SyncContext:readStdin(): a virtual method for reading input via stdin

The new method is needed for importing item data from stdin, a new
feature for the command line. The default implementation which is
used when executing the command line locally reads from std::cin
directly.

The syncevo-dbus-server would have to ask its client for the data;
this hasn't been implemented yet. To catch the problem and inform
the user, an exception is thrown there.

src/syncevo-dbus-server.cpp

@@ -1451,6 +1451,11 @@ public:
     bool savePassword(const string &passwordName, 
                       const string &password, 
                       const ConfigPasswordKey &key);
+
+    /**
+     * Read stdin via InfoRequest/Response.
+     */
+    void readStdin(string &content);
 };
 
 /**
@@ -2711,6 +2716,10 @@ bool DBusUserInterface::savePassword(const string &passwordName,
 #endif
 }
 
+void DBusUserInterface::readStdin(string &content)
+{
+    throwError("reading stdin in D-Bus server not supported, use --daemon=no in command line");
+}
 
 /***************** DBusSync implementation **********************/
 

src/syncevo/SyncContext.cpp

@@ -1401,6 +1401,13 @@ string SyncContext::askPassword(const string &passwordName, const string &descr,
     }
 }
 
+void SyncContext::readStdin(string &content)
+{
+    if (!ReadFile(cin, content)) {
+        throwError("stdin", errno);
+    }
+}
+
 string SyncContext::getUsedSyncURL() {
     vector<string> urls = getSyncURL();
     BOOST_FOREACH (string url, urls) {

src/syncevo/SyncContext.h

@@ -432,6 +432,14 @@ class SyncContext : public SyncConfig, public ConfigUserInterface {
     bool getRemoteInitiated() {return m_remoteInitiated;}
     void setRemoteInitiated(bool remote) {m_remoteInitiated = remote;}
 
+    /**
+     * Read from stdin until end of stream.
+     *
+     * Default implementation reads from real stdin,
+     * D-Bus server implementation must ask client.
+     */
+    virtual void readStdin(string &content);
+
   protected:
     /** exchange active Synthesis engine */
     SharedEngine swapEngine(SharedEngine newengine) {