/* SPDX-License-Identifier: LGPL-2.1+ */

  /*
   * Declarations for System V style searching functions.
   * Copyright (C) 1995-1999, 2000 Free Software Foundation, Inc.
   * This file is part of the GNU C Library.

   */
  
  /*
   * Based on code from uClibc-0.9.30.3
   * Extensions for use within U-Boot

   * Copyright (C) 2010-2013 Wolfgang Denk <wd@denx.de>

   */

  #ifndef _SEARCH_H_
  #define _SEARCH_H_

  #include <env.h>

  #include <stddef.h>

  #define set_errno(val) do { errno = val; } while (0)

  /* enum env_action: action which shall be performed in the call to hsearch */
  enum env_action {
  	ENV_FIND,
  	ENV_ENTER,
  };

  /** struct env_entry - An entry in the environment hashtable */
  struct env_entry {

  	const char *key;

  	char *data;

  	int (*callback)(const char *name, const char *value, enum env_op op,
  		int flags);

  	int flags;

  };

  /*
   * Family of hash table handling functions.  The functions also
   * have reentrant counterparts ending with _r.  The non-reentrant

   * functions all work on a single internal hash table.

   */
  
  /* Data type for reentrant functions.  */
  struct hsearch_data {

  	struct env_entry_node *table;

  	unsigned int size;
  	unsigned int filled;

  /*
   * Callback function which will check whether the given change for variable

   * "item" to "newval" may be applied or not, and possibly apply such change.

   * When (flag & H_FORCE) is set, it shall not print out any error message and
   * shall force overwriting of write-once variables.

   * Must return 0 for approval, 1 for denial.

   */

  	int (*change_ok)(const struct env_entry *item, const char *newval,

  			 enum env_op, int flag);

  };

  /* Create a new hash table which will contain at most "nel" elements.  */
  int hcreate_r(size_t nel, struct hsearch_data *htab);

  /* Destroy current internal hash table.  */

  void hdestroy_r(struct hsearch_data *htab);

  
  /*

   * Search for entry matching item.key in internal hash table.  If
   * action is `ENV_FIND' return found entry or signal error by returning
   * NULL.  If action is `ENV_ENTER' replace existing data (if any) with
   * item.data.

   * */

  int hsearch_r(struct env_entry item, enum env_action action,
  	      struct env_entry **retval, struct hsearch_data *htab, int flag);

  /*

   * Search for an entry matching "match".  Otherwise, Same semantics

   * as hsearch_r().
   */

  int hmatch_r(const char *match, int last_idx, struct env_entry **retval,
  	     struct hsearch_data *htab);

  /* Search and delete entry matching "key" in internal hash table. */
  int hdelete_r(const char *key, struct hsearch_data *htab, int flag);

  ssize_t hexport_r(struct hsearch_data *htab, const char sep, int flag,
  		  char **resp, size_t size, int argc, char * const argv[]);

  /*
   * nvars: length of vars array
   * vars: array of strings (variable names) to import (nvars == 0 means all)
   */

  int himport_r(struct hsearch_data *htab, const char *env, size_t size,
  	      const char sep, int flag, int crlf_is_lf, int nvars,
  	      char * const vars[]);

  /* Walk the whole table calling the callback on each element */

  int hwalk_r(struct hsearch_data *htab,
  	    int (*callback)(struct env_entry *entry));

  /* Flags for himport_r(), hexport_r(), hdelete_r(), and hsearch_r() */

  #define H_NOCLEAR	(1 << 0) /* do not clear hash table before importing */
  #define H_FORCE		(1 << 1) /* overwrite read-only/write-once variables */
  #define H_INTERACTIVE	(1 << 2) /* indicate that an import is user directed */

  #define H_HIDE_DOT	(1 << 3) /* don't print env vars that begin with '.' */

  #define H_MATCH_KEY	(1 << 4) /* search/grep key  = variable names	     */
  #define H_MATCH_DATA	(1 << 5) /* search/grep data = variable values	     */
  #define H_MATCH_BOTH	(H_MATCH_KEY | H_MATCH_DATA) /* search/grep both     */
  #define H_MATCH_IDENT	(1 << 6) /* search for indentical strings	     */

  #define H_MATCH_SUBSTR	(1 << 7) /* search for substring matches	     */
  #define H_MATCH_REGEX	(1 << 8) /* search for regular expression matches    */
  #define H_MATCH_METHOD	(H_MATCH_IDENT | H_MATCH_SUBSTR | H_MATCH_REGEX)

  #define H_PROGRAMMATIC	(1 << 9) /* indicate that an import is from env_set() */

  #define H_ORIGIN_FLAGS	(H_INTERACTIVE | H_PROGRAMMATIC)

  #endif /* _SEARCH_H_ */