tor: Implement ControlPortFileParser

Presently, we parse Tor's log file to detect when the control port is ready. This is unstable and could break with any Tor update. A better approach is to use Tor's 'ControlPortWriteToFile' config option and parse the control port from that file.

Ref: bisq-network#1798

network/tor/tor/src/main/java/bisq/tor/process/ControlPortFileParseFailureException.java

@@ -0,0 +1,28 @@
+/*
+ * This file is part of Bisq.
+ *
+ * Bisq is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or (at
+ * your option) any later version.
+ *
+ * Bisq is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public
+ * License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with Bisq. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package bisq.tor.process;
+
+public class ControlPortFileParseFailureException extends RuntimeException {
+    public ControlPortFileParseFailureException(String message) {
+        super(message);
+    }
+
+    public ControlPortFileParseFailureException(Throwable cause) {
+        super(cause);
+    }
+}

network/tor/tor/src/main/java/bisq/tor/process/ControlPortFileParser.java

@@ -0,0 +1,66 @@
+/*
+ * This file is part of Bisq.
+ *
+ * Bisq is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or (at
+ * your option) any later version.
+ *
+ * Bisq is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public
+ * License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with Bisq. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package bisq.tor.process;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+public class ControlPortFileParser {
+    private static final String PORT_MARKER = "PORT=";
+
+    public static int parse(Path controlPortFilePath) {
+        try {
+            String fileContent = Files.readString(controlPortFilePath);
+
+            if (isControlPortFileReady(fileContent)) {
+                for (String line : fileContent.split("\n")) {
+                    if (isPortLine(line)) {
+                        return parsePort(line);
+                    }
+                }
+            }
+
+            throw new ControlPortFileParseFailureException("Parsed file is invalid or incomplete: " + fileContent);
+
+        } catch (IOException e) {
+            throw new ControlPortFileParseFailureException(e);
+        }
+    }
+
+    private static boolean isControlPortFileReady(String fileContent) {
+        return fileContent.contains("\n") && fileContent.contains(PORT_MARKER);
+    }
+
+    private static boolean isPortLine(String line) {
+        return line.startsWith("PORT=");
+    }
+
+    private static int parsePort(String line) {
+        // PORT=127.0.0.1:37611
+        String lineWithoutPrefix = line.replace("PORT=", "");
+        String[] ipAndPort = lineWithoutPrefix.split(":");
+
+        if (ipAndPort.length == 2) {
+            String port = ipAndPort[1];
+            return Integer.parseInt(port);
+        }
+
+        throw new ControlPortFileParseFailureException("Couldn't parse control port line: " + line);
+    }
+}