1 /*
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
3 *
4 * Copyright 2024 Mike Becker, Olaf Wintermann 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 are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 *
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28 /**
29 * @file properties.h
30 * @brief Interface for parsing data from properties files.
31 * @author Mike Becker
32 * @author Olaf Wintermann
33 * @copyright 2-Clause BSD License
34 */
35
36 #ifndef UCX_PROPERTIES_H
37 #define UCX_PROPERTIES_H
38
39 #include "common.h"
40 #include "string.h"
41 #include "map.h"
42 #include "buffer.h"
43
44 #include <stdio.h>
45 #include <string.h>
46
47 #ifdef __cplusplus
48 extern "C" {
49 #endif
50
51 /**
52 * Configures the expected characters for the properties parser.
53 */
54 struct cx_properties_config_s {
55 /**
56 * The key/value delimiter that shall be used.
57 * This is '=' by default.
58 */
59 char delimiter;
60
61 /**
62 * The first comment character.
63 * This is '#' by default.
64 */
65 char comment1;
66
67 /**
68 * The second comment character.
69 * This is not set by default.
70 */
71 char comment2;
72
73 /**
74 * The third comment character.
75 * This is not set by default.
76 */
77 char comment3;
78
79 /*
80 * The character, when appearing at the end of a line, continues that line.
81 * This is '\' by default.
82 */
83 /**
84 * Reserved for future use.
85 */
86 char continuation;
87 };
88
89 /**
90 * Typedef for the properties config.
91 */
92 typedef struct cx_properties_config_s CxPropertiesConfig;
93
94 /**
95 * Default properties configuration.
96 */
97 CX_EXPORT extern const CxPropertiesConfig cx_properties_config_default;
98
99 /**
100 * Status codes for the properties interface.
101 */
102 enum cx_properties_status {
103 /**
104 * Everything is fine.
105 */
106 CX_PROPERTIES_NO_ERROR,
107 /**
108 * The input buffer does not contain more data.
109 */
110 CX_PROPERTIES_NO_DATA,
111 /**
112 * The input ends unexpectedly.
113 *
114 * This either happens when the last line does not terminate with a line
115 * break, or when the input ends with a parsed key but no value.
116 */
117 CX_PROPERTIES_INCOMPLETE_DATA,
118 /**
119 * Not used as a status and never returned by any function.
120 *
121 * You can use this enumerator to check for all "good" status results
122 * by checking if the status is less than @c CX_PROPERTIES_OK.
123 *
124 * A "good" status means that you can refill data and continue parsing.
125 */
126 CX_PROPERTIES_OK,
127 /**
128 * Input buffer is @c NULL.
129 */
130 CX_PROPERTIES_NULL_INPUT,
131 /**
132 * The line contains a delimiter but no key.
133 */
134 CX_PROPERTIES_INVALID_EMPTY_KEY,
135 /**
136 * The line contains data but no delimiter.
137 */
138 CX_PROPERTIES_INVALID_MISSING_DELIMITER,
139 /**
140 * More internal buffer was needed, but could not be allocated.
141 */
142 CX_PROPERTIES_BUFFER_ALLOC_FAILED,
143 /**
144 * Initializing the properties source failed.
145 *
146 * @see cx_properties_read_init_func
147 */
148 CX_PROPERTIES_READ_INIT_FAILED,
149 /**
150 * Reading from a properties source failed.
151 *
152 * @see cx_properties_read_func
153 */
154 CX_PROPERTIES_READ_FAILED,
155 /**
156 * Sinking a k/v-pair failed.
157 *
158 * @see cx_properties_sink_func
159 */
160 CX_PROPERTIES_SINK_FAILED,
161 };
162
163 /**
164 * Typedef for the properties status enum.
165 */
166 typedef enum cx_properties_status CxPropertiesStatus;
167
168 /**
169 * Interface for working with properties data.
170 */
171 struct cx_properties_s {
172 /**
173 * The configuration.
174 */
175 CxPropertiesConfig config;
176
177 /**
178 * The text input buffer.
179 */
180 CxBuffer input;
181
182 /**
183 * Internal buffer.
184 */
185 CxBuffer buffer;
186 };
187
188 /**
189 * Typedef for the properties interface.
190 */
191 typedef struct cx_properties_s CxProperties;
192
193
194 /**
195 * Typedef for a properties sink.
196 */
197 typedef struct cx_properties_sink_s CxPropertiesSink;
198
199 /**
200 * A function that consumes a k/v-pair in a sink.
201 *
202 * The sink could be a map, and the sink function would be calling
203 * a map function to store the k/v-pair.
204 *
205 * @param prop the properties interface that wants to sink a k/v-pair
206 * @param sink the sink
207 * @param key the key
208 * @param value the value
209 * @retval zero success
210 * @retval non-zero sinking the k/v-pair failed
211 */
212 typedef int(*cx_properties_sink_func)(
213 CxProperties *prop,
214 CxPropertiesSink *sink,
215 cxstring key,
216 cxstring value
217 );
218
219 /**
220 * Defines a sink for k/v-pairs.
221 */
222 struct cx_properties_sink_s {
223 /**
224 * The sink object.
225 */
226 void *sink;
227 /**
228 * Optional custom data.
229 */
230 void *data;
231 /**
232 * A function for consuming k/v-pairs into the sink.
233 */
234 cx_properties_sink_func sink_func;
235 };
236
237
238 /**
239 * Typedef for a properties source.
240 */
241 typedef struct cx_properties_source_s CxPropertiesSource;
242
243 /**
244 * A function that reads data from a source.
245 *
246 * When the source is depleted, implementations SHALL provide an empty
247 * string in the @p target and return zero.
248 * A non-zero return value is only permitted in case of an error.
249 *
250 * The meaning of the optional parameters is implementation-dependent.
251 *
252 * @param prop the properties interface that wants to read from the source
253 * @param src the source
254 * @param target a string buffer where the read data shall be stored
255 * @retval zero success
256 * @retval non-zero reading the data failed
257 */
258 typedef int(*cx_properties_read_func)(
259 CxProperties *prop,
260 CxPropertiesSource *src,
261 cxstring *target
262 );
263
264 /**
265 * A function that may initialize additional memory for the source.
266 *
267 * @param prop the properties interface that wants to read from the source
268 * @param src the source
269 * @retval zero initialization was successful
270 * @retval non-zero otherwise
271 */
272 typedef int(*cx_properties_read_init_func)(
273 CxProperties *prop,
274 CxPropertiesSource *src
275 );
276
277 /**
278 * A function that cleans memory initialized by the read_init_func.
279 *
280 * @param prop the properties interface that wants to read from the source
281 * @param src the source
282 */
283 typedef void(*cx_properties_read_clean_func)(
284 CxProperties *prop,
285 CxPropertiesSource *src
286 );
287
288 /**
289 * Defines a properties source.
290 */
291 struct cx_properties_source_s {
292 /**
293 * The source object.
294 *
295 * For example, a file stream or a string.
296 */
297 void *src;
298 /**
299 * Optional additional data pointer.
300 */
301 void *data_ptr;
302 /**
303 * Optional size information.
304 */
305 size_t data_size;
306 /**
307 * A function that reads data from the source.
308 */
309 cx_properties_read_func read_func;
310 /**
311 * Optional function that may prepare the source for reading data.
312 */
313 cx_properties_read_init_func read_init_func;
314 /**
315 * Optional function that cleans additional memory allocated by the
316 * read_init_func.
317 */
318 cx_properties_read_clean_func read_clean_func;
319 };
320
321 /**
322 * Initialize a properties interface.
323 *
324 * @param prop the properties interface
325 * @param config the properties configuration
326 * @see cxPropertiesInitDefault()
327 */
328 cx_attr_nonnull
329 CX_EXPORT void cxPropertiesInit(CxProperties *prop, CxPropertiesConfig config);
330
331 /**
332 * Destroys the properties interface.
333 *
334 * @note Even when you are certain that you did not use the interface in a
335 * way that caused a memory allocation, you should call this function anyway.
336 * Future versions of the library might add features that need additional memory,
337 * and you really don't want to search the entire code where you might need to
338 * add a call to this function.
339 *
340 * @param prop the properties interface
341 */
342 cx_attr_nonnull
343 CX_EXPORT void cxPropertiesDestroy(CxProperties *prop);
344
345 /**
346 * Destroys and re-initializes the properties interface.
347 *
348 * You might want to use this to reset the parser after
349 * encountering a syntax error.
350 *
351 * @param prop the properties interface
352 */
353 cx_attr_nonnull
354 CX_EXPORT void cxPropertiesReset(CxProperties *prop);
355
356 /**
357 * Initialize a properties parser with the default configuration.
358 *
359 * @param prop (@c CxProperties*) the properties interface
360 * @see cxPropertiesInit()
361 */
362 #define cxPropertiesInitDefault(prop) \
363 cxPropertiesInit(prop, cx_properties_config_default)
364
365 /**
366 * Fills the input buffer with data.
