package com.danikula.videocache;
import android.content.Context;
import android.net.Uri;
import com.danikula.videocache.file.DiskUsage;
import com.danikula.videocache.file.FileNameGenerator;
import com.danikula.videocache.file.Md5FileNameGenerator;
import com.danikula.videocache.file.TotalCountLruDiskUsage;
import com.danikula.videocache.file.TotalSizeLruDiskUsage;
import com.danikula.videocache.headers.EmptyHeadersInjector;
import com.danikula.videocache.headers.HeaderInjector;
import com.danikula.videocache.sourcestorage.SourceInfoStorage;
import com.danikula.videocache.sourcestorage.SourceInfoStorageFactory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.File;
import java.io.IOException;
import java.net.InetAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.SocketException;
import java.util.Locale;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import static com.danikula.videocache.Preconditions.checkAllNotNull;
import static com.danikula.videocache.Preconditions.checkNotNull;
/**
* Simple lightweight proxy server with file caching support that handles HTTP requests.
* Typical usage:
* <pre><code>
* public onCreate(Bundle state) {
* super.onCreate(state);
*
* HttpProxyCacheServer proxy = getProxy();
* String proxyUrl = proxy.getProxyUrl(VIDEO_URL);
* videoView.setVideoPath(proxyUrl);
* }
*
* private HttpProxyCacheServer getProxy() {
* // should return single instance of HttpProxyCacheServer shared for whole app.
* }
* </code></pre>
*
* @author Alexey Danilov ([email protected]).
*/
public class HttpProxyCacheServer {
private static final Logger LOG = LoggerFactory.getLogger("HttpProxyCacheServer");
private static final String PROXY_HOST = "127.0.0.1";
private final Object clientsLock = new Object();
private final ExecutorService socketProcessor = Executors.newFixedThreadPool(8);
private final Map<String, HttpProxyCacheServerClients> clientsMap = new ConcurrentHashMap<>();
private final ServerSocket serverSocket;
private final int port;
private final Thread waitConnectionThread;
private final Config config;
private final Pinger pinger;
public HttpProxyCacheServer(Context context) {
this(new Builder(context).buildConfig());
}
private HttpProxyCacheServer(Config config) {
this.config = checkNotNull(config);
try {
InetAddress inetAddress = InetAddress.getByName(PROXY_HOST);
this.serverSocket = new ServerSocket(0, 8, inetAddress);
this.port = serverSocket.getLocalPort();
IgnoreHostProxySelector.install(PROXY_HOST, port);
CountDownLatch startSignal = new CountDownLatch(1);
this.waitConnectionThread = new Thread(new WaitRequestsRunnable(startSignal));
this.waitConnectionThread.start();
startSignal.await(); // freeze thread, wait for server starts
this.pinger = new Pinger(PROXY_HOST, port);
LOG.info("Proxy cache server started. Is it alive? " + isAlive());
} catch (IOException | InterruptedException e) {
socketProcessor.shutdown();
throw new IllegalStateException("Error starting local proxy server", e);
}
}
/**
* Returns url that wrap original url and should be used for client (MediaPlayer, ExoPlayer, etc).
* <p>
* If file for this url is fully cached (it means method {@link #isCached(String)} returns {@code true})
* then file:// uri to cached file will be returned.
* <p>
* Calling this method has same effect as calling {@link #getProxyUrl(String, boolean)} with 2nd parameter set to {@code true}.
*
* @param url a url to file that should be cached.
* @return a wrapped by proxy url if file is not fully cached or url pointed to cache file otherwise.
*/
public String getProxyUrl(String url) {
return getProxyUrl(url, true);
}
/**
* Returns url that wrap original url and should be used for client (MediaPlayer, ExoPlayer, etc).
* <p>
* If parameter {@code allowCachedFileUri} is {@code true} and file for this url is fully cached
* (it means method {@link #isCached(String)} returns {@code true}) then file:// uri to cached file will be returned.
*
* @param url a url to file that should be cached.
* @param allowCachedFileUri {@code true} if allow to return file:// uri if url is fully cached
* @return a wrapped by proxy url if file is not fully cached or url pointed to cache file otherwise (if {@code allowCachedFileUri} is {@code true}).
