package com.limelight.computers;
import java.io.IOException;
import java.io.OutputStream;
import java.io.StringReader;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.Socket;
import java.util.LinkedList;
import java.util.List;
import java.util.UUID;
import java.util.concurrent.atomic.AtomicInteger;
import com.limelight.LimeLog;
import com.limelight.binding.PlatformBinding;
import com.limelight.discovery.DiscoveryService;
import com.limelight.nvstream.http.ComputerDetails;
import com.limelight.nvstream.http.NvApp;
import com.limelight.nvstream.http.NvHTTP;
import com.limelight.nvstream.mdns.MdnsComputer;
import com.limelight.nvstream.mdns.MdnsDiscoveryListener;
import com.limelight.utils.CacheHelper;
import android.app.Service;
import android.content.ComponentName;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Binder;
import android.os.IBinder;
import org.xmlpull.v1.XmlPullParserException;
public class ComputerManagerService extends Service {
private static final int SERVERINFO_POLLING_PERIOD_MS = 1500;
private static final int APPLIST_POLLING_PERIOD_MS = 30000;
private static final int APPLIST_FAILED_POLLING_RETRY_MS = 2000;
private static final int MDNS_QUERY_PERIOD_MS = 1000;
private static final int FAST_POLL_TIMEOUT = 500;
private static final int OFFLINE_POLL_TRIES = 5;
private static final int INITIAL_POLL_TRIES = 2;
private static final int EMPTY_LIST_THRESHOLD = 3;
private static final int POLL_DATA_TTL_MS = 30000;
private final ComputerManagerBinder binder = new ComputerManagerBinder();
private ComputerDatabaseManager dbManager;
private final AtomicInteger dbRefCount = new AtomicInteger(0);
private IdentityManager idManager;
private final LinkedList<PollingTuple> pollingTuples = new LinkedList<>();
private ComputerManagerListener listener = null;
private final AtomicInteger activePolls = new AtomicInteger(0);
private boolean pollingActive = false;
private DiscoveryService.DiscoveryBinder discoveryBinder;
private final ServiceConnection discoveryServiceConnection = new ServiceConnection() {
public void onServiceConnected(ComponentName className, IBinder binder) {
synchronized (discoveryServiceConnection) {
DiscoveryService.DiscoveryBinder privateBinder = ((DiscoveryService.DiscoveryBinder)binder);
// Set us as the event listener
privateBinder.setListener(createDiscoveryListener());
// Signal a possible waiter that we're all setup
discoveryBinder = privateBinder;
discoveryServiceConnection.notifyAll();
}
}
public void onServiceDisconnected(ComponentName className) {
discoveryBinder = null;
}
};
// Returns true if the details object was modified
private boolean runPoll(ComputerDetails details, boolean newPc, int offlineCount) throws InterruptedException {
if (!getLocalDatabaseReference()) {
return false;
}
final int pollTriesBeforeOffline = details.state == ComputerDetails.State.UNKNOWN ?
INITIAL_POLL_TRIES : OFFLINE_POLL_TRIES;
activePolls.incrementAndGet();
// Poll the machine
try {
if (!pollComputer(details)) {
if (!newPc && offlineCount < pollTriesBeforeOffline) {
// Return without calling the listener
releaseLocalDatabaseReference();
return false;
}
details.state = ComputerDetails.State.OFFLINE;
details.reachability = ComputerDetails.Reachability.OFFLINE;
}
} catch (InterruptedException e) {
releaseLocalDatabaseReference();
throw e;
} finally {
activePolls.decrementAndGet();
}
// If it's online, update our persistent state
if (details.state == ComputerDetails.State.ONLINE) {
if (!newPc) {
// Check if it's in the database because it could have been
// removed after this was issued
if (dbManager.getComputerByName(details.name) == null) {
// It's gone
releaseLocalDatabaseReference();
return false;
}
}
dbManager.updateComputer(details);
}
// Don't call the listener if this is a failed lookup of a new PC
if ((!newPc || details.state == ComputerDetails.State.ONLINE) && listener != null) {
listener.notifyComputerUpdated(details);
}
releaseLocalDatabaseReference();
return true;
}
private Thread createPollingThread(final PollingTuple tuple) {
Thread t = new Thread() {
@Override
public void run() {
int offlineCount = 0;
while (!isInterrupted() && pollingActive) {
try {
