c8c7482e796f4438aeafdb8eebe4588223636e7b
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 */
51 };
53 #define SDB_TYPE_TO_STRING(t) \
54 (((t) == SDB_TYPE_INTEGER) ? "INTEGER" \
55 : ((t) == SDB_TYPE_DECIMAL) ? "DECIMAL" \
56 : ((t) == SDB_TYPE_STRING) ? "STRING" \
57 : ((t) == SDB_TYPE_DATETIME) ? "DATETIME" \
58 : ((t) == SDB_TYPE_BINARY) ? "BINARY" \
59 : ((t) == SDB_TYPE_REGEX) ? "REGEX" : "UNKNOWN")
61 /*
62 * sdb_data_t:
63 * A datum retrieved from an arbitrary data source.
64 */
65 typedef struct {
66 int type;
67 union {
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 */
80 } data;
81 } sdb_data_t;
82 #define SDB_DATA_INIT { SDB_TYPE_NULL, { .integer = 0 } }
84 extern const sdb_data_t SDB_DATA_NULL;
86 /*
87 * sdb_data_copy:
88 * Copy the datum stored in 'src' to the memory location pointed to by 'dst'.
89 * Any dynamic data (strings, binary data) is copied to newly allocated
90 * memory. Use, for example, sdb_data_free_datum() to free any dynamic memory
91 * stored in a datum. On error, 'dst' is unchanged. Else, any dynamic memory
92 * in 'dst' will be freed.
93 *
94 * Returns:
95 * - 0 on success
96 * - a negative value else
97 */
98 int
99 sdb_data_copy(sdb_data_t *dst, const sdb_data_t *src);
101 /*
102 * sdb_data_free_datum:
103 * Free any dynamic memory referenced by the specified datum. Does not free
104 * the memory allocated by the sdb_data_t object itself. This function must
105 * not be used if any static or stack memory is referenced from the data
106 * object.
107 */
108 void
109 sdb_data_free_datum(sdb_data_t *datum);
111 /*
112 * sdb_data_cmp:
113 * Compare two data points. A NULL datum is considered less than any non-NULL
114 * datum. On data-type mismatch, the function always returns a non-zero value.
115 *
116 * Returns:
117 * - a value less than zero if d1 compares less than d2
118 * - zero if d1 compares equal to d2
119 * - a value greater than zero if d1 compares greater than d2
120 */
121 int
122 sdb_data_cmp(const sdb_data_t *d1, const sdb_data_t *d2);
124 /*
125 * sdb_data_strcmp:
126 * Compare the string values of two data points. A NULL datum is considered
127 * less than any non-NULL. This function works for arbitrary combination of
128 * data-types.
129 *
130 * Returns:
131 * - a value less than zero if d1 compares less than d2
132 * - zero if d1 compares equal to d2
133 * - a value greater than zero if d1 compares greater than d2
134 */
135 int
136 sdb_data_strcmp(const sdb_data_t *d1, const sdb_data_t *d2);
138 /*
139 * sdb_data_isnull:
140 * Determine whether a datum is NULL. A datum is considered to be NULL if
141 * either datum is NULL or if the type is SDB_TYPE_NULL or if the string or
142 * binary datum is NULL.
143 */
144 _Bool
145 sdb_data_isnull(const sdb_data_t *datum);
147 /*
148 * Operators supported by sdb_data_eval_expr.
149 */
150 enum {
151 SDB_DATA_ADD = 1, /* addition */
152 SDB_DATA_SUB, /* substraction */
153 SDB_DATA_MUL, /* multiplication */
154 SDB_DATA_DIV, /* division */
155 SDB_DATA_MOD, /* modulo */
156 SDB_DATA_CONCAT, /* string / binary data concatenation */
157 };
159 #define SDB_DATA_OP_TO_STRING(op) \
160 (((op) == SDB_DATA_ADD) ? "+" \
161 : ((op) == SDB_DATA_SUB) ? "-" \
162 : ((op) == SDB_DATA_MUL) ? "*" \
163 : ((op) == SDB_DATA_DIV) ? "/" \
164 : ((op) == SDB_DATA_MOD) ? "%" \
165 : ((op) == SDB_DATA_CONCAT) ? "||" : "UNKNOWN")
167 /*
168 * sdb_data_parse_op:
169 * Parse the string representation of an operator supported by
170 * sdb_data_expr_eval.
