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 <stdbool.h>
35 #include <stddef.h>
37 #include <sys/types.h>
38 #include <regex.h>
40 #ifdef __cplusplus
41 extern "C" {
42 #endif
44 enum {
45 SDB_TYPE_NULL = 0,
46 SDB_TYPE_BOOLEAN,
47 SDB_TYPE_INTEGER,
48 SDB_TYPE_DECIMAL,
49 SDB_TYPE_STRING,
50 SDB_TYPE_DATETIME,
51 SDB_TYPE_BINARY,
52 SDB_TYPE_REGEX, /* extended, case-insensitive POSIX regex */
54 /* flags: */
55 SDB_TYPE_ARRAY = 1 << 8,
56 };
58 #define SDB_TYPE_TO_STRING(t) \
59 (((t) == SDB_TYPE_NULL) ? "NULL" \
60 : ((t) == SDB_TYPE_BOOLEAN) ? "BOOLEAN" \
61 : ((t) == SDB_TYPE_INTEGER) ? "INTEGER" \
62 : ((t) == SDB_TYPE_DECIMAL) ? "DECIMAL" \
63 : ((t) == SDB_TYPE_STRING) ? "STRING" \
64 : ((t) == SDB_TYPE_DATETIME) ? "DATETIME" \
65 : ((t) == SDB_TYPE_BINARY) ? "BINARY" \
66 : ((t) == SDB_TYPE_REGEX) ? "REGEX" \
67 : ((t) == (SDB_TYPE_ARRAY | SDB_TYPE_BOOLEAN)) ? "[]BOOLEAN" \
68 : ((t) == (SDB_TYPE_ARRAY | SDB_TYPE_INTEGER)) ? "[]INTEGER" \
69 : ((t) == (SDB_TYPE_ARRAY | SDB_TYPE_DECIMAL)) ? "[]DECIMAL" \
70 : ((t) == (SDB_TYPE_ARRAY | SDB_TYPE_STRING)) ? "[]STRING" \
71 : ((t) == (SDB_TYPE_ARRAY | SDB_TYPE_DATETIME)) ? "[]DATETIME" \
72 : ((t) == (SDB_TYPE_ARRAY | SDB_TYPE_BINARY)) ? "[]BINARY" \
73 : ((t) == (SDB_TYPE_ARRAY | SDB_TYPE_REGEX)) ? "[]REGEX" \
74 : "UNKNOWN")
76 union sdb_datum;
77 typedef union sdb_datum sdb_datum_t;
79 union sdb_datum {
80 bool boolean; /* SDB_TYPE_BOOLEAN */
81 int64_t integer; /* SDB_TYPE_INTEGER */
82 double decimal; /* SDB_TYPE_DECIMAL */
83 char *string; /* SDB_TYPE_STRING */
84 sdb_time_t datetime; /* SDB_TYPE_DATETIME */
85 struct {
86 size_t length;
87 unsigned char *datum;
88 } binary; /* SDB_TYPE_BINARY */
89 struct {
90 char *raw;
91 regex_t regex;
92 } re; /* SDB_TYPE_REGEX */
94 struct {
95 size_t length;
96 void *values;
97 } array;
98 };
100 /*
101 * sdb_data_t:
102 * An arbitrary value of a specified type.
103 */
104 typedef struct {
105 int type; /* type of the datum */
106 sdb_datum_t data;
107 } sdb_data_t;
108 #define SDB_DATA_INIT { SDB_TYPE_NULL, { .integer = 0 } }
110 extern const sdb_data_t SDB_DATA_NULL;
112 /*
113 * sdb_data_copy:
114 * Copy the datum stored in 'src' to the memory location pointed to by 'dst'.
115 * Any dynamic data (strings, binary data) is copied to newly allocated
116 * memory. Use, for example, sdb_data_free_datum() to free any dynamic memory
117 * stored in a datum. On error, 'dst' is unchanged. Else, any dynamic memory
118 * in 'dst' will be freed.
