add a 'buffers' debug command to get info on alive buffers

src/buffer.cc

@@ -519,4 +519,33 @@ ByteCoord Buffer::last_modification_coord() const
     return m_history.back().back().coord;
 }
 
+String Buffer::debug_description() const
+{
+    String res = display_name() + "\n";
+
+    res += "  Flags: ";
+    if (m_flags & Flags::File)
+        res += "File (" + name() + ") ";
+    if (m_flags & Flags::New)
+        res += "New ";
+    if (m_flags & Flags::Fifo)
+        res += "Fifo ";
+    if (m_flags & Flags::NoUndo)
+        res += "NoUndo ";
+    res += "\n";
+
+    size_t content_size = 0;
+    for (auto& line : m_lines)
+        content_size += (int)line.length();
+
+    size_t additional_size = 0;
+    for (auto& undo_group : m_history)
+        additional_size += undo_group.size() * sizeof(Modification);
+    additional_size += m_changes.size() * sizeof(Change);
+
+    res += "  Used mem: content=" + to_string(content_size) +
+           " additional=" + to_string(additional_size) + "\n";
+    return res;
+}
+
 }

src/buffer.hh

@@ -172,6 +172,8 @@ public:
         bool at_end;
     };
     memoryview<Change> changes_since(size_t timestamp) const;
+
+    String debug_description() const;
 private:
 
     void on_option_changed(const Option& option) override;

src/commands.cc

@@ -754,7 +754,7 @@ const CommandDesc debug_cmd = {
     "debug",
     nullptr,
     "debug <command>: write some debug informations in the debug buffer\n"
-    "    existing commands: info",
+    "    existing commands: info, buffers",
     ParameterDesc{ SwitchMap{}, ParameterDesc::Flags::SwitchesOnlyAtStart, 1 },
     CommandFlags::None,
     CommandCompleter{},
@@ -765,6 +765,12 @@ const CommandDesc debug_cmd = {
             write_debug("pid: " + to_string(getpid()));
             write_debug("session: " + Server::instance().session());
         }
+        if (parser[0] == "buffers")
+        {
+            write_debug("Buffers:");
+            for (auto& buffer : BufferManager::instance())
+                write_debug(buffer->debug_description());
+        }
         else
             throw runtime_error("unknown debug command '" + parser[0] + "'");
     }