permanently cache last resolver result

src/main/java/eu/siacs/conversations/persistance/DatabaseBackend.java

@@ -52,6 +52,7 @@ import eu.siacs.conversations.entities.ServiceDiscoveryResult;
 import eu.siacs.conversations.services.ShortcutService;
 import eu.siacs.conversations.utils.CryptoHelper;
 import eu.siacs.conversations.utils.MimeUtils;
+import eu.siacs.conversations.utils.Resolver;
 import eu.siacs.conversations.xmpp.jid.InvalidJidException;
 import eu.siacs.conversations.xmpp.jid.Jid;
 import eu.siacs.conversations.xmpp.mam.MamReference;
@@ -61,7 +62,7 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 	private static DatabaseBackend instance = null;
 
 	private static final String DATABASE_NAME = "history";
-	private static final int DATABASE_VERSION = 38;
+	private static final int DATABASE_VERSION = 39;
 
 	private static String CREATE_CONTATCS_STATEMENT = "create table "
 			+ Contact.TABLENAME + "(" + Contact.ACCOUNT + " TEXT, "
@@ -148,9 +149,18 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 			+ ") ON CONFLICT IGNORE"
 			+ ");";
 
-	private static String START_TIMES_TABLE = "start_times";
+	private static String RESOLVER_RESULTS_TABLENAME = "resolver_results";
 
-	private static String CREATE_START_TIMES_TABLE = "create table "+START_TIMES_TABLE+" (timestamp NUMBER);";
+	private static String CREATE_RESOLVER_RESULTS_TABLE = "create table "+RESOLVER_RESULTS_TABLENAME+"("
+			+ Resolver.Result.DOMAIN + " TEXT,"
+			+ Resolver.Result.HOSTNAME + " TEXT,"
+			+ Resolver.Result.IP + " BLOB,"
+			+ Resolver.Result.PRIORITY + " NUMBER,"
+			+ Resolver.Result.DIRECT_TLS + " NUMBER,"
+			+ Resolver.Result.AUTHENTICATED + " NUMBER,"
+			+ Resolver.Result.PORT + " NUMBER,"
+			+ "UNIQUE("+Resolver.Result.DOMAIN+") ON CONFLICT REPLACE"
+			+ ");";
 
 	private static String CREATE_MESSAGE_TIME_INDEX = "create INDEX message_time_index ON "+Message.TABLENAME+"("+Message.TIME_SENT+")";
 	private static String CREATE_MESSAGE_CONVERSATION_INDEX = "create INDEX message_conversation_index ON "+Message.TABLENAME+"("+Message.CONVERSATION+")";
@@ -213,7 +223,7 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 		db.execSQL(CREATE_SIGNED_PREKEYS_STATEMENT);
 		db.execSQL(CREATE_IDENTITIES_STATEMENT);
 		db.execSQL(CREATE_PRESENCE_TEMPLATES_STATEMENT);
-		db.execSQL(CREATE_START_TIMES_TABLE);
+		db.execSQL(CREATE_RESOLVER_RESULTS_TABLE);
 	}
 
 	@Override
@@ -369,9 +379,6 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 		if (oldVersion < 29 && newVersion >= 29) {
 			db.execSQL("ALTER TABLE " + Message.TABLENAME + " ADD COLUMN " + Message.ERROR_MESSAGE + " TEXT");
 		}
-		if (oldVersion < 30 && newVersion >= 30) {
-			db.execSQL(CREATE_START_TIMES_TABLE);
-		}
 		if (oldVersion >= 15 && oldVersion < 31 && newVersion >= 31) {
 			db.execSQL("ALTER TABLE "+ SQLiteAxolotlStore.IDENTITIES_TABLENAME + " ADD COLUMN "+SQLiteAxolotlStore.TRUST + " TEXT");
 			db.execSQL("ALTER TABLE "+ SQLiteAxolotlStore.IDENTITIES_TABLENAME + " ADD COLUMN "+SQLiteAxolotlStore.ACTIVE + " NUMBER");
@@ -465,6 +472,10 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 		if (oldVersion < 38 && newVersion >= 38) {
 			db.execSQL("ALTER TABLE " + Message.TABLENAME + " ADD COLUMN " + Message.MARKABLE + " NUMBER DEFAULT 0");
 		}
+
+		if (oldVersion < 39 && newVersion >= 39) {
+			db.execSQL(CREATE_RESOLVER_RESULTS_TABLE);
+		}
 	}
 
 	private static ContentValues createFingerprintStatusContentValues(FingerprintStatus.Trust trust, boolean active) {
@@ -605,6 +616,28 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 		return result;
 	}
 
+	public void saveResolverResult(String domain, Resolver.Result result) {
+		SQLiteDatabase db = this.getWritableDatabase();
+		ContentValues contentValues = result.toContentValues();
+		contentValues.put(Resolver.Result.DOMAIN,domain);
+		db.insert(RESOLVER_RESULTS_TABLENAME, null, contentValues);
+	}
+
+	public Resolver.Result findResolverResult(String domain) {
+		SQLiteDatabase db = this.getReadableDatabase();
+		String where = Resolver.Result.DOMAIN+"=?";
+		String[] whereArgs = {domain};
+		Cursor cursor = db.query(RESOLVER_RESULTS_TABLENAME,null,where,whereArgs,null,null,null);
+		Resolver.Result result = null;
+		if (cursor != null) {
+			if (cursor.moveToFirst()) {
+				result = Resolver.Result.fromCursor(cursor);
+			}
+			cursor.close();
+		}
+		return result;
+	}
+
 	public void insertPresenceTemplate(PresenceTemplate template) {
 		SQLiteDatabase db = this.getWritableDatabase();
 		db.insert(PresenceTemplate.TABELNAME, null, template.getContentValues());

src/main/java/eu/siacs/conversations/utils/Resolver.java

@@ -1,12 +1,14 @@
 package eu.siacs.conversations.utils;
 
-import android.content.Context;
+import android.content.ContentValues;
+import android.database.Cursor;
 import android.support.annotation.NonNull;
 import android.util.Log;
 
 import java.io.IOException;
 import java.net.Inet4Address;
 import java.net.InetAddress;
+import java.net.UnknownHostException;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashSet;
@@ -57,29 +59,29 @@ public class Resolver {
 		} catch (MultipleIoException e) {
 			messages.addAll(extractMessages(e));
 		} catch (Throwable throwable) {
-            Log.d(Config.LOGTAG,Resolver.class.getSimpleName()+": error resolving SRV record (direct TLS)",throwable);
+			Log.d(Config.LOGTAG, Resolver.class.getSimpleName() + ": error resolving SRV record (direct TLS)", throwable);
 		}
 		try {
 			results.addAll(resolveSrv(domain, false));
 		} catch (MultipleIoException e) {
 			messages.addAll(extractMessages(e));
 		} catch (Throwable throwable) {
-            Log.d(Config.LOGTAG,Resolver.class.getSimpleName()+": error resolving SRV record (STARTTLS)",throwable);
+			Log.d(Config.LOGTAG, Resolver.class.getSimpleName() + ": error resolving SRV record (STARTTLS)", throwable);
 		}
 		if (results.size() == 0) {
 			if (messages.size() == 1 && messages.contains(NETWORK_IS_UNREACHABLE)) {
 				throw new NetworkIsUnreachableException();
 			}
-            results.addAll(resolveNoSrvRecords(DNSName.from(domain),true));
+			results.addAll(resolveNoSrvRecords(DNSName.from(domain), true));
 		}
 		Collections.sort(results);
-        Log.d(Config.LOGTAG,Resolver.class.getSimpleName()+": "+results.toString());
+		Log.d(Config.LOGTAG, Resolver.class.getSimpleName() + ": " + results.toString());
 		return results;
 	}
 
 	private static HashSet<String> extractMessages(MultipleIoException e) {
 		HashSet<String> messages = new HashSet<>();
-        for(Exception inner : e.getExceptions()) {
+		for (Exception inner : e.getExceptions()) {
 			if (inner instanceof MultipleIoException) {
 				messages.addAll(extractMessages((MultipleIoException) inner));
 			} else {
@@ -93,12 +95,12 @@ public class Resolver {
 		if (Thread.currentThread().isInterrupted()) {
 			return Collections.emptyList();
 		}
-        DNSName dnsName = DNSName.from((directTls ? DIRECT_TLS_SERVICE : STARTTLS_SERICE)+"._tcp."+domain);
+		DNSName dnsName = DNSName.from((directTls ? DIRECT_TLS_SERVICE : STARTTLS_SERICE) + "._tcp." + domain);
-        ResolverResult<SRV> result = resolveWithFallback(dnsName,SRV.class);
+		ResolverResult<SRV> result = resolveWithFallback(dnsName, SRV.class);
 		List<Result> results = new ArrayList<>();
-        for(SRV record : result.getAnswersOrEmptySet()) {
+		for (SRV record : result.getAnswersOrEmptySet()) {
-            final boolean addedIPv4 = results.addAll(resolveIp(record,A.class,result.isAuthenticData(),directTls));
+			final boolean addedIPv4 = results.addAll(resolveIp(record, A.class, result.isAuthenticData(), directTls));
-            results.addAll(resolveIp(record,AAAA.class,result.isAuthenticData(),directTls));
+			results.addAll(resolveIp(record, AAAA.class, result.isAuthenticData(), directTls));
 			if (!addedIPv4 && !Thread.currentThread().isInterrupted()) {
 				Result resolverResult = Result.fromRecord(record, directTls);
 				resolverResult.authenticated = resolverResult.isAuthenticated();
@@ -114,7 +116,7 @@ public class Resolver {
 		}
 		List<Result> list = new ArrayList<>();
 		try {
-            ResolverResult<D> results = resolveWithFallback(srv.name,type, authenticated);
+			ResolverResult<D> results = resolveWithFallback(srv.name, type, authenticated);
 			for (D record : results.getAnswersOrEmptySet()) {
 				Result resolverResult = Result.fromRecord(srv, directTls);
 				resolverResult.authenticated = results.isAuthenticData() && authenticated;
@@ -122,7 +124,7 @@ public class Resolver {
 				list.add(resolverResult);
 			}
 		} catch (Throwable t) {
-            Log.d(Config.LOGTAG,Resolver.class.getSimpleName()+": error resolving "+type.getSimpleName()+" "+t.getMessage());
+			Log.d(Config.LOGTAG, Resolver.class.getSimpleName() + ": error resolving " + type.getSimpleName() + " " + t.getMessage());
 		}
 		return list;
 	}
@@ -130,11 +132,11 @@ public class Resolver {
 	private static List<Result> resolveNoSrvRecords(DNSName dnsName, boolean withCnames) {
 		List<Result> results = new ArrayList<>();
 		try {
-            for(A a : resolveWithFallback(dnsName,A.class,false).getAnswersOrEmptySet()) {
+			for (A a : resolveWithFallback(dnsName, A.class, false).getAnswersOrEmptySet()) {
-                results.add(Result.createDefault(dnsName,a.getInetAddress()));
+				results.add(Result.createDefault(dnsName, a.getInetAddress()));
 			}
-            for(AAAA aaaa : resolveWithFallback(dnsName,AAAA.class,false).getAnswersOrEmptySet()) {
+			for (AAAA aaaa : resolveWithFallback(dnsName, AAAA.class, false).getAnswersOrEmptySet()) {
-                results.add(Result.createDefault(dnsName,aaaa.getInetAddress()));
+				results.add(Result.createDefault(dnsName, aaaa.getInetAddress()));
 			}
 			if (results.size() == 0 && withCnames) {
 				for (CNAME cname : resolveWithFallback(dnsName, CNAME.class, false).getAnswersOrEmptySet()) {
@@ -142,14 +144,14 @@ public class Resolver {
 				}
 			}
 		} catch (Throwable throwable) {
-            Log.d(Config.LOGTAG, Resolver.class.getSimpleName() + "error resolving fallback records",throwable);
+			Log.d(Config.LOGTAG, Resolver.class.getSimpleName() + "error resolving fallback records", throwable);
 		}
 		results.add(Result.createDefault(dnsName));
 		return results;
 	}
 
 	private static <D extends Data> ResolverResult<D> resolveWithFallback(DNSName dnsName, Class<D> type) throws IOException {
-        return resolveWithFallback(dnsName,type,validateHostname());
+		return resolveWithFallback(dnsName, type, validateHostname());
 	}
 
 	private static <D extends Data> ResolverResult<D> resolveWithFallback(DNSName dnsName, Class<D> type, boolean validateHostname) throws IOException {
@@ -174,11 +176,46 @@ public class Resolver {
 	}
 
