1 files changed, 73 insertions, 9 deletions

diff --git a/sql/item_sum.h b/sql/item_sum.h
index 811e9d5c59c..e766e69a1c5 100644
--- a/sql/item_sum.h
+++ b/sql/item_sum.h
@@ -109,6 +109,7 @@ public:
 
 
 class st_select_lex;
+class Window_spec;
 
 /**
   Class Item_sum is the base class used for special expressions that SQL calls
@@ -347,7 +348,9 @@ public:
   enum Sumfunctype
   { COUNT_FUNC, COUNT_DISTINCT_FUNC, SUM_FUNC, SUM_DISTINCT_FUNC, AVG_FUNC,
     AVG_DISTINCT_FUNC, MIN_FUNC, MAX_FUNC, STD_FUNC,
-    VARIANCE_FUNC, SUM_BIT_FUNC, UDF_SUM_FUNC, GROUP_CONCAT_FUNC
+    VARIANCE_FUNC, SUM_BIT_FUNC, UDF_SUM_FUNC, GROUP_CONCAT_FUNC,
+    ROW_NUMBER_FUNC, RANK_FUNC, DENSE_RANK_FUNC, PERCENT_RANK_FUNC,
+    CUME_DIST_FUNC, NTILE_FUNC
   };
 
   Item **ref_by; /* pointer to a ref to the object used to register it */
@@ -540,12 +543,16 @@ public:
   virtual void clear()= 0;
   virtual bool add()= 0;
   virtual bool setup(THD *thd) { return false; }
+  
+  virtual void remove() { DBUG_ASSERT(0); }
 
   virtual void cleanup();
   bool check_vcol_func_processor(uchar *int_arg) 
   {
     return trace_unsupported_by_check_vcol_func_processor(func_name()); 
   }
+  
+  virtual void setup_window_func(THD *thd, Window_spec *window_spec) {}
 };
 
 
@@ -710,6 +717,7 @@ public:
 class Item_sum_int :public Item_sum_num
 {
 public:
+  Item_sum_int(THD *thd): Item_sum_num(thd) {}
   Item_sum_int(THD *thd, Item *item_par): Item_sum_num(thd, item_par) {}
   Item_sum_int(THD *thd, List<Item> &list): Item_sum_num(thd, list) {}
   Item_sum_int(THD *thd, Item_sum_int *item) :Item_sum_num(thd, item) {}
@@ -724,7 +732,7 @@ public:
 
 
 class Item_sum_sum :public Item_sum_num,
-                    public Type_handler_hybrid_field_type
+                   public Type_handler_hybrid_field_type 
 {
 protected:
   double sum;
@@ -763,6 +771,11 @@ public:
     return has_with_distinct() ? "sum(distinct " : "sum("; 
   }
   Item *copy_or_same(THD* thd);
+  void remove();
+
+private:
+  void add_helper(bool perform_removal);
+  ulonglong count;
 };
 
 
@@ -775,6 +788,7 @@ class Item_sum_count :public Item_sum_int
   void clear();
   bool add();
   void cleanup();
+  void remove();
 
   public:
   Item_sum_count(THD *thd, Item *item_par):
@@ -821,6 +835,8 @@ class Item_sum_count :public Item_sum_int
 class Item_sum_avg :public Item_sum_sum
 {
 public:
+  // TODO-cvicentiu given that Item_sum_sum now uses a counter of its own, in
+  // order to implement remove(), it is possible to remove this member.
   ulonglong count;
   uint prec_increment;
   uint f_precision, f_scale, dec_bin_size;
@@ -839,6 +855,7 @@ public:
   }
   void clear();
   bool add();
+  void remove();
   double val_real();
   // In SPs we might force the "wrong" type with select into a declare variable
   longlong val_int() { return val_int_from_real(); }
@@ -1019,14 +1036,18 @@ public:
 
 class Item_sum_bit :public Item_sum_int
 {
-protected:
-  ulonglong reset_bits,bits;
-
 public:
   Item_sum_bit(THD *thd, Item *item_par, ulonglong reset_arg):
-    Item_sum_int(thd, item_par), reset_bits(reset_arg), bits(reset_arg) {}
+    Item_sum_int(thd, item_par), reset_bits(reset_arg), bits(reset_arg),
+    as_window_function(FALSE), num_values_added(0) {}
   Item_sum_bit(THD *thd, Item_sum_bit *item):
-    Item_sum_int(thd, item), reset_bits(item->reset_bits), bits(item->bits) {}
+    Item_sum_int(thd, item), reset_bits(item->reset_bits), bits(item->bits),
+    as_window_function(item->as_window_function),
+    num_values_added(item->num_values_added)
+  {
+    if (as_window_function)
+      memcpy(bit_counters, item->bit_counters, sizeof(bit_counters));
+  }
   enum Sumfunctype sum_func () const {return SUM_BIT_FUNC;}
   void clear();
   longlong val_int();
@@ -1037,8 +1058,42 @@ public:
   void cleanup()
   {
     bits= reset_bits;
+    if (as_window_function)
+      clear_as_window();
     Item_sum_int::cleanup();
   }
+  void setup_window_func(THD *thd __attribute__((unused)),
+                         Window_spec *window_spec __attribute__((unused)))
+  {
+    as_window_function= TRUE;
+    clear_as_window();
+  }
+  void remove()
+  {
+    if (as_window_function)
+    {
+      remove_as_window(args[0]->val_int());
+      return;
+    }
+    // Unless we're counting bits, we can not remove anything.
+    DBUG_ASSERT(0);
+  }
+
+protected:
+  static const int NUM_BIT_COUNTERS= 64;
+  ulonglong reset_bits,bits;
+  /*
+    Marks whether the function is to be computed as a window function.
+  */
+  bool as_window_function;
+  // When used as an aggregate window function, we need to store
+  // this additional information.
+  ulonglong num_values_added;
+  ulonglong bit_counters[NUM_BIT_COUNTERS];
+  bool add_as_window(ulonglong value);
+  bool remove_as_window(ulonglong value);
+  bool clear_as_window();
+  virtual void set_bits_from_counters()= 0;
 };
 
 
@@ -1050,28 +1105,37 @@ public:
   bool add();
   const char *func_name() const { return "bit_or("; }
   Item *copy_or_same(THD* thd);
+
+private:
+  void set_bits_from_counters();
 };
 
 
 class Item_sum_and :public Item_sum_bit
 {
-  public:
+public:
   Item_sum_and(THD *thd, Item *item_par):
     Item_sum_bit(thd, item_par, ULONGLONG_MAX) {}
   Item_sum_and(THD *thd, Item_sum_and *item) :Item_sum_bit(thd, item) {}
   bool add();
   const char *func_name() const { return "bit_and("; }
   Item *copy_or_same(THD* thd);
+
+private:
+  void set_bits_from_counters();
 };
 
 class Item_sum_xor :public Item_sum_bit
 {
-  public:
+public:
   Item_sum_xor(THD *thd, Item *item_par): Item_sum_bit(thd, item_par, 0) {}
   Item_sum_xor(THD *thd, Item_sum_xor *item) :Item_sum_bit(thd, item) {}
   bool add();
   const char *func_name() const { return "bit_xor("; }
   Item *copy_or_same(THD* thd);
+
+private:
+  void set_bits_from_counters();
 };