ConsoleDevice: Use a temporary buffer for backspace handling

kernel/src/fs/devices/ConsoleDevice.cpp

@@ -2,6 +2,7 @@
 #include "video/TextConsole.h"
 #include <luna/Buffer.h>
 #include <luna/CString.h>
+#include <luna/Vector.h>
 
 static Buffer g_console_input;
 
@@ -34,7 +35,24 @@ bool ConsoleDevice::blocking() const
     return g_console_input.size() == 0;
 }
 
+static Vector<u8> g_temp_input;
+
 void ConsoleDevice::did_press_key(char key)
 {
-    *g_console_input.slice_at_end(1).value() = (u8)key;
+    if (key == '\b')
+    {
+        if (g_temp_input.try_pop().has_value()) TextConsole::putwchar(L'\b');
+
+        return;
+    }
+
+    g_temp_input.try_append(key).value();
+
+    if (key == '\n')
+    {
+        g_console_input.append_data(g_temp_input.data(), g_temp_input.size()).value();
+        g_temp_input.clear();
+    }
+
+    TextConsole::putchar(key);
 }

libluna/include/luna/Buffer.h

@@ -19,6 +19,8 @@ class Buffer
 
     Result<u8*> slice(usize offset, usize size);
 
+    Result<void> append_data(u8* data, usize size);
+
     u8* data()
     {
         return m_data;

libluna/include/luna/Vector.h

@@ -160,6 +160,12 @@ template <typename T> class Vector
         return m_size;
     }
 
+    void clear()
+    {
+        m_size = m_capacity = 0;
+        free_impl(m_data);
+    }
+
   private:
     T* m_data { nullptr };
     usize m_capacity { 0 };

libluna/src/Buffer.cpp

@@ -1,4 +1,5 @@
 #include <luna/Buffer.h>
+#include <luna/CString.h>
 #include <luna/Heap.h>
 
 Buffer::Buffer()
@@ -44,3 +45,10 @@ Result<u8*> Buffer::slice(usize offset, usize size)
     if (offset + size > m_size) { TRY(try_resize(offset + size)); }
     return m_data + offset;
 }
+
+Result<void> Buffer::append_data(u8* data, usize size)
+{
+    memcpy(TRY(slice_at_end(size)), data, size);
+
+    return {};
+}