net.jpountz.util.Native Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of lz4 Show documentation
Java ports and bindings of the LZ4 compression algorithm and the xxHash hashing algorithm
There is a newer version: 1.3.0
package net.jpountz.util;

/*
 * 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.
 */

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;

/** FOR INTERNAL USE ONLY */
public enum Native {
  ;

  private enum OS {
    // Even on Windows, the default compiler from cpptasks (gcc) uses .so as a shared lib extension
    WINDOWS("win32", "so"), LINUX("linux", "so"), MAC("darwin", "dylib"), SOLARIS("solaris", "so");
    public final String name, libExtension;

    private OS(String name, String libExtension) {
      this.name = name;
      this.libExtension = libExtension;
    }
  }

  private static String arch() {
    return System.getProperty("os.arch");
  }

  private static OS os() {
    String osName = System.getProperty("os.name");
    if (osName.contains("Linux")) {
      return OS.LINUX;
    } else if (osName.contains("Mac")) {
      return OS.MAC;
    } else if (osName.contains("Windows")) {
      return OS.WINDOWS;
    } else if (osName.contains("Solaris") || osName.contains("SunOS")) {
      return OS.SOLARIS;
    } else {
      throw new UnsupportedOperationException("Unsupported operating system: "
          + osName);
    }
  }

  private static String resourceName() {
    OS os = os();
    return "/" + os.name + "/" + arch() + "/liblz4-java." + os.libExtension;
  }

  private static boolean loaded = false;

  public static synchronized boolean isLoaded() {
    return loaded;
  }

  public static synchronized void load() {
    if (loaded) {
      return;
    }
    String resourceName = resourceName();
    InputStream is = Native.class.getResourceAsStream(resourceName);
    if (is == null) {
      throw new UnsupportedOperationException("Unsupported OS/arch, cannot find " + resourceName + ". Please try building from source.");
    }
    File tempLib;
    try {
      tempLib = File.createTempFile("liblz4-java", "." + os().libExtension);
      // copy to tempLib
      FileOutputStream out = new FileOutputStream(tempLib);
      try {
        byte[] buf = new byte[4096];
        while (true) {
          int read = is.read(buf);
          if (read == -1) {
            break;
          }
          out.write(buf, 0, read);
        }
        try {
          out.close();
          out = null;
        } catch (IOException e) {
          // ignore
        }
        System.load(tempLib.getAbsolutePath());
        loaded = true;
      } finally {
        try {
          if (out != null) {
            out.close();
          }
        } catch (IOException e) {
          // ignore
        }
        if (tempLib != null && tempLib.exists()) {
          if (!loaded) {
            tempLib.delete();
          } else {
            // try to delete on exit, does it work on Windows?
            tempLib.deleteOnExit();
          }
        }
      }
    } catch (IOException e) {
        throw new ExceptionInInitializerError("Cannot unpack liblz4-java");
    }
  }

}