Merge 2e150358ad into fb54d8b549

ann/src/main/java/com/twitter/ann/faiss/NativeUtils.java

@@ -7,6 +7,7 @@ import java.io.InputStream;
 import java.nio.file.Files;
 import java.nio.file.StandardCopyOption;
 import java.util.Locale;
+import java.util.Objects; 
 
 public final class NativeUtils {
 
@@ -19,7 +20,8 @@ public final class NativeUtils {
   }
 
   private static File unpackLibraryFromJarInternal(String path) throws IOException {
-    if (null == path || !path.startsWith("/")) {
+    Objects.requireNonNull(path, "The path cannot be null.");
+    if (!path.startsWith("/")) {
         throw new IllegalArgumentException("The path has to be absolute (start with '/').");
     }
 
@@ -30,12 +32,8 @@ public final class NativeUtils {
         throw new IllegalArgumentException("The filename has to be at least 3 characters long.");
     }
 
-    if (temporaryDir == null) {
-      temporaryDir = createTempDirectory(NATIVE_FOLDER_PATH_PREFIX);
-      temporaryDir.deleteOnExit();
-    }
-
-    File temp = new File(temporaryDir, filename);
+    File temp = Files.createTempFile(NATIVE_FOLDER_PATH_PREFIX, filename).toFile();
+    temp.deleteOnExit();
 
     try (InputStream is = NativeUtils.class.getResourceAsStream(path)) {
         Files.copy(is, temp.toPath(), StandardCopyOption.REPLACE_EXISTING);
@@ -48,7 +46,7 @@ public final class NativeUtils {
     }
 
     return temp;
-  }
+}
 
   /**
    * Unpack library from JAR into temporary path