1 /*
2 * SysDB - src/include/core/data.h
3 * Copyright (C) 2012-2014 Sebastian 'tokkee' Harl <sh@tokkee.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
17 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
18 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
19 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
20 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
28 #ifndef SDB_CORE_DATA_H
29 #define SDB_CORE_DATA_H 1
31 #include "core/time.h"
33 #include <inttypes.h>
34 #include <stddef.h>
36 #include <sys/types.h>
37 #include <regex.h>
39 #ifdef __cplusplus
40 extern "C" {
41 #endif
43 enum {
44 SDB_TYPE_NULL = 0,
45 SDB_TYPE_INTEGER,
46 SDB_TYPE_DECIMAL,
47 SDB_TYPE_STRING,
48 SDB_TYPE_DATETIME,
49 SDB_TYPE_BINARY,
50 SDB_TYPE_REGEX, /* extended, case-insensitive POSIX regex */
52 /* flags: */
53 SDB_TYPE_ARRAY = 1 << 8,
54 };
56 #define SDB_TYPE_TO_STRING(t) \
57 (((t) == SDB_TYPE_INTEGER) ? "INTEGER" \
58 : ((t) == SDB_TYPE_DECIMAL) ? "DECIMAL" \
59 : ((t) == SDB_TYPE_STRING) ? "STRING" \
60 : ((t) == SDB_TYPE_DATETIME) ? "DATETIME" \
61 : ((t) == SDB_TYPE_BINARY) ? "BINARY" \
62 : ((t) == SDB_TYPE_REGEX) ? "REGEX" : "UNKNOWN")
64 union sdb_datum;
65 typedef union sdb_datum sdb_datum_t;
67 union sdb_datum {
68 int64_t integer; /* SDB_TYPE_INTEGER */
69 double decimal; /* SDB_TYPE_DECIMAL */
70 char *string; /* SDB_TYPE_STRING */
71 sdb_time_t datetime; /* SDB_TYPE_DATETIME */
72 struct {
73 size_t length;
74 unsigned char *datum;
75 } binary; /* SDB_TYPE_BINARY */
76 struct {
77 char *raw;
78 regex_t regex;
79 } re; /* SDB_TYPE_REGEX */
81 struct {
82 size_t length;
83 void *values;
84 } array;
85 };
87 /*
88 * sdb_data_t:
89 * An arbitrary value of a specified type.
90 */
91 typedef struct {
92 int type; /* type of the datum */
93 sdb_datum_t data;
94 } sdb_data_t;
95 #define SDB_DATA_INIT { SDB_TYPE_NULL, { .integer = 0 } }
97 extern const sdb_data_t SDB_DATA_NULL;
99 /*
100 * sdb_data_copy:
101 * Copy the datum stored in 'src' to the memory location pointed to by 'dst'.
102 * Any dynamic data (strings, binary data) is copied to newly allocated
103 * memory. Use, for example, sdb_data_free_datum() to free any dynamic memory
104 * stored in a datum. On error, 'dst' is unchanged. Else, any dynamic memory
105 * in 'dst' will be freed.
106 *
107 * Returns:
108 * - 0 on success
109 * - a negative value else
110 */
111 int
112 sdb_data_copy(sdb_data_t *dst, const sdb_data_t *src);
114 /*
115 * sdb_data_free_datum:
116 * Free any dynamic memory referenced by the specified datum. Does not free
117 * the memory allocated by the sdb_data_t object itself. This function must
118 * not be used if any static or stack memory is referenced from the data
119 * object.
120 */
121 void
122 sdb_data_free_datum(sdb_data_t *datum);
124 /*
125 * sdb_data_cmp:
126 * Compare two data points. A NULL datum is considered less than any non-NULL
127 * datum. On data-type mismatch, the function always returns a non-zero value.
128 *
129 * Returns:
130 * - a value less than zero if d1 compares less than d2
131 * - zero if d1 compares equal to d2
132 * - a value greater than zero if d1 compares greater than d2
133 */
134 int
135 sdb_data_cmp(const sdb_data_t *d1, const sdb_data_t *d2);
137 /*
138 * sdb_data_strcmp:
139 * Compare the string values of two data points. A NULL datum is considered
140 * less than any non-NULL. This function works for arbitrary combination of
141 * data-types.
142 *
143 * Returns:
144 * - a value less than zero if d1 compares less than d2
145 * - zero if d1 compares equal to d2
146 * - a value greater than zero if d1 compares greater than d2
147 */
148 int
149 sdb_data_strcmp(const sdb_data_t *d1, const sdb_data_t *d2);
151 /*
152 * sdb_data_isnull:
153 * Determine whether a datum is NULL. A datum is considered to be NULL if
154 * either datum is NULL or if the type is SDB_TYPE_NULL or if the string or
155 * binary datum is NULL.
