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" \
63 : ((t) == (SDB_TYPE_ARRAY | SDB_TYPE_INTEGER)) ? "[]INTEGER" \
64 : ((t) == (SDB_TYPE_ARRAY | SDB_TYPE_DECIMAL)) ? "[]DECIMAL" \
65 : ((t) == (SDB_TYPE_ARRAY | SDB_TYPE_STRING)) ? "[]STRING" \
66 : ((t) == (SDB_TYPE_ARRAY | SDB_TYPE_DATETIME)) ? "[]DATETIME" \
67 : ((t) == (SDB_TYPE_ARRAY | SDB_TYPE_BINARY)) ? "[]BINARY" \
68 : ((t) == (SDB_TYPE_ARRAY | SDB_TYPE_REGEX)) ? "[]REGEX" \
69 : "UNKNOWN")
71 union sdb_datum;
72 typedef union sdb_datum sdb_datum_t;
74 union sdb_datum {
75 int64_t integer; /* SDB_TYPE_INTEGER */
76 double decimal; /* SDB_TYPE_DECIMAL */
77 char *string; /* SDB_TYPE_STRING */
78 sdb_time_t datetime; /* SDB_TYPE_DATETIME */
79 struct {
80 size_t length;
81 unsigned char *datum;
82 } binary; /* SDB_TYPE_BINARY */
83 struct {
84 char *raw;
85 regex_t regex;
86 } re; /* SDB_TYPE_REGEX */
88 struct {
89 size_t length;
90 void *values;
91 } array;
92 };
94 /*
95 * sdb_data_t:
96 * An arbitrary value of a specified type.
97 */
98 typedef struct {
99 int type; /* type of the datum */
100 sdb_datum_t data;
101 } sdb_data_t;
102 #define SDB_DATA_INIT { SDB_TYPE_NULL, { .integer = 0 } }
104 extern const sdb_data_t SDB_DATA_NULL;
106 /*
107 * sdb_data_copy:
108 * Copy the datum stored in 'src' to the memory location pointed to by 'dst'.
109 * Any dynamic data (strings, binary data) is copied to newly allocated
110 * memory. Use, for example, sdb_data_free_datum() to free any dynamic memory
111 * stored in a datum. On error, 'dst' is unchanged. Else, any dynamic memory
112 * in 'dst' will be freed.
113 *
114 * Returns:
115 * - 0 on success
116 * - a negative value else
117 */
118 int
119 sdb_data_copy(sdb_data_t *dst, const sdb_data_t *src);
121 /*
122 * sdb_data_free_datum:
123 * Free any dynamic memory referenced by the specified datum. Does not free
124 * the memory allocated by the sdb_data_t object itself. This function must
125 * not be used if any static or stack memory is referenced from the data
126 * object.
127 */
128 void
129 sdb_data_free_datum(sdb_data_t *datum);
131 /*
132 * sdb_data_cmp:
133 * Compare two data points. A NULL datum is considered less than any non-NULL
134 * datum. On data-type mismatch, the function always returns a non-zero value.
135 *
136 * Returns:
137 * - a value less than zero if d1 compares less than d2
138 * - zero if d1 compares equal to d2
139 * - a value greater than zero if d1 compares greater than d2
140 */
141 int
142 sdb_data_cmp(const sdb_data_t *d1, const sdb_data_t *d2);
144 /*
145 * sdb_data_strcmp:
146 * Compare the string values of two data points. A NULL datum is considered
147 * less than any non-NULL. This function works for arbitrary combination of
148 * data-types.
149 *
150 * Returns:
151 * - a value less than zero if d1 compares less than d2
152 * - zero if d1 compares equal to d2
153 * - a value greater than zero if d1 compares greater than d2
154 */
155 int
156 sdb_data_strcmp(const sdb_data_t *d1, const sdb_data_t *d2);
158 /*
159 * sdb_data_isnull:
160 * Determine whether a datum is NULL. A datum is considered to be NULL if
161 * either datum is NULL or if the type is SDB_TYPE_NULL or if the string or
162 * binary datum is NULL.
163 */
164 _Bool
165 sdb_data_isnull(const sdb_data_t *datum);
167 /*
168 * sdb_data_inarray:
169 * Determine whether a datum is included in an array based on the usual
170 * comparison function of the value's type. The element type of the array has
171 * to match the type of the value.
172 */
173 _Bool
174 sdb_data_inarray(const sdb_data_t *value, const sdb_data_t *array);
176 /*
177 * sdb_data_array_get:
178 * Get the i-th value stored in the specified array and store an alias in
179 * 'value'. Storing an alias means that the value points to the actual array
180 * element. Do *not* free the value after using it (i.e., don't use
181 * sdb_data_free_datum).
182 *
183 * Returns:
184 * - 0 on success
185 * - a negative value else
186 */
187 int
188 sdb_data_array_get(const sdb_data_t *array, size_t i, sdb_data_t *value);
190 /*
191 * Operators supported by sdb_data_eval_expr.
