/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package dalvik.system;
import android.system.ErrnoException;
import android.system.StructStat;
import java.io.File;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Enumeration;
import java.util.List;
import java.util.zip.ZipEntry;
import libcore.io.IoUtils;
import libcore.io.Libcore;
import libcore.io.ClassPathURLStreamHandler;
import static android.system.OsConstants.S_ISDIR;
/**
* A pair of lists of entries, associated with a {@code ClassLoader}.
* One of the lists is a dex/resource path — typically referred
* to as a "class path" — list, and the other names directories
* containing native code libraries. Class path entries may be any of:
* a {@code .jar} or {@code .zip} file containing an optional
* top-level {@code classes.dex} file as well as arbitrary resources,
* or a plain {@code .dex} file (with no possibility of associated
* resources).
*
* <p>This class also contains methods to use these lists to look up
* classes and resources.</p>
*/
/*package*/ final class DexPathList {
private static final String DEX_SUFFIX = ".dex";
private static final String zipSeparator = "!/";
/** class definition context */
private final ClassLoader definingContext;
/**
* List of dex/resource (class path) elements.
* Should be called pathElements, but the Facebook app uses reflection
* to modify 'dexElements' (http://b/7726934).
*/
private Element[] dexElements;
/** List of native library path elements. */
private final Element[] nativeLibraryPathElements;
/** List of application native library directories. */
private final List<File> nativeLibraryDirectories;
/** List of system native library directories. */
private final List<File> systemNativeLibraryDirectories;
/**
* Exceptions thrown during creation of the dexElements list.
*/
private IOException[] dexElementsSuppressedExceptions;
/**
* Constructs an instance.
*
* @param definingContext the context in which any as-yet unresolved
* classes should be defined
* @param dexPath list of dex/resource path elements, separated by
* {@code File.pathSeparator}
* @param librarySearchPath list of native library directory path elements,
* separated by {@code File.pathSeparator}
* @param libraryPermittedPath is path containing permitted directories for
* linker isolated namespaces (in addition to librarySearchPath which is allowed
* implicitly). Note that this path does not affect the search order for the library
* and intended for white-listing additional paths when loading native libraries
* by absolute path.
* @param optimizedDirectory directory where optimized {@code .dex} files
* should be found and written to, or {@code null} to use the default
* system directory for same
*/
public DexPathList(ClassLoader definingContext, String dexPath,
String librarySearchPath, File optimizedDirectory) {
if (definingContext == null) {
throw new NullPointerException("definingContext == null");
}
if (dexPath == null) {
throw new NullPointerException("dexPath == null");
}
if (optimizedDirectory != null) {
if (!optimizedDirectory.exists()) {
throw new IllegalArgumentException(
"optimizedDirectory doesn't exist: "
+ optimizedDirectory);
}
if (!(optimizedDirectory.canRead()
&& optimizedDirectory.canWrite())) {
throw new IllegalArgumentException(
"optimizedDirectory not readable/writable: "
+ optimizedDirectory);
}
}
this.definingContext = definingContext;
ArrayList<IOException> suppressedExceptions = new ArrayList<IOException>();
// save dexPath for BaseDexClassLoader
this.dexElements = makeDexElements(splitDexPath(dexPath), optimizedDirectory,
suppressedExceptions, definingContext);
// Native libraries may exist in both the system and
// application library paths, and we use this search order:
//
// 1. This class loader's library path for application libraries (librarySearchPath):
// 1.1. Native library directories
// 1.2. Path to libraries in apk-files
// 2. The VM's library path from the system property for system libraries
// also known as java.library.path
//
// This order was reversed prior to Gingerbread; see http://b/2933456.
