sdi_file.h

/* Copyright (c) 2015, 2022, Oracle and/or its affiliates.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License, version 2.0,
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   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */

#ifndef DD__SDI_FILE_INCLUDED
#define DD__SDI_FILE_INCLUDED

#include <stddef.h>
#include <utility>

#include "mysql/mysql_lex_string.h"
#include "prealloced_array.h"    // Prealloced_array
#include "sql/dd/impl/sdi.h"     // dd::Sdi_type
#include "sql/dd/object_id.h"    // dd::Object_id
#include "sql/dd/string_type.h"  // dd::String_type

class THD;
struct handlerton;
struct MYSQL_LEX_CSTRING;

namespace dd {
class Entity_object;
class Schema;
class Table;

namespace sdi_file {
/** Number of character (not bytes) of a tablename which will
    contrubute to the sdi file name. The whole name is not needed as
    the Object_id is added so that uniqueness is ensured */
const size_t FILENAME_PREFIX_CHARS = 16;

/** File name extension for sdi files. */
const String_type EXT = ".sdi";

/**
  Formats an sdi filename according to the mysql conventions for an entity
  name and schema name, where the schema may be "".

  @param id object id if dd object
  @param entity_name name (as returned by dd::Entity_object::name())
         of dd object.
  @param schema name of schema, or "" for schemaless entities (schemata).
  @retval filename to use for sdi file
 */
String_type sdi_filename(Object_id id, const String_type &entity_name,
                         const String_type &schema);

/**
  Stores sdi for table in a file.

  @param sdi json string to store
  @param table dd object from which sdi was generated
  @param schema object which table belongs to
  @retval true if an error occurs
  @retval false otherwise
*/
bool store_tbl_sdi(const Sdi_type &sdi, const dd::Table &table,
                   const dd::Schema &schema);

/**
  Remove a file name from the file system.

  @param fname file name to remove from file system.
  @retval true if an error occurs
  @retval false otherwise
*/
bool remove(const String_type &fname);

/**
  Removes sdi file for a table.

  @param table dd object for which to remove sdi
  @param schema object which table belongs to
  @retval true if an error occurs
  @retval false otherwise
*/
bool drop_tbl_sdi(const dd::Table &table, const dd::Schema &schema);

/**
  Read an sdi file from disk and store in a buffer.

  @param thd thread handle
  @param fname path to sdi file to load
  @param buf where to store file content
  @retval true if an error occurs
  @retval false otherwise
*/
bool load(THD *thd, const dd::String_type &fname, dd::String_type *buf);

/**
  Instantiation of std::pair to represent the full path to an sdi
  file. Member first is the path, second is true if the path is inside
  datadir, false otherwise.
*/
typedef std::pair<dd::String_type, bool> Path_type;

/**
  Typedef for container type to use as out-parameter when expanding
  sdi file patterns into paths.
*/
typedef Prealloced_array<Path_type, 3> Paths_type;

/**
  Expand an sdi filename pattern into the set of full paths that
  match. The paths and a bool indicating if the path is inside data
  dir is appended to the Paths_type collection provided as argument.

  @param thd thread handle
  @param pattern filenam pattern to expand
  @param paths collection of expanded file paths
  @retval true if an error occurs
  @retval false otherwise
*/
bool expand_pattern(THD *thd, const MYSQL_LEX_STRING &pattern,
                    Paths_type *paths);

/**
  Check that the MYD and MYI files for table exists.

  @param schema_name schema name
  @param table_name table name
  @retval true if an error occurs
  @retval false otherwise
 */
bool check_data_files_exist(const dd::String_type &schema_name,
                            const dd::String_type &table_name);
}  // namespace sdi_file
}  // namespace dd
#endif  // !DD__SDI_FILE_INCLUDED