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Diffstat (limited to 'include/search.h')
-rw-r--r-- | include/search.h | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/include/search.h b/include/search.h new file mode 100644 index 00000000000..7faf23f4aca --- /dev/null +++ b/include/search.h @@ -0,0 +1,127 @@ +/* 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; +#ifndef CONFIG_SPL_BUILD + int (*callback)(const char *name, const char *value, enum env_op op, + int flags); +#endif + 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); + +/** + * hdelete_r() - Search and delete entry in internal hash table + * + * @key: Name of entry to delete + * @htab: Hash table + * @flag: Flags to use (H_...) + * Return: 0 on success, -ENOENT if not found, -EPERM if the hash table callback + * rejected changing the variable, -EINVAL if the hash table refused to + * delete the variable + */ +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) +#define H_DEFAULT (1 << 10) /* indicate that an import is default env */ +#define H_EXTERNAL (1 << 11) /* indicate that an import is external env */ + +#endif /* _SEARCH_H_ */ |