this.nativeLibraryDirectories = splitPaths(librarySearchPath, false);
this.systemNativeLibraryDirectories =
splitPaths(System.getProperty("java.library.path"), true);
List<File> allNativeLibraryDirectories = new ArrayList<>(nativeLibraryDirectories);
allNativeLibraryDirectories.addAll(systemNativeLibraryDirectories);
this.nativeLibraryPathElements = makePathElements(allNativeLibraryDirectories,
suppressedExceptions,
definingContext);
if (suppressedExceptions.size() > 0) {
this.dexElementsSuppressedExceptions =
suppressedExceptions.toArray(new IOException[suppressedExceptions.size()]);
} else {
dexElementsSuppressedExceptions = null;
}
}
@Override public String toString() {
List<File> allNativeLibraryDirectories = new ArrayList<>(nativeLibraryDirectories);
allNativeLibraryDirectories.addAll(systemNativeLibraryDirectories);
File[] nativeLibraryDirectoriesArray =
allNativeLibraryDirectories.toArray(
new File[allNativeLibraryDirectories.size()]);
return "DexPathList[" + Arrays.toString(dexElements) +
",nativeLibraryDirectories=" + Arrays.toString(nativeLibraryDirectoriesArray) + "]";
}
/**
* For BaseDexClassLoader.getLdLibraryPath.
*/
public List<File> getNativeLibraryDirectories() {
return nativeLibraryDirectories;
}
/**
* Adds a new path to this instance
* @param dexPath list of dex/resource path element, separated by
* {@code File.pathSeparator}
* @param optimizedDirectory directory where optimized {@code .dex} files
* should be found and written to, or {@code null} to use the default
* system directory for same
*/
public void addDexPath(String dexPath, File optimizedDirectory) {
final List<IOException> suppressedExceptionList = new ArrayList<IOException>();
final Element[] newElements = makeDexElements(splitDexPath(dexPath), optimizedDirectory,
suppressedExceptionList, definingContext);
if (newElements != null && newElements.length > 0) {
final Element[] oldElements = dexElements;
dexElements = new Element[oldElements.length + newElements.length];
System.arraycopy(
oldElements, 0, dexElements, 0, oldElements.length);
System.arraycopy(
newElements, 0, dexElements, oldElements.length, newElements.length);
}
if (suppressedExceptionList.size() > 0) {
final IOException[] newSuppressedExceptions = suppressedExceptionList.toArray(
new IOException[suppressedExceptionList.size()]);
if (dexElementsSuppressedExceptions != null) {
final IOException[] oldSuppressedExceptions = dexElementsSuppressedExceptions;
final int suppressedExceptionsLength = oldSuppressedExceptions.length +
newSuppressedExceptions.length;
dexElementsSuppressedExceptions = new IOException[suppressedExceptionsLength];
System.arraycopy(oldSuppressedExceptions, 0, dexElementsSuppressedExceptions,
0, oldSuppressedExceptions.length);
System.arraycopy(newSuppressedExceptions, 0, dexElementsSuppressedExceptions,
oldSuppressedExceptions.length, newSuppressedExceptions.length);
} else {
dexElementsSuppressedExceptions = newSuppressedExceptions;
}
}
}
/**
* Splits the given dex path string into elements using the path
* separator, pruning out any elements that do not refer to existing
* and readable files.
*/
private static List<File> splitDexPath(String path) {
return splitPaths(path, false);
}
/**
* Splits the given path strings into file elements using the path
* separator, combining the results and filtering out elements
* that don't exist, aren't readable, or aren't either a regular
* file or a directory (as specified). Either string may be empty
* or {@code null}, in which case it is ignored. If both strings
* are empty or {@code null}, or all elements get pruned out, then
* this returns a zero-element list.
*/
private static List<File> splitPaths(String searchPath, boolean directoriesOnly) {
List<File> result = new ArrayList<>();
if (searchPath != null) {
for (String path : searchPath.split(File.pathSeparator)) {
if (directoriesOnly) {
try {
StructStat sb = Libcore.os.stat(path);
if (!S_ISDIR(sb.st_mode)) {
continue;
}
} catch (ErrnoException ignored) {
continue;
}
}
result.add(new File(path));
}
}
return result;
}
/**
* Makes an array of dex/resource path elements, one per element of
* the given array.
*/
private static Element[] makeDexElements(List<File> files, File optimizedDirectory,
List<IOException> suppressedExceptions,
ClassLoader loader) {
return makeElements(files, optimizedDirectory, suppressedExceptions, false, loader);
}
/**
* Makes an array of directory/zip path elements, one per element of the given array.