171 *
172 * Returns:
173 * - the ID of the operator
174 * - a negative value in case the operator does not exist
175 */
176 int
177 sdb_data_parse_op(const char *op);
179 /*
180 * sdb_data_expr_eval:
181 * Evaluate a simple arithmetic expression on two data points. String and
182 * binary data only support concatenation and all other data types only
183 * support the other operators. The result may be allocated dynamically and
184 * has to be freed by the caller (using sdb_data_free_datum).
185 *
186 * If any of the data points is a NULL value, the result is also NULL.
187 *
188 * The data-types of d1 and d2 have to be the same, except for the following
189 * cases:
190 * - <integer> or <decimal> <mul> <datetime>
191 * - <datetime> <mul> or <div> or <mod> <integer> or <decimal>
192 *
193 * Returns:
194 * - 0 on success
195 * - a negative value else
196 */
197 int
198 sdb_data_expr_eval(int op, const sdb_data_t *d1, const sdb_data_t *d2,
199 sdb_data_t *res);
201 /*
202 * sdb_data_strlen:
203 * Returns a (worst-case) estimate for the number of bytes required to format
204 * the datum as a string. Does not take the terminating null byte into
205 * account.
206 */
207 size_t
208 sdb_data_strlen(const sdb_data_t *datum);
210 enum {
211 SDB_UNQUOTED = 0,
212 SDB_SINGLE_QUOTED,
213 SDB_DOUBLE_QUOTED,
214 };
216 /*
217 * sdb_data_format:
218 * Output the specified datum to the specified string using a default format.
219 * The value of 'quoted' determines whether and how non-integer and
220 * non-decimal values are quoted. If the buffer size is less than the return
221 * value of sdb_data_strlen, the datum may be truncated. The buffer will
222 * always be nul-terminated after calling this function.
223 *
224 * Returns:
225 * - the number of characters written to the buffer (excluding the terminated
226 * null byte) or the number of characters which would have been written in
227 * case the output was truncated
228 * - a negative value else
229 */
230 int
231 sdb_data_format(const sdb_data_t *datum, char *buf, size_t buflen, int quoted);
233 /*
234 * sdb_data_parse:
235 * Parse the specified string into a datum using the specified type. The
236 * string value is expected to be a raw value of the specified type. Integer
237 * and decimal numbers may be signed or unsigned octal (base 8, if the first
238 * character of the string is "0"), sedecimal (base 16, if the string includes
239 * the "0x" prefix), or decimal. Decimal numbers may also be "infinity" or
240 * "NaN" or may use a decimal exponent. Date-time values are expected to be
241 * specified as (floating point) number of seconds since the epoch. For string
242 * and binary data, the input string is passed to the datum. The function does
243 * not allocate new memory for that purpose. Use sdb_data_copy() if you want
244 * to do that. For regex data, the input string is copied to newly allocated
245 * memory and also compiled to a regex. Use sdb_data_free_datum() to free the
246 * dynamically allocated memory.
247 *
248 * The input string may be stored in 'data', that is, the function may be used
249 * to do an inline cast from a string to any other type. It is the callers
250 * responsibility to free the memory used by the string in case the target
251 * type does not keep a reference to it.
252 *
253 * Returns:
254 * - 0 on success
255 * - a negative value else
256 */
257 int
258 sdb_data_parse(char *str, int type, sdb_data_t *data);
260 /*
261 * sdb_data_sizeof:
262 * Return the size of the data-type identified by the specified type.
263 *
264 * Returns:
265 * - the size of the data-type on success
266 * - 0 else
267 */
268 size_t
269 sdb_data_sizeof(int type);
271 #ifdef __cplusplus
272 } /* extern "C" */
273 #endif
275 #endif /* ! SDB_CORE_DATA_H */
277 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */