com.swoval.runtime.NativeLoader Maven / Gradle / Ivy
package com.swoval.runtime;
import com.swoval.files.FileTreeView;
import java.io.BufferedReader;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.nio.file.DirectoryNotEmptyException;
import java.nio.file.FileVisitResult;
import java.nio.file.FileVisitor;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.attribute.BasicFileAttributes;
/**
* Manages the loading of the swoval-files0 library. This library provides the native implementation
* of {@link FileTreeView}. On OSX, it also provides a native interface to the apple file system
* api. The loader will first try to load the library using System.loadLibrary, which will succeed
* if the library is present in the (DY)LD_LIBRARY_PATH. Otherwise the loader extracts the packaged
* library (.so, .dll or .dylib) to a temporary directory and loads it from there. On jvm shutdown,
* it marks the extracted library for deletion. It will generally be deleted the next time a
* different jvm loads the library.
*
* This class is not intended to be used outside of com.swoval.files, but it doesn't belong in
* that package, so it has to be public here.
*/
public class NativeLoader {
private static final String NATIVE_LIBRARY = "swoval-files0";
private static final String lib = System.mapLibraryName(NATIVE_LIBRARY);
@SuppressWarnings("EmptyCatchBlock")
private static void cleanupTask(final Path path) {
try {
Files.walkFileTree(
path,
new FileVisitor() {
@Override
public FileVisitResult preVisitDirectory(
final Path dir, final BasicFileAttributes attrs) {
return FileVisitResult.CONTINUE;
}
@Override
public FileVisitResult visitFile(final Path file, final BasicFileAttributes attrs)
throws IOException {
if (Platform.isWin()) {
try {
Files.deleteIfExists(file);
} catch (final IOException e) {
}
} else if (file.toString().endsWith(".pid")) {
final String pid = new String(Files.readAllBytes(file));
boolean pidExists = true;
if (ShutdownHooks.isShutdown()) {
pidExists = !pid.equals(ShutdownHooks.getPid());
} else {
final Process process = new ProcessBuilder("ps", "-p", pid).start();
try {
process.waitFor();
final InputStreamReader is = new InputStreamReader(process.getInputStream());
final BufferedReader reader = new BufferedReader(is);
String line = reader.readLine();
while (line != null) {
pidExists = line.contains(pid + " ");
line = reader.readLine();
}
} catch (final InterruptedException e) {
}
}
if (!pidExists) {
Files.deleteIfExists(Paths.get(file.toString().replaceAll(".pid", "")));
Files.deleteIfExists(file);
}
}
return FileVisitResult.CONTINUE;
}
@Override
public FileVisitResult visitFileFailed(Path file, IOException exc) {
return FileVisitResult.CONTINUE;
}
@Override
public FileVisitResult postVisitDirectory(Path dir, IOException exc)
throws IOException {
try {
Files.deleteIfExists(dir);
} catch (final DirectoryNotEmptyException e) {
} catch (final IOException e) {
throw e;
}
return FileVisitResult.CONTINUE;
}
});
} catch (final IOException e) {
}
}
private static void loadPackaged(final String arch) throws IOException {
final Path swoval =
Files.createDirectories(
Paths.get(
System.getProperty(
"swoval.tmpdir", System.getProperty("java.io.tmpdir", "/tmp")))
.resolve("swoval-jni"));
final String osSubDir =
System.getProperty("os.name", "").startsWith("FreeBSD") ? "/freebsd/" : "/";
final String resourcePath = "/native/" + arch + osSubDir + lib;
final InputStream resourceStream = NativeLoader.class.getResourceAsStream(resourcePath);
if (resourceStream == null) {
String msg = "Native library " + lib + " (" + resourcePath + ") can't be loaded.";
throw new UnsatisfiedLinkError(msg);
}
final Path extractedPath = Files.createTempFile(swoval, "", "-" + lib);
OutputStream out = new FileOutputStream(extractedPath.toFile());
try {
byte[] buf = new byte[1024];
int len;
while ((len = resourceStream.read(buf)) >= 0) {
out.write(buf, 0, len);
}
} catch (Exception e) {
throw new UnsatisfiedLinkError("Error while extracting native library: " + e);
} finally {
resourceStream.close();
out.close();
}
final Runnable cleanupRunnable =
new Runnable() {
@Override
public void run() {
cleanupTask(swoval);
}
};
try {
System.load(extractedPath.toString());
if (!Platform.isWin()) {
Files.write(
Paths.get(extractedPath.toString() + ".pid"), ShutdownHooks.getPid().getBytes());
ShutdownHooks.addHook(1, cleanupRunnable);
}
} catch (final UnsatisfiedLinkError e) {
Files.deleteIfExists(extractedPath);
throw e;
}
final Thread thread =
new Thread(cleanupRunnable, "com.swoval.runtime.NativeLoader.cleanupThread");
thread.setDaemon(true);
thread.start();
}
/**
* Loads the swoval-files0 shared library. It will first try to load the library from
* the system library path and fallback to extracting a platform-specific jar to a temporary
* directory.
*
* @throws IOException if the packaged native binary cannot be written to a temp directory.
* @throws UnsatisfiedLinkError if no compatible binary for the platform is present.
*/
public static void loadPackaged() throws IOException, UnsatisfiedLinkError {
try {
System.loadLibrary(NATIVE_LIBRARY);
} catch (UnsatisfiedLinkError e) {
try {
loadPackaged("x86_64");
} catch (UnsatisfiedLinkError ex) {
loadPackaged("i686");
}
}
}
}