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_INTEGER,
47 SDB_TYPE_DECIMAL,
48 SDB_TYPE_STRING,
49 SDB_TYPE_DATETIME,
50 SDB_TYPE_BINARY,
51 SDB_TYPE_REGEX, /* extended, case-insensitive POSIX regex */
53 /* flags: */
54 SDB_TYPE_ARRAY = 1 << 8,
55 };
57 #define SDB_TYPE_TO_STRING(t) \
58 (((t) == SDB_TYPE_INTEGER) ? "INTEGER" \
59 : ((t) == SDB_TYPE_DECIMAL) ? "DECIMAL" \
60 : ((t) == SDB_TYPE_STRING) ? "STRING" \
61 : ((t) == SDB_TYPE_DATETIME) ? "DATETIME" \
62 : ((t) == SDB_TYPE_BINARY) ? "BINARY" \
63 : ((t) == SDB_TYPE_REGEX) ? "REGEX" \
64 : ((t) == (SDB_TYPE_ARRAY | SDB_TYPE_INTEGER)) ? "[]INTEGER" \
65 : ((t) == (SDB_TYPE_ARRAY | SDB_TYPE_DECIMAL)) ? "[]DECIMAL" \
66 : ((t) == (SDB_TYPE_ARRAY | SDB_TYPE_STRING)) ? "[]STRING" \
67 : ((t) == (SDB_TYPE_ARRAY | SDB_TYPE_DATETIME)) ? "[]DATETIME" \
68 : ((t) == (SDB_TYPE_ARRAY | SDB_TYPE_BINARY)) ? "[]BINARY" \
69 : ((t) == (SDB_TYPE_ARRAY | SDB_TYPE_REGEX)) ? "[]REGEX" \
70 : "UNKNOWN")
72 union sdb_datum;
73 typedef union sdb_datum sdb_datum_t;
75 union sdb_datum {
76 int64_t integer; /* SDB_TYPE_INTEGER */
77 double decimal; /* SDB_TYPE_DECIMAL */
78 char *string; /* SDB_TYPE_STRING */
79 sdb_time_t datetime; /* SDB_TYPE_DATETIME */
80 struct {
81 size_t length;
82 unsigned char *datum;
83 } binary; /* SDB_TYPE_BINARY */
84 struct {
85 char *raw;
86 regex_t regex;
87 } re; /* SDB_TYPE_REGEX */
89 struct {
90 size_t length;
91 void *values;
92 } array;
93 };
95 /*
96 * sdb_data_t:
97 * An arbitrary value of a specified type.
98 */
99 typedef struct {
100 int type; /* type of the datum */
101 sdb_datum_t data;
102 } sdb_data_t;
103 #define SDB_DATA_INIT { SDB_TYPE_NULL, { .integer = 0 } }
105 extern const sdb_data_t SDB_DATA_NULL;
107 /*
108 * sdb_data_copy:
109 * Copy the datum stored in 'src' to the memory location pointed to by 'dst'.
110 * Any dynamic data (strings, binary data) is copied to newly allocated
111 * memory. Use, for example, sdb_data_free_datum() to free any dynamic memory
112 * stored in a datum. On error, 'dst' is unchanged. Else, any dynamic memory
113 * in 'dst' will be freed.
114 *
115 * Returns:
116 * - 0 on success
117 * - a negative value else
118 */
119 int
120 sdb_data_copy(sdb_data_t *dst, const sdb_data_t *src);
122 /*
123 * sdb_data_free_datum:
124 * Free any dynamic memory referenced by the specified datum. Does not free
125 * the memory allocated by the sdb_data_t object itself. This function must
126 * not be used if any static or stack memory is referenced from the data
127 * object.
128 */
129 void
130 sdb_data_free_datum(sdb_data_t *datum);
132 /*
133 * sdb_data_cmp:
134 * Compare two data points. A NULL datum is considered less than any non-NULL
135 * datum. On data-type mismatch, the function always returns a non-zero value.
136 *
137 * Returns:
138 * - a value less than zero if d1 compares less than d2
139 * - zero if d1 compares equal to d2
140 * - a value greater than zero if d1 compares greater than d2
141 */
142 int
143 sdb_data_cmp(const sdb_data_t *d1, const sdb_data_t *d2);
145 /*
146 * sdb_data_strcmp:
147 * Compare the string values of two data points. A NULL datum is considered
148 * less than any non-NULL. This function works for arbitrary combination of
149 * data-types.
150 *
151 * Returns:
152 * - a value less than zero if d1 compares less than d2
153 * - zero if d1 compares equal to d2
154 * - a value greater than zero if d1 compares greater than d2
155 */
156 int
157 sdb_data_strcmp(const sdb_data_t *d1, const sdb_data_t *d2);
159 /*
160 * sdb_data_isnull:
161 * Determine whether a datum is NULL. A datum is considered to be NULL if
162 * either datum is NULL or if the type is SDB_TYPE_NULL or if the string or
163 * binary datum is NULL.
164 */
165 bool
166 sdb_data_isnull(const sdb_data_t *datum);
168 /*
169 * sdb_data_inarray:
170 * Determine whether a datum is included in an array based on the usual
171 * comparison function of the value's type. The element type of the array has
172 * to match the type of the value. The value may be another array. In that
173 * case, the element types have to match and the function returns true if all
174 * elements of the first array are included in the second where order does not
175 * matter.