*/
public String getProxyUrl(String url, boolean allowCachedFileUri) {
if (allowCachedFileUri && isCached(url)) {
File cacheFile = getCacheFile(url);
touchFileSafely(cacheFile);
return Uri.fromFile(cacheFile).toString();
}
return isAlive() ? appendToProxyUrl(url) : url;
}
public void registerCacheListener(CacheListener cacheListener, String url) {
checkAllNotNull(cacheListener, url);
synchronized (clientsLock) {
try {
getClients(url).registerCacheListener(cacheListener);
} catch (ProxyCacheException e) {
LOG.warn("Error registering cache listener", e);
}
}
}
public void unregisterCacheListener(CacheListener cacheListener, String url) {
checkAllNotNull(cacheListener, url);
synchronized (clientsLock) {
try {
getClients(url).unregisterCacheListener(cacheListener);
} catch (ProxyCacheException e) {
LOG.warn("Error registering cache listener", e);
}
}
}
public void unregisterCacheListener(CacheListener cacheListener) {
checkNotNull(cacheListener);
synchronized (clientsLock) {
for (HttpProxyCacheServerClients clients : clientsMap.values()) {
clients.unregisterCacheListener(cacheListener);
}
}
}
/**
* Checks is cache contains fully cached file for particular url.
*
* @param url an url cache file will be checked for.
* @return {@code true} if cache contains fully cached file for passed in parameters url.
*/
public boolean isCached(String url) {
checkNotNull(url, "Url can't be null!");
return getCacheFile(url).exists();
}
public void shutdown() {
LOG.info("Shutdown proxy server");
shutdownClients();
config.sourceInfoStorage.release();
waitConnectionThread.interrupt();
try {
if (!serverSocket.isClosed()) {
serverSocket.close();
}
} catch (IOException e) {
onError(new ProxyCacheException("Error shutting down proxy server", e));
}
}
private boolean isAlive() {
return pinger.ping(3, 70); // 70+140+280=max~500ms
}
private String appendToProxyUrl(String url) {
return String.format(Locale.US, "http://%s:%d/%s", PROXY_HOST, port, ProxyCacheUtils.encode(url));
}
private File getCacheFile(String url) {
File cacheDir = config.cacheRoot;
String fileName = config.fileNameGenerator.generate(url);
return new File(cacheDir, fileName);
}
private void touchFileSafely(File cacheFile) {
try {
config.diskUsage.touch(cacheFile);
} catch (IOException e) {
LOG.error("Error touching file " + cacheFile, e);
}
}
private void shutdownClients() {
synchronized (clientsLock) {
for (HttpProxyCacheServerClients clients : clientsMap.values()) {
clients.shutdown();
}
clientsMap.clear();
}
}
private void waitForRequest() {
try {
while (!Thread.currentThread().isInterrupted()) {
Socket socket = serverSocket.accept();
LOG.debug("Accept new socket " + socket);
socketProcessor.submit(new SocketProcessorRunnable(socket));
}
} catch (IOException e) {
onError(new ProxyCacheException("Error during waiting connection", e));
}
}
private void processSocket(Socket socket) {
try {
GetRequest request = GetRequest.read(socket.getInputStream());
LOG.debug("Request to cache proxy:" + request);
String url = ProxyCacheUtils.decode(request.uri);
if (pinger.isPingRequest(url)) {
pinger.responseToPing(socket);
} else {
HttpProxyCacheServerClients clients = getClients(url);
clients.processRequest(request, socket);
}
} catch (SocketException e) {
// There is no way to determine that client closed connection http://stackoverflow.com/a/10241044/999458
// So just to prevent log flooding don't log stacktrace
LOG.debug("Closing socket… Socket is closed by client.");
} catch (ProxyCacheException | IOException e) {
onError(new ProxyCacheException("Error processing request", e));
} finally {
releaseSocket(socket);
LOG.debug("Opened connections: " + getClientsCount());
}
}
private HttpProxyCacheServerClients getClients(String url) throws ProxyCacheException {
synchronized (clientsLock) {
HttpProxyCacheServerClients clients = clientsMap.get(url);
if (clients == null) {
clients = new HttpProxyCacheServerClients(url, config);
clientsMap.put(url, clients);
}
return clients;
}
}
private int getClientsCount() {
synchronized (clientsLock) {
int count = 0;
for (HttpProxyCacheServerClients clients : clientsMap.values()) {
count += clients.getClientsCount();
}
return count;
}
}
private void releaseSocket(Socket socket) {
closeSocketInput(socket);
closeSocketOutput(socket);
closeSocket(socket);
}
private void closeSocketInput(Socket socket) {
try {
if (!socket.isInputShutdown()) {
socket.shutdownInput();
}
} catch (SocketException e) {
// There is no way to determine that client closed connection http://stackoverflow.com/a/10241044/999458
// So just to prevent log flooding don't log stacktrace
LOG.debug("Releasing input stream… Socket is closed by client.");
} catch (IOException e) {
onError(new ProxyCacheException("Error closing socket input stream", e));
}
}
private void closeSocketOutput(Socket socket) {
try {
if (!socket.isOutputShutdown()) {
socket.shutdownOutput();
}
} catch (IOException e) {
LOG.warn("Failed to close socket on proxy side: {}. It seems client have already closed connection.", e.getMessage());
}
}
private void closeSocket(Socket socket) {
try {
if (!socket.isClosed()) {
socket.close();
}
} catch (IOException e) {
onError(new ProxyCacheException("Error closing socket", e));
}
}
private void onError(Throwable e) {
LOG.error("HttpProxyCacheServer error", e);
}
private final class WaitRequestsRunnable implements Runnable {
private final CountDownLatch startSignal;
public WaitRequestsRunnable(CountDownLatch startSignal) {
this.startSignal = startSignal;
}
@Override
public void run() {
startSignal.countDown();
waitForRequest();
}
}
private final class SocketProcessorRunnable implements Runnable {
private final Socket socket;
public SocketProcessorRunnable(Socket socket) {
this.socket = socket;
}
@Override
public void run() {
processSocket(socket);
}
}
/**
* Builder for {@link HttpProxyCacheServer}.