119 *
120 * Returns:
121 * - 0 on success
122 * - a negative value else
123 */
124 int
125 sdb_data_copy(sdb_data_t *dst, const sdb_data_t *src);
127 /*
128 * sdb_data_free_datum:
129 * Free any dynamic memory referenced by the specified datum. Does not free
130 * the memory allocated by the sdb_data_t object itself. This function must
131 * not be used if any static or stack memory is referenced from the data
132 * object.
133 */
134 void
135 sdb_data_free_datum(sdb_data_t *datum);
137 /*
138 * sdb_data_cmp:
139 * Compare two data points. A NULL datum is considered less than any non-NULL
140 * datum. On data-type mismatch, the function always returns a non-zero value.
141 *
142 * Returns:
143 * - a value less than zero if d1 compares less than d2
144 * - zero if d1 compares equal to d2
145 * - a value greater than zero if d1 compares greater than d2
146 */
147 int
148 sdb_data_cmp(const sdb_data_t *d1, const sdb_data_t *d2);
150 /*
151 * sdb_data_strcmp:
152 * Compare the string values of two data points. A NULL datum is considered
153 * less than any non-NULL. This function works for arbitrary combination of
154 * data-types.
155 *
156 * Returns:
157 * - a value less than zero if d1 compares less than d2
158 * - zero if d1 compares equal to d2
159 * - a value greater than zero if d1 compares greater than d2
160 */
161 int
162 sdb_data_strcmp(const sdb_data_t *d1, const sdb_data_t *d2);
164 /*
165 * sdb_data_isnull:
166 * Determine whether a datum is NULL. A datum is considered to be NULL if
167 * either datum is NULL or if the type is SDB_TYPE_NULL or if the string or
168 * binary datum is NULL.
169 */
170 bool
171 sdb_data_isnull(const sdb_data_t *datum);
173 /*
174 * sdb_data_inarray:
175 * Determine whether a datum is included in an array based on the usual
176 * comparison function of the value's type. The element type of the array has
177 * to match the type of the value. The value may be another array. In that
178 * case, the element types have to match and the function returns true if all
179 * elements of the first array are included in the second where order does not
180 * matter.
181 */
182 bool
183 sdb_data_inarray(const sdb_data_t *value, const sdb_data_t *array);
185 /*
186 * sdb_data_array_get:
187 * Get the i-th value stored in the specified array and store an alias in
188 * 'value'. Storing an alias means that the value points to the actual array
189 * element. Do *not* free the value after using it (i.e., don't use
190 * sdb_data_free_datum).
191 *
192 * Returns:
193 * - 0 on success
194 * - a negative value else
195 */
196 int
197 sdb_data_array_get(const sdb_data_t *array, size_t i, sdb_data_t *value);
199 /*
200 * Operators supported by sdb_data_eval_expr.
201 */
202 enum {
203 SDB_DATA_ADD = 1, /* addition */
204 SDB_DATA_SUB, /* substraction */
205 SDB_DATA_MUL, /* multiplication */
206 SDB_DATA_DIV, /* division */
207 SDB_DATA_MOD, /* modulo */
208 SDB_DATA_CONCAT, /* string / binary data concatenation */
209 };
211 #define SDB_DATA_OP_TO_STRING(op) \
212 (((op) == SDB_DATA_ADD) ? "+" \
213 : ((op) == SDB_DATA_SUB) ? "-" \
214 : ((op) == SDB_DATA_MUL) ? "*" \
215 : ((op) == SDB_DATA_DIV) ? "/" \
216 : ((op) == SDB_DATA_MOD) ? "%" \
217 : ((op) == SDB_DATA_CONCAT) ? "||" : "UNKNOWN")
219 /*
220 * sdb_data_parse_op:
221 * Parse the string representation of an operator supported by
222 * sdb_data_expr_eval.
