/*
* private static int openDexFile(String sourceName, String outputName,
* int flags) throws IOException
*
* Open a DEX file, returning a pointer to our internal data structure.
*
* "sourceName" should point to the "source" jar or DEX file.
*
* If "outputName" is NULL, the DEX code will automatically find the
* "optimized" version in the cache directory, creating it if necessary.
* If it's non-NULL, the specified file will be used instead.
*
* TODO: at present we will happily open the same file more than once.
* To optimize this away we could search for existing entries in the hash
* table and refCount them. Requires atomic ops or adding "synchronized"
* to the non-native code that calls here.
*/
static void Dalvik_dalvik_system_DexFile_openDexFile(const u4* args,
JValue* pResult)
{
StringObject* sourceNameObj = (StringObject*) args[0];
StringObject* outputNameObj = (StringObject*) args[1];
int flags = args[2];
DexOrJar* pDexOrJar = NULL;
JarFile* pJarFile;
RawDexFile* pRawDexFile;
char* sourceName;
char* outputName;
if (sourceNameObj == NULL) {
dvmThrowException("Ljava/lang/NullPointerException;", NULL);
RETURN_VOID();
}
sourceName = dvmCreateCstrFromString(sourceNameObj);
if (outputNameObj != NULL)
outputName = dvmCreateCstrFromString(outputNameObj);
else
outputName = NULL;
/*
* We have to deal with the possibility that somebody might try to
* open one of our bootstrap class DEX files. The set of dependencies
* will be different, and hence the results of optimization might be
* different, which means we'd actually need to have two versions of
* the optimized DEX: one that only knows about part of the boot class
* path, and one that knows about everything in it. The latter might
* optimize field/method accesses based on a class that appeared later
* in the class path.
*
* We can't let the user-defined class loader open it and start using
* the classes, since the optimized form of the code skips some of
* the method and field resolution that we would ordinarily do, and
* we'd have the wrong semantics.
*
* We have to reject attempts to manually open a DEX file from the boot
* class path. The easiest way to do this is by filename, which works
* out because variations in name (e.g. "/system/framework/./ext.jar")
* result in us hitting a different dalvik-cache entry. It's also fine
* if the caller specifies their own output file.
*/
if (dvmClassPathContains(gDvm.bootClassPath, sourceName)) {
LOGW("Refusing to reopen boot DEX '%s'\n", sourceName);
dvmThrowException("Ljava/io/IOException;",
"Re-opening BOOTCLASSPATH DEX files is not allowed");
free(sourceName);
RETURN_VOID();
}
/*
* Try to open it directly as a DEX. If that fails, try it as a Zip
* with a "classes.dex" inside.
*/
if (dvmRawDexFileOpen(sourceName, outputName, &pRawDexFile, false) == 0) {
LOGV("Opening DEX file '%s' (DEX)\n", sourceName);
pDexOrJar = (DexOrJar*) malloc(sizeof(DexOrJar));
pDexOrJar->isDex = true;
pDexOrJar->pRawDexFile = pRawDexFile;
} else if (dvmJarFileOpen(sourceName, outputName, &pJarFile, false) == 0) {
LOGV("Opening DEX file '%s' (Jar)\n", sourceName);
pDexOrJar = (DexOrJar*) malloc(sizeof(DexOrJar));
pDexOrJar->isDex = false;
pDexOrJar->pJarFile = pJarFile;
} else {
LOGV("Unable to open DEX file '%s'\n", sourceName);
dvmThrowException("Ljava/io/IOException;", "unable to open DEX file");
}
if (pDexOrJar != NULL) {
pDexOrJar->fileName = sourceName;
/* add to hash table */
u4 hash = dvmComputeUtf8Hash(sourceName);
void* result;
dvmHashTableLock(gDvm.userDexFiles);
result = dvmHashTableLookup(gDvm.userDexFiles, hash, pDexOrJar,
hashcmpDexOrJar, true);
dvmHashTableUnlock(gDvm.userDexFiles);
if (result != pDexOrJar) {
LOGE("Pointer has already been added?\n");
dvmAbort();
}
pDexOrJar->okayToFree = true;
} else
free(sourceName);
RETURN_PTR(pDexOrJar);
}
/*
* private static int openDexFile(String sourceName, String outputName,
* int flags) throws IOException
*
* Open a DEX file, returning a pointer to our internal data structure.
