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 #ifdef __cplusplus
37 extern "C" {
38 #endif
40 enum {
41 SDB_TYPE_INTEGER = 1,
42 SDB_TYPE_DECIMAL,
43 SDB_TYPE_STRING,
44 SDB_TYPE_DATETIME,
45 SDB_TYPE_BINARY,
46 };
48 #define SDB_TYPE_TO_STRING(t) \
49 (((t) == SDB_TYPE_INTEGER) \
50 ? "INTEGER" \
51 : ((t) == SDB_TYPE_DECIMAL) \
52 ? "DECIMAL" \
53 : ((t) == SDB_TYPE_STRING) \
54 ? "STRING" \
55 : ((t) == SDB_TYPE_DATETIME) \
56 ? "DATETIME" \
57 : ((t) == SDB_TYPE_BINARY) \
58 ? "BINARY" \
59 : "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 } data;
77 } sdb_data_t;
78 #define SDB_DATA_INIT { 0, { .integer = 0 } }
80 /*
81 * sdb_data_copy:
82 * Copy the datum stored in 'src' to the memory location pointed to by 'dst'.
83 * Any dynamic data (strings, binary data) is copied to newly allocated
84 * memory. Use, for example, sdb_data_free_datum() to free any dynamic memory
85 * stored in a datum. On error, 'dst' is unchanged. Else, any dynamic memory
86 * in 'dst' will be freed.
87 *
88 * Returns:
89 * - 0 on success
90 * - a negative value else
91 */
92 int
93 sdb_data_copy(sdb_data_t *dst, const sdb_data_t *src);
95 /*
96 * sdb_data_free_datum:
97 * Free any dynamic memory referenced by the specified datum. Does not free
98 * the memory allocated by the sdb_data_t object itself. This function must
99 * not be used if any static or stack memory is referenced from the data
100 * object.
101 */
102 void
103 sdb_data_free_datum(sdb_data_t *datum);
105 /*
106 * sdb_data_cmp:
107 * Compare two data points. A NULL datum is considered less than any non-NULL
108 * datum. On data-type mismatch, the function always returns a negative value.
109 *
110 * Returns:
111 * - a value less than zero if d1 compares less than d2
112 * - zero if d1 compares equal to d2
113 * - a value greater than zero if d1 compares greater than d2
114 */
115 int
116 sdb_data_cmp(const sdb_data_t *d1, const sdb_data_t *d2);
118 /*
119 * Operators supported by sdb_data_eval_expr.
120 */
121 enum {
122 SDB_DATA_ADD = 1, /* addition */
123 SDB_DATA_SUB, /* substraction */
124 SDB_DATA_MUL, /* multiplication */
125 SDB_DATA_DIV, /* division */
126 SDB_DATA_MOD, /* modulo */
127 SDB_DATA_CONCAT, /* string / binary data concatenation */
128 };
130 #define SDB_DATA_OP_TO_STRING(op) \
131 (((op) == SDB_DATA_ADD) \
132 ? "+" \
133 : ((op) == SDB_DATA_SUB) \
134 ? "-" \
135 : ((op) == SDB_DATA_MUL) \
136 ? "*" \
137 : ((op) == SDB_DATA_DIV) \
138 ? "/" \
139 : ((op) == SDB_DATA_MOD) \
140 ? "%" \
141 : ((op) == SDB_DATA_CONCAT) \
142 ? "||" : "UNKNOWN")
144 /*
145 * sdb_data_expr_eval:
146 * Evaluate a simple arithmetic expression on two data points. The data-type
147 * of d1 and d2 have to be the same. String and binary data only support
148 * concatenation and all other data types only support the other operators.
149 *
150 * Returns:
151 * - 0 on success
152 * - a negative value else
153 */
154 int
155 sdb_data_expr_eval(int op, const sdb_data_t *d1, const sdb_data_t *d2,
156 sdb_data_t *res);
158 /*
159 * sdb_data_strlen:
160 * Returns a (worst-case) estimate for the number of bytes required to format
161 * the datum as a string. Does not take the terminating null byte into
162 * account.
163 */
164 size_t
165 sdb_data_strlen(const sdb_data_t *datum);
167 enum {
168 SDB_UNQUOTED = 0,
169 SDB_SINGLE_QUOTED,
170 SDB_DOUBLE_QUOTED,
171 };
173 /*
174 * sdb_data_format:
175 * Output the specified datum to the specified string using a default format.
176 * The value of 'quoted' determines whether and how non-integer and
177 * non-decimal values are quoted. If the buffer size is less than the return
178 * value of sdb_data_strlen, the datum may be truncated. The buffer will
179 * always be nul-terminated after calling this function.
180 *
181 * Returns:
182 * - the number of characters written to the buffer (excluding the terminated
183 * null byte) or the number of characters which would have been written in
184 * case the output was truncated
185 * - a negative value else
186 */
187 int
188 sdb_data_format(const sdb_data_t *datum, char *buf, size_t buflen, int quoted);
190 /*
191 * sdb_data_parse:
192 * Parse the specified string into a datum using the specified type. The
193 * string value is expected to be a raw value of the specified type. Integer
194 * and decimal numbers may be signed or unsigned octal (base 8, if the first
195 * character of the string is "0"), sedecimal (base 16, if the string includes
196 * the "0x" prefix), or decimal. Decimal numbers may also be "infinity" or
197 * "NaN" or may use a decimal exponent. Date-time values are expected to be
198 * specified as (floating point) number of seconds since the epoch. For string
199 * and binary data, the input string is passed to the datum. The function does
200 * not allocate new memory for that purpose. Use sdb_data_copy() if you want
201 * to do that.
202 *
203 * Returns:
204 * - 0 on success
205 * - a negative value else
206 */
207 int
208 sdb_data_parse(char *str, int type, sdb_data_t *data);
210 #ifdef __cplusplus
211 } /* extern "C" */
212 #endif
214 #endif /* ! SDB_CORE_DATA_H */
216 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */