android.os.CancellationSignal#setRemote ( )源码实例Demo

/**
 * This allows clients to request an explicit refresh of content identified by {@code uri}.
 * <p>
 * Client code should only invoke this method when there is a strong indication (such as a user
 * initiated pull to refresh gesture) that the content is stale.
 * <p>
 *
 * @param url The Uri identifying the data to refresh.
 * @param args Additional options from the client. The definitions of these are specific to the
 *            content provider being called.
 * @param cancellationSignal A signal to cancel the operation in progress, or {@code null} if
 *            none. For example, if you called refresh on a particular uri, you should call
 *            {@link CancellationSignal#throwIfCanceled()} to check whether the client has
 *            canceled the refresh request.
 * @return true if the provider actually tried refreshing.
 */
public final boolean refresh(@NonNull Uri url, @Nullable Bundle args,
        @Nullable CancellationSignal cancellationSignal) {
    Preconditions.checkNotNull(url, "url");
    IContentProvider provider = acquireProvider(url);
    if (provider == null) {
        return false;
    }

    try {
        ICancellationSignal remoteCancellationSignal = null;
        if (cancellationSignal != null) {
            cancellationSignal.throwIfCanceled();
            remoteCancellationSignal = provider.createCancellationSignal();
            cancellationSignal.setRemote(remoteCancellationSignal);
        }
        return provider.refresh(mPackageName, url, args, remoteCancellationSignal);
    } catch (RemoteException e) {
        // Arbitrary and not worth documenting, as Activity
        // Manager will kill this process shortly anyway.
        return false;
    } finally {
        releaseProvider(provider);
    }
}
 

/**
 * This allows clients to request an explicit refresh of content identified by {@code uri}.
 * <p>
 * Client code should only invoke this method when there is a strong indication (such as a user
 * initiated pull to refresh gesture) that the content is stale.
 * <p>
 *
 * @param url The Uri identifying the data to refresh.
 * @param args Additional options from the client. The definitions of these are specific to the
 *            content provider being called.
 * @param cancellationSignal A signal to cancel the operation in progress, or {@code null} if
 *            none. For example, if you called refresh on a particular uri, you should call
 *            {@link CancellationSignal#throwIfCanceled()} to check whether the client has
 *            canceled the refresh request.
 * @return true if the provider actually tried refreshing.
 */
public final boolean refresh(@NonNull Uri url, @Nullable Bundle args,
        @Nullable CancellationSignal cancellationSignal) {
    Preconditions.checkNotNull(url, "url");
    IContentProvider provider = acquireProvider(url);
    if (provider == null) {
        return false;
    }

    try {
        ICancellationSignal remoteCancellationSignal = null;
        if (cancellationSignal != null) {
            cancellationSignal.throwIfCanceled();
            remoteCancellationSignal = provider.createCancellationSignal();
            cancellationSignal.setRemote(remoteCancellationSignal);
        }
        return provider.refresh(mPackageName, url, args, remoteCancellationSignal);
    } catch (RemoteException e) {
        // Arbitrary and not worth documenting, as Activity
        // Manager will kill this process shortly anyway.
        return false;
    } finally {
        releaseProvider(provider);
    }
}
 

/** See {@link ContentProvider#refresh} */
public boolean refresh(Uri url, @Nullable Bundle args,
        @Nullable CancellationSignal cancellationSignal) throws RemoteException {
    Preconditions.checkNotNull(url, "url");

    beforeRemote();
    try {
        ICancellationSignal remoteCancellationSignal = null;
        if (cancellationSignal != null) {
            cancellationSignal.throwIfCanceled();
            remoteCancellationSignal = mContentProvider.createCancellationSignal();
            cancellationSignal.setRemote(remoteCancellationSignal);
        }
        return mContentProvider.refresh(mPackageName, url, args, remoteCancellationSignal);
    } catch (DeadObjectException e) {
        if (!mStable) {
            mContentResolver.unstableProviderDied(mContentProvider);
        }
        throw e;
    } finally {
        afterRemote();
    }
}
 