176 */
177 bool
178 sdb_data_inarray(const sdb_data_t *value, const sdb_data_t *array);
180 /*
181 * sdb_data_array_get:
182 * Get the i-th value stored in the specified array and store an alias in
183 * 'value'. Storing an alias means that the value points to the actual array
184 * element. Do *not* free the value after using it (i.e., don't use
185 * sdb_data_free_datum).
186 *
187 * Returns:
188 * - 0 on success
189 * - a negative value else
190 */
191 int
192 sdb_data_array_get(const sdb_data_t *array, size_t i, sdb_data_t *value);
194 /*
195 * Operators supported by sdb_data_eval_expr.
196 */
197 enum {
198 SDB_DATA_ADD = 1, /* addition */
199 SDB_DATA_SUB, /* substraction */
200 SDB_DATA_MUL, /* multiplication */
201 SDB_DATA_DIV, /* division */
202 SDB_DATA_MOD, /* modulo */
203 SDB_DATA_CONCAT, /* string / binary data concatenation */
204 };
206 #define SDB_DATA_OP_TO_STRING(op) \
207 (((op) == SDB_DATA_ADD) ? "+" \
208 : ((op) == SDB_DATA_SUB) ? "-" \
209 : ((op) == SDB_DATA_MUL) ? "*" \
210 : ((op) == SDB_DATA_DIV) ? "/" \
211 : ((op) == SDB_DATA_MOD) ? "%" \
212 : ((op) == SDB_DATA_CONCAT) ? "||" : "UNKNOWN")
214 /*
215 * sdb_data_parse_op:
216 * Parse the string representation of an operator supported by
217 * sdb_data_expr_eval.
218 *
219 * Returns:
220 * - the ID of the operator
221 * - a negative value in case the operator does not exist
222 */
223 int
224 sdb_data_parse_op(const char *op);
226 /*
227 * sdb_data_expr_eval:
228 * Evaluate a simple arithmetic expression on two data points. String and
229 * binary data only support concatenation and all other data types only
230 * support the other operators. The result may be allocated dynamically and
231 * has to be freed by the caller (using sdb_data_free_datum).
232 *
233 * If any of the data points is a NULL value, the result is also NULL.
234 *
235 * The data-types of d1 and d2 have to be the same, except for the following
236 * cases:
237 * - <integer> or <decimal> <mul> <datetime>
238 * - <datetime> <mul> or <div> or <mod> <integer> or <decimal>
239 *
240 * Returns:
241 * - 0 on success
242 * - a negative value else
243 */
244 int
245 sdb_data_expr_eval(int op, const sdb_data_t *d1, const sdb_data_t *d2,
246 sdb_data_t *res);
248 /*
249 * sdb_data_expr_type:
250 * Determine the type of the expression when applying the specified operator
251 * to the specified types. Note that if an actual value is a typed NULL value
252 * (e.g. a NULL string value), the return value of this function does not
253 * match the return type of sdb_data_expr_eval.
254 *
255 * See the documentation of sdb_data_expr_eval() for a description of which
256 * operations are supported.
257 *
258 * Returns:
259 * - the type id on success
260 * - a negative value else
261 */
262 int
263 sdb_data_expr_type(int op, int type1, int type2);
265 /*
266 * sdb_data_strlen:
267 * Returns a (worst-case) estimate for the number of bytes required to format
268 * the datum as a string. Does not take the terminating null byte into
269 * account.
270 */
271 size_t
272 sdb_data_strlen(const sdb_data_t *datum);
274 enum {
275 SDB_UNQUOTED = 0,
276 SDB_SINGLE_QUOTED,
277 SDB_DOUBLE_QUOTED,
278 };
280 /*
281 * sdb_data_format:
282 * Output the specified datum to the specified string using a default format.
283 * The value of 'quoted' determines whether and how non-integer and
284 * non-decimal values are quoted. If the buffer size is less than the return
285 * value of sdb_data_strlen, the datum may be truncated. The buffer will
286 * always be nul-terminated after calling this function.
287 *
288 * Returns:
289 * - the number of characters written to the buffer (excluding the terminated
290 * null byte) or the number of characters which would have been written in
291 * case the output was truncated
292 * - a negative value else
293 */
294 int
295 sdb_data_format(const sdb_data_t *datum, char *buf, size_t buflen, int quoted);
297 /*
298 * sdb_data_parse:
299 * Parse the specified string into a datum using the specified type. The
300 * string value is expected to be a raw value of the specified type. Integer
301 * and decimal numbers may be signed or unsigned octal (base 8, if the first
302 * character of the string is "0"), sedecimal (base 16, if the string includes
303 * the "0x" prefix), or decimal. Decimal numbers may also be "infinity" or
304 * "NaN" or may use a decimal exponent. Date-time values are expected to be
305 * specified as (floating point) number of seconds since the epoch. New memory
306 * will be allocated as necessary and will have to be free'd using
307 * sdb_data_free_datum().
308 *
309 * Returns:
310 * - 0 on success
311 * - a negative value else
312 */
313 int
314 sdb_data_parse(const char *str, int type, sdb_data_t *data);
316 /*
317 * sdb_data_sizeof:
318 * Return the size of the data-type identified by the specified type.
319 *
320 * Returns:
321 * - the size of the data-type on success
322 * - 0 else
323 */
324 size_t
325 sdb_data_sizeof(int type);
327 #ifdef __cplusplus
328 } /* extern "C" */
329 #endif
331 #endif /* ! SDB_CORE_DATA_H */
333 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */