Add a BufferManager singleton class, handling buffer lifetime

it also provide access to buffers by name

src/buffer.cc

@@ -1,4 +1,7 @@
 #include "buffer.hh"
+
+#include "buffer_manager.hh"
+
 #include <cassert>
 
 namespace Kakoune
@@ -122,6 +125,8 @@ Buffer::Buffer(const std::string& name, const BufferString& initial_content)
     : m_name(name), m_history(1), m_history_cursor(m_history.begin()),
       m_content(initial_content)
 {
+    BufferManager::instance().register_buffer(this);
+
     compute_lines();
 }
 

src/buffer_manager.cc

@@ -0,0 +1,60 @@
+#include "buffer_manager.hh"
+
+#include "buffer.hh"
+#include "window.hh"
+#include <cassert>
+
+namespace Kakoune
+{
+
+struct name_not_unique {};
+
+
+BufferManager* BufferManager::ms_instance = nullptr;
+
+BufferManager& BufferManager::instance()
+{
+    if (not ms_instance)
+        ms_instance = new BufferManager();
+
+    return *ms_instance;
+}
+
+void BufferManager::delete_instance()
+{
+    delete ms_instance;
+    ms_instance = nullptr;
+}
+
+BufferManager::BufferManager()
+{
+}
+
+void BufferManager::register_buffer(Buffer* buffer)
+{
+    assert(buffer);
+    const std::string& name = buffer->name();
+    if (m_buffers.find(name) != m_buffers.end())
+        throw name_not_unique();
+
+    m_buffers[name] = std::unique_ptr<Buffer>(buffer);
+}
+
+void BufferManager::delete_buffer(Buffer* buffer)
+{
+    assert(buffer);
+    auto buffer_it = m_buffers.find(buffer->name());
+    assert(buffer_it->second.get() == buffer);
+    m_buffers.erase(buffer_it);
+}
+
+Buffer* BufferManager::get_buffer(const std::string& name)
+{
+    if (m_buffers.find(name) == m_buffers.end())
+        return nullptr;
+
+    return m_buffers[name].get();
+}
+
+
+}

src/buffer_manager.hh

@@ -0,0 +1,32 @@
+#ifndef buffer_manager_hh_INCLUDED
+#define buffer_manager_hh_INCLUDED
+
+#include "buffer.hh"
+
+#include <unordered_map>
+#include <memory>
+
+namespace Kakoune
+{
+
+class BufferManager
+{
+public:
+    void register_buffer(Buffer* buffer);
+    void delete_buffer(Buffer* buffer);
+
+    Buffer* get_buffer(const std::string& name);
+
+    static BufferManager& instance();
+    static void delete_instance();
+
+private:
+    BufferManager();
+    static BufferManager* ms_instance;
+
+    std::unordered_map<std::string, std::unique_ptr<Buffer>> m_buffers;
+};
+
+}
+
+#endif // buffer_manager_hh_INCLUDED