// Only allow one request to the machine at a time
synchronized (tuple.networkLock) {
// Check if this poll has modified the details
if (!runPoll(tuple.computer, false, offlineCount)) {
LimeLog.warning(tuple.computer.name + " is offline (try " + offlineCount + ")");
offlineCount++;
} else {
tuple.lastSuccessfulPollMs = System.currentTimeMillis();
offlineCount = 0;
}
}
// Wait until the next polling interval
Thread.sleep(SERVERINFO_POLLING_PERIOD_MS);
} catch (InterruptedException e) {
break;
}
}
}
};
t.setName("Polling thread for " + tuple.computer.localIp.getHostAddress());
return t;
}
public class ComputerManagerBinder extends Binder {
public void startPolling(ComputerManagerListener listener) {
// Polling is active
pollingActive = true;
// Set the listener
ComputerManagerService.this.listener = listener;
// Start mDNS autodiscovery too
discoveryBinder.startDiscovery(MDNS_QUERY_PERIOD_MS);
synchronized (pollingTuples) {
for (PollingTuple tuple : pollingTuples) {
// Enforce the poll data TTL
if (System.currentTimeMillis() - tuple.lastSuccessfulPollMs > POLL_DATA_TTL_MS) {
LimeLog.info("Timing out polled state for "+tuple.computer.name);
tuple.computer.state = ComputerDetails.State.UNKNOWN;
tuple.computer.reachability = ComputerDetails.Reachability.UNKNOWN;
}
// Report this computer initially
listener.notifyComputerUpdated(tuple.computer);
// This polling thread might already be there
if (tuple.thread == null) {
tuple.thread = createPollingThread(tuple);
tuple.thread.start();
}
}
}
}
public void waitForReady() {
synchronized (discoveryServiceConnection) {
try {
while (discoveryBinder == null) {
// Wait for the bind notification
discoveryServiceConnection.wait(1000);
}
} catch (InterruptedException ignored) {
}
}
}
public void waitForPollingStopped() {
while (activePolls.get() != 0) {
try {
Thread.sleep(250);
} catch (InterruptedException ignored) {}
}
}
public boolean addComputerBlocking(InetAddress addr) {
return ComputerManagerService.this.addComputerBlocking(addr);
}
public void removeComputer(String name) {
ComputerManagerService.this.removeComputer(name);
}
public void stopPolling() {
// Just call the unbind handler to cleanup
ComputerManagerService.this.onUnbind(null);
}
public ApplistPoller createAppListPoller(ComputerDetails computer) {
return new ApplistPoller(computer);
}
public String getUniqueId() {
return idManager.getUniqueId();
}
public ComputerDetails getComputer(UUID uuid) {
synchronized (pollingTuples) {
for (PollingTuple tuple : pollingTuples) {
if (uuid.equals(tuple.computer.uuid)) {
return tuple.computer;
}
}
}
return null;
}
public void invalidateStateForComputer(UUID uuid) {
synchronized (pollingTuples) {
for (PollingTuple tuple : pollingTuples) {
if (uuid.equals(tuple.computer.uuid)) {
// We need the network lock to prevent a concurrent poll
// from wiping this change out
synchronized (tuple.networkLock) {
tuple.computer.state = ComputerDetails.State.UNKNOWN;
tuple.computer.reachability = ComputerDetails.Reachability.UNKNOWN;
}
}
}
}
}
}
@Override
public boolean onUnbind(Intent intent) {
if (discoveryBinder != null) {
// Stop mDNS autodiscovery
discoveryBinder.stopDiscovery();
}
// Stop polling
pollingActive = false;
synchronized (pollingTuples) {
for (PollingTuple tuple : pollingTuples) {
if (tuple.thread != null) {
// Interrupt and remove the thread
tuple.thread.interrupt();
tuple.thread = null;
}
}
}
// Remove the listener
listener = null;
return false;
}
private MdnsDiscoveryListener createDiscoveryListener() {
return new MdnsDiscoveryListener() {
@Override
public void notifyComputerAdded(MdnsComputer computer) {
// Kick off a serverinfo poll on this machine
addComputerBlocking(computer.getAddress());
}
@Override
public void notifyComputerRemoved(MdnsComputer computer) {
// Nothing to do here
}
@Override
public void notifyDiscoveryFailure(Exception e) {
LimeLog.severe("mDNS discovery failed");
e.printStackTrace();
}
};
}
private void addTuple(ComputerDetails details) {
synchronized (pollingTuples) {
for (PollingTuple tuple : pollingTuples) {
// Check if this is the same computer
if (tuple.computer.uuid.equals(details.uuid)) {
// Update details anyway in case this machine has been re-added by IP
