Migrate old autosave XML files. (Disabled for now)

Code and tests to demonstrate migrating of older auto-save files, with
blacklisting support to exclude properties. Disabled pending agreement
on the required blacklisting values.

src/Main/CMakeLists.txt

@@ -187,4 +187,5 @@ endif()
 
 if (COMMAND flightgear_test)
 	flightgear_test(posinit test_posinit.cxx)
+	flightgear_test(autosaveMigration test_autosaveMigration.cxx)
 endif()

src/Main/globals.cxx

@@ -675,6 +675,103 @@ SGPath FGGlobals::autosaveFilePath(SGPath userDataPath) const
     return simgear::Dir(userDataPath).file(autosaveName());
 }
 
+static void deleteProperties(SGPropertyNode* props, const string_list& blacklist)
+{
+    const std::string path(props->getPath());
+    auto it = std::find_if(blacklist.begin(), blacklist.end(), [path](const std::string& black)
+                           { return simgear::strutils::matchPropPathToTemplate(path, black); });
+    if (it != blacklist.end()) {
+        SGPropertyNode* pr = props->getParent();
+        pr->removeChild(props);
+        return;
+    }
+
+    // recurse
+    for (int c=0; c < props->nChildren(); ++c) {
+        deleteProperties(props->getChild(c), blacklist);
+    }
+
+}
+
+using VersionPair = std::pair<int, int>;
+
+static bool operator<(const VersionPair& a, const VersionPair& b)
+{
+    if (a.first == b.first) {
+        return a.second < b.second;
+    }
+
+    return a.first < b.first;
+}
+
+static void tryAutosaveMigration(const SGPath& userDataPath, SGPropertyNode* props)
+{
+    const string_list versionParts = simgear::strutils::split(VERSION, ".");
+    if (versionParts.size() < 2) {
+        return;
+    }
+
+    simgear::Dir userDataDir(userDataPath);
+    SGPath migratePath;
+    VersionPair foundVersion(0, 0);
+    const VersionPair currentVersion(simgear::strutils::to_int(versionParts[0]),
+                                     simgear::strutils::to_int(versionParts[1]));
+
+    for (auto previousSave : userDataDir.children(simgear::Dir::TYPE_FILE, ".xml")) {
+        const std::string base = previousSave.file_base();
+        VersionPair v;
+        // extract version from name
+        const int matches = ::sscanf(base.c_str(), "autosave_%d_%d", &v.first, &v.second);
+        if (matches != 2) {
+            continue;
+        }
+        
+        if (currentVersion < v) {
+            // ignore autosaves from more recent versions; this happens when
+            // running unsable and stable at the same time
+            continue;
+        }
+
+        if (v.first < 2000) {
+            // ignore autosaves from older versions, too much change to deal
+            // with.
+            continue;
+        }
+
+        if (foundVersion < v) {
+            foundVersion = v;
+            migratePath = previousSave;
+        }
+    }
+
+    if (!migratePath.exists()) {
+        return;
+    }
+
+    SG_LOG(SG_GENERAL, SG_INFO, "Migrating old autosave:" << migratePath);
+    SGPropertyNode oldProps;
+
+    try {
+        readProperties(migratePath, &oldProps, SGPropertyNode::USERARCHIVE);
+    } catch (sg_exception& e) {
+        SG_LOG(SG_GENERAL, SG_WARN, "failed to read previous user settings:" << e.getMessage()
+               << "(from " << e.getOrigin() << ")");
+        return;
+    }
+
+    // read migration blacklist
+    string_list blacklist;
+    for (auto node : fgGetNode("/sim/autosave-migration/blacklist")->getChildren("path")) {
+        blacklist.push_back(node->getStringValue());
+    }
+
+    // apply migration filters for each property in turn
+    deleteProperties(&oldProps, blacklist);
+
+    // copy remaining props out
+    copyProperties(&oldProps, props);
+}
+
 // Load user settings from the autosave file (normally in $FG_HOME)
 void
 FGGlobals::loadUserSettings(SGPath userDataPath)
@@ -697,6 +794,10 @@ FGGlobals::loadUserSettings(SGPath userDataPath)
           SG_LOG(SG_INPUT, SG_WARN, "failed to read user settings:" << e.getMessage()
             << "(from " << e.getOrigin() << ")");
       }
+    } else {
+#if 0
+        tryAutosaveMigration(userDataPath, &autosave);
+#endif
     }
     copyProperties(&autosave, globals->get_props());
 }

