content: /*
   * Copyright (C) 2020 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 androidx.test.services.storage.internal;
  
  import static androidx.test.internal.util.Checks.checkNotNull;
  
  import android.content.ContentProviderClient;
  import android.content.ContentResolver;
  import android.net.Uri;
  import android.os.ParcelFileDescriptor;
  import android.os.RemoteException;
  import androidx.annotation.RestrictTo;
  import androidx.annotation.RestrictTo.Scope;
  import androidx.test.services.storage.TestStorageException;
  import java.io.BufferedInputStream;
  import java.io.FileNotFoundException;
  import java.io.InputStream;
  import java.io.OutputStream;
  
  /**
   * Helper methods for the test storage implementations.
   *
   * @hide
   */
  @RestrictTo(Scope.LIBRARY)
  public final class TestStorageUtil {
    /**
     * Gets the input stream for a given Uri.
     *
     * @param uri The Uri for which the InputStream is required.
     */
    public static InputStream getInputStream(Uri uri, ContentResolver contentResolver)
        throws FileNotFoundException {
      checkNotNull(uri);
  
      ContentProviderClient providerClient = null;
      try {
        providerClient = makeContentProviderClient(contentResolver, uri);
        // Assignment to a variable is required. Do not inline.
        ParcelFileDescriptor pfd = providerClient.openFile(uri, "r");
        // Buffered to improve performance.
        return new BufferedInputStream(new ParcelFileDescriptor.AutoCloseInputStream(pfd));
      } catch (RemoteException re) {
        throw new TestStorageException("Unable to access content provider: " + uri, re);
      } finally {
        if (providerClient != null) {
          // Uses #release() to be compatible with API < 24.
          providerClient.release();
        }
      }
    }
  
    /**
     * Gets the output stream for a given Uri.
     *
     * <p>The returned OutputStream is essentially a {@link java.io.FileOutputStream} which likely
     * should be buffered to avoid {@code UnbufferedIoViolation} when running under strict mode.
     *
     * @param uri The Uri for which the OutputStream is required.
     */
    public static OutputStream getOutputStream(Uri uri, ContentResolver contentResolver)
        throws FileNotFoundException {
      return getOutputStream(uri, contentResolver, false);
    }
  
    /**
     * Gets the output stream for a given Uri.
     *
     * <p>The returned OutputStream is essentially a {@link java.io.FileOutputStream} which likely
     * should be buffered to avoid {@code UnbufferedIoViolation} when running under strict mode.
     *
     * @param uri The Uri for which the OutputStream is required.
     * @param append if true, then the lines will be added to the end of the file rather than
     *     overwriting.
     */
    public static OutputStream getOutputStream(
        Uri uri, ContentResolver contentResolver, boolean append) throws FileNotFoundException {
      checkNotNull(uri);
  
      ContentProviderClient providerClient = null;
      try {
        providerClient = makeContentProviderClient(contentResolver, uri);
        // https://developer.android.com/reference/android/os/ParcelFileDescriptor#parseMode(java.lang.String)
        String mode = append ? "wa" : "wt"; // t is "truncate", not "text".
        return new ParcelFileDescriptor.AutoCloseOutputStream(providerClient.openFile(uri, mode));
      } catch (RemoteException re) {
        throw new TestStorageException("Unable to access content provider: " + uri, re);
      } finally {
        if (providerClient != null) {
          // Uses #release() to be compatible with API < 24.
          providerClient.release();
        }
      }
    }
  
    private static ContentProviderClient makeContentProviderClient(
        ContentResolver resolver, Uri uri) {
      checkNotNull(resolver);
  
      ContentProviderClient providerClient = resolver.acquireContentProviderClient(uri);
      if (null == providerClient) {
        throw new TestStorageException(
            String.format(
                "No content provider registered for: %s. Are all test services apks installed?",
                uri));
      }
      return providerClient;
    }
  
    private TestStorageUtil() {}
  }
  