*/
private static Element[] makePathElements(List<File> files,
List<IOException> suppressedExceptions,
ClassLoader loader) {
return makeElements(files, null, suppressedExceptions, true, loader);
}
/*
* TODO (dimitry): Revert after apps stops relying on the existence of this
* method (see http://b/21957414 and http://b/26317852 for details)
*/
private static Element[] makePathElements(List<File> files, File optimizedDirectory,
List<IOException> suppressedExceptions) {
return makeElements(files, optimizedDirectory, suppressedExceptions, false, null);
}
private static Element[] makeElements(List<File> files, File optimizedDirectory,
List<IOException> suppressedExceptions,
boolean ignoreDexFiles,
ClassLoader loader) {
Element[] elements = new Element[files.size()];
int elementsPos = 0;
/*
* Open all files and load the (direct or contained) dex files
* up front.
*/
for (File file : files) {
File zip = null;
File dir = new File("");
DexFile dex = null;
String path = file.getPath();
String name = file.getName();
if (path.contains(zipSeparator)) {
String split[] = path.split(zipSeparator, 2);
zip = new File(split[0]);
dir = new File(split[1]);
} else if (file.isDirectory()) {
// We support directories for looking up resources and native libraries.
// Looking up resources in directories is useful for running libcore tests.
elements[elementsPos++] = new Element(file, true, null, null);
} else if (file.isFile()) {
if (!ignoreDexFiles && name.endsWith(DEX_SUFFIX)) {
// Raw dex file (not inside a zip/jar).
try {
dex = loadDexFile(file, optimizedDirectory, loader, elements);
} catch (IOException suppressed) {
System.logE("Unable to load dex file: " + file, suppressed);
suppressedExceptions.add(suppressed);
}
} else {
zip = file;
if (!ignoreDexFiles) {
try {
dex = loadDexFile(file, optimizedDirectory, loader, elements);
} catch (IOException suppressed) {
/*
* IOException might get thrown "legitimately" by the DexFile constructor if
* the zip file turns out to be resource-only (that is, no classes.dex file
* in it).
* Let dex == null and hang on to the exception to add to the tea-leaves for
* when findClass returns null.
*/
suppressedExceptions.add(suppressed);
}
}
}
} else {
System.logW("ClassLoader referenced unknown path: " + file);
}
if ((zip != null) || (dex != null)) {
elements[elementsPos++] = new Element(dir, false, zip, dex);
}
}
if (elementsPos != elements.length) {
elements = Arrays.copyOf(elements, elementsPos);
}
return elements;
}
/**
* Constructs a {@code DexFile} instance, as appropriate depending on whether
* {@code optimizedDirectory} is {@code null}. An application image file may be associated with
* the {@code loader} if it is not null.
*/
private static DexFile loadDexFile(File file, File optimizedDirectory, ClassLoader loader,
Element[] elements)
throws IOException {
if (optimizedDirectory == null) {
return new DexFile(file, loader, elements);
} else {
String optimizedPath = optimizedPathFor(file, optimizedDirectory);
return DexFile.loadDex(file.getPath(), optimizedPath, 0, loader, elements);
}
}
/**
* Converts a dex/jar file path and an output directory to an
* output file path for an associated optimized dex file.
*/
private static String optimizedPathFor(File path,
File optimizedDirectory) {
/*
* Get the filename component of the path, and replace the
* suffix with ".dex" if that's not already the suffix.
*
* We don't want to use ".odex", because the build system uses
* that for files that are paired with resource-only jar
* files. If the VM can assume that there's no classes.dex in
* the matching jar, it doesn't need to open the jar to check
* for updated dependencies, providing a slight performance
* boost at startup. The use of ".dex" here matches the use on
* files in /data/dalvik-cache.
*/
String fileName = path.getName();
if (!fileName.endsWith(DEX_SUFFIX)) {
int lastDot = fileName.lastIndexOf(".");
if (lastDot < 0) {
fileName += DEX_SUFFIX;
} else {
StringBuilder sb = new StringBuilder(lastDot + 4);
sb.append(fileName, 0, lastDot);
sb.append(DEX_SUFFIX);
fileName = sb.toString();
}
}
File result = new File(optimizedDirectory, fileName);
return result.getPath();
}
/**
* Finds the named class in one of the dex files pointed at by
* this instance. This will find the one in the earliest listed
* path element. If the class is found but has not yet been
* defined, then this method will define it in the defining
* context that this instance was constructed with.