 	public static class Result implements Comparable<Result> {
+		@Override
+		public boolean equals(Object o) {
+			if (this == o) return true;
+			if (o == null || getClass() != o.getClass()) return false;
+
+			Result result = (Result) o;
+
+			if (port != result.port) return false;
+			if (directTls != result.directTls) return false;
+			if (authenticated != result.authenticated) return false;
+			if (priority != result.priority) return false;
+			if (ip != null ? !ip.equals(result.ip) : result.ip != null) return false;
+			return hostname != null ? hostname.equals(result.hostname) : result.hostname == null;
+		}
+
+		@Override
+		public int hashCode() {
+			int result = ip != null ? ip.hashCode() : 0;
+			result = 31 * result + (hostname != null ? hostname.hashCode() : 0);
+			result = 31 * result + port;
+			result = 31 * result + (directTls ? 1 : 0);
+			result = 31 * result + (authenticated ? 1 : 0);
+			result = 31 * result + priority;
+			return result;
+		}
+
+		public static final String DOMAIN = "domain";
+
+		public static final String IP = "ip";
+		public static final String HOSTNAME = "hostname";
+		public static final String PORT = "port";
+		public static final String PRIORITY = "priority";
+		public static final String DIRECT_TLS = "directTls";
+		public static final String AUTHENTICATED = "authenticated";
+
 		private InetAddress ip;
 		private DNSName hostname;
 		private int port = 5222;
 		private boolean directTls = false;
-        private boolean authenticated =false;
+		private boolean authenticated = false;
 		private int priority;
 
 		public InetAddress getIp() {
@@ -204,7 +241,7 @@ public class Resolver {
 		@Override
 		public String toString() {
 			return "Result{" +
-                    "ip='" + (ip==null?null:ip.getHostAddress()) + '\'' +
+					"ip='" + (ip == null ? null : ip.getHostAddress()) + '\'' +
 					", hostame='" + hostname.toString() + '\'' +
 					", port=" + port +
 					", directTls=" + directTls +
@@ -254,9 +291,36 @@ public class Resolver {
 		}
 
 		public static Result createDefault(DNSName hostname) {
-            return createDefault(hostname,null);
+			return createDefault(hostname, null);
+		}
+
+		public static Result fromCursor(Cursor cursor) {
+			final Result result = new Result();
+			try {
+				result.ip = InetAddress.getByAddress(cursor.getBlob(cursor.getColumnIndex(IP)));
+			} catch (UnknownHostException e) {
+				result.ip = null;
+			}
+			result.hostname = DNSName.from(cursor.getString(cursor.getColumnIndex(HOSTNAME)));
+			result.port = cursor.getInt(cursor.getColumnIndex(PORT));
+			result.priority = cursor.getInt(cursor.getColumnIndex(PRIORITY));
+			result.authenticated = cursor.getInt(cursor.getColumnIndex(AUTHENTICATED)) > 0;
+			result.directTls = cursor.getInt(cursor.getColumnIndex(DIRECT_TLS)) > 0;
+			return result;
+		}
+
+		public ContentValues toContentValues() {
+			final ContentValues contentValues = new ContentValues();
+			contentValues.put(IP, ip.getAddress());
+			contentValues.put(HOSTNAME, hostname.toString());
+			contentValues.put(PORT, port);
+			contentValues.put(PRIORITY, priority);
+			contentValues.put(DIRECT_TLS, directTls ? 1 : 0);
+			contentValues.put(AUTHENTICATED, authenticated ? 1 : 0);
+			return contentValues;
 		}
 	}
+
 	public static class NetworkIsUnreachableException extends Exception {
 
 	}

src/main/java/eu/siacs/conversations/xmpp/XmppConnection.java

@@ -351,7 +351,18 @@ public class XmppConnection implements Runnable {
 					throw new IOException(e.getMessage());
 				}
 			} else {
+				final String domain = account.getJid().getDomainpart();
 				List<Resolver.Result> results = Resolver.resolve(account.getJid().getDomainpart());
+				Resolver.Result storedBackupResult;
+				if (!Thread.currentThread().isInterrupted()) {
+					storedBackupResult = mXmppConnectionService.databaseBackend.findResolverResult(domain);
+					if (storedBackupResult != null && !results.contains(storedBackupResult)) {
+						results.add(storedBackupResult);
+						Log.d(Config.LOGTAG, account.getJid().toBareJid() + ": loaded backup resolver result from db: " + storedBackupResult);
+					}
+				} else {
+					storedBackupResult = null;
+				}
 				for (Iterator<Resolver.Result> iterator = results.iterator(); iterator.hasNext(); ) {
 					final Resolver.Result result = iterator.next();
 					if (Thread.currentThread().isInterrupted()) {
@@ -400,6 +411,9 @@ public class XmppConnection implements Runnable {
 							}
 						}
 						if (startXmpp(localSocket)) {
+							if (!result.equals(storedBackupResult)) {
+								mXmppConnectionService.databaseBackend.saveResolverResult(domain, result);
+							}
 							break; // successfully connected to server that speaks xmpp
 						} else {
 							localSocket.close();