1 files changed, 191 insertions, 0 deletions
diff --git a/java/com/android/voicemail/impl/transcribe/TranscriptionTask.java b/java/com/android/voicemail/impl/transcribe/TranscriptionTask.java
new file mode 100644
index 000000000..0fbc33ad5
--- /dev/null
+++ b/java/com/android/voicemail/impl/transcribe/TranscriptionTask.java
@@ -0,0 +1,191 @@
+/*
+ * Copyright (C) 2017 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.android.voicemail.impl.transcribe;
+
+import android.annotation.TargetApi;
+import android.app.job.JobWorkItem;
+import android.content.Context;
+import android.net.Uri;
+import android.text.TextUtils;
+import com.android.dialer.common.concurrent.ThreadUtil;
+import com.android.voicemail.impl.VvmLog;
+import com.android.voicemail.impl.transcribe.TranscriptionService.JobCallback;
+import com.android.voicemail.impl.transcribe.grpc.TranscriptionClient;
+import com.android.voicemail.impl.transcribe.grpc.TranscriptionClientFactory;
+import com.google.internal.communications.voicemailtranscription.v1.AudioFormat;
+import com.google.internal.communications.voicemailtranscription.v1.TranscribeVoicemailRequest;
+import com.google.protobuf.ByteString;
+import io.grpc.Status;
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * Background task to get a voicemail transcription and update the database.
+ *
+ * <pre>
+ * This task performs the following steps:
+ *   1. Update the transcription-state in the database to 'in-progress'
+ *   2. Create grpc client and transcription request
+ *   3. Make synchronous grpc transcription request to backend server
+ *     3a. On response
+ *       Update the database with transcription (if successful) and new transcription-state
+ *     3b. On network error
+ *       If retry-count < max then increment retry-count and retry the request
+ *       Otherwise update the transcription-state in the database to 'transcription-failed'
+ *   4. Notify the callback that the work item is complete
+ * </pre>
+ */
+public class TranscriptionTask implements Runnable {
+  private static final String TAG = "TranscriptionTask";
+
+  private final Context context;
+  private final JobCallback callback;
+  private final JobWorkItem workItem;
+  private final TranscriptionClientFactory clientFactory;
+  private final Uri voicemailUri;
+  private final TranscriptionDbHelper databaseHelper;
+  private ByteString audioData;
+  private AudioFormat encoding;
+
+  private static final int MAX_RETRIES = 2;
+  static final String AMR_PREFIX = "#!AMR\n";
+
+  public TranscriptionTask(
+      Context context,
+      JobCallback callback,
+      JobWorkItem workItem,
+      TranscriptionClientFactory clientFactory) {
+    this.context = context;
+    this.callback = callback;
+    this.workItem = workItem;
+    this.clientFactory = clientFactory;
+    this.voicemailUri = getVoicemailUri(workItem);
+    databaseHelper = new TranscriptionDbHelper(context, voicemailUri);
+  }
+
+  @Override
+  public void run() {
+    VvmLog.i(TAG, "run");
+    if (readAndValidateAudioFile()) {
+      updateTranscriptionState(VoicemailCompat.TRANSCRIPTION_IN_PROGRESS);
+      transcribeVoicemail();
+    } else {
+      updateTranscriptionState(VoicemailCompat.TRANSCRIPTION_FAILED);
+    }
+    ThreadUtil.postOnUiThread(
+        () -> {
+          callback.onWorkCompleted(workItem);
+        });
+  }
+
+  private void transcribeVoicemail() {
+    VvmLog.i(TAG, "transcribeVoicemail");
+    TranscribeVoicemailRequest request = makeRequest();
+    TranscriptionClient client = clientFactory.getClient();
+    String transcript = null;
+    for (int i = 0; transcript == null && i < MAX_RETRIES; i++) {
+      VvmLog.i(TAG, "transcribeVoicemail, try: " + (i + 1));
+      TranscriptionClient.TranscriptionResponseWrapper responseWrapper =
+          client.transcribeVoicemail(request);
+      if (responseWrapper.status != null) {
+        VvmLog.i(TAG, "transcribeVoicemail, status: " + responseWrapper.status.getCode());
+        if (shouldRetryRequest(responseWrapper.status)) {
+          backoff(i);
+        } else {
+          break;
+        }
+      } else if (responseWrapper.response != null) {
+        if (!TextUtils.isEmpty(responseWrapper.response.getTranscript())) {
+          VvmLog.i(TAG, "transcribeVoicemail, got response");
+          transcript = responseWrapper.response.getTranscript();
+        } else {
+          VvmLog.i(TAG, "transcribeVoicemail, empty transcription");
+        }
+      } else {
+        VvmLog.w(TAG, "transcribeVoicemail, no response");
+      }
+    }
+
+    int newState =
+        (transcript == null)
+            ? VoicemailCompat.TRANSCRIPTION_FAILED
+            : VoicemailCompat.TRANSCRIPTION_AVAILABLE;
+    updateTranscriptionAndState(transcript, newState);
+  }
+
+  private static boolean shouldRetryRequest(Status status) {
+    return status.getCode() == Status.Code.UNAVAILABLE;
+  }
+
+  private static void backoff(int retryCount) {
+    VvmLog.i(TAG, "backoff, count: " + retryCount);
+    try {
+      long millis = (1 << retryCount) * 1000;
+      Thread.sleep(millis);
+    } catch (InterruptedException e) {
+      VvmLog.w(TAG, "interrupted");
+      Thread.currentThread().interrupt();
+    }
+  }
+
+  private void updateTranscriptionAndState(String transcript, int newState) {
+    databaseHelper.setTranscriptionAndState(transcript, newState);
+  }
+
+  private void updateTranscriptionState(int newState) {
+    databaseHelper.setTranscriptionState(newState);
+  }
+
+  private TranscribeVoicemailRequest makeRequest() {
+    return TranscribeVoicemailRequest.newBuilder()
+        .setVoicemailData(audioData)
+        .setAudioFormat(encoding)
+        .build();
+  }
+
+  // Uses try-with-resource
+  @TargetApi(android.os.Build.VERSION_CODES.M)
+  private boolean readAndValidateAudioFile() {
+    if (voicemailUri == null) {
+      VvmLog.i(TAG, "Transcriber.readAndValidateAudioFile, file not found.");
+      return false;
+    } else {
+      VvmLog.i(TAG, "Transcriber.readAndValidateAudioFile, reading: " + voicemailUri);
+    }
+
+    try (InputStream in = context.getContentResolver().openInputStream(voicemailUri)) {
+      audioData = ByteString.readFrom(in);
+      VvmLog.i(TAG, "Transcriber.readAndValidateAudioFile, read " + audioData.size() + " bytes");
+    } catch (IOException e) {
+      VvmLog.e(TAG, "Transcriber.readAndValidateAudioFile", e);
+      return false;
+    }
+
+    if (audioData.startsWith(ByteString.copyFromUtf8(AMR_PREFIX))) {
+      encoding = AudioFormat.AMR_NB_8KHZ;
+    } else {
+      VvmLog.i(TAG, "Transcriber.readAndValidateAudioFile, unknown encoding");
+      encoding = AudioFormat.AUDIO_FORMAT_UNSPECIFIED;
+      return false;
+    }
+
+    return true;
+  }
+
+  private static Uri getVoicemailUri(JobWorkItem workItem) {
+    return workItem.getIntent().getParcelableExtra(TranscriptionService.EXTRA_VOICEMAIL_URI);
+  }
+}