content: /*
   * Copyright (C) 2012 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 android.drm;
  
  import static android.drm.DrmConvertedStatus.STATUS_OK;
  import static android.drm.DrmManagerClient.INVALID_SESSION;
  import static android.system.OsConstants.SEEK_SET;
  
  import android.os.ParcelFileDescriptor;
  import android.system.ErrnoException;
  import android.system.Os;
  import android.util.Log;
  
  import libcore.io.IoBridge;
  import libcore.io.Streams;
  import libcore.util.ArrayUtils;
  
  import java.io.FileDescriptor;
  import java.io.FilterOutputStream;
  import java.io.IOException;
  import java.io.OutputStream;
  import java.net.UnknownServiceException;
  
  /**
   * Stream that applies a {@link DrmManagerClient} transformation to data before
   * writing to disk, similar to a {@link FilterOutputStream}.
   *
   * @hide
   */
  public class DrmOutputStream extends OutputStream {
      private static final String TAG = "DrmOutputStream";
  
      private final DrmManagerClient mClient;
      private final ParcelFileDescriptor mPfd;
      private final FileDescriptor mFd;
  
      private int mSessionId = INVALID_SESSION;
  
      /**
       * @param pfd Opened with "rw" mode.
       */
      public DrmOutputStream(DrmManagerClient client, ParcelFileDescriptor pfd, String mimeType)
              throws IOException {
          mClient = client;
          mPfd = pfd;
          mFd = pfd.getFileDescriptor();
  
          mSessionId = mClient.openConvertSession(mimeType);
          if (mSessionId == INVALID_SESSION) {
              throw new UnknownServiceException("Failed to open DRM session for " + mimeType);
          }
      }
  
      public void finish() throws IOException {
          final DrmConvertedStatus status = mClient.closeConvertSession(mSessionId);
          if (status.statusCode == STATUS_OK) {
              try {
                  Os.lseek(mFd, status.offset, SEEK_SET);
              } catch (ErrnoException e) {
                  e.rethrowAsIOException();
              }
              IoBridge.write(mFd, status.convertedData, 0, status.convertedData.length);
              mSessionId = INVALID_SESSION;
          } else {
              throw new IOException("Unexpected DRM status: " + status.statusCode);
          }
      }
  
      @Override
      public void close() throws IOException {
          if (mSessionId == INVALID_SESSION) {
              Log.w(TAG, "Closing stream without finishing");
          }
  
          mPfd.close();
      }
  
      @Override
      public void write(byte[] buffer, int offset, int count) throws IOException {
          ArrayUtils.throwsIfOutOfBounds(buffer.length, offset, count);
  
          final byte[] exactBuffer;
          if (count == buffer.length) {
              exactBuffer = buffer;
          } else {
              exactBuffer = new byte[count];
              System.arraycopy(buffer, offset, exactBuffer, 0, count);
          }
  
          final DrmConvertedStatus status = mClient.convertData(mSessionId, exactBuffer);
          if (status.statusCode == STATUS_OK) {
              IoBridge.write(mFd, status.convertedData, 0, status.convertedData.length);
          } else {
              throw new IOException("Unexpected DRM status: " + status.statusCode);
          }
      }
  
      @Override
      public void write(int oneByte) throws IOException {
          Streams.writeSingleByte(this, oneByte);
      }
  }
  