Support for max download size that may go over mobile

This change introduces support for a maximum download size that may go
over a mobile connection.  Downloads above this limit will wait for a
wifi connection.

To accomplish this, I moved a lot of the logic for checking
connectivity info into DownloadInfo itself.  I then moved the code to
call these checks from DownloadService, where it would call the checks
before spawning a DownloadThread, into DownloadThread itself.  This
makes it simpler to check connectivity after we get Content-Length
info.  It also eliminates the risk of a race condition where
connectivity changes between the check and the actual request
execution.

I realize this change reduces efficiency, because we now call into
ConnectivityManager/TelephonyManager twice per DownloadThread, rather
than once per DownloadService "tick".  I feel that it's OK since its a
small amount of computation running relatively infrequently.  If we
feel that it's a serious concern, and that the efficiency issues
outweigh the race problem, I can go easily back to the old approach.

I've left out the code to actually fetch the limit. I think this will
come from system settings, but I want to double-check, so I'll put it
in a separate change.

Other changes:
* simplify SystemFacade's interface to get connectivity info - rather
  than returning all connected types, just return the active type,
  since that should be all we care about
* adding @LargeTest to PublicApiFunctionalTest

Change-Id: Id1faa2c45bf2dade9fe779440721a1d42cbdfcd1

2 files changed, 25 insertions, 9 deletions

diff --git a/tests/src/com/android/providers/downloads/FakeSystemFacade.java b/tests/src/com/android/providers/downloads/FakeSystemFacade.java
index c48f815d..4ff313ab 100644
--- a/tests/src/com/android/providers/downloads/FakeSystemFacade.java
+++ b/tests/src/com/android/providers/downloads/FakeSystemFacade.java
@@ -2,12 +2,11 @@ package com.android.providers.downloads;
 
 import android.net.ConnectivityManager;
 
-import java.util.BitSet;
-
 public class FakeSystemFacade implements SystemFacade {
     long mTimeMillis = 0;
     Integer mActiveNetworkType = ConnectivityManager.TYPE_WIFI;
     boolean mIsRoaming = false;
+    Integer mMaxBytesOverMobile = null;
 
     void incrementTimeMillis(long delta) {
         mTimeMillis += delta;
@@ -17,15 +16,15 @@ public class FakeSystemFacade implements SystemFacade {
         return mTimeMillis;
     }
 
-    public BitSet getConnectedNetworkTypes() {
-        BitSet connectedTypes = new BitSet();
-        if (mActiveNetworkType != null) {
-            connectedTypes.set(mActiveNetworkType);
-        }
-        return connectedTypes;
+    public Integer getActiveNetworkType() {
+        return mActiveNetworkType;
     }
 
     public boolean isNetworkRoaming() {
         return mIsRoaming;
     }
+
+    public Integer getMaxBytesOverMobile() {
+        return mMaxBytesOverMobile ;
+    }
 }
diff --git a/tests/src/com/android/providers/downloads/PublicApiFunctionalTest.java b/tests/src/com/android/providers/downloads/PublicApiFunctionalTest.java
index e9195609..a9810fc1 100644
--- a/tests/src/com/android/providers/downloads/PublicApiFunctionalTest.java
+++ b/tests/src/com/android/providers/downloads/PublicApiFunctionalTest.java
@@ -17,10 +17,11 @@
 package com.android.providers.downloads;
 
 import android.database.Cursor;
+import android.net.ConnectivityManager;
 import android.net.DownloadManager;
 import android.net.Uri;
 import android.os.Environment;
-import android.util.Log;
+import android.test.suitebuilder.annotation.LargeTest;
 import tests.http.RecordedRequest;
 
 import java.io.File;
@@ -28,6 +29,7 @@ import java.io.FileInputStream;
 import java.io.InputStream;
 import java.net.MalformedURLException;
 
+@LargeTest
 public class PublicApiFunctionalTest extends AbstractDownloadManagerFunctionalTest {
     private static final String REQUEST_PATH = "/path";
 
@@ -293,6 +295,21 @@ public class PublicApiFunctionalTest extends AbstractDownloadManagerFunctionalTe
         }
     }
 
+    public void testSizeLimitOverMobile() throws Exception {
+        mSystemFacade.mMaxBytesOverMobile = FILE_CONTENT.length() - 1;
+
+        mSystemFacade.mActiveNetworkType = ConnectivityManager.TYPE_MOBILE;
+        enqueueResponse(HTTP_OK, FILE_CONTENT);
+        Download download = enqueueRequest(getRequest());
+        download.runUntilStatus(DownloadManager.STATUS_PAUSED);
+
+        mSystemFacade.mActiveNetworkType = ConnectivityManager.TYPE_WIFI;
+        // first response was read, but aborted after the DL manager processed the Content-Length
+        // header, so we need to enqueue a second one
+        enqueueResponse(HTTP_OK, FILE_CONTENT);
+        download.runUntilStatus(DownloadManager.STATUS_SUCCESSFUL);
+    }
+
     private DownloadManager.Request getRequest() throws MalformedURLException {
         return getRequest(getServerUri(REQUEST_PATH));
     }