[Fix] Implement destructors preventing memleaks.

Fixes a bunch of memleaks related to the new Machine and VFS
architecture.

The Machine and vfs_node objects were created with 'new' but were never
properly destroyed, leading to memleaks during CoW operations and on
server shutdown.

- Added a recursive 'delete_vfs_tree' function
- Machine destructor calls this function to lean up its VFS
- CommandProcessor correctly deletes old Machine objects after a CoW
- Player destructor cleans up the player's home machine.
- NetworkManager destructor cleans up all world machines.

common/src/command_processor.cpp

@@ -113,8 +113,10 @@ void CommandProcessor::ensure_vfs_is_writable(void) {
       new_machine->services       = _home_machine->services;
       new_machine->is_vfs_a_copy  = true;
 
+      Machine* old_machine = _home_machine;
       _home_machine = new_machine;
       set_session_machine(new_machine);
+      delete old_machine;
       _current_dir = find_node_by_path(_session_machine->vfs_root, original_path);
       if(!_current_dir) { _current_dir = _session_machine->vfs_root; }
     } else {
@@ -139,8 +141,10 @@ void CommandProcessor::ensure_vfs_is_writable(void) {
         new_machine->services       = _session_machine->services;
         new_machine->is_vfs_a_copy  = true;
 
+        Machine* old_machine = _world_machines[remote_ip];
         _world_machines[remote_ip] = new_machine;
         set_session_machine(new_machine);
+        delete old_machine;
 
         _current_dir = find_node_by_path(_session_machine->vfs_root, original_path);
         if(!_current_dir) { _current_dir = _session_machine->vfs_root; }

common/src/machine.cpp

@@ -0,0 +1,6 @@
+#include "machine.h"
+#include "vfs.h"
+
+Machine::~Machine(void) {
+  delete_vfs_tree(vfs_root);
+}

common/src/machine_manager.cpp

@@ -55,7 +55,7 @@ MachineManager::MachineManager(void) {
 }
 
 MachineManager::~MachineManager(void) {
-  /* TODO: Implement recursive deletion of all created VFS nodes.*/
+  delete_vfs_tree(_vfs_template_root);
 }
 
 Machine* MachineManager::create_machine(uint32_t id, const std::string& hostname,

common/src/vfs.cpp

@@ -9,3 +9,16 @@ std::string get_full_path(vfs_node* node) {
   }
   return get_full_path(node->parent) + "/" + node->name;
 }
+
+void delete_vfs_tree(vfs_node* node) {
+  if(!node) {
+    return;
+  }
+
+  if(node->type == DIR_NODE) {
+    for(auto const& [key, val] : node->children) {
+      delete_vfs_tree(val);
+    }
+  }
+  delete node;
+}

common/src/vfs.h

@@ -26,3 +26,4 @@ struct vfs_node {
 };
 
 std::string get_full_path(vfs_node* node);
+void delete_vfs_tree(vfs_node* node);

server/src/network_manager.cpp

@@ -26,7 +26,12 @@ NetworkManager::NetworkManager(void) : _acceptor(_io_context) {
   fprintf(stderr, "Created world with %zu networks\n", _world_machines.size());
 }
 
-NetworkManager::~NetworkManager(void) { stop(); }
+NetworkManager::~NetworkManager(void) {
+  for(auto const& [ip, machine] : _world_machines) {
+    delete machine;
+  }
+  stop();
+}
 
 void NetworkManager::stop(void) {
   _io_context.stop();

server/src/player.cpp

@@ -5,11 +5,18 @@
 Player::Player(uint32_t new_id, Machine* home_machine,
                std::map<std::string, Machine*>& world_machines) :
     id(new_id) {
+
   cmd_processor = new CommandProcessor(home_machine, world_machines);
 }
 
 Player::~Player(void) {
   if(cmd_processor) {
+    /*
+     * Player is owner of their own machine. CommandProcessor
+     * holds the most current pointer to it (in case of CoW).
+     * Delete the machine first, then the processor point to it.
+     */
+    delete cmd_processor->get_home_machine();
     delete cmd_processor;
   }
 }