content: /*
   * Copyright (C) 2025 AlexMofer
   *
   * 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 io.github.alexmofer.android.support.io;
  
  import androidx.annotation.NonNull;
  import androidx.annotation.Nullable;
  
  import java.io.FilterInputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.util.function.LongConsumer;
  
  /**
   * InputStream 读取计数.
   * Created by Alex on 2025/7/7.
   *
   * @since 1.12.0
   */
  public final class CountingInputStream extends FilterInputStream {
  
      private final LongConsumer progress;
      private long count;
      private long mark = -1;
  
      public CountingInputStream(@NonNull InputStream in, @Nullable LongConsumer progress) {
          super(in);
          this.progress = progress;
      }
  
      /**
       * 获取总数
       * @return 总数
       */
      public long getCount() {
          return count;
      }
  
      @Override
      public int read() throws IOException {
          int result = in.read();
          if (result != -1) {
              count++;
          }
          notifyProgress();
          return result;
      }
  
      @Override
      public int read(byte[] b, int off, int len) throws IOException {
          int result = in.read(b, off, len);
          if (result != -1) {
              count += result;
          }
          notifyProgress();
          return result;
      }
  
      @Override
      public long skip(long n) throws IOException {
          long result = in.skip(n);
          count += result;
          notifyProgress();
          return result;
      }
  
      @Override
      public synchronized void mark(int readlimit) {
          in.mark(readlimit);
          mark = count;
      }
  
      @Override
      public synchronized void reset() throws IOException {
          if (!in.markSupported()) {
              throw new IOException("Mark not supported");
          }
          if (mark == -1) {
              throw new IOException("Mark not set");
          }
          in.reset();
          count = mark;
          notifyProgress();
      }
  
      private void notifyProgress() {
          if (progress != null) {
              progress.accept(count);
          }
      }
  }
  