1 files changed, 15 insertions, 2 deletions

diff --git a/mem.py b/mem.py
index 7137ede..c83d69d 100644
--- a/mem.py
+++ b/mem.py
@@ -8,6 +8,7 @@ class Memory:
   def __init__(self, main_size, virt_size):
     self.main = [None] * main_size
     self.virt = [None] * virt_size
+    self._virt_cursor = 0
 
   def _mem_to_string(self, mem):
     return ''.join(['%d' % n if n is not None else 'x' for n in mem])
@@ -18,6 +19,18 @@ class Memory:
   def dump_virt(self):
     return self._mem_to_string(self.virt)
 
-  def has_page(self, page):
-    return 0 <= page < len(self.virt)
+  def page_in_range(self, page):
+    return 0 <= page < len(self.main + self.virt)
+
+  def put_virt(self, page):
+    self.virt[self._virt_cursor] = page
+    self._virt_cursor += 1
+
+  def remove_virt(self, page):
+    for i in range(len(self.virt)):
+      if self.virt[i] == page:
+        self._virt_cursor -= 1
+        self.virt[i] = self.virt[self._virt_cursor]
+        self.virt[self._virt_cursor] = None
+        break