xref: /openbmc/u-boot/include/search.h (revision b20c38a9)
1 /*
2  * Declarations for System V style searching functions.
3  * Copyright (C) 1995-1999, 2000 Free Software Foundation, Inc.
4  * This file is part of the GNU C Library.
5  *
6  * SPDX-License-Identifier:	LGPL-2.1+
7  */
8 
9 /*
10  * Based on code from uClibc-0.9.30.3
11  * Extensions for use within U-Boot
12  * Copyright (C) 2010-2013 Wolfgang Denk <wd@denx.de>
13  */
14 
15 #ifndef _SEARCH_H
16 #define	_SEARCH_H 1
17 
18 #include <stddef.h>
19 
20 #define __set_errno(val) do { errno = val; } while (0)
21 
22 enum env_op {
23 	env_op_create,
24 	env_op_delete,
25 	env_op_overwrite,
26 };
27 
28 /* Action which shall be performed in the call the hsearch.  */
29 typedef enum {
30 	FIND,
31 	ENTER
32 } ACTION;
33 
34 typedef struct entry {
35 	const char *key;
36 	char *data;
37 	int (*callback)(const char *name, const char *value, enum env_op op,
38 		int flags);
39 	int flags;
40 } ENTRY;
41 
42 /* Opaque type for internal use.  */
43 struct _ENTRY;
44 
45 /*
46  * Family of hash table handling functions.  The functions also
47  * have reentrant counterparts ending with _r.  The non-reentrant
48  * functions all work on a signle internal hashing table.
49  */
50 
51 /* Data type for reentrant functions.  */
52 struct hsearch_data {
53 	struct _ENTRY *table;
54 	unsigned int size;
55 	unsigned int filled;
56 /*
57  * Callback function which will check whether the given change for variable
58  * "item" to "newval" may be applied or not, and possibly apply such change.
59  * When (flag & H_FORCE) is set, it shall not print out any error message and
60  * shall force overwriting of write-once variables.
61 .* Must return 0 for approval, 1 for denial.
62  */
63 	int (*change_ok)(const ENTRY *__item, const char *newval, enum env_op,
64 		int flag);
65 };
66 
67 /* Create a new hashing table which will at most contain NEL elements.  */
68 extern int hcreate_r(size_t __nel, struct hsearch_data *__htab);
69 
70 /* Destroy current internal hashing table.  */
71 extern void hdestroy_r(struct hsearch_data *__htab);
72 
73 /*
74  * Search for entry matching ITEM.key in internal hash table.  If
75  * ACTION is `FIND' return found entry or signal error by returning
76  * NULL.  If ACTION is `ENTER' replace existing data (if any) with
77  * ITEM.data.
78  * */
79 extern int hsearch_r(ENTRY __item, ACTION __action, ENTRY ** __retval,
80 		     struct hsearch_data *__htab, int __flag);
81 
82 /*
83  * Search for an entry matching `MATCH'.  Otherwise, Same semantics
84  * as hsearch_r().
85  */
86 extern int hmatch_r(const char *__match, int __last_idx, ENTRY ** __retval,
87 		    struct hsearch_data *__htab);
88 
89 /* Search and delete entry matching ITEM.key in internal hash table. */
90 extern int hdelete_r(const char *__key, struct hsearch_data *__htab,
91 		     int __flag);
92 
93 extern ssize_t hexport_r(struct hsearch_data *__htab,
94 		     const char __sep, int __flag, char **__resp, size_t __size,
95 		     int argc, char * const argv[]);
96 
97 /*
98  * nvars: length of vars array
99  * vars: array of strings (variable names) to import (nvars == 0 means all)
100  * do_apply: whether to call callback function to check the new argument,
101  * and possibly apply changes (false means accept everything)
102  */
103 extern int himport_r(struct hsearch_data *__htab,
104 		     const char *__env, size_t __size, const char __sep,
105 		     int __flag, int __crlf_is_lf, int nvars,
106 		     char * const vars[]);
107 
108 /* Walk the whole table calling the callback on each element */
109 extern int hwalk_r(struct hsearch_data *__htab, int (*callback)(ENTRY *));
110 
111 /* Flags for himport_r(), hexport_r(), hdelete_r(), and hsearch_r() */
112 #define H_NOCLEAR	(1 << 0) /* do not clear hash table before importing */
113 #define H_FORCE		(1 << 1) /* overwrite read-only/write-once variables */
114 #define H_INTERACTIVE	(1 << 2) /* indicate that an import is user directed */
115 #define H_HIDE_DOT	(1 << 3) /* don't print env vars that begin with '.' */
116 #define H_MATCH_KEY	(1 << 4) /* search/grep key  = variable names	     */
117 #define H_MATCH_DATA	(1 << 5) /* search/grep data = variable values	     */
118 #define H_MATCH_BOTH	(H_MATCH_KEY | H_MATCH_DATA) /* search/grep both     */
119 #define H_MATCH_IDENT	(1 << 6) /* search for indentical strings	     */
120 #define H_MATCH_SUBSTR	(1 << 7) /* search for substring matches	     */
121 #define H_MATCH_REGEX	(1 << 8) /* search for regular expression matches    */
122 #define H_MATCH_METHOD	(H_MATCH_IDENT | H_MATCH_SUBSTR | H_MATCH_REGEX)
123 #define H_PROGRAMMATIC	(1 << 9) /* indicate that an import is from setenv() */
124 #define H_ORIGIN_FLAGS	(H_INTERACTIVE | H_PROGRAMMATIC)
125 
126 #endif /* search.h */
127