*
* @param name of class to find
* @param suppressed exceptions encountered whilst finding the class
* @return the named class or {@code null} if the class is not
* found in any of the dex files
*/
public Class findClass(String name, List<Throwable> suppressed) {
for (Element element : dexElements) {
DexFile dex = element.dexFile;
if (dex != null) {
Class clazz = dex.loadClassBinaryName(name, definingContext, suppressed);
if (clazz != null) {
return clazz;
}
}
}
if (dexElementsSuppressedExceptions != null) {
suppressed.addAll(Arrays.asList(dexElementsSuppressedExceptions));
}
return null;
}
/**
* Finds the named resource in one of the zip/jar files pointed at
* by this instance. This will find the one in the earliest listed
* path element.
*
* @return a URL to the named resource or {@code null} if the
* resource is not found in any of the zip/jar files
*/
public URL findResource(String name) {
for (Element element : dexElements) {
URL url = element.findResource(name);
if (url != null) {
return url;
}
}
return null;
}
/**
* Finds all the resources with the given name, returning an
* enumeration of them. If there are no resources with the given
* name, then this method returns an empty enumeration.
*/
public Enumeration<URL> findResources(String name) {
ArrayList<URL> result = new ArrayList<URL>();
for (Element element : dexElements) {
URL url = element.findResource(name);
if (url != null) {
result.add(url);
}
}
return Collections.enumeration(result);
}
/**
* Finds the named native code library on any of the library
* directories pointed at by this instance. This will find the
* one in the earliest listed directory, ignoring any that are not
* readable regular files.
*
* @return the complete path to the library or {@code null} if no
* library was found
*/
public String findLibrary(String libraryName) {
String fileName = System.mapLibraryName(libraryName);
for (Element element : nativeLibraryPathElements) {
String path = element.findNativeLibrary(fileName);
if (path != null) {
return path;
}
}
return null;
}
/**
* Element of the dex/resource/native library path
*/
/*package*/ static class Element {
private final File dir;
private final boolean isDirectory;
private final File zip;
private final DexFile dexFile;
private ClassPathURLStreamHandler urlHandler;
private boolean initialized;
public Element(File dir, boolean isDirectory, File zip, DexFile dexFile) {
this.dir = dir;
this.isDirectory = isDirectory;
this.zip = zip;
this.dexFile = dexFile;
}
@Override public String toString() {
if (isDirectory) {
return "directory \"" + dir + "\"";
} else if (zip != null) {
return "zip file \"" + zip + "\"" +
(dir != null && !dir.getPath().isEmpty() ? ", dir \"" + dir + "\"" : "");
} else {
return "dex file \"" + dexFile + "\"";
}
}
public synchronized void maybeInit() {
if (initialized) {
return;
}
initialized = true;
if (isDirectory || zip == null) {
return;
}
try {
urlHandler = new ClassPathURLStreamHandler(zip.getPath());
} catch (IOException ioe) {
/*
* Note: ZipException (a subclass of IOException)
* might get thrown by the ZipFile constructor
* (e.g. if the file isn't actually a zip/jar
* file).
*/
System.logE("Unable to open zip file: " + zip, ioe);
urlHandler = null;
}
}
public String findNativeLibrary(String name) {
maybeInit();
if (isDirectory) {
String path = new File(dir, name).getPath();
if (IoUtils.canOpenReadOnly(path)) {
return path;
}
} else if (urlHandler != null) {
// Having a urlHandler means the element has a zip file.
// In this case Android supports loading the library iff
// it is stored in the zip uncompressed.
String entryName = new File(dir, name).getPath();
if (urlHandler.isEntryStored(entryName)) {
return zip.getPath() + zipSeparator + entryName;
}
}
return null;
}
public URL findResource(String name) {
maybeInit();
// We support directories so we can run tests and/or legacy code
// that uses Class.getResource.
if (isDirectory) {
File resourceFile = new File(dir, name);
if (resourceFile.exists()) {
try {
return resourceFile.toURI().toURL();
} catch (MalformedURLException ex) {
throw new RuntimeException(ex);
}
}
}
if (urlHandler == null) {
/* This element has no zip/jar file.
*/
return null;
}
return urlHandler.getEntryUrlOrNull(name);
}
}
}