More work to RewindManager; all the 'ugly' code has been removed.

Thomas, it should be fine for you to proceed now.

src/common/LinkedObjectPool.hxx

@@ -55,7 +55,6 @@ class LinkedObjectPool
   public:
     using iter = typename std::list<T>::iterator;
     using const_iter = typename std::list<T>::const_iterator;
-    using size_type = typename std::list<T>::size_type;
 
     /*
       Create a pool of size CAPACITY; the active list starts out empty.
@@ -72,13 +71,13 @@ class LinkedObjectPool
 
       Make sure to call 'currentIsValid()' before accessing this method.
     */
-    T& current() { return *myCurrent; }
+    T& current() const { return *myCurrent; }
 
     /**
       Does the 'current' iterator point to a valid node in the active list?
       This must be called before 'current()' is called.
     */
-    bool currentIsValid() { return myCurrent != myList.end(); }
+    bool currentIsValid() const { return myCurrent != myList.end(); }
 
     /**
       Advance 'current' iterator to previous position in the active list.
@@ -101,12 +100,28 @@ class LinkedObjectPool
     /**
       Return an iterator to the first node in the active list.
     */
-    iter first() { return myList.begin(); }
+    const_iter first() const { return myList.begin(); }
 
     /**
       Return an iterator to the last node in the active list.
     */
-    iter last() { return std::prev(myList.end(), 1); }
+    const_iter last() const { return std::prev(myList.end(), 1); }
+
+    /**
+      Return an iterator to the previous node of 'i' in the active list.
+    */
+    const_iter previous(const_iter i) const { return std::prev(i, 1); }
+
+    /**
+      Return an iterator to the next node to 'current' in the active list.
+    */
+    const_iter next(const_iter i) const { return std::next(i, 1); }
+
+    /**
+      Answer whether 'current' is at the specified iterator.
+    */
+    bool atFirst() const { return myCurrent == first(); }
+    bool atLast() const  { return myCurrent == last();  }
 
     /**
       Add a new node at the beginning of the active list, and update 'current'
@@ -131,7 +146,7 @@ class LinkedObjectPool
       happens to be the one removed.
     */
     void removeFirst() {
-      const_iter i = myList.begin();
+      const_iter i = myList.cbegin();
       myPool.splice(myPool.end(), myList, i);
       if(myCurrent == i)  // did we just invalidate 'current'
         moveToNext();     // if so, move to the next node
@@ -201,9 +216,9 @@ class LinkedObjectPool
 #endif
     uInt32 capacity() const { return CAPACITY; }
 
-    size_type size() const { return myList.size();             }
-    bool empty() const  { return myList.size() == 0;        }
-    bool full() const   { return myList.size() >= CAPACITY; }
+    uInt32 size() const { return uInt32(myList.size()); }
+    bool empty() const  { return size() == 0;           }
+    bool full() const   { return size() >= CAPACITY;    }
 
   private:
     std::list<T> myList, myPool;

src/common/RewindManager.cxx

@@ -119,27 +119,29 @@ void RewindManager::compressStates()
   //bool debugMode = myOSystem.eventHandler().state() == EventHandler::S_DEBUGGER;
   // TODO: let user control these:
   const double DENSITY = 1.15; // exponential growth of cycle intervals
-  const uInt32 STEP_STATES = 60; // single step rewind length
+  const uInt32 STEP_STATES = 6;  // single step rewind length (change back to '60')
   //const uInt32 SECONDS_STATES = 10; // TODO: one second rewind length
 
   uInt64 currentCycle = myOSystem.console().tia().cycles();
   uInt64 lastCycle = currentCycle;
   double expectedCycles = 76 * 262.0; // == cycles of 1 frame, TODO: use actual number of scanlines
   double maxDelta = 0;
-  size_type removeIdx = 0;
+  uInt32 removeIdx = 0;
 
-  size_type idx = myStateList.size() - 1;
+  uInt32 idx = myStateList.size() - 1;
+cerr << "idx: " << idx << endl;
   for(auto it = myStateList.last(); it != myStateList.first(); --it)
   {
-cerr << *it << endl << endl;  // debug code
     if(idx >= STEP_STATES)
     {
+cerr << *it << endl << endl;  // debug code
       expectedCycles *= DENSITY;
 
       double expected = expectedCycles * (1 + DENSITY);
-      uInt64 prev = (--it)->cycle; ++it; // UGLY!
-      uInt64 next = (++it)->cycle; --it; // UGLY!
+      uInt64 prev = myStateList.previous(it)->cycle;
+      uInt64 next = myStateList.next(it)->cycle;
       double delta = expected / (prev - next);
+cerr << "prev: " << prev << ", next: " << next << ", delta: " << delta << endl;
 
       if(delta > maxDelta)
       {
@@ -150,6 +152,7 @@ cerr << *it << endl << endl;  // debug code
     lastCycle = it->cycle;
     --idx;
   }
+cerr << "END\n";
   if (maxDelta < 1)
   {
     // the horizon is getting too big

src/common/RewindManager.hxx

@@ -66,8 +66,8 @@ class RewindManager
     */
     bool unwindState();
 
-    bool atLast() const { return myStateList.empty(); }
-    bool atFirst() const { return false; } // TODO
+    bool atFirst() const { return myStateList.atFirst(); }
+    bool atLast() const  { return myStateList.atLast();  }
     void clear() { myStateList.clear(); }
 
     /**
@@ -99,8 +99,6 @@ class RewindManager
       }
     };
 
-    using size_type = Common::LinkedObjectPool<RewindState>::size_type;
-
     // The linked-list to store states (internally it takes care of reducing
     // frequent (de)-allocations)
     Common::LinkedObjectPool<RewindState, MAX_SIZE> myStateList;