Adding upstream version 1:10.11.6.upstream/1%10.11.6

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 578 insertions, 0 deletions

diff --git a/sql/item_windowfunc.cc b/sql/item_windowfunc.cc
new file mode 100644
index 00000000..5438cade
--- /dev/null
+++ b/sql/item_windowfunc.cc
@@ -0,0 +1,578 @@
+/*
+   Copyright (c) 2016, 2020, MariaDB
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */
+
+#include "mariadb.h"
+#include "item_windowfunc.h" 
+#include "sql_select.h" // test if group changed
+
+
+bool
+Item_window_func::resolve_window_name(THD *thd)
+{
+  if (window_spec)
+  {
+    /* The window name has been already resolved */
+    return false;
+  }
+  DBUG_ASSERT(window_name != NULL && window_spec == NULL);
+  const char *ref_name= window_name->str;
+
+  /* !TODO: Add the code to resolve ref_name in outer queries */ 
+  /* 
+    First look for the deinition of the window with 'window_name'
+    in the current select
+  */
+  List<Window_spec> curr_window_specs= 
+    List<Window_spec> (thd->lex->current_select->window_specs);
+  List_iterator_fast<Window_spec> it(curr_window_specs);
+  Window_spec *win_spec;
+  while((win_spec= it++))
+  {
+    const char *win_spec_name= win_spec->name();
+    if (win_spec_name &&
+        my_strcasecmp(system_charset_info, ref_name, win_spec_name) == 0)
+    {
+      window_spec= win_spec;
+      break;
+    }
+  }
+
+  if (!window_spec)
+  {
+    my_error(ER_WRONG_WINDOW_SPEC_NAME, MYF(0), ref_name);
+    return true;
+  }
+
+  return false;
+}
+
+
+void
+Item_window_func::update_used_tables()
+{
+  used_tables_cache= 0;
+  window_func()->update_used_tables();
+  used_tables_cache|= window_func()->used_tables();
+  for (ORDER *ord= window_spec->partition_list->first; ord; ord=ord->next)
+  {
+    Item *item= *ord->item;
+    item->update_used_tables();
+    used_tables_cache|= item->used_tables();
+  }
+  for (ORDER *ord= window_spec->order_list->first; ord; ord=ord->next)
+  {
+    Item *item= *ord->item;
+    item->update_used_tables();
+    used_tables_cache|= item->used_tables();
+  }  
+}
+
+
+bool
+Item_window_func::fix_fields(THD *thd, Item **ref)
+{
+  DBUG_ASSERT(fixed() == 0);
+
+  if (!thd->lex->current_select ||
+      (thd->lex->current_select->context_analysis_place != SELECT_LIST &&
+       thd->lex->current_select->context_analysis_place != IN_ORDER_BY))
+  {
+    my_error(ER_WRONG_PLACEMENT_OF_WINDOW_FUNCTION, MYF(0));
+    return true;
+  }
+
+  if (window_name && resolve_window_name(thd))
+    return true;
+  
+  if (window_spec->window_frame && is_frame_prohibited())
+  {
+    my_error(ER_NOT_ALLOWED_WINDOW_FRAME, MYF(0),
+             window_func()->func_name());
+    return true;
+  }
+
+  if (window_spec->order_list->elements == 0 && is_order_list_mandatory())
+  {
+    my_error(ER_NO_ORDER_LIST_IN_WINDOW_SPEC, MYF(0),
+             window_func()->func_name());
+    return true;
+  }
+
+  window_func()->mark_as_window_func_sum_expr();
+
+  /*
+    TODO: why the last parameter is 'ref' in this call? What if window_func
+    decides to substitute itself for something else and does *ref=.... ? 
+    This will substitute *this (an Item_window_func object) with Item_sum
+    object. Is this the intent?
+  */
+  if (window_func()->fix_fields(thd, ref))
+    return true;
+
+  const_item_cache= false;
+
+  with_flags= (with_flags & ~item_with_t::SUM_FUNC) | item_with_t::WINDOW_FUNC;
+
+  if (fix_length_and_dec(thd))
+    return TRUE;
+
+  max_length= window_func()->max_length;
+  set_maybe_null(window_func()->maybe_null());
+
+  base_flags|= item_base_t::FIXED;
+  set_phase_to_initial();
+  return false;
+}
+
+
+/*
+  @detail
+    Window function evaluates its arguments when it is scanning the temporary
+    table in partition/order-by order. That is, arguments should be read from
+    the temporary table, not from the original base columns.
+
+    In order for this to work, we need to call "split_sum_func" for each
+    argument. The effect of the call is:
+     1. the argument is added into ref_pointer_array. This will cause the
+        argument to be saved in the temp.table
+     2. argument item is replaced with an Item_ref object. this object refers
+        the argument through the ref_pointer_array.
+
+    then, change_to_use_tmp_fields() will replace ref_pointer_array with an
+    array that points to the temp.table fields.
+    This way, when window_func attempts to evaluate its arguments, it will use
+    Item_ref objects which will read data from the temp.table.
+
+    Note: Before window functions, aggregate functions never needed to do such
+    transformations on their arguments. This is because grouping operation
+    does not need to read from the temp.table.
+    (Q: what happens when we first sort and then do grouping in a
+      group-after-group mode? dont group by items read from temp.table, then?)
+*/
+
+void Item_window_func::split_sum_func(THD *thd, Ref_ptr_array ref_pointer_array,
+                                      List<Item> &fields, uint flags)
+{
+  for (uint i=0; i < window_func()->argument_count(); i++)
+  {
+    Item **p_item= &window_func()->arguments()[i];
+    (*p_item)->split_sum_func2(thd, ref_pointer_array, fields, p_item, flags);
+  }
+  window_func()->setup_caches(thd);
+}
+
+bool Item_window_func::check_result_type_of_order_item()
+{
+  switch (window_func()->sum_func()) {
+  case Item_sum::PERCENTILE_CONT_FUNC:
+  {
+    Item_result rtype= window_spec->order_list->first->item[0]->cmp_type();
+    // TODO (varun) : support date type in percentile_cont function
+    if (rtype != REAL_RESULT && rtype != INT_RESULT &&
+        rtype != DECIMAL_RESULT && rtype != TIME_RESULT)
+    {
+      my_error(ER_WRONG_TYPE_FOR_PERCENTILE_FUNC, MYF(0),
+               window_func()->func_name());
+      return true;
+    }
+    return false;
+  }
+  case Item_sum::PERCENTILE_DISC_FUNC:
+  {
+    Item *src_item= window_spec->order_list->first->item[0];
+    Item_sum_percentile_disc *func=
+      static_cast<Item_sum_percentile_disc*>(window_func());
+    func->set_handler(src_item->type_handler());
+    func->Type_std_attributes::set(src_item);
+    Type_std_attributes::set(src_item);
+    return false;
+  }
+  default:
+    break;
+  }
+  return FALSE;
+}
+
+/*
+  This must be called before attempting to compute the window function values.
+  @detail
+    If we attempt to do it in fix_fields(), partition_fields will refer
+    to the original window function arguments.
+    We need it to refer to temp.table columns.
+*/
+
+void Item_sum_rank::setup_window_func(THD *thd, Window_spec *window_spec)
+{
+  /* TODO: move this into Item_window_func? */
+  peer_tracker = new Group_bound_tracker(thd, window_spec->order_list);
+  peer_tracker->init();
+  clear();
+}
+
+void Item_sum_dense_rank::setup_window_func(THD *thd, Window_spec *window_spec)
+{
+  /* TODO: consider moving this && Item_sum_rank's implementation */
+  peer_tracker = new Group_bound_tracker(thd, window_spec->order_list);
+  peer_tracker->init();
+  clear();
+}
+
+void Item_sum_percentile_disc::setup_window_func(THD *thd, Window_spec *window_spec)
+{
+  order_item= window_spec->order_list->first->item[0];
+  if (!(value= order_item->get_cache(thd)))
+    return;
+  value->setup(thd, order_item);
+  value->store(order_item);
+}
+
+void Item_sum_percentile_cont::setup_window_func(THD *thd, Window_spec *window_spec)
+{
+  order_item= window_spec->order_list->first->item[0];
+  /* TODO(varun): need to discuss and finalise what type should we
