SQL, IB: (0.10) VTMD tracking [closes #124]

IB: Fixes in logic when to do versioned or usual row updates. Now it is
able to do unversioned updates for versioned tables just by disabling
`TABLE_SHARE::versioned` flag.

SQL: DDL tracking for:
* RENAME TABLE, ALTER TABLE .. RENAME TO;
* DROP TABLE;
* data-modifying operations (f.ex. ALTER TABLE .. ADD/DROP COLUMN).

1 files changed, 165 insertions, 0 deletions

diff --git a/sql/vers_utils.h b/sql/vers_utils.h
new file mode 100644
index 00000000000..ee08fcbb2bc
--- /dev/null
+++ b/sql/vers_utils.h
@@ -0,0 +1,165 @@
+#ifndef VERS_UTILS_INCLUDED
+#define VERS_UTILS_INCLUDED
+
+#include "table.h"
+#include "sql_class.h"
+
+class MDL_auto_lock
+{
+  THD *thd;
+  TABLE_LIST &table;
+  bool error;
+
+public:
+  MDL_auto_lock(THD *_thd, TABLE_LIST &_table) :
+    thd(_thd), table(_table)
+  {
+    DBUG_ASSERT(thd);
+    table.mdl_request.init(MDL_key::TABLE, table.db, table.table_name, MDL_EXCLUSIVE, MDL_EXPLICIT);
+    error= thd->mdl_context.acquire_lock(&table.mdl_request, thd->variables.lock_wait_timeout);
+  }
+  ~MDL_auto_lock()
+  {
+    if (!error)
+    {
+      DBUG_ASSERT(table.mdl_request.ticket);
+      thd->mdl_context.release_lock(table.mdl_request.ticket);
+      table.mdl_request.ticket= NULL;
+    }
+  }
+  bool acquire_error() const { return error; }
+};
+
+struct Compare_strncmp
+{
+  int operator()(const LEX_STRING& a, const LEX_STRING& b) const
+  {
+    return strncmp(a.str, b.str, a.length);
+  }
+  static CHARSET_INFO* charset()
+  {
+    return system_charset_info;
+  }
+};
+
+template <CHARSET_INFO* &CS= system_charset_info>
+struct Compare_my_strcasecmp
+{
+  int operator()(const LEX_STRING& a, const LEX_STRING& b) const
+  {
+    DBUG_ASSERT(a.str[a.length] == 0 && b.str[b.length] == 0);
+    return my_strcasecmp(CS, a.str, b.str);
+  }
+  static CHARSET_INFO* charset()
+  {
+    return CS;
+  }
+};
+
+typedef Compare_my_strcasecmp<files_charset_info> Compare_fs;
+typedef Compare_my_strcasecmp<table_alias_charset> Compare_t;
+
+struct LEX_STRING_u : public LEX_STRING
+{
+  LEX_STRING_u()
+  {
+    str= NULL;
+    LEX_STRING::length= 0;
+  }
+  LEX_STRING_u(const char *_str, uint32 _len, CHARSET_INFO *)
+  {
+    str= const_cast<char *>(_str);
+    LEX_STRING::length= _len;
+  }
+  uint32 length() const
+  {
+    return LEX_STRING::length;
+  }
+  const char *ptr() const
+  {
+    return LEX_STRING::str;
+  }
+  const LEX_STRING& lex_string() const
+  {
+    return *this;
+  }
+};
+
+template <class Compare= Compare_strncmp, class Storage= LEX_STRING_u>
+struct XString : public Storage
+{
+public:
+  XString() {}
+  XString(char *_str, size_t _len) :
+    Storage(_str, _len, Compare::charset())
+  {
+  }
+  XString(LEX_STRING& src) :
+    Storage(src.str, src.length, Compare::charset())
+  {
+  }
+  XString(char *_str) :
+    Storage(_str, strlen(_str), Compare::charset())
+  {
+  }
+  bool operator== (const XString& b) const
+  {
+    return Storage::length() == b.length() && 0 == Compare()(this->lex_string(), b.lex_string());
+  }
+  bool operator!= (const XString& b) const
+  {
+    return !(*this == b);
+  }
+  operator const char* () const
+  {
+    return Storage::ptr();
+  }
+};
+
+typedef XString<> LString;
+typedef XString<Compare_fs> LString_fs;
+
+typedef XString<Compare_strncmp, String> SString;
+typedef XString<Compare_fs, String> SString_fs;
+typedef XString<Compare_t, String> SString_t;
+
+
+#define XSTRING_WITH_LEN(X) (X).ptr(), (X).length()
+#define DB_WITH_LEN(X) (X).db, (X).db_length
+#define TABLE_NAME_WITH_LEN(X) (X).table_name, (X).table_name_length
+
+
+class Local_da : public Diagnostics_area
+{
+  THD *thd;
+  uint sql_error;
+  Diagnostics_area *saved_da;
+
+public:
+  Local_da(THD *_thd, uint _sql_error= 0) :
+    Diagnostics_area(_thd->query_id, false, true),
+    thd(_thd),
+    sql_error(_sql_error),
+    saved_da(_thd->get_stmt_da())
+  {
+    thd->set_stmt_da(this);
+  }
+  ~Local_da()
+  {
+    if (saved_da)
+      finish();
+  }
+  void finish()
+  {
+    DBUG_ASSERT(saved_da && thd);
+    thd->set_stmt_da(saved_da);
+    if (is_error())
+      my_error(sql_error ? sql_error : sql_errno(), MYF(0), message());
+    if (warn_count() > error_count())
+      saved_da->copy_non_errors_from_wi(thd, get_warning_info());
+    saved_da= NULL;
+  }
+};
+
+
+#endif // VERS_UTILS_INCLUDED