[MDEV-11357] Split Item_cache::get_cache() into virtual methods in Type_handler - Jira

As a part of preparatory work for ~~MDEV-4912~~, we'll add a new virtual method in Type_handler:

virtual Item_cache *Item_get_cache(THD *thd, const Item *item) const;

and split this code into implementations of the new virtual method:

Item_cache* Item_cache::get_cache(THD *thd, const Item *item,

                                  const Item_result type)

  MEM_ROOT *mem_root= thd->mem_root;

  switch (type) {

  case INT_RESULT:

    return new (mem_root) Item_cache_int(thd, item->field_type());

  case REAL_RESULT:

    return new (mem_root) Item_cache_real(thd);

  case DECIMAL_RESULT:

    return new (mem_root) Item_cache_decimal(thd);

  case STRING_RESULT:

    return new (mem_root) Item_cache_str(thd, item);

  case ROW_RESULT:

    return new (mem_root) Item_cache_row(thd);

  case TIME_RESULT:

    return new (mem_root) Item_cache_temporal(thd, item->field_type());

  return 0;                                     // Impossible

This will allow data type plugins to create their own versions of Item_cache, to optimize comparison with constants.

blocks

MDEV-4912 Data type plugin API version 1

Error rendering 'com.xiplink.jira.git.jira_git_plugin:git-issue-webpanel'. Please contact your Jira administrators.

MariaDB Server