+     return for percentile cont functions
+  */
+  if (!(ceil_value= order_item->get_cache(thd)))
+    return;
+  ceil_value->setup(thd, order_item);
+  ceil_value->store(order_item);
+
+  if (!(floor_value= order_item->get_cache(thd)))
+    return;
+  floor_value->setup(thd, order_item);
+  floor_value->store(order_item);
+}
+bool Item_sum_percentile_cont::fix_fields(THD *thd, Item **ref)
+{
+  bool res;
+  res= Item_sum_num::fix_fields(thd, ref);
+  if (res)
+    return res;
+
+  switch(args[0]->cmp_type())
+  {
+    case DECIMAL_RESULT:
+    case REAL_RESULT:
+    case INT_RESULT:
+      break;
+    default:
+      my_error(ER_WRONG_TYPE_OF_ARGUMENT, MYF(0), func_name());
+      return TRUE;
+  }
+  return res;
+}
+bool Item_sum_percentile_disc::fix_fields(THD *thd, Item **ref)
+{
+  bool res;
+  res= Item_sum_num::fix_fields(thd, ref);
+  if (res)
+    return res;
+
+  switch(args[0]->cmp_type())
+  {
+    case DECIMAL_RESULT:
+    case REAL_RESULT:
+    case INT_RESULT:
+      break;
+    default:
+      my_error(ER_WRONG_TYPE_OF_ARGUMENT, MYF(0), func_name());
+      return TRUE;
+  }
+  return res;
+
+}
+
+bool Item_sum_dense_rank::add()
+{
+  if (peer_tracker->check_if_next_group() || first_add)
+  {
+    first_add= false;
+    dense_rank++;
+  }
+
+  return false;
+}
+
+
+bool Item_sum_rank::add()
+{
+  row_number++;
+  if (peer_tracker->check_if_next_group())
+  {
+    /* Row value changed */
+    cur_rank= row_number;
+  }
+  return false; 
+}
+
+bool Item_sum_percent_rank::add()
+{
+  row_number++;
+  if (peer_tracker->check_if_next_group())
+  {
+    /* Row value changed. */
+    cur_rank= row_number;
+  }
+  return false;
+}
+
+void Item_sum_percent_rank::setup_window_func(THD *thd, Window_spec *window_spec)
+{
+  /* TODO: move this into Item_window_func? */
+  peer_tracker = new Group_bound_tracker(thd, window_spec->order_list);
+  peer_tracker->init();
+  clear();
+}
+
+
+bool Item_sum_hybrid_simple::fix_fields(THD *thd, Item **ref)
+{
+  DBUG_ASSERT(fixed() == 0);
+
+  if (init_sum_func_check(thd))
+    return TRUE;
+
+  for (uint i= 0; i < arg_count; i++)
+  {
+    if (args[i]->fix_fields_if_needed_for_scalar(thd, &args[i]))
+      return TRUE;
+    with_flags|= args[i]->with_flags;
+  }
+
+  if (fix_length_and_dec(thd))
+    return TRUE;
+
+  setup_hybrid(thd, args[0]);
+  result_field=0;
+
+  if (check_sum_func(thd, ref))
+    return TRUE;
+  for (uint i= 0; i < arg_count; i++)
+    orig_args[i]= args[i];
+
+  base_flags|= item_base_t::FIXED;
+  return FALSE;
+}
+
+
+bool Item_sum_hybrid_simple::fix_length_and_dec(THD *thd)
+{
+  set_maybe_null();
+  null_value= true;
+  return args[0]->type_handler()->Item_sum_hybrid_fix_length_and_dec(this);
+}
+
+
+bool Item_sum_hybrid_simple::add()
+{
+  value->store(args[0]);
+  value->cache_value();
+  null_value= value->null_value;
+  return false;
+}
+
+void Item_sum_hybrid_simple::setup_hybrid(THD *thd, Item *item)
+{
+  if (!(value= item->get_cache(thd)))
+    return;
+  value->setup(thd, item);
+  value->store(item);
+  if (!item->const_item())
+    value->set_used_tables(RAND_TABLE_BIT);
+  collation.set(item->collation);
+}
+
+double Item_sum_hybrid_simple::val_real()
+{
+  DBUG_ASSERT(fixed());
+  if (null_value)
+    return 0.0;
+  double retval= value->val_real();
+  if ((null_value= value->null_value))
+    DBUG_ASSERT(retval == 0.0);
+  return retval;
+}
+
+longlong Item_sum_hybrid_simple::val_int()
+{
+  DBUG_ASSERT(fixed());
+  if (null_value)
+    return 0;
+  longlong retval= value->val_int();
+  if ((null_value= value->null_value))
+    DBUG_ASSERT(retval == 0);