367 *
368 * After calling this function, you can parse the data by calling
369 * cxPropertiesNext().
370 *
371 * @remark The properties interface tries to avoid allocations.
372 * When you use this function and cxPropertiesNext() interleaving,
373 * no allocations are performed. However, you must not free the
374 * pointer to the data in that case. When you invoke the fill
375 * function more than once before calling cxPropertiesNext(),
376 * the additional data is appended - inevitably leading to
377 * an allocation of a new buffer and copying the previous contents.
378 *
379 * @param prop the properties interface
380 * @param buf a pointer to the data
381 * @param len the length of the data
382 * @retval zero success
383 * @retval non-zero a memory allocation was necessary but failed
384 * @see cxPropertiesFill()
385 */
386 cx_attr_nonnull cx_attr_access_r(2, 3)
387 CX_EXPORT int cxPropertiesFilln(CxProperties *prop, const char *buf, size_t len);
388
389 /**
390 * Internal function, do not use.
391 *
392 * @param prop the properties interface
393 * @param str the text to fill in
394 * @retval zero success
395 * @retval non-zero a memory allocation was necessary but failed
396 */
397 cx_attr_nonnull
398 CX_INLINE int cx_properties_fill(CxProperties *prop, cxstring str) {
399 return cxPropertiesFilln(prop, str.ptr, str.length);
400 }
401
402 /**
403 * Fills the input buffer with data.
404 *
405 * After calling this function, you can parse the data by calling
406 * cxPropertiesNext().
407 *
408 * @attention The properties interface tries to avoid allocations.
409 * When you use this function and cxPropertiesNext() interleaving,
410 * no allocations are performed. However, you must not free the
411 * pointer to the data in that case. When you invoke the fill
412 * function more than once before calling cxPropertiesNext(),
413 * the additional data is appended - inevitably leading to
414 * an allocation of a new buffer and copying the previous contents.
415 *
416 * @param prop the properties interface
417 * @param str the text to fill in
418 * @retval zero success
419 * @retval non-zero a memory allocation was necessary but failed
420 * @see cxPropertiesFilln()
421 */
422 #define cxPropertiesFill(prop, str) cx_properties_fill(prop, cx_strcast(str))
423
424 /**
425 * Specifies stack memory that shall be used as an internal buffer.
426 *
427 * @param prop the properties interface
428 * @param buf a pointer to stack memory
429 * @param capacity the capacity of the stack memory
430 */
431 cx_attr_nonnull
432 CX_EXPORT void cxPropertiesUseStack(CxProperties *prop, char *buf, size_t capacity);
433
434 /**
435 * Retrieves the next key/value-pair.
436 *
437 * This function returns zero as long as there are key/value-pairs found.
438 * If no more key/value-pairs are found, #CX_PROPERTIES_NO_DATA is returned.
439 *
440 * When an incomplete line is encountered, #CX_PROPERTIES_INCOMPLETE_DATA is
441 * returned, and you can add more data with #cxPropertiesFill().
442 *
443 * @remark The incomplete line will be stored in an internal buffer, which is
444 * allocated on the heap, by default. If you want to avoid allocations,
445 * you can specify sufficient space with cxPropertiesUseStack() after
446 * initialization with cxPropertiesInit().
447 *
448 * @attention The returned strings will point into a buffer that might not be
449 * available later. It is strongly recommended to copy the strings for further
450 * use.
451 *
452 * @param prop the properties interface
453 * @param key a pointer to the cxstring that shall contain the property name
454 * @param value a pointer to the cxstring that shall contain the property value
455 * @retval CX_PROPERTIES_NO_ERROR (zero) a key/value pair was found
456 * @retval CX_PROPERTIES_NO_DATA there is no (more) data in the input buffer
457 * @retval CX_PROPERTIES_INCOMPLETE_DATA the data in the input buffer is incomplete
458 * (fill more data and try again)
459 * @retval CX_PROPERTIES_NULL_INPUT the input buffer was never filled
460 * @retval CX_PROPERTIES_INVALID_EMPTY_KEY the properties data contains an illegal empty key
461 * @retval CX_PROPERTIES_INVALID_MISSING_DELIMITER the properties data contains a line without delimiter
462 * @retval CX_PROPERTIES_BUFFER_ALLOC_FAILED an internal allocation was necessary but failed
463 */
464 cx_attr_nonnull cx_attr_nodiscard
465 CX_EXPORT CxPropertiesStatus cxPropertiesNext(CxProperties *prop, cxstring *key, cxstring *value);
466
467 /**
468 * Creates a properties sink for an UCX map.