/**
 * See {@link ContentProvider#openFile ContentProvider.openFile}.  Note that
 * this <em>does not</em>
 * take care of non-content: URIs such as file:.  It is strongly recommended
 * you use the {@link ContentResolver#openFileDescriptor
 * ContentResolver.openFileDescriptor} API instead.
 */
public @Nullable ParcelFileDescriptor openFile(@NonNull Uri url, @NonNull String mode,
        @Nullable CancellationSignal signal) throws RemoteException, FileNotFoundException {
    Preconditions.checkNotNull(url, "url");
    Preconditions.checkNotNull(mode, "mode");

    beforeRemote();
    try {
        ICancellationSignal remoteSignal = null;
        if (signal != null) {
            signal.throwIfCanceled();
            remoteSignal = mContentProvider.createCancellationSignal();
            signal.setRemote(remoteSignal);
        }
        return mContentProvider.openFile(mPackageName, url, mode, remoteSignal, null);
    } catch (DeadObjectException e) {
        if (!mStable) {
            mContentResolver.unstableProviderDied(mContentProvider);
        }
        throw e;
    } finally {
        afterRemote();
    }
}
 

/**
 * See {@link ContentProvider#openAssetFile ContentProvider.openAssetFile}.
 * Note that this <em>does not</em>
 * take care of non-content: URIs such as file:.  It is strongly recommended
 * you use the {@link ContentResolver#openAssetFileDescriptor
 * ContentResolver.openAssetFileDescriptor} API instead.
 */
public @Nullable AssetFileDescriptor openAssetFile(@NonNull Uri url, @NonNull String mode,
        @Nullable CancellationSignal signal) throws RemoteException, FileNotFoundException {
    Preconditions.checkNotNull(url, "url");
    Preconditions.checkNotNull(mode, "mode");

    beforeRemote();
    try {
        ICancellationSignal remoteSignal = null;
        if (signal != null) {
            signal.throwIfCanceled();
            remoteSignal = mContentProvider.createCancellationSignal();
            signal.setRemote(remoteSignal);
        }
        return mContentProvider.openAssetFile(mPackageName, url, mode, remoteSignal);
    } catch (DeadObjectException e) {
        if (!mStable) {
            mContentResolver.unstableProviderDied(mContentProvider);
        }
        throw e;
    } finally {
        afterRemote();
    }
}
 

/** See {@link ContentProvider#openTypedAssetFile ContentProvider.openTypedAssetFile} */
public final @Nullable AssetFileDescriptor openTypedAssetFileDescriptor(@NonNull Uri uri,
        @NonNull String mimeType, @Nullable Bundle opts, @Nullable CancellationSignal signal)
                throws RemoteException, FileNotFoundException {
    Preconditions.checkNotNull(uri, "uri");
    Preconditions.checkNotNull(mimeType, "mimeType");

    beforeRemote();
    try {
        ICancellationSignal remoteSignal = null;
        if (signal != null) {
            signal.throwIfCanceled();
            remoteSignal = mContentProvider.createCancellationSignal();
            signal.setRemote(remoteSignal);
        }
        return mContentProvider.openTypedAssetFile(
                mPackageName, uri, mimeType, opts, remoteSignal);
    } catch (DeadObjectException e) {
        if (!mStable) {
            mContentResolver.unstableProviderDied(mContentProvider);
        }
        throw e;
    } finally {
        afterRemote();
    }
}
 

/** See {@link ContentProvider#query ContentProvider.query} */
public @Nullable Cursor query(@NonNull Uri uri, @Nullable String[] projection,
        Bundle queryArgs, @Nullable CancellationSignal cancellationSignal)
                throws RemoteException {
    Preconditions.checkNotNull(uri, "url");

    beforeRemote();
    try {
        ICancellationSignal remoteCancellationSignal = null;
        if (cancellationSignal != null) {
            cancellationSignal.throwIfCanceled();
            remoteCancellationSignal = mContentProvider.createCancellationSignal();
            cancellationSignal.setRemote(remoteCancellationSignal);
        }
        final Cursor cursor = mContentProvider.query(
                mPackageName, uri, projection, queryArgs, remoteCancellationSignal);
        if (cursor == null) {
            return null;
        }
        return new CursorWrapperInner(cursor);
    } catch (DeadObjectException e) {
        if (!mStable) {
            mContentResolver.unstableProviderDied(mContentProvider);
        }
        throw e;
    } finally {
        afterRemote();
    }
}