+  return retval;
+}
+
+my_decimal *Item_sum_hybrid_simple::val_decimal(my_decimal *val)
+{
+  DBUG_ASSERT(fixed());
+  if (null_value)
+    return 0;
+  my_decimal *retval= value->val_decimal(val);
+  if ((null_value= value->null_value))
+    DBUG_ASSERT(retval == NULL);
+  return retval;
+}
+
+String *
+Item_sum_hybrid_simple::val_str(String *str)
+{
+  DBUG_ASSERT(fixed());
+  if (null_value)
+    return 0;
+  String *retval= value->val_str(str);
+  if ((null_value= value->null_value))
+    DBUG_ASSERT(retval == NULL);
+  return retval;
+}
+
+bool Item_sum_hybrid_simple::val_native(THD *thd, Native *to)
+{
+  DBUG_ASSERT(fixed());
+  if (null_value)
+    return true;
+  return val_native_from_item(thd, value, to);
+}
+
+bool Item_sum_hybrid_simple::get_date(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate)
+{
+  DBUG_ASSERT(fixed());
+  if (null_value)
+    return true;
+  bool retval= value->get_date(thd, ltime, fuzzydate);
+  if ((null_value= value->null_value))
+    DBUG_ASSERT(retval == true);
+  return retval;
+}
+
+Field *Item_sum_hybrid_simple::create_tmp_field(MEM_ROOT *root,
+                                                bool group, TABLE *table)
+{
+  DBUG_ASSERT(0);
+  return NULL;
+}
+
+void Item_sum_hybrid_simple::reset_field()
+{
+  switch(result_type()) {
+  case STRING_RESULT:
+  {
+    char buff[MAX_FIELD_WIDTH];
+    String tmp(buff,sizeof(buff),result_field->charset()),*res;
+
+    res=args[0]->val_str(&tmp);
+    if (args[0]->null_value)
+    {
+      result_field->set_null();
+      result_field->reset();
+    }
+    else
+    {
+      result_field->set_notnull();
+      result_field->store(res->ptr(),res->length(),tmp.charset());
+    }
+    break;
+  }
+  case INT_RESULT:
+  {
+    longlong nr=args[0]->val_int();
+
+    if (maybe_null())
+    {
+      if (args[0]->null_value)
+      {
+	nr=0;
+	result_field->set_null();
+      }
+      else
+	result_field->set_notnull();
+    }
+    result_field->store(nr, unsigned_flag);
+    break;
+  }
+  case REAL_RESULT:
+  {
+    double nr= args[0]->val_real();
+
+    if (maybe_null())
+    {
+      if (args[0]->null_value)
+      {
+	nr=0.0;
+	result_field->set_null();
+      }
+      else
+	result_field->set_notnull();
+    }
+    result_field->store(nr);
+    break;
+  }
+  case DECIMAL_RESULT:
+  {
+    VDec arg_dec(args[0]);
+
+    if (maybe_null())
+    {
+      if (arg_dec.is_null())
+        result_field->set_null();
+      else
+        result_field->set_notnull();
+    }
+    /*
+      We must store zero in the field as we will use the field value in
+      add()
+    */
+    result_field->store_decimal(arg_dec.ptr_or(&decimal_zero));
+    break;
+  }
+  case ROW_RESULT:
+  case TIME_RESULT:
+    DBUG_ASSERT(0);
+  }
+}
+
+void Item_sum_hybrid_simple::update_field()
+{
+  DBUG_ASSERT(0);
+}
+
+void Item_window_func::print(String *str, enum_query_type query_type)
+{
+  if (only_single_element_order_list())
+  {
+    print_for_percentile_functions(str, query_type);
+    return;
+  }
+  window_func()->print(str, query_type);
+  str->append(STRING_WITH_LEN(" over "));
+  if (!window_spec)
+    str->append(window_name);
+  else
+    window_spec->print(str, query_type);
+}
+void Item_window_func::print_for_percentile_functions(String *str, enum_query_type query_type)
+{
+  window_func()->print(str, query_type);
+  str->append(STRING_WITH_LEN(" within group "));
+  str->append('(');
+  window_spec->print_order(str,query_type);
+  str->append(')');
+  str->append(STRING_WITH_LEN(" over "));
+  str->append('(');
+  window_spec->print_partition(str,query_type);
+  str->append(')');
+}