| /* |
| * Copyright 2022 Google LLC |
| * |
| * 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.libraries.mobiledatadownload.downloader.inline; |
| |
| import static com.google.android.libraries.mobiledatadownload.internal.MddConstants.INLINE_FILE_URL_SCHEME; |
| |
| import com.google.android.libraries.mobiledatadownload.DownloadException; |
| import com.google.android.libraries.mobiledatadownload.DownloadException.DownloadResultCode; |
| import com.google.android.libraries.mobiledatadownload.downloader.DownloadRequest; |
| import com.google.android.libraries.mobiledatadownload.downloader.FileDownloader; |
| import com.google.android.libraries.mobiledatadownload.downloader.InlineDownloadParams; |
| import com.google.android.libraries.mobiledatadownload.file.SynchronousFileStorage; |
| import com.google.android.libraries.mobiledatadownload.file.openers.ReadStreamOpener; |
| import com.google.android.libraries.mobiledatadownload.file.openers.WriteStreamOpener; |
| import com.google.android.libraries.mobiledatadownload.internal.logging.LogUtil; |
| import com.google.common.io.ByteStreams; |
| import com.google.common.util.concurrent.Futures; |
| import com.google.common.util.concurrent.ListenableFuture; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.OutputStream; |
| import java.util.concurrent.Executor; |
| |
| /** |
| * An implementation of {@link FileDownloader} that supports copying in-memory data to disk. |
| * |
| * <p>This implementation only supports copying for "inlinefile:" url schemes. For more details see |
| * <internal>. |
| * |
| * <p>NOTE: copying in-memory data can be thought of as "inline file downloading," hence the naming |
| * of this class. |
| */ |
| public final class InlineFileDownloader implements FileDownloader { |
| private static final String TAG = "InlineFileDownloader"; |
| |
| private final SynchronousFileStorage fileStorage; |
| private final Executor downloadExecutor; |
| |
| /** |
| * Construct InlineFileDownloader instance. |
| * |
| * @param fileStorage a file storage instance used to perform I/O |
| * @param downloadExecutor executor that will perfrom the download. This should be |
| * the @MddDownloadExecutor |
| */ |
| public InlineFileDownloader(SynchronousFileStorage fileStorage, Executor downloadExecutor) { |
| this.fileStorage = fileStorage; |
| this.downloadExecutor = downloadExecutor; |
| } |
| |
| @Override |
| public ListenableFuture<Void> startDownloading(DownloadRequest downloadRequest) { |
| if (!downloadRequest.urlToDownload().startsWith(INLINE_FILE_URL_SCHEME)) { |
| LogUtil.e( |
| "%s: Invalid url given, expected to start with 'inlinefile:', but was %s", |
| TAG, downloadRequest.urlToDownload()); |
| return Futures.immediateFailedFuture( |
| DownloadException.builder() |
| .setDownloadResultCode(DownloadResultCode.INVALID_INLINE_FILE_URL_SCHEME) |
| .setMessage("InlineFileDownloader only supports copying inlinefile: scheme") |
| .build()); |
| } |
| // DownloadRequest requires InlineDownloadParams to be present when building a request with |
| // inlinefile scheme, so we can access it directly here. |
| InlineDownloadParams inlineDownloadParams = |
| downloadRequest.inlineDownloadParamsOptional().get(); |
| |
| return Futures.submitAsync( |
| () -> { |
| try (InputStream inlineFileStream = getInputStream(inlineDownloadParams); |
| OutputStream destinationStream = |
| fileStorage.open(downloadRequest.fileUri(), WriteStreamOpener.create())) { |
| ByteStreams.copy(inlineFileStream, destinationStream); |
| destinationStream.flush(); |
| } catch (IOException e) { |
| LogUtil.e(e, "%s: Unable to copy file content.", TAG); |
| return Futures.immediateFailedFuture( |
| DownloadException.builder() |
| .setCause(e) |
| .setDownloadResultCode(DownloadResultCode.INLINE_FILE_IO_ERROR) |
| .build()); |
| } |
| return Futures.immediateVoidFuture(); |
| }, |
| downloadExecutor); |
| } |
| |
| private InputStream getInputStream(InlineDownloadParams params) throws IOException { |
| switch (params.inlineFileContent().getKind()) { |
| case URI: |
| return fileStorage.open(params.inlineFileContent().uri(), ReadStreamOpener.create()); |
| case BYTESTRING: |
| return params.inlineFileContent().byteString().newInput(); |
| } |
| throw new IllegalStateException("unreachable"); |
| } |
| } |