content: /*
   * Copyright (C) 2016 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 com.google.android.exoplayer2.util;
  
  /**
   * Configurable loader for native libraries.
   */
  public final class LibraryLoader {
  
    private String[] nativeLibraries;
    private boolean loadAttempted;
    private boolean isAvailable;
  
    /**
     * @param libraries The names of the libraries to load.
     */
    public LibraryLoader(String... libraries) {
      nativeLibraries = libraries;
    }
  
    /**
     * Overrides the names of the libraries to load. Must be called before any call to
     * {@link #isAvailable()}.
     */
    public synchronized void setLibraries(String... libraries) {
      Assertions.checkState(!loadAttempted, "Cannot set libraries after loading");
      nativeLibraries = libraries;
    }
  
    /**
     * Returns whether the underlying libraries are available, loading them if necessary.
     */
    public synchronized boolean isAvailable() {
      if (loadAttempted) {
        return isAvailable;
      }
      loadAttempted = true;
      try {
        for (String lib : nativeLibraries) {
          System.loadLibrary(lib);
        }
        isAvailable = true;
      } catch (UnsatisfiedLinkError exception) {
        // Do nothing.
      }
      return isAvailable;
    }
  
  }
  