Skip to content
This repository was archived by the owner on Feb 25, 2025. It is now read-only.

Download dynamic patch to separate file to avoid races #7428

Merged
merged 1 commit into from
Jan 10, 2019
Merged

Download dynamic patch to separate file to avoid races #7428

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 1 addition & 1 deletion shell/platform/android/io/flutter/app/FlutterActivityDelegate.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -345,7 +345,7 @@ private void runBundle(String appBundlePath) {
FlutterRunArguments args = new FlutterRunArguments();
ArrayList<String> bundlePaths = new ArrayList<>();
if (FlutterMain.getResourceUpdater() != null) {
File patchFile = FlutterMain.getResourceUpdater().getPatch();
File patchFile = FlutterMain.getResourceUpdater().getInstalledPatch();
bundlePaths.add(patchFile.getPath());
}
bundlePaths.add(appBundlePath);
Expand Down
79 changes: 55 additions & 24 deletions shell/platform/android/io/flutter/view/ResourceExtractor.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -51,37 +51,68 @@ private class ExtractTask extends AsyncTask<Void, Void, Void> {
protected Void doInBackground(Void... unused) {
final File dataDir = new File(PathUtils.getDataDirectory(mContext));

JSONObject updateManifest = readUpdateManifest();
if (!validateUpdateManifest(updateManifest)) {
updateManifest = null;
ResourceUpdater resourceUpdater = FlutterMain.getResourceUpdater();
if (resourceUpdater != null) {
// Protect patch file from being overwritten by downloader while
// it's being extracted since downloading happens asynchronously.
resourceUpdater.getInstallationLock().lock();
}

final String timestamp = checkTimestamp(dataDir, updateManifest);
if (timestamp == null) {
return null;
}
try {
if (resourceUpdater != null) {
File updateFile = resourceUpdater.getDownloadedPatch();
File activeFile = resourceUpdater.getInstalledPatch();

if (updateFile.exists()) {
// Graduate patch file as active for asset manager.
if (activeFile.exists() && !activeFile.delete()) {
Log.w(TAG, "Could not delete file " + activeFile);
return null;
}
if (!updateFile.renameTo(activeFile)) {
Log.w(TAG, "Could not create file " + activeFile);
return null;
}
}
}

deleteFiles();
JSONObject updateManifest = readUpdateManifest();
if (!validateUpdateManifest(updateManifest)) {
updateManifest = null;
}

if (updateManifest != null) {
if (!extractUpdate(dataDir)) {
final String timestamp = checkTimestamp(dataDir, updateManifest);
if (timestamp == null) {
return null;
}
}

if (!extractAPK(dataDir)) {
return null;
}
deleteFiles();

if (timestamp != null) {
try {
new File(dataDir, timestamp).createNewFile();
} catch (IOException e) {
Log.w(TAG, "Failed to write resource timestamp");
if (updateManifest != null) {
if (!extractUpdate(dataDir)) {
return null;
}
}
}

return null;
if (!extractAPK(dataDir)) {
return null;
}

if (timestamp != null) {
try {
new File(dataDir, timestamp).createNewFile();
} catch (IOException e) {
Log.w(TAG, "Failed to write resource timestamp");
}
}

return null;

} finally {
if (resourceUpdater != null) {
resourceUpdater.getInstallationLock().unlock();
}
}
}
}

Expand Down Expand Up @@ -201,7 +232,7 @@ private boolean extractUpdate(File dataDir) {
return true;
}

File updateFile = resourceUpdater.getPatch();
File updateFile = resourceUpdater.getInstalledPatch();
if (!updateFile.exists()) {
return true;
}
Expand Down Expand Up @@ -289,7 +320,7 @@ private String checkTimestamp(File dataDir, JSONObject updateManifest) {
} else {
ResourceUpdater resourceUpdater = FlutterMain.getResourceUpdater();
assert resourceUpdater != null;
File patchFile = resourceUpdater.getPatch();
File patchFile = resourceUpdater.getInstalledPatch();
assert patchFile.exists();
if (patchNumber != null) {
expectedTimestamp += "-" + patchNumber + "-" + patchFile.lastModified();
Expand Down Expand Up @@ -362,7 +393,7 @@ private JSONObject readUpdateManifest() {
return null;
}

File updateFile = resourceUpdater.getPatch();
File updateFile = resourceUpdater.getInstalledPatch();
if (!updateFile.exists()) {
return null;
}
Expand Down
56 changes: 50 additions & 6 deletions shell/platform/android/io/flutter/view/ResourceUpdater.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -15,13 +15,16 @@
import java.io.InputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.lang.Math;
import java.net.HttpURLConnection;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;
import java.util.Date;
import java.util.concurrent.CancellationException;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

public final class ResourceUpdater {
private static final String TAG = "ResourceUpdater";
Expand Down Expand Up @@ -58,20 +61,44 @@ enum InstallMode {
IMMEDIATE
}

/// Lock that prevents replacement of the install file by the downloader
/// while this file is being extracted, since these can happen in parallel.
Lock getInstallationLock() {
return installationLock;
}

// Patch file that's fully installed and is ready to serve assets.
// This file represents the final stage in the installation process.
public File getInstalledPatch() {
return new File(context.getFilesDir().toString() + "/patch.zip");
}

// Patch file that's finished downloading and is ready to be installed.
// This is a separate file in order to prevent serving assets from patch
// that failed installing for any reason, such as mismatched APK version.
File getDownloadedPatch() {
return new File(getInstalledPatch().getPath() + ".install");
}

private class DownloadTask extends AsyncTask<String, String, Void> {
@Override
protected Void doInBackground(String... unused) {
try {
URL unresolvedURL = new URL(buildUpdateDownloadURL());
File localFile = getPatch();

// Download to transient file to avoid extracting incomplete download.
File localFile = new File(getInstalledPatch().getPath() + ".download");

long startMillis = new Date().getTime();
Log.i(TAG, "Checking for updates at " + unresolvedURL);

HttpURLConnection connection =
(HttpURLConnection)unresolvedURL.openConnection();

long lastDownloadTime = localFile.lastModified();
long lastDownloadTime = Math.max(
getDownloadedPatch().lastModified(),
getInstalledPatch().lastModified());

if (lastDownloadTime != 0) {
Log.i(TAG, "Active update timestamp " + lastDownloadTime);
connection.setIfModifiedSince(lastDownloadTime);
Expand Down Expand Up @@ -107,9 +134,29 @@ protected Void doInBackground(String... unused) {

long totalMillis = new Date().getTime() - startMillis;
Log.i(TAG, "Update downloaded in " + totalMillis / 100 / 10. + "s");
}
}

// Wait renaming the file if extraction is in progress.
installationLock.lock();

try {
File updateFile = getDownloadedPatch();

// Graduate downloaded file as ready for installation.
if (updateFile.exists() && !updateFile.delete()) {
Log.w(TAG, "Could not delete file " + updateFile);
return null;
}
if (!localFile.renameTo(updateFile)) {
Log.w(TAG, "Could not create file " + updateFile);
return null;
}

return null;

} finally {
installationLock.unlock();
}

} catch (IOException e) {
Expand All @@ -121,6 +168,7 @@ protected Void doInBackground(String... unused) {

private final Context context;
private DownloadTask downloadTask;
private final Lock installationLock = new ReentrantLock();

public ResourceUpdater(Context context) {
this.context = context;
Expand All @@ -137,10 +185,6 @@ private String getAPKVersion() {
}
}

public File getPatch() {
return new File(context.getFilesDir().toString() + "/patch.zip");
}

private String buildUpdateDownloadURL() {
Bundle metaData;
try {
Expand Down