// after not being reachable by our existing information
tuple.computer.localIp = details.localIp;
tuple.computer.remoteIp = details.remoteIp;
// Start a polling thread if polling is active
if (pollingActive && tuple.thread == null) {
tuple.thread = createPollingThread(tuple);
tuple.thread.start();
}
// Found an entry so we're done
return;
}
}
// If we got here, we didn't find an entry
PollingTuple tuple = new PollingTuple(details, null);
if (pollingActive) {
tuple.thread = createPollingThread(tuple);
}
pollingTuples.add(tuple);
if (tuple.thread != null) {
tuple.thread.start();
}
}
}
public boolean addComputerBlocking(InetAddress addr) {
// Setup a placeholder
ComputerDetails fakeDetails = new ComputerDetails();
fakeDetails.localIp = addr;
fakeDetails.remoteIp = addr;
// Block while we try to fill the details
try {
runPoll(fakeDetails, true, 0);
} catch (InterruptedException e) {
return false;
}
// If the machine is reachable, it was successful
if (fakeDetails.state == ComputerDetails.State.ONLINE) {
LimeLog.info("New PC ("+fakeDetails.name+") is UUID "+fakeDetails.uuid);
// Start a polling thread for this machine
addTuple(fakeDetails);
return true;
}
else {
return false;
}
}
public void removeComputer(String name) {
if (!getLocalDatabaseReference()) {
return;
}
// Remove it from the database
dbManager.deleteComputer(name);
synchronized (pollingTuples) {
// Remove the computer from the computer list
for (PollingTuple tuple : pollingTuples) {
if (tuple.computer.name.equals(name)) {
if (tuple.thread != null) {
// Interrupt the thread on this entry
tuple.thread.interrupt();
}
pollingTuples.remove(tuple);
break;
}
}
}
releaseLocalDatabaseReference();
}
private boolean getLocalDatabaseReference() {
if (dbRefCount.get() == 0) {
return false;
}
dbRefCount.incrementAndGet();
return true;
}
private void releaseLocalDatabaseReference() {
if (dbRefCount.decrementAndGet() == 0) {
dbManager.close();
}
}
private ComputerDetails tryPollIp(ComputerDetails details, InetAddress ipAddr) {
// Fast poll this address first to determine if we can connect at the TCP layer
if (!fastPollIp(ipAddr)) {
return null;
}
try {
NvHTTP http = new NvHTTP(ipAddr, idManager.getUniqueId(),
null, PlatformBinding.getCryptoProvider(ComputerManagerService.this));
ComputerDetails newDetails = http.getComputerDetails();
// Check if this is the PC we expected
if (details.uuid != null && newDetails.uuid != null &&
!details.uuid.equals(newDetails.uuid)) {
// We got the wrong PC!
LimeLog.info("Polling returned the wrong PC!");
return null;
}
return newDetails;
} catch (Exception e) {
return null;
}
}
// Just try to establish a TCP connection to speculatively detect a running
// GFE server
private boolean fastPollIp(InetAddress addr) {
Socket s = new Socket();
try {
s.connect(new InetSocketAddress(addr, NvHTTP.HTTPS_PORT), FAST_POLL_TIMEOUT);
s.close();
return true;
} catch (IOException e) {
return false;
}
}
private void startFastPollThread(final InetAddress addr, final boolean[] info) {
Thread t = new Thread() {
@Override
public void run() {
boolean pollRes = fastPollIp(addr);
synchronized (info) {
info[0] = true; // Done
info[1] = pollRes; // Polling result
info.notify();
}
}
};
t.setName("Fast Poll - "+addr.getHostAddress());
t.start();
}
private ComputerDetails.Reachability fastPollPc(final InetAddress local, final InetAddress remote) throws InterruptedException {
final boolean[] remoteInfo = new boolean[2];
final boolean[] localInfo = new boolean[2];
startFastPollThread(local, localInfo);
startFastPollThread(remote, remoteInfo);
// Check local first
synchronized (localInfo) {
while (!localInfo[0]) {
localInfo.wait(500);
}
if (localInfo[1]) {
return ComputerDetails.Reachability.LOCAL;
}
}
// Now remote
synchronized (remoteInfo) {
while (!remoteInfo[0]) {
remoteInfo.wait(500);
}
if (remoteInfo[1]) {
return ComputerDetails.Reachability.REMOTE;
}
}
return ComputerDetails.Reachability.OFFLINE;
}
private ReachabilityTuple pollForReachability(ComputerDetails details) throws InterruptedException {
ComputerDetails polledDetails;
ComputerDetails.Reachability reachability;
// If the local address is routable across the Internet,
// always consider this PC remote to be conservative
if (details.localIp.equals(details.remoteIp)) {
reachability = ComputerDetails.Reachability.REMOTE;
}
else {
// Do a TCP-level connection to the HTTP server to see if it's listening
LimeLog.info("Starting fast poll for "+details.name+" ("+details.localIp+", "+details.remoteIp+")");
reachability = fastPollPc(details.localIp, details.remoteIp);
LimeLog.info("Fast poll for "+details.name+" returned "+reachability.toString());
// If no connection could be established to either IP address, there's nothing we can do
if (reachability == ComputerDetails.Reachability.OFFLINE) {
return null;
}
}
boolean localFirst = (reachability == ComputerDetails.Reachability.LOCAL);
if (localFirst) {
polledDetails = tryPollIp(details, details.localIp);
}
else {
polledDetails = tryPollIp(details, details.remoteIp);
}
InetAddress reachableAddr = null;
if (polledDetails == null && !details.localIp.equals(details.remoteIp)) {
// Failed, so let's try the fallback
if (!localFirst) {
polledDetails = tryPollIp(details, details.localIp);
}
else {
polledDetails = tryPollIp(details, details.remoteIp);
}
if (polledDetails != null) {
// The fallback poll worked
reachableAddr = !localFirst ? details.localIp : details.remoteIp;
}
}
else if (polledDetails != null) {
reachableAddr = localFirst ? details.localIp : details.remoteIp;
}
if (reachableAddr == null) {
return null;
}
if (polledDetails.remoteIp.equals(reachableAddr)) {
polledDetails.reachability = ComputerDetails.Reachability.REMOTE;
}
else if (polledDetails.localIp.equals(reachableAddr)) {
polledDetails.reachability = ComputerDetails.Reachability.LOCAL;
}
else {
polledDetails.reachability = ComputerDetails.Reachability.UNKNOWN;
}
return new ReachabilityTuple(polledDetails, reachableAddr);
}
private boolean pollComputer(ComputerDetails details) throws InterruptedException {
ReachabilityTuple initialReachTuple = pollForReachability(details);
if (initialReachTuple == null) {
return false;
}
if (initialReachTuple.computer.reachability == ComputerDetails.Reachability.UNKNOWN) {
// Neither IP address reported in the serverinfo response was the one we used.
// Poll again to see if we can contact this machine on either of its reported addresses.
ReachabilityTuple confirmationReachTuple = pollForReachability(initialReachTuple.computer);
if (confirmationReachTuple == null) {
// Neither of those seem to work, so we'll hold onto the address that did work
initialReachTuple.computer.localIp = initialReachTuple.reachableAddress;
initialReachTuple.computer.reachability = ComputerDetails.Reachability.LOCAL;
}
else {
// We got it on one of the returned addresses; replace the original reach tuple
// with the new one
initialReachTuple = confirmationReachTuple;
}
}
// Save the old MAC address
String savedMacAddress = details.macAddress;
// If we got here, it's reachable
details.update(initialReachTuple.computer);
// If the new MAC address is empty, restore the old one (workaround for GFE bug)
if (details.macAddress.equals("00:00:00:00:00:00") && savedMacAddress != null) {
LimeLog.info("MAC address was empty; using existing value: "+savedMacAddress);
details.macAddress = savedMacAddress;
}
return true;
}
@Override
public void onCreate() {
// Bind to the discovery service
bindService(new Intent(this, DiscoveryService.class),
discoveryServiceConnection, Service.BIND_AUTO_CREATE);
// Lookup or generate this device's UID
idManager = new IdentityManager(this);
// Initialize the DB
dbManager = new ComputerDatabaseManager(this);
dbRefCount.set(1);
// Grab known machines into our computer list
if (!getLocalDatabaseReference()) {
return;
}
for (ComputerDetails computer : dbManager.getAllComputers()) {
// Add tuples for each computer
addTuple(computer);
}
releaseLocalDatabaseReference();
}
@Override
public void onDestroy() {
if (discoveryBinder != null) {
// Unbind from the discovery service
unbindService(discoveryServiceConnection);
}
// FIXME: Should await termination here but we have timeout issues in HttpURLConnection
// Remove the initial DB reference
releaseLocalDatabaseReference();
}
@Override
public IBinder onBind(Intent intent) {
return binder;
}
public class ApplistPoller {
private Thread thread;
private final ComputerDetails computer;
private final Object pollEvent = new Object();
private boolean receivedAppList = false;
public ApplistPoller(ComputerDetails computer) {
this.computer = computer;
}
public void pollNow() {
synchronized (pollEvent) {
pollEvent.notify();
}
}
private boolean waitPollingDelay() {
try {
synchronized (pollEvent) {
if (receivedAppList) {
// If we've already reported an app list successfully,
// wait the full polling period
pollEvent.wait(APPLIST_POLLING_PERIOD_MS);
}
else {
// If we've failed to get an app list so far, retry much earlier
pollEvent.wait(APPLIST_FAILED_POLLING_RETRY_MS);
}
}
} catch (InterruptedException e) {
return false;
}
return thread != null && !thread.isInterrupted();
}
private PollingTuple getPollingTuple(ComputerDetails details) {
synchronized (pollingTuples) {
for (PollingTuple tuple : pollingTuples) {
if (details.uuid.equals(tuple.computer.uuid)) {
return tuple;
}
}
}
return null;
}
public void start() {
thread = new Thread() {
@Override
public void run() {
int emptyAppListResponses = 0;
do {
InetAddress selectedAddr;
// Can't poll if it's not online
if (computer.state != ComputerDetails.State.ONLINE) {
if (listener != null) {
listener.notifyComputerUpdated(computer);
}
continue;
}
// Can't poll if there's no UUID yet
if (computer.uuid == null) {
continue;
}
if (computer.reachability == ComputerDetails.Reachability.LOCAL) {
selectedAddr = computer.localIp;
}
else {
selectedAddr = computer.remoteIp;
}
NvHTTP http = new NvHTTP(selectedAddr, idManager.getUniqueId(),
null, PlatformBinding.getCryptoProvider(ComputerManagerService.this));
PollingTuple tuple = getPollingTuple(computer);
try {
String appList;
if (tuple != null) {
// If we're polling this machine too, grab the network lock
// while doing the app list request to prevent other requests
// from being issued in the meantime.
synchronized (tuple.networkLock) {
appList = http.getAppListRaw();
}
}
else {
// No polling is happening now, so we just call it directly
appList = http.getAppListRaw();
}
List<NvApp> list = NvHTTP.getAppListByReader(new StringReader(appList));
if (list.isEmpty()) {
LimeLog.warning("Empty app list received from "+computer.uuid);
// The app list might actually be empty, so if we get an empty response a few times
// in a row, we'll go ahead and believe it.
emptyAppListResponses++;
}
if (appList != null && !appList.isEmpty() &&
(!list.isEmpty() || emptyAppListResponses >= EMPTY_LIST_THRESHOLD)) {
// Open the cache file
OutputStream cacheOut = null;
try {
cacheOut = CacheHelper.openCacheFileForOutput(getCacheDir(), "applist", computer.uuid.toString());
CacheHelper.writeStringToOutputStream(cacheOut, appList);
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (cacheOut != null) {
cacheOut.close();
}
} catch (IOException ignored) {}
}
// Reset empty count if it wasn't empty this time
if (!list.isEmpty()) {
emptyAppListResponses = 0;
}
// Update the computer
computer.rawAppList = appList;
receivedAppList = true;
// Notify that the app list has been updated
// and ensure that the thread is still active
if (listener != null && thread != null) {
listener.notifyComputerUpdated(computer);
}
}
else if (appList == null || appList.isEmpty()) {
LimeLog.warning("Null app list received from "+computer.uuid);
}
} catch (IOException e) {
e.printStackTrace();
} catch (XmlPullParserException e) {
e.printStackTrace();
}
} while (waitPollingDelay());
}
};
thread.start();
}
public void stop() {
if (thread != null) {
thread.interrupt();
// Don't join here because we might be blocked on network I/O
thread = null;
}
}
}
}
class PollingTuple {
public Thread thread;
public final ComputerDetails computer;
public final Object networkLock;
public long lastSuccessfulPollMs;
public PollingTuple(ComputerDetails computer, Thread thread) {
this.computer = computer;
this.thread = thread;
this.networkLock = new Object();
}
}
class ReachabilityTuple {
public final InetAddress reachableAddress;
public final ComputerDetails computer;
public ReachabilityTuple(ComputerDetails computer, InetAddress reachableAddress) {
this.computer = computer;
this.reachableAddress = reachableAddress;
}
}