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 * Operators supported by sdb_data_eval_expr.
178 */
179 enum {
180 SDB_DATA_ADD = 1, /* addition */
181 SDB_DATA_SUB, /* substraction */
182 SDB_DATA_MUL, /* multiplication */
183 SDB_DATA_DIV, /* division */
184 SDB_DATA_MOD, /* modulo */
185 SDB_DATA_CONCAT, /* string / binary data concatenation */
186 };
188 #define SDB_DATA_OP_TO_STRING(op) \
189 (((op) == SDB_DATA_ADD) ? "+" \
190 : ((op) == SDB_DATA_SUB) ? "-" \
191 : ((op) == SDB_DATA_MUL) ? "*" \
192 : ((op) == SDB_DATA_DIV) ? "/" \
193 : ((op) == SDB_DATA_MOD) ? "%" \
194 : ((op) == SDB_DATA_CONCAT) ? "||" : "UNKNOWN")
196 /*
197 * sdb_data_parse_op:
198 * Parse the string representation of an operator supported by
199 * sdb_data_expr_eval.
200 *
201 * Returns:
202 * - the ID of the operator
203 * - a negative value in case the operator does not exist
204 */
205 int
206 sdb_data_parse_op(const char *op);
208 /*
209 * sdb_data_expr_eval:
210 * Evaluate a simple arithmetic expression on two data points. String and
211 * binary data only support concatenation and all other data types only
212 * support the other operators. The result may be allocated dynamically and
213 * has to be freed by the caller (using sdb_data_free_datum).
214 *
215 * If any of the data points is a NULL value, the result is also NULL.
216 *
217 * The data-types of d1 and d2 have to be the same, except for the following
218 * cases:
219 * - <integer> or <decimal> <mul> <datetime>
220 * - <datetime> <mul> or <div> or <mod> <integer> or <decimal>
221 *
222 * Returns:
223 * - 0 on success
224 * - a negative value else
225 */
226 int
227 sdb_data_expr_eval(int op, const sdb_data_t *d1, const sdb_data_t *d2,
228 sdb_data_t *res);
230 /*
231 * sdb_data_expr_type:
232 * Determine the type of the expression when applying the specified operator
233 * to the specified types. Note that if an actual value is a typed NULL value
234 * (e.g. a NULL string value), the return value of this function does not
235 * match the return type of sdb_data_expr_eval.
236 *
237 * See the documentation of sdb_data_expr_eval() for a description of which
238 * operations are supported.
239 *
240 * Returns:
241 * - the type id on success
242 * - a negative value else
243 */
244 int
245 sdb_data_expr_type(int op, int type1, int type2);
247 /*
248 * sdb_data_strlen:
249 * Returns a (worst-case) estimate for the number of bytes required to format
250 * the datum as a string. Does not take the terminating null byte into
251 * account.
252 */
253 size_t
254 sdb_data_strlen(const sdb_data_t *datum);
256 enum {
257 SDB_UNQUOTED = 0,
258 SDB_SINGLE_QUOTED,
259 SDB_DOUBLE_QUOTED,
260 };
262 /*
263 * sdb_data_format:
264 * Output the specified datum to the specified string using a default format.
265 * The value of 'quoted' determines whether and how non-integer and
266 * non-decimal values are quoted. If the buffer size is less than the return
267 * value of sdb_data_strlen, the datum may be truncated. The buffer will
268 * always be nul-terminated after calling this function.
269 *
270 * Returns:
271 * - the number of characters written to the buffer (excluding the terminated
272 * null byte) or the number of characters which would have been written in
273 * case the output was truncated
274 * - a negative value else
275 */
276 int
277 sdb_data_format(const sdb_data_t *datum, char *buf, size_t buflen, int quoted);
279 /*
280 * sdb_data_parse:
281 * Parse the specified string into a datum using the specified type. The
282 * string value is expected to be a raw value of the specified type. Integer
283 * and decimal numbers may be signed or unsigned octal (base 8, if the first
284 * character of the string is "0"), sedecimal (base 16, if the string includes
285 * the "0x" prefix), or decimal. Decimal numbers may also be "infinity" or
286 * "NaN" or may use a decimal exponent. Date-time values are expected to be
287 * specified as (floating point) number of seconds since the epoch. For string
288 * and binary data, the input string is passed to the datum. The function does
289 * not allocate new memory for that purpose. Use sdb_data_copy() if you want
290 * to do that. For regex data, the input string is copied to newly allocated
291 * memory and also compiled to a regex. Use sdb_data_free_datum() to free the
292 * dynamically allocated memory.
293 *
294 * The input string may be stored in 'data', that is, the function may be used
295 * to do an inline cast from a string to any other type. It is the callers
296 * responsibility to free the memory used by the string in case the target
297 * type does not keep a reference to it.
298 *
299 * Returns:
300 * - 0 on success
301 * - a negative value else
302 */
303 int
304 sdb_data_parse(char *str, int type, sdb_data_t *data);
306 /*
307 * sdb_data_sizeof:
308 * Return the size of the data-type identified by the specified type.
309 *
310 * Returns:
311 * - the size of the data-type on success
312 * - 0 else
313 */
314 size_t
315 sdb_data_sizeof(int type);
317 #ifdef __cplusplus
318 } /* extern "C" */
319 #endif
321 #endif /* ! SDB_CORE_DATA_H */
323 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */