content: /*
   * Copyright (C) 2015 AChep@xda <artemchep@gmail.com>
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License
   * as published by the Free Software Foundation; either version 2
   * of the License, or (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
   * MA  02110-1301, USA.
   */
  package com.achep.base.utils;
  
  import androidx.annotation.Nullable;
  import android.util.Base64;
  import android.util.Log;
  
  import java.io.ByteArrayInputStream;
  import java.io.ByteArrayOutputStream;
  import java.io.IOException;
  import java.util.zip.GZIPInputStream;
  import java.util.zip.GZIPOutputStream;
  
  import static com.achep.base.Build.DEBUG;
  
  /**
   * Created by Artem Chepurnoy on 11.04.2015.
   */
  public class GzipUtils {
  
      private static final String TAG = "GzipUtils";
  
      private static final int BUFFER_SIZE = 32;
  
      @Nullable
      public static String compress(String input) {
          byte[] bytes = null;
          ByteArrayOutputStream os = null;
          GZIPOutputStream gos = null;
          final int size = input.length();
          try {
              os = new ByteArrayOutputStream(size);
              gos = new GZIPOutputStream(os);
              gos.write(input.getBytes());
              gos.close();
          } catch (IOException e) {
              return null;
          } finally {
              try {
                  if (gos != null) gos.close();
                  if (os != null) {
                      bytes = os.toByteArray();
                      os.close();
                  }
              } catch (IOException e) {
                  e.printStackTrace();
              }
          }
  
          // Convert bytes to a string.
          assert bytes != null;
          String output = Base64.encodeToString(bytes, Base64.DEFAULT);
  
          // Print debug info.
          if (DEBUG) {
              final float rate = (float) output.length() / size;
              Log.d(TAG, "Gzip compress rate is " + Float.toString(rate));
          }
  
          return output;
      }
  
      @Nullable
      public static String decompress(String input) {
          StringBuilder sb = new StringBuilder();
          ByteArrayInputStream is = null;
          GZIPInputStream gis = null;
          try {
              final byte[] bytes = Base64.decode(input, Base64.DEFAULT);
              is = new ByteArrayInputStream(bytes);
              gis = new GZIPInputStream(is, BUFFER_SIZE);
  
              int cache;
              final byte[] data = new byte[BUFFER_SIZE];
              while ((cache = gis.read(data)) != -1) {
                  sb.append(new String(data, 0, cache));
              }
          } catch (IOException e) {
              return null;
          } finally {
              try {
                  if (gis != null) gis.close();
                  if (is != null) is.close();
              } catch (IOException e) {
                  e.printStackTrace();
              }
          }
          return sb.toString();
      }
  
  }
  