*/
public static final class Builder {
private static final long DEFAULT_MAX_SIZE = 512 * 1024 * 1024;
private File cacheRoot;
private FileNameGenerator fileNameGenerator;
private DiskUsage diskUsage;
private SourceInfoStorage sourceInfoStorage;
private HeaderInjector headerInjector;
public Builder(Context context) {
this.sourceInfoStorage = SourceInfoStorageFactory.newSourceInfoStorage(context);
this.cacheRoot = StorageUtils.getIndividualCacheDirectory(context);
this.diskUsage = new TotalSizeLruDiskUsage(DEFAULT_MAX_SIZE);
this.fileNameGenerator = new Md5FileNameGenerator();
this.headerInjector = new EmptyHeadersInjector();
}
/**
* Overrides default cache folder to be used for caching files.
* <p>
* By default AndroidVideoCache uses
* '/Android/data/[app_package_name]/cache/video-cache/' if card is mounted and app has appropriate permission
* or 'video-cache' subdirectory in default application's cache directory otherwise.
* </p>
* <b>Note</b> directory must be used <b>only</b> for AndroidVideoCache files.
*
* @param file a cache directory, can't be null.
* @return a builder.
*/
public Builder cacheDirectory(File file) {
this.cacheRoot = checkNotNull(file);
return this;
}
/**
* Overrides default cache file name generator {@link Md5FileNameGenerator} .
*
* @param fileNameGenerator a new file name generator.
* @return a builder.
*/
public Builder fileNameGenerator(FileNameGenerator fileNameGenerator) {
this.fileNameGenerator = checkNotNull(fileNameGenerator);
return this;
}
/**
* Sets max cache size in bytes.
* <p>
* All files that exceeds limit will be deleted using LRU strategy.
* Default value is 512 Mb.
* </p>
* Note this method overrides result of calling {@link #maxCacheFilesCount(int)}
*
* @param maxSize max cache size in bytes.
* @return a builder.
*/
public Builder maxCacheSize(long maxSize) {
this.diskUsage = new TotalSizeLruDiskUsage(maxSize);
return this;
}
/**
* Sets max cache files count.
* All files that exceeds limit will be deleted using LRU strategy.
* Note this method overrides result of calling {@link #maxCacheSize(long)}
*
* @param count max cache files count.
* @return a builder.
*/
public Builder maxCacheFilesCount(int count) {
this.diskUsage = new TotalCountLruDiskUsage(count);
return this;
}
/**
* Set custom DiskUsage logic for handling when to keep or clean cache.
*
* @param diskUsage a disk usage strategy, cant be {@code null}.
* @return a builder.
*/
public Builder diskUsage(DiskUsage diskUsage) {
this.diskUsage = checkNotNull(diskUsage);
return this;
}
/**
* Add headers along the request to the server
*
* @param headerInjector to inject header base on url
* @return a builder
*/
public Builder headerInjector(HeaderInjector headerInjector) {
this.headerInjector = checkNotNull(headerInjector);
return this;
}
/**
* Builds new instance of {@link HttpProxyCacheServer}.
*
* @return proxy cache. Only single instance should be used across whole app.
*/
public HttpProxyCacheServer build() {
Config config = buildConfig();
return new HttpProxyCacheServer(config);
}
private Config buildConfig() {
return new Config(cacheRoot, fileNameGenerator, diskUsage, sourceInfoStorage, headerInjector);
}
}
}
