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 * sdb_data_inarray:
162 * Determine whether a datum is included in an array based on the usual
163 * comparison function of the value's type. The element type of the array has
164 * to match the type of the value.
165 */
166 _Bool
167 sdb_data_inarray(const sdb_data_t *value, const sdb_data_t *array);
169 /*
170 * Operators supported by sdb_data_eval_expr.
171 */
172 enum {
173 SDB_DATA_ADD = 1, /* addition */
174 SDB_DATA_SUB, /* substraction */
175 SDB_DATA_MUL, /* multiplication */
176 SDB_DATA_DIV, /* division */
177 SDB_DATA_MOD, /* modulo */
178 SDB_DATA_CONCAT, /* string / binary data concatenation */
179 };
181 #define SDB_DATA_OP_TO_STRING(op) \
182 (((op) == SDB_DATA_ADD) ? "+" \
183 : ((op) == SDB_DATA_SUB) ? "-" \
184 : ((op) == SDB_DATA_MUL) ? "*" \
185 : ((op) == SDB_DATA_DIV) ? "/" \
186 : ((op) == SDB_DATA_MOD) ? "%" \
187 : ((op) == SDB_DATA_CONCAT) ? "||" : "UNKNOWN")
189 /*
190 * sdb_data_parse_op:
191 * Parse the string representation of an operator supported by
192 * sdb_data_expr_eval.
193 *
194 * Returns:
195 * - the ID of the operator
196 * - a negative value in case the operator does not exist
197 */
198 int
199 sdb_data_parse_op(const char *op);
201 /*
202 * sdb_data_expr_eval:
203 * Evaluate a simple arithmetic expression on two data points. String and
204 * binary data only support concatenation and all other data types only
205 * support the other operators. The result may be allocated dynamically and
206 * has to be freed by the caller (using sdb_data_free_datum).
207 *
208 * If any of the data points is a NULL value, the result is also NULL.
209 *
210 * The data-types of d1 and d2 have to be the same, except for the following
211 * cases:
212 * - <integer> or <decimal> <mul> <datetime>
213 * - <datetime> <mul> or <div> or <mod> <integer> or <decimal>
214 *
215 * Returns:
216 * - 0 on success
217 * - a negative value else
218 */
219 int
220 sdb_data_expr_eval(int op, const sdb_data_t *d1, const sdb_data_t *d2,
221 sdb_data_t *res);
223 /*
224 * sdb_data_expr_type:
225 * Determine the type of the expression when applying the specified operator
226 * to the specified types. Note that if an actual value is a typed NULL value
227 * (e.g. a NULL string value), the return value of this function does not
228 * match the return type of sdb_data_expr_eval.
229 *
230 * See the documentation of sdb_data_expr_eval() for a description of which
231 * operations are supported.
232 *
233 * Returns:
234 * - the type id on success
235 * - a negative value else
236 */
237 int
238 sdb_data_expr_type(int op, int type1, int type2);
240 /*
241 * sdb_data_strlen:
242 * Returns a (worst-case) estimate for the number of bytes required to format
243 * the datum as a string. Does not take the terminating null byte into
244 * account.
245 */
246 size_t
247 sdb_data_strlen(const sdb_data_t *datum);
249 enum {
250 SDB_UNQUOTED = 0,
251 SDB_SINGLE_QUOTED,
252 SDB_DOUBLE_QUOTED,
253 };
255 /*
256 * sdb_data_format:
257 * Output the specified datum to the specified string using a default format.
258 * The value of 'quoted' determines whether and how non-integer and
259 * non-decimal values are quoted. If the buffer size is less than the return
260 * value of sdb_data_strlen, the datum may be truncated. The buffer will
261 * always be nul-terminated after calling this function.
262 *
263 * Returns:
264 * - the number of characters written to the buffer (excluding the terminated
265 * null byte) or the number of characters which would have been written in
266 * case the output was truncated
267 * - a negative value else
268 */
269 int
270 sdb_data_format(const sdb_data_t *datum, char *buf, size_t buflen, int quoted);
272 /*
273 * sdb_data_parse:
274 * Parse the specified string into a datum using the specified type. The
275 * string value is expected to be a raw value of the specified type. Integer
276 * and decimal numbers may be signed or unsigned octal (base 8, if the first
277 * character of the string is "0"), sedecimal (base 16, if the string includes
278 * the "0x" prefix), or decimal. Decimal numbers may also be "infinity" or
279 * "NaN" or may use a decimal exponent. Date-time values are expected to be
280 * specified as (floating point) number of seconds since the epoch. For string
281 * and binary data, the input string is passed to the datum. The function does
282 * not allocate new memory for that purpose. Use sdb_data_copy() if you want
283 * to do that. For regex data, the input string is copied to newly allocated
284 * memory and also compiled to a regex. Use sdb_data_free_datum() to free the
285 * dynamically allocated memory.
286 *
287 * The input string may be stored in 'data', that is, the function may be used
288 * to do an inline cast from a string to any other type. It is the callers
289 * responsibility to free the memory used by the string in case the target
290 * type does not keep a reference to it.
291 *
292 * Returns:
293 * - 0 on success
294 * - a negative value else
295 */
296 int
297 sdb_data_parse(char *str, int type, sdb_data_t *data);
299 /*
300 * sdb_data_sizeof:
301 * Return the size of the data-type identified by the specified type.
302 *
303 * Returns:
304 * - the size of the data-type on success
305 * - 0 else
306 */
307 size_t
308 sdb_data_sizeof(int type);
310 #ifdef __cplusplus
311 } /* extern "C" */
312 #endif
314 #endif /* ! SDB_CORE_DATA_H */
316 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */