长度
dexOffset = lseek(cacheFd, 0, SEEK_CUR);
if (dexOffset < 0)
goto bail;
/*
* Open the zip archive, find the DEX entry.
*/
if (dexZipPrepArchive(zipFd, debugFileName, &zippy) != 0) {
ALOGW("DexOptZ: unable to open zip archive '%s'", debugFileName);
goto bail;
}
// 获取目标Dex文件的解压入口
zipEntry = dexZipFindEntry(&zippy, kClassesDex);
if (zipEntry == NULL) {
ALOGW("DexOptZ: zip archive '%s' does not include %s",
debugFileName, kClassesDex);
goto bail;
}
/*
* Extract some info about the zip entry.
*/
if (dexZipGetEntryInfo(&zippy, zipEntry, NULL, &uncompLen, NULL, NULL,
&modWhen, &crc32) != 0)
{
ALOGW("DexOptZ: zip archive GetEntryInfo failed on %s", debugFileName);
goto bail;
}
uncompLen = uncompLen;
modWhen = modWhen;
crc32 = crc32;
/*
* Extract the DEX data into the cache file at the current offset.
* 从ZIP文件将目标Dex文件解压出来，并写入cacheFd所指文件，此时cacheFd所指文件非空，
* 包括一个Odex文件头部加上一个原始的Dex文件
*/
if (dexZipExtractEntryToFile(&zippy, zipEntry, cacheFd) != 0) {
ALOGW("DexOptZ: extraction of %s from %s failed",
kClassesDex, debugFileName);
goto bail;
}
/* Parse the options. */
/*
* 入口参数dexoptFlagStr，对验证优化需求进行分析，dexoptFlagStr实际上是一个字符串，
* 记录了验证优化选项
*/
if (dexoptFlagStr[0] != '\0') {
const char* opc;
const char* val;
// 设置验证模式
opc = strstr(dexoptFlagStr, "v="); /* verification */
if (opc != NULL) {
switch (*(opc+2)) {
case 'n': verifyMode = VERIFY_MODE_NONE; break;
case 'r': verifyMode = VERIFY_MODE_REMOTE; break;
case 'a': verifyMode = VERIFY_MODE_ALL; break;
default: break;
}
}
// 设置优化模式
opc = strstr(dexoptFlagStr, "o="); /* optimization */
if (opc != NULL) {
switch (*(opc+2)) {
case 'n': dexOptMode = OPTIMIZE_MODE_NONE; break;
case 'v': dexOptMode = OPTIMIZE_MODE_VERIFIED; break;
case 'a': dexOptMode = OPTIMIZE_MODE_ALL; break;
case 'f': dexOptMode = OPTIMIZE_MODE_FULL; break;
default: break;
}
}
opc = strstr(dexoptFlagStr, "m=y"); /* register map */
if (opc != NULL) {
dexoptFlags |= DEXOPT_GEN_REGISTER_MAPS;
}
opc = strstr(dexoptFlagStr, "u="); /* uniprocessor target */
if (opc != NULL) {
switch (*(opc+2)) {
case 'y': dexoptFlags |= DEXOPT_UNIPROCESSOR; break;
case 'n': dexoptFlags |= DEXOPT_SMP; break;
default: break;
}
}
}
/*
* Prep the VM and perform the optimization.
* 完成了原Dex文件的提取以及验证优化选项的设置，即可以开始真正的优化工作，需要
* 初始化一个虚拟机专门用于验证优化工作
*/
if (dvmPrepForDexOpt(bootClassPath, dexOptMode, verifyMode,
dexoptFlags) != 0)
{
ALOGE("DexOptZ: VM init failed");
goto bail;
}
//vmStarted = 1;
/* do the optimization */
if (!dvmContinueOptimization(cacheFd, dexOffset, uncompLen, debugFileName,
modWhen, crc32, isBootstrap))
{
ALOGE("Optimization failed");
goto bail;
}
/* we don't shut the VM down -- process is about to exit */
result = 0;
bail:
dexZipCloseArchive(&zippy);
return result;
}
DexCacheStatus dvmDexCacheStatus(const char *fileName)
{
ZipArchive archive;
char* cachedName = NULL;
int fd;
DexCacheStatus result = DEX_CACHE_ERROR;
ZipEntry entry;
if (dvmClassPathContains(gDvm.bootClassPath, fileName)) {
return DEX_CACHE_OK;
}
if (dexZipOpenArchive(fileName, &archive) != 0) {
return DEX_CACHE_BAD_ARCHIVE;
}
entry = dexZipFindEntry(&archive, kDexInJarName);
if (entry != NULL) {
bool newFile = false;
ALOGV("dvmDexCacheStatus: Checking cache for %s", fileName);
cachedName = dexOptGenerateCacheFileName(fileName, kDexInJarName);
if (cachedName == NULL)
return DEX_CACHE_BAD_ARCHIVE;
fd = dvmOpenCachedDexFile(fileName, cachedName,
dexGetZipEntryModTime(&archive, entry),
dexGetZipEntryCrc32(&archive, entry),
/*isBootstrap=*/false, &newFile, /*createIfMissing=*/false);
ALOGV("dvmOpenCachedDexFile returned fd %d", fd);
if (fd < 0) {
result = DEX_CACHE_STALE;
goto bail;
}
if (!dvmUnlockCachedDexFile(fd)) {
/* uh oh -- this process needs to exit or we'll wedge the system */
ALOGE("Unable to unlock DEX file");
goto bail;
}
} else {
fd = openAlternateSuffix(fileName, "odex", O_RDONLY, &cachedName);
if (fd < 0) {
ALOGI("Zip is good, but no %s inside, and no .odex "
"file in the same directory", kDexInJarName);
result = DEX_CACHE_BAD_ARCHIVE;
goto bail;
}
ALOGV("Using alternate file (odex) for %s ...", fileName);
if (!dvmCheckOptHeaderAndDependencies(fd, false, 0, 0, true, true)) {
ALOGE("%s odex has stale dependencies", fileName);
ALOGE("odex source not available -- failing");
result = DEX_CACHE_STALE_ODEX;
goto bail;
} else {
ALOGV("%s odex has good dependencies", fileName);
}
}
result = DEX_CACHE_OK;
bail:
dexZipCloseArchive(&archive);
free(cachedName);
if (fd >= 0) {
close(fd);
}
return result;
}
int dvmJarFileOpen(const char* fileName, const char* odexOutputName,
JarFile** ppJarFile, bool isBootstrap)
{
ZipArchive archive;
DvmDex* pDvmDex = NULL;
char* cachedName = NULL;
bool archiveOpen = false;
bool locked = false;
int fd = -1;
int result = -1;
if (dexZipOpenArchive(fileName, &archive) != 0)
goto bail;
archiveOpen = true;
dvmSetCloseOnExec(dexZipGetArchiveFd(&archive));
fd = openAlternateSuffix(fileName, "odex", O_RDONLY, &cachedName);
if (fd >= 0) {
ALOGV("Using alternate file (odex) for %s ...", fileName);
if (!dvmCheckOptHeaderAndDependencies(fd, false, 0, 0, true, true)) {
ALOGE("%s odex has stale dependencies", fileName);
free(cachedName);
cachedName = NULL;
close(fd);
fd = -1;
goto tryArchive;
} else {
ALOGV("%s odex has good dependencies", fileName);
}
} else {
ZipEntry entry;
tryArchive:
entry = dexZipFindEntry(&archive, kDexInJarName);
if (entry != NULL) {
bool newFile = false;
if (odexOutputName == NULL) {
cachedName = dexOptGenerateCacheFileName(fileName,
kDexInJarName);
if (cachedName == NULL)
goto bail;
} else {
cachedName = strdup(odexOutputName);
}
ALOGV("dvmJarFileOpen: Checking cache for %s (%s)",
fileName, cachedName);
fd = dvmOpenCachedDexFile(fileName, cachedName,
dexGetZipEntryModTime(&archive, entry),
dexGetZipEntryCrc32(&archive, entry),
isBootstrap, &newFile, /*createIfMissing=*/true);
if (fd < 0) {
ALOGI("Unable to open or create cache for %s (%s)",
fileName, cachedName);
goto bail;
}
locked = true;
/*
Generate the optimized DEX.
*/
if (newFile) {
u8 startWhen, extractWhen, endWhen;
bool result;
off_t dexOffset;
dexOffset = lseek(fd, 0, SEEK_CUR);
result = (dexOffset > 0);
if (result) {
startWhen = dvmGetRelativeTimeUsec();
result = dexZipExtractEntryToFile(&archive, entry, fd) == 0;
extractWhen = dvmGetRelativeTimeUsec();
}
if (result) {
result = dvmOptimizeDexFile(fd, dexOffset,
dexGetZipEntryUncompLen(&archive, entry),
fileName,
dexGetZipEntryModTime(&archive, entry),
dexGetZipEntryCrc32(&archive, entry),
isBootstrap);
}
if (!result) {
ALOGE("Unable to extract+optimize DEX from '%s'",
fileName);
goto bail;
}
endWhen = dvmGetRelativeTimeUsec();
ALOGD("DEX prep '%s': unzip in %dms, rewrite %dms",
fileName,
(int) (extractWhen - startWhen) / 1000,
(int) (endWhen - extractWhen) / 1000);
}
} else {
ALOGI("Zip is good, but no %s inside, and no valid .odex "
"file in the same directory", kDexInJarName);
goto bail;
}
}
if (dvmDexFileOpenFromFd(fd, &pDvmDex) != 0) {
ALOGI("Unable to map %s in %s", kDexInJarName, fileName);
goto bail;
}
if (locked) {
/* unlock the fd */
if (!dvmUnlockCachedDexFile(fd)) {
/* This process needs to exit or we'll wedge the system O_O */
ALOGE("Unable to unlock DEX file");
goto bail;
}
locked = false;
}
ALOGV("Successfully opened '%s' in '%s'", kDexInJarName, fileName);
*ppJarFile = (JarFile*) calloc(1, sizeof(JarFile));
(*ppJarFile)->archive = archive;
(*ppJarFile)->cacheFileName = cachedName;
(*ppJarFile)->pDvmDex = pDvmDex;
cachedName = NULL; // don't free it below
result = 0;
bail:
if (archiveOpen && result != 0)
dexZipCloseArchive(&archive);
free(cachedName);
if (fd >= 0) {
if (locked)
(void) dvmUnlockCachedDexFile(fd);
close(fd);
}
return result;
}
