content: /*
   *
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you 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 org.apache.bookkeeper.common.util.nativelib;
  
  import java.io.File;
  import java.io.FileNotFoundException;
  import java.io.FileOutputStream;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.nio.file.Files;
  import java.nio.file.Path;
  import java.util.Locale;
  import lombok.NonNull;
  import lombok.experimental.UtilityClass;
  
  /**
   * Utility class to load jni library from inside a JAR.
   */
  @UtilityClass
  public class NativeUtils {
  
      public static final String OS_NAME = System.getProperty("os.name").toLowerCase(Locale.US);
      public static final String TEMP_WORKDIR_PROPERTY_NAME = "org.apache.bookkeeper.native.workdir";
  
      private static final String TEMP_DIR_NAME = "native";
  
      /**
       * loads given library from the this jar. ie: this jar contains: /lib/pulsar-checksum.jnilib
       *
       * @param path
       *            : absolute path of the library in the jar <br/>
       *            if this jar contains: /lib/pulsar-checksum.jnilib then provide the same absolute path as input
       * @throws Exception
       */
  
      public static void loadLibraryFromJar(String path) throws Exception {
          checkArgument(path.startsWith("/"), "absolute path must start with /");
  
          String[] parts = path.split("/");
          checkArgument(parts.length > 0, "absolute path must contain file name");
  
          String filename = parts[parts.length - 1];
  
          // create the temp dir
          final Path dir;
          final String tempWorkDirName = System.getProperty(TEMP_WORKDIR_PROPERTY_NAME);
          if (tempWorkDirName == null || tempWorkDirName.isEmpty()) {
              dir = Files.createTempDirectory(TEMP_DIR_NAME);
          } else {
              final File tempWorkDir = new File(tempWorkDirName);
              if (!tempWorkDir.exists() || !tempWorkDir.isDirectory()) {
                  throw new FileNotFoundException("The tempWorkDir doesn't exist: " + tempWorkDirName);
              }
              dir = Files.createTempDirectory(tempWorkDir.toPath(), TEMP_DIR_NAME);
          }
          dir.toFile().deleteOnExit();
  
          // create the temp file
          File temp = new File(dir.toString(), filename);
          temp.deleteOnExit();
  
          byte[] buffer = new byte[1024];
          int read;
  
          try (InputStream input = NativeUtils.class.getResourceAsStream(path);
               OutputStream out = new FileOutputStream(temp)) {
              if (input == null) {
                  throw new FileNotFoundException("Couldn't find file into jar " + path);
              }
  
              while ((read = input.read(buffer)) != -1) {
                  out.write(buffer, 0, read);
              }
          }
  
          if (!temp.exists()) {
              throw new FileNotFoundException("Failed to copy file from jar at " + temp.getAbsolutePath());
          }
  
          System.load(temp.getAbsolutePath());
      }
  
      /**
       * Returns jni library extension based on OS specification. Maven-nar generates jni library based on different OS :
       * http://mark.donszelmann.org/maven-nar-plugin/aol.html (jni.extension)
       *
       * @return library type
       */
      public static String libType() {
          if (OS_NAME.indexOf("mac") >= 0) {
              return "jnilib";
          } else if (OS_NAME.indexOf("nix") >= 0 || OS_NAME.indexOf("nux") >= 0 || OS_NAME.indexOf("aix") > 0) {
              return "so";
          } else if (OS_NAME.indexOf("win") >= 0) {
              return "dll";
          }
          throw new TypeNotPresentException(OS_NAME + " not supported", null);
      }
  
      public static void checkArgument(boolean expression, @NonNull Object errorMessage) {
          if (!expression) {
              throw new IllegalArgumentException(String.valueOf(errorMessage));
          }
      }
  }
  