192 */
193 enum {
194 SDB_DATA_ADD = 1, /* addition */
195 SDB_DATA_SUB, /* substraction */
196 SDB_DATA_MUL, /* multiplication */
197 SDB_DATA_DIV, /* division */
198 SDB_DATA_MOD, /* modulo */
199 SDB_DATA_CONCAT, /* string / binary data concatenation */
200 };
202 #define SDB_DATA_OP_TO_STRING(op) \
203 (((op) == SDB_DATA_ADD) ? "+" \
204 : ((op) == SDB_DATA_SUB) ? "-" \
205 : ((op) == SDB_DATA_MUL) ? "*" \
206 : ((op) == SDB_DATA_DIV) ? "/" \
207 : ((op) == SDB_DATA_MOD) ? "%" \
208 : ((op) == SDB_DATA_CONCAT) ? "||" : "UNKNOWN")
210 /*
211 * sdb_data_parse_op:
212 * Parse the string representation of an operator supported by
213 * sdb_data_expr_eval.
214 *
215 * Returns:
216 * - the ID of the operator
217 * - a negative value in case the operator does not exist
218 */
219 int
220 sdb_data_parse_op(const char *op);
222 /*
223 * sdb_data_expr_eval:
224 * Evaluate a simple arithmetic expression on two data points. String and
225 * binary data only support concatenation and all other data types only
226 * support the other operators. The result may be allocated dynamically and
227 * has to be freed by the caller (using sdb_data_free_datum).
228 *
229 * If any of the data points is a NULL value, the result is also NULL.
230 *
231 * The data-types of d1 and d2 have to be the same, except for the following
232 * cases:
233 * - <integer> or <decimal> <mul> <datetime>
234 * - <datetime> <mul> or <div> or <mod> <integer> or <decimal>
235 *
236 * Returns:
237 * - 0 on success
238 * - a negative value else
239 */
240 int
241 sdb_data_expr_eval(int op, const sdb_data_t *d1, const sdb_data_t *d2,
242 sdb_data_t *res);
244 /*
245 * sdb_data_expr_type:
246 * Determine the type of the expression when applying the specified operator
247 * to the specified types. Note that if an actual value is a typed NULL value
248 * (e.g. a NULL string value), the return value of this function does not
249 * match the return type of sdb_data_expr_eval.
250 *
251 * See the documentation of sdb_data_expr_eval() for a description of which
252 * operations are supported.
253 *
254 * Returns:
255 * - the type id on success
256 * - a negative value else
257 */
258 int
259 sdb_data_expr_type(int op, int type1, int type2);
261 /*
262 * sdb_data_strlen:
263 * Returns a (worst-case) estimate for the number of bytes required to format
264 * the datum as a string. Does not take the terminating null byte into
265 * account.
266 */
267 size_t
268 sdb_data_strlen(const sdb_data_t *datum);
270 enum {
271 SDB_UNQUOTED = 0,
272 SDB_SINGLE_QUOTED,
273 SDB_DOUBLE_QUOTED,
274 };
276 /*
277 * sdb_data_format:
278 * Output the specified datum to the specified string using a default format.
279 * The value of 'quoted' determines whether and how non-integer and
280 * non-decimal values are quoted. If the buffer size is less than the return
281 * value of sdb_data_strlen, the datum may be truncated. The buffer will
282 * always be nul-terminated after calling this function.
283 *
284 * Returns:
285 * - the number of characters written to the buffer (excluding the terminated
286 * null byte) or the number of characters which would have been written in
287 * case the output was truncated
288 * - a negative value else
289 */
290 int
291 sdb_data_format(const sdb_data_t *datum, char *buf, size_t buflen, int quoted);
293 /*
294 * sdb_data_parse:
295 * Parse the specified string into a datum using the specified type. The
296 * string value is expected to be a raw value of the specified type. Integer
297 * and decimal numbers may be signed or unsigned octal (base 8, if the first
298 * character of the string is "0"), sedecimal (base 16, if the string includes
299 * the "0x" prefix), or decimal. Decimal numbers may also be "infinity" or
300 * "NaN" or may use a decimal exponent. Date-time values are expected to be
301 * specified as (floating point) number of seconds since the epoch. For string
302 * and binary data, the input string is passed to the datum. The function does
303 * not allocate new memory for that purpose. Use sdb_data_copy() if you want
304 * to do that. For regex data, the input string is copied to newly allocated
305 * memory and also compiled to a regex. Use sdb_data_free_datum() to free the
306 * dynamically allocated memory.
307 *
308 * The input string may be stored in 'data', that is, the function may be used
309 * to do an inline cast from a string to any other type. It is the callers
310 * responsibility to free the memory used by the string in case the target
311 * type does not keep a reference to it.
312 *
313 * Returns:
314 * - 0 on success
315 * - a negative value else
316 */
317 int
318 sdb_data_parse(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 : */