156 */
157 _Bool
158 sdb_data_isnull(const sdb_data_t *datum);
160 /*
161 * Operators supported by sdb_data_eval_expr.
162 */
163 enum {
164 SDB_DATA_ADD = 1, /* addition */
165 SDB_DATA_SUB, /* substraction */
166 SDB_DATA_MUL, /* multiplication */
167 SDB_DATA_DIV, /* division */
168 SDB_DATA_MOD, /* modulo */
169 SDB_DATA_CONCAT, /* string / binary data concatenation */
170 };
172 #define SDB_DATA_OP_TO_STRING(op) \
173 (((op) == SDB_DATA_ADD) ? "+" \
174 : ((op) == SDB_DATA_SUB) ? "-" \
175 : ((op) == SDB_DATA_MUL) ? "*" \
176 : ((op) == SDB_DATA_DIV) ? "/" \
177 : ((op) == SDB_DATA_MOD) ? "%" \
178 : ((op) == SDB_DATA_CONCAT) ? "||" : "UNKNOWN")
180 /*
181 * sdb_data_parse_op:
182 * Parse the string representation of an operator supported by
183 * sdb_data_expr_eval.
184 *
185 * Returns:
186 * - the ID of the operator
187 * - a negative value in case the operator does not exist
188 */
189 int
190 sdb_data_parse_op(const char *op);
192 /*
193 * sdb_data_expr_eval:
194 * Evaluate a simple arithmetic expression on two data points. String and
195 * binary data only support concatenation and all other data types only
196 * support the other operators. The result may be allocated dynamically and
197 * has to be freed by the caller (using sdb_data_free_datum).
198 *
199 * If any of the data points is a NULL value, the result is also NULL.
200 *
201 * The data-types of d1 and d2 have to be the same, except for the following
202 * cases:
203 * - <integer> or <decimal> <mul> <datetime>
204 * - <datetime> <mul> or <div> or <mod> <integer> or <decimal>
205 *
206 * Returns:
207 * - 0 on success
208 * - a negative value else
209 */
210 int
211 sdb_data_expr_eval(int op, const sdb_data_t *d1, const sdb_data_t *d2,
212 sdb_data_t *res);
214 /*
215 * sdb_data_strlen:
216 * Returns a (worst-case) estimate for the number of bytes required to format
217 * the datum as a string. Does not take the terminating null byte into
218 * account.
219 */
220 size_t
221 sdb_data_strlen(const sdb_data_t *datum);
223 enum {
224 SDB_UNQUOTED = 0,
225 SDB_SINGLE_QUOTED,
226 SDB_DOUBLE_QUOTED,
227 };
229 /*
230 * sdb_data_format:
231 * Output the specified datum to the specified string using a default format.
232 * The value of 'quoted' determines whether and how non-integer and
233 * non-decimal values are quoted. If the buffer size is less than the return
234 * value of sdb_data_strlen, the datum may be truncated. The buffer will
235 * always be nul-terminated after calling this function.
236 *
237 * Returns:
238 * - the number of characters written to the buffer (excluding the terminated
239 * null byte) or the number of characters which would have been written in
240 * case the output was truncated
241 * - a negative value else
242 */
243 int
244 sdb_data_format(const sdb_data_t *datum, char *buf, size_t buflen, int quoted);
246 /*
247 * sdb_data_parse:
248 * Parse the specified string into a datum using the specified type. The
249 * string value is expected to be a raw value of the specified type. Integer
250 * and decimal numbers may be signed or unsigned octal (base 8, if the first
251 * character of the string is "0"), sedecimal (base 16, if the string includes
252 * the "0x" prefix), or decimal. Decimal numbers may also be "infinity" or
253 * "NaN" or may use a decimal exponent. Date-time values are expected to be
254 * specified as (floating point) number of seconds since the epoch. For string
255 * and binary data, the input string is passed to the datum. The function does
256 * not allocate new memory for that purpose. Use sdb_data_copy() if you want
257 * to do that. For regex data, the input string is copied to newly allocated
258 * memory and also compiled to a regex. Use sdb_data_free_datum() to free the
259 * dynamically allocated memory.
260 *
261 * The input string may be stored in 'data', that is, the function may be used
262 * to do an inline cast from a string to any other type. It is the callers
263 * responsibility to free the memory used by the string in case the target
264 * type does not keep a reference to it.
265 *
266 * Returns:
267 * - 0 on success
268 * - a negative value else
269 */
270 int
271 sdb_data_parse(char *str, int type, sdb_data_t *data);
273 /*
274 * sdb_data_sizeof:
275 * Return the size of the data-type identified by the specified type.
276 *
277 * Returns:
278 * - the size of the data-type on success
279 * - 0 else
280 */
281 size_t
282 sdb_data_sizeof(int type);
284 #ifdef __cplusplus
285 } /* extern "C" */
286 #endif
288 #endif /* ! SDB_CORE_DATA_H */
290 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */