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.upstream;
  
  import static com.google.android.exoplayer2.util.Util.castNonNull;
  import static java.lang.Math.min;
  
  import android.net.Uri;
  import android.system.ErrnoException;
  import android.system.OsConstants;
  import android.text.TextUtils;
  import androidx.annotation.DoNotInline;
  import androidx.annotation.Nullable;
  import androidx.annotation.RequiresApi;
  import com.google.android.exoplayer2.C;
  import com.google.android.exoplayer2.PlaybackException;
  import com.google.android.exoplayer2.util.Assertions;
  import com.google.android.exoplayer2.util.Util;
  import com.google.errorprone.annotations.CanIgnoreReturnValue;
  import java.io.FileNotFoundException;
  import java.io.IOException;
  import java.io.RandomAccessFile;
  
  /** A {@link DataSource} for reading local files. */
  public final class FileDataSource extends BaseDataSource {
  
    /** Thrown when a {@link FileDataSource} encounters an error reading a file. */
    public static class FileDataSourceException extends DataSourceException {
  
      /**
       * @deprecated Use {@link #FileDataSourceException(Throwable, int)}
       */
      @Deprecated
      public FileDataSourceException(Exception cause) {
        super(cause, PlaybackException.ERROR_CODE_IO_UNSPECIFIED);
      }
  
      /**
       * @deprecated Use {@link #FileDataSourceException(String, Throwable, int)}
       */
      @Deprecated
      public FileDataSourceException(String message, IOException cause) {
        super(message, cause, PlaybackException.ERROR_CODE_IO_UNSPECIFIED);
      }
  
      /** Creates a {@code FileDataSourceException}. */
      public FileDataSourceException(Throwable cause, @PlaybackException.ErrorCode int errorCode) {
        super(cause, errorCode);
      }
  
      /** Creates a {@code FileDataSourceException}. */
      public FileDataSourceException(
          @Nullable String message,
          @Nullable Throwable cause,
          @PlaybackException.ErrorCode int errorCode) {
        super(message, cause, errorCode);
      }
    }
  
    /** {@link DataSource.Factory} for {@link FileDataSource} instances. */
    public static final class Factory implements DataSource.Factory {
  
      @Nullable private TransferListener listener;
  
      /**
       * Sets a {@link TransferListener} for {@link FileDataSource} instances created by this factory.
       *
       * @param listener The {@link TransferListener}.
       * @return This factory.
       */
      @CanIgnoreReturnValue
      public Factory setListener(@Nullable TransferListener listener) {
        this.listener = listener;
        return this;
      }
  
      @Override
      public FileDataSource createDataSource() {
        FileDataSource dataSource = new FileDataSource();
        if (listener != null) {
          dataSource.addTransferListener(listener);
        }
        return dataSource;
      }
    }
  
    @Nullable private RandomAccessFile file;
    @Nullable private Uri uri;
    private long bytesRemaining;
    private boolean opened;
  
    public FileDataSource() {
      super(/* isNetwork= */ false);
    }
  
    @Override
    public long open(DataSpec dataSpec) throws FileDataSourceException {
      Uri uri = dataSpec.uri;
      this.uri = uri;
      transferInitializing(dataSpec);
      this.file = openLocalFile(uri);
      try {
        file.seek(dataSpec.position);
        bytesRemaining =
            dataSpec.length == C.LENGTH_UNSET ? file.length() - dataSpec.position : dataSpec.length;
      } catch (IOException e) {
        throw new FileDataSourceException(e, PlaybackException.ERROR_CODE_IO_UNSPECIFIED);
      }
      if (bytesRemaining < 0) {
        throw new FileDataSourceException(
            /* message= */ null,
            /* cause= */ null,
            PlaybackException.ERROR_CODE_IO_READ_POSITION_OUT_OF_RANGE);
      }
  
      opened = true;
      transferStarted(dataSpec);
  
      return bytesRemaining;
    }
  
    @Override
    public int read(byte[] buffer, int offset, int length) throws FileDataSourceException {
      if (length == 0) {
        return 0;
      } else if (bytesRemaining == 0) {
        return C.RESULT_END_OF_INPUT;
      } else {
        int bytesRead;
        try {
          bytesRead = castNonNull(file).read(buffer, offset, (int) min(bytesRemaining, length));
        } catch (IOException e) {
          throw new FileDataSourceException(e, PlaybackException.ERROR_CODE_IO_UNSPECIFIED);
        }
  
        if (bytesRead > 0) {
          bytesRemaining -= bytesRead;
          bytesTransferred(bytesRead);
        }
  
        return bytesRead;
      }
    }
  
    @Override
    @Nullable
    public Uri getUri() {
      return uri;
    }
  
    @Override
    public void close() throws FileDataSourceException {
      uri = null;
      try {
        if (file != null) {
          file.close();
        }
      } catch (IOException e) {
        throw new FileDataSourceException(e, PlaybackException.ERROR_CODE_IO_UNSPECIFIED);
      } finally {
        file = null;
        if (opened) {
          opened = false;
          transferEnded();
        }
      }
    }
  
    private static RandomAccessFile openLocalFile(Uri uri) throws FileDataSourceException {
      try {
        return new RandomAccessFile(Assertions.checkNotNull(uri.getPath()), "r");
      } catch (FileNotFoundException e) {
        if (!TextUtils.isEmpty(uri.getQuery()) || !TextUtils.isEmpty(uri.getFragment())) {
          throw new FileDataSourceException(
              String.format(
                  "uri has query and/or fragment, which are not supported. Did you call Uri.parse()"
                      + " on a string containing '?' or '#'? Use Uri.fromFile(new File(path)) to"
                      + " avoid this. path=%s,query=%s,fragment=%s",
                  uri.getPath(), uri.getQuery(), uri.getFragment()),
              e,
              PlaybackException.ERROR_CODE_FAILED_RUNTIME_CHECK);
        }
  
        // TODO(internal b/193503588): Add tests to ensure the correct error codes are assigned under
        // different SDK versions.
        throw new FileDataSourceException(
            e,
            Util.SDK_INT >= 21 && Api21.isPermissionError(e.getCause())
                ? PlaybackException.ERROR_CODE_IO_NO_PERMISSION
                : PlaybackException.ERROR_CODE_IO_FILE_NOT_FOUND);
      } catch (SecurityException e) {
        throw new FileDataSourceException(e, PlaybackException.ERROR_CODE_IO_NO_PERMISSION);
      } catch (RuntimeException e) {
        throw new FileDataSourceException(e, PlaybackException.ERROR_CODE_IO_UNSPECIFIED);
      }
    }
  
    @RequiresApi(21)
    private static final class Api21 {
      @DoNotInline
      private static boolean isPermissionError(@Nullable Throwable e) {
        return e instanceof ErrnoException && ((ErrnoException) e).errno == OsConstants.EACCES;
      }
    }
  }
  