469 *
470 * The values stored in the map will be pointers to freshly allocated,
471 * zero-terminated C strings (@c char*), which means the @p map should have been
472 * created with #CX_STORE_POINTERS.
473 *
474 * The cxDefaultAllocator will be used unless you specify a custom
475 * allocator in the optional @c data field of the returned sink.
476 *
477 * @param map the map that shall consume the k/v-pairs.
478 * @return the sink
479 * @see cxPropertiesLoad()
480 */
481 cx_attr_nonnull cx_attr_nodiscard
482 CX_EXPORT CxPropertiesSink cxPropertiesMapSink(CxMap *map);
483
484 /**
485 * Creates a properties source based on an UCX string.
486 *
487 * @param str the string
488 * @return the properties source
489 * @see cxPropertiesLoad()
490 */
491 cx_attr_nodiscard
492 CX_EXPORT CxPropertiesSource cxPropertiesStringSource(cxstring str);
493
494 /**
495 * Creates a properties source based on C string with the specified length.
496 *
497 * @param str the string
498 * @param len the length
499 * @return the properties source
500 * @see cxPropertiesLoad()
501 */
502 cx_attr_nonnull cx_attr_nodiscard cx_attr_access_r(1, 2)
503 CX_EXPORT CxPropertiesSource cxPropertiesCstrnSource(const char *str, size_t len);
504
505 /**
506 * Creates a properties source based on a C string.
507 *
508 * The length will be determined with strlen(), so the string MUST be
509 * zero-terminated.
510 *
511 * @param str the string
512 * @return the properties source
513 * @see cxPropertiesLoad()
514 */
515 cx_attr_nonnull cx_attr_nodiscard cx_attr_cstr_arg(1)
516 CX_EXPORT CxPropertiesSource cxPropertiesCstrSource(const char *str);
517
518 /**
519 * Creates a properties source based on an FILE.
520 *
521 * @param file the file
522 * @param chunk_size how many bytes may be read in one operation
523 *
524 * @return the properties source
525 * @see cxPropertiesLoad()
526 */
527 cx_attr_nonnull cx_attr_nodiscard cx_attr_access_r(1)
528 CX_EXPORT CxPropertiesSource cxPropertiesFileSource(FILE *file, size_t chunk_size);
529
530
531 /**
532 * Loads properties data from a source and transfers it to a sink.
533 *
534 * This function tries to read as much data from the source as possible.
535 * When the source was completely consumed and at least on k/v-pair was found,
536 * the return value will be #CX_PROPERTIES_NO_ERROR.
537 * When the source was consumed but no k/v-pairs were found, the return value
538 * will be #CX_PROPERTIES_NO_DATA.
539 * In case the source data ends unexpectedly, the #CX_PROPERTIES_INCOMPLETE_DATA
540 * is returned. In that case you should call this function again with the same
541 * sink and either an updated source or the same source if the source is able to
542 * yield the missing data.
543 *
544 * The other result codes apply, according to their description.
545 *
546 * @param prop the properties interface
547 * @param sink the sink
548 * @param source the source
549 * @retval CX_PROPERTIES_NO_ERROR (zero) a key/value pair was found
550 * @retval CX_PROPERTIES_READ_INIT_FAILED initializing the source failed
551 * @retval CX_PROPERTIES_READ_FAILED reading from the source failed
552 * @retval CX_PROPERTIES_SINK_FAILED sinking the properties into the sink failed
553 * @retval CX_PROPERTIES_NO_DATA the source did not provide any key/value pairs
554 * @retval CX_PROPERTIES_INCOMPLETE_DATA the source did not provide enough data
555 * @retval CX_PROPERTIES_INVALID_EMPTY_KEY the properties data contains an illegal empty key
556 * @retval CX_PROPERTIES_INVALID_MISSING_DELIMITER the properties data contains a line without delimiter
557 * @retval CX_PROPERTIES_BUFFER_ALLOC_FAILED an internal allocation was necessary but failed
558 */
559 cx_attr_nonnull
560 CX_EXPORT CxPropertiesStatus cxPropertiesLoad(CxProperties *prop,
561 CxPropertiesSink sink, CxPropertiesSource source);
562
563 #ifdef __cplusplus
564 } // extern "C"
565 #endif
566
567 #endif // UCX_PROPERTIES_H
568