* 打开一个DEX文件,返回一个指向我们内部数据结构体
* "sourceName" should point to the "source" jar or DEX file.
* 'sourceName'应该是指jar或dex文件
*
* If "outputName" is NULL, the DEX code will automatically find the
* "optimized" version in the cache directory, creating it if necessary.
* If it's non-NULL, the specified file will be used instead.
*
* TODO: at present we will happily open the same file more than once.
* To optimize this away we could search for existing entries in the hash
* table and refCount them. Requires atomic ops or adding "synchronized"
* to the non-native code that calls here.
*
* TODO: should be using "long" for a pointer.
*/
static void Dalvik_dalvik_system_DexFile_openDexFile(const u4* args,
JValue* pResult)
{
StringObject* sourceNameObj = (StringObject*) args[0];
StringObject* outputNameObj = (StringObject*) args[1];
DexOrJar* pDexOrJar = NULL;
JarFile* pJarFile;
RawDexFile* pRawDexFile;
char* sourceName;
char* outputName;
if (sourceNameObj == NULL) {
dvmThrowNullPointerException("sourceName == null");
RETURN_VOID();
}
/*转换java数据类型成为c数据类型*/
sourceName = dvmCreateCstrFromString(sourceNameObj);
if (outputNameObj != NULL)
outputName = dvmCreateCstrFromString(outputNameObj);
else
outputName = NULL;
/*
* We have to deal with the possibility that somebody might try to
* open one of our bootstrap class DEX files. The set of dependencies
* will be different, and hence the results of optimization might be
* different, which means we'd actually need to have two versions of
* the optimized DEX: one that only knows about part of the boot class
* path, and one that knows about everything in it. The latter might
* optimize field/method accesses based on a class that appeared later
* in the class path.
*
* We can't let the user-defined class loader open it and start using
* the classes, since the optimized form of the code skips some of
* the method and field resolution that we would ordinarily do, and
* we'd have the wrong semantics.
*
* We have to reject attempts to manually open a DEX file from the boot
* class path. The easiest way to do this is by filename, which works
* out because variations in name (e.g. "/system/framework/./ext.jar")
* result in us hitting a different dalvik-cache entry. It's also fine
* if the caller specifies their own output file.
*/
if (dvmClassPathContains(gDvm.bootClassPath, sourceName)) {
ALOGW("Refusing to reopen boot DEX '%s'", sourceName);
dvmThrowIOException(
"Re-opening BOOTCLASSPATH DEX files is not allowed");
free(sourceName);
free(outputName);
RETURN_VOID();
}
/*
* Try to open it directly as a DEX if the name ends with ".dex".
* If that fails (or isn't tried in the first place), try it as a
* Zip with a "classes.dex" inside.
*/
/*判断扩展后缀名.eg .dex或.jar*/
if (hasDexExtension(sourceName)
&& dvmRawDexFileOpen(sourceName, outputName, &pRawDexFile, false) == 0) {
ALOGV("Opening DEX file '%s' (DEX)", sourceName);
pDexOrJar = (DexOrJar*) malloc(sizeof(DexOrJar));
pDexOrJar->isDex = true;
pDexOrJar->pRawDexFile = pRawDexFile;
pDexOrJar->pDexMemory = NULL;
} else if (dvmJarFileOpen(sourceName, outputName, &pJarFile, false) == 0) {
ALOGV("Opening DEX file '%s' (Jar)", sourceName);
pDexOrJar = (DexOrJar*) malloc(sizeof(DexOrJar));
pDexOrJar->isDex = false;
pDexOrJar->pJarFile = pJarFile;
pDexOrJar->pDexMemory = NULL;
} else {
ALOGV("Unable to open DEX file '%s'", sourceName);
dvmThrowIOException("unable to open DEX file");
}
if (pDexOrJar != NULL) {
pDexOrJar->fileName = sourceName;
addToDexFileTable(pDexOrJar);
} else {
free(sourceName);
}
RETURN_PTR(pDexOrJar);
}