src/Main/test_autosaveMigration.cxx

@@ -0,0 +1,166 @@
+// Written by James Turner, started 2017.
+//
+// Copyright (C) 2017  James Turner
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License as
+// published by the Free Software Foundation; either version 2 of the
+// License, or (at your option) any later version.
+//
+// This program 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
+// General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+
+#include "config.h"
+
+#include "unitTestHelpers.hxx"
+
+#include <simgear/misc/test_macros.hxx>
+#include <simgear/props/props_io.hxx>
+#include <simgear/misc/sgstream.hxx>
+#include <simgear/misc/sg_dir.hxx>
+
+#include "Main/globals.hxx"
+#include "Main/options.hxx"
+#include "Main/fg_props.hxx"
+
+using namespace flightgear;
+
+void writeLegacyAutosave(SGPath userData, int majorVersion, int minorVersion)
+{
+    std::ostringstream os;
+    os << "autosave_" << majorVersion << "_" << minorVersion << ".xml";
+
+    sg_ofstream of(userData / os.str());
+    {
+        of << "<?xml version=\"1.0\"?>" \
+            "<PropertyList>" \
+            "<sim>" \
+            "<window-height>42</window-height>" \
+            "<presets>" \
+            "<foo>12</foo>" \
+            "<child><bar>12</bar></child>" \
+            "</presets>" \
+            "<presets n=\"1\">" \
+            "<foo>13</foo>" \
+            "</presets>" \
+            "<rendering>" \
+            "<msaa>10</msaa>" \
+            "<texture-size>512</texture-size>" \
+            "<texture-pack>" \
+            "<foo>abc</foo>" \
+            "<wibble>abc</wibble>" \
+            "</texture-pack>" \
+            "</rendering>" \
+            "<gui>" \
+            "<dialog n=\"1\">" \
+            "<widget>button</widget>" \
+            "</dialog>" \
+            "<dialog n=\"2\">" \
+            "<widget>slider</widget>" \
+            "</dialog>"\
+            "</gui>" \
+            "</sim>" \
+            "<some-setting>888</some-setting>" \
+            "<views>" \
+            "<view>" \
+            "<new-prop>somevalue</new-prop>" \
+            "<old-prop>somevalue</old-prop>" \
+            "</view>" \
+            "</views>" \
+            "</PropertyList>";
+
+    }
+    of.close();
+}
+
+void writeLegacyAutosave2(SGPath userData, int majorVersion, int minorVersion)
+{
+    std::ostringstream os;
+    os << "autosave_" << majorVersion << "_" << minorVersion << ".xml";
+
+    sg_ofstream of(userData / os.str());
+    {
+        of << "<?xml version=\"1.0\"?>" \
+        "<PropertyList>" \
+        "<sim>" \
+        "<bad>1</bad>" \
+        "</sim>" \
+        "</views>" \
+        "</PropertyList>";
+
+    }
+    of.close();
+}
+
+
+void testMigration()
+{
+    fgtest::initTestGlobals("autosaveMigration");
+
+    Options::reset();
+
+    SGPath testUserDataPath = globals->get_fg_home() / "test_autosave_migrate";
+    if (!testUserDataPath.exists()) {
+        SGPath p = testUserDataPath / "foo";
+        p.create_dir(0755);
+    }
+
+    simgear::Dir homeDir(testUserDataPath);
+    for (auto path : homeDir.children(simgear::Dir::TYPE_FILE, ".xml")) {
+        path.remove();
+    }
+
+    writeLegacyAutosave(testUserDataPath, 2016, 1);
+
+    const string_list versionParts = simgear::strutils::split(VERSION, ".");
+    SG_VERIFY(versionParts.size() == 3);
+    const int currentMajor = simgear::strutils::to_int(versionParts[0]);
+    const int currentMinor = simgear::strutils::to_int(versionParts[1]);
+
+    // none of these should not be read
+    writeLegacyAutosave2(testUserDataPath, 2016, 0);
+    writeLegacyAutosave2(testUserDataPath, currentMajor, currentMinor + 1);
+    writeLegacyAutosave2(testUserDataPath, currentMajor+1, currentMinor + 1);
+
+    SGPath p = globals->autosaveFilePath(testUserDataPath);
+    if (p.exists()) {
+        SG_VERIFY(p.remove());
+    }
+
+    // write some blck-list rules to property tree
+    SGPropertyNode_ptr blacklist = fgGetNode("/sim/autosave-migration/blacklist", true);
+    blacklist->addChild("path")->setStringValue("/sim[0]/presets[0]/*");
+    blacklist->addChild("path")->setStringValue("/sim[0]/rendering[0]/texture-");
+    blacklist->addChild("path")->setStringValue("/views[0]/view[*]/old-prop");
+    blacklist->addChild("path")->setStringValue("/sim[0]/gui");
+
+    // execute method under test
+    globals->loadUserSettings(testUserDataPath);
+
+    SG_CHECK_EQUAL(globals->get_props()->getNode("sim")->getChildren("presets").size(), 2);
+    SG_CHECK_EQUAL(globals->get_props()->getNode("sim")->getChildren("gui").size(), 0);
+
+    SG_CHECK_EQUAL(globals->get_props()->getIntValue("sim/window-height"), 42);
+    SG_CHECK_EQUAL(globals->get_props()->getIntValue("sim/presets/foo"), 0);
+    SG_CHECK_EQUAL(globals->get_props()->getIntValue("sim/presets[1]/foo"), 13);
+
+    SG_CHECK_EQUAL(globals->get_props()->getIntValue("some-setting"), 888);
+
+    // if this is not zero, one of the bad autosaves was read
+    SG_CHECK_EQUAL(globals->get_props()->getIntValue("sim/bad"), 0);
+
+
+    fgtest::shutdownTestGlobals();
+}
+
+int main(int argc, char* argv[])
+{
+    testMigration();
+    return EXIT_SUCCESS;
+}

src/Main/test_posinit.cxx

@@ -1,3 +1,21 @@
+// Written by James Turner, started 2017.
+//
+// Copyright (C) 2017  James Turner
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License as
+// published by the Free Software Foundation; either version 2 of the
+// License, or (at your option) any later version.
+//
+// This program 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
+// General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+
 #include "config.h"
 
 #include "unitTestHelpers.hxx"
@@ -114,6 +132,6 @@ int main(int argc, char* argv[])
     testDefaultStartup();
     testAirportOnlyStartup();
     testAirportAndMetarStartup();
-    
+
     return EXIT_SUCCESS;
 }