223 *
224 * Returns:
225 * - the ID of the operator
226 * - a negative value in case the operator does not exist
227 */
228 int
229 sdb_data_parse_op(const char *op);
231 /*
232 * sdb_data_expr_eval:
233 * Evaluate a simple arithmetic expression on two data points. String and
234 * binary data only support concatenation and all other data types only
235 * support the other operators. The result may be allocated dynamically and
236 * has to be freed by the caller (using sdb_data_free_datum).
237 *
238 * If any of the data points is a NULL value, the result is also NULL.
239 *
240 * The data-types of d1 and d2 have to be the same, except for the following
241 * cases:
242 * - <integer> or <decimal> <mul> <datetime>
243 * - <datetime> <mul> or <div> or <mod> <integer> or <decimal>
244 *
245 * Returns:
246 * - 0 on success
247 * - a negative value else
248 */
249 int
250 sdb_data_expr_eval(int op, const sdb_data_t *d1, const sdb_data_t *d2,
251 sdb_data_t *res);
253 /*
254 * sdb_data_expr_type:
255 * Determine the type of the expression when applying the specified operator
256 * to the specified types. Note that if an actual value is a typed NULL value
257 * (e.g. a NULL string value), the return value of this function does not
258 * match the return type of sdb_data_expr_eval.
259 *
260 * See the documentation of sdb_data_expr_eval() for a description of which
261 * operations are supported.
262 *
263 * Returns:
264 * - the type id on success
265 * - a negative value else
266 */
267 int
268 sdb_data_expr_type(int op, int type1, int type2);
270 /*
271 * sdb_data_strlen:
272 * Returns a (worst-case) estimate for the number of bytes required to format
273 * the datum as a string. Does not take the terminating null byte into
274 * account.
275 */
276 size_t
277 sdb_data_strlen(const sdb_data_t *datum);
279 enum {
280 SDB_UNQUOTED = 0,
281 SDB_SINGLE_QUOTED,
282 SDB_DOUBLE_QUOTED,
283 };
285 /*
286 * sdb_data_format:
287 * Output the specified datum to the specified string using a default format.
288 * The value of 'quoted' determines whether and how non-integer and
289 * non-decimal values are quoted. If the buffer size is less than the return
290 * value of sdb_data_strlen, the datum may be truncated. The buffer will
291 * always be nul-terminated after calling this function.
292 *
293 * Returns:
294 * - the number of characters written to the buffer (excluding the terminated
295 * null byte) or the number of characters which would have been written in
296 * case the output was truncated
297 */
298 size_t
299 sdb_data_format(const sdb_data_t *datum, char *buf, size_t buflen, int quoted);
301 /*
302 * sdb_data_parse:
303 * Parse the specified string into a datum using the specified type. The
304 * string value is expected to be a raw value of the specified type. Integer
305 * and decimal numbers may be signed or unsigned octal (base 8, if the first
306 * character of the string is "0"), sedecimal (base 16, if the string includes
307 * the "0x" prefix), or decimal. Decimal numbers may also be "infinity" or
308 * "NaN" or may use a decimal exponent. Date-time values are expected to be
309 * specified as (floating point) number of seconds since the epoch. New memory
310 * will be allocated as necessary and will have to be free'd using
311 * sdb_data_free_datum().
312 *
313 * Returns:
314 * - 0 on success
315 * - a negative value else
316 */
317 int
318 sdb_data_parse(const char *str, int type, sdb_data_t *data);
320 /*
321 * sdb_data_sizeof:
322 * Return the size of the data-type identified by the specified type.
323 *
324 * Returns:
325 * - the size of the data-type on success
326 * - 0 else
327 */
328 size_t
329 sdb_data_sizeof(int type);
331 #ifdef __cplusplus
332 } /* extern "C" */
333 #endif
335 #endif /* ! SDB_CORE_DATA_H */
337 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */