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17 * @file include/gnunet_pq_lib.h
18 * @brief helper functions for DB interactions
19 * @author Christian Grothoff
21 #ifndef GNUNET_PQ_LIB_H_
22 #define GNUNET_PQ_LIB_H_
25 #include "gnunet_util_lib.h"
29 * Function called to convert input argument into SQL parameters.
32 * @param data pointer to input argument
33 * @param data_len number of bytes in @a data (if applicable)
34 * @param[out] param_values SQL data to set
35 * @param[out] param_lengths SQL length data to set
36 * @param[out] param_formats SQL format data to set
37 * @param param_length number of entries available in the @a param_values, @a param_lengths and @a param_formats arrays
38 * @param[out] scratch buffer for dynamic allocations (to be done via #GNUNET_malloc()
39 * @param scratch_length number of entries left in @a scratch
40 * @return -1 on error, number of offsets used in @a scratch otherwise
43 (*GNUNET_PQ_QueryConverter)(void *cls,
49 unsigned int param_length,
51 unsigned int scratch_length);
55 * @brief Description of a DB query parameter.
57 struct GNUNET_PQ_QueryParam
61 * Format of the rest of the entry, determines the data
62 * type that is being added to the query.
64 GNUNET_PQ_QueryConverter conv;
67 * Closure for @e conv.
82 * Number of parameters eaten by this operation.
84 unsigned int num_params;
89 * End of query parameter specification.
91 #define GNUNET_PQ_query_param_end { NULL, NULL, NULL, 0, 0 }
95 * Generate query parameter for a buffer @a ptr of
98 * @param ptr pointer to the query parameter to pass
99 * @oaran ptr_size number of bytes in @a ptr
101 struct GNUNET_PQ_QueryParam
102 GNUNET_PQ_query_param_fixed_size (const void *ptr,
107 * Generate fixed-size query parameter with size determined
110 * @param x pointer to the query parameter to pass.
112 #define GNUNET_PQ_query_param_auto_from_type(x) GNUNET_PQ_query_param_fixed_size ((x), sizeof (*(x)))
116 * Generate query parameter for an RSA public key. The
117 * database must contain a BLOB type in the respective position.
119 * @param x the query parameter to pass.
121 struct GNUNET_PQ_QueryParam
122 GNUNET_PQ_query_param_rsa_public_key (const struct GNUNET_CRYPTO_rsa_PublicKey *x);
126 * Generate query parameter for an RSA signature. The
127 * database must contain a BLOB type in the respective position.
129 * @param x the query parameter to pass
131 struct GNUNET_PQ_QueryParam
132 GNUNET_PQ_query_param_rsa_signature (const struct GNUNET_CRYPTO_rsa_Signature *x);
136 * Generate query parameter for an absolute time value.
137 * The database must store a 64-bit integer.
139 * @param x pointer to the query parameter to pass
141 struct GNUNET_PQ_QueryParam
142 GNUNET_PQ_query_param_absolute_time (const struct GNUNET_TIME_Absolute *x);
146 * Generate query parameter for an absolute time value.
147 * The database must store a 64-bit integer.
149 * @param x pointer to the query parameter to pass
151 struct GNUNET_PQ_QueryParam
152 GNUNET_PQ_query_param_absolute_time_nbo (const struct GNUNET_TIME_AbsoluteNBO *x);
156 * Generate query parameter for an uint16_t in host byte order.
158 * @param x pointer to the query parameter to pass
160 struct GNUNET_PQ_QueryParam
161 GNUNET_PQ_query_param_uint16 (const uint16_t *x);
165 * Generate query parameter for an uint32_t in host byte order.
167 * @param x pointer to the query parameter to pass
169 struct GNUNET_PQ_QueryParam
170 GNUNET_PQ_query_param_uint32 (const uint32_t *x);
174 * Generate query parameter for an uint16_t in host byte order.
176 * @param x pointer to the query parameter to pass
178 struct GNUNET_PQ_QueryParam
179 GNUNET_PQ_query_param_uint64 (const uint64_t *x);
183 * Extract data from a Postgres database @a result at row @a row.
186 * @param result where to extract data from
187 * @param int row to extract data from
188 * @param fname name (or prefix) of the fields to extract from
189 * @param[in,out] dst_size where to store size of result, may be NULL
190 * @param[out] dst where to store the result
192 * #GNUNET_YES if all results could be extracted
193 * #GNUNET_NO if at least one result was NULL
194 * #GNUNET_SYSERR if a result was invalid (non-existing field)
197 (*GNUNET_PQ_ResultConverter)(void *cls,
206 * Function called to clean up memory allocated
207 * by a #GNUNET_PQ_ResultConverter.
210 * @param rd result data to clean up
213 (*GNUNET_PQ_ResultCleanup)(void *cls,
218 * @brief Description of a DB result cell.
220 struct GNUNET_PQ_ResultSpec
224 * What is the format of the result?
226 GNUNET_PQ_ResultConverter conv;
229 * Function to clean up result data, NULL if cleanup is
232 GNUNET_PQ_ResultCleanup cleaner;
235 * Closure for @e conv and @e cleaner.
240 * Destination for the data.
245 * Allowed size for the data, 0 for variable-size
246 * (in this case, the type of @e dst is a `void **`
247 * and we need to allocate a buffer of the right size).
252 * Field name of the desired result.
257 * Where to store actual size of the result.
265 * End of result parameter specification.
267 * @return array last entry for the result specification to use
269 #define GNUNET_PQ_result_spec_end { NULL, NULL, NULL, NULL, 0, NULL, NULL }
273 * Variable-size result expected.
275 * @param name name of the field in the table
276 * @param[out] dst where to store the result, allocated
277 * @param[out] sptr where to store the size of @a dst
278 * @return array entry for the result specification to use
280 struct GNUNET_PQ_ResultSpec
281 GNUNET_PQ_result_spec_variable_size (const char *name,
287 * Fixed-size result expected.
289 * @param name name of the field in the table
290 * @param[out] dst where to store the result
291 * @param dst_size number of bytes in @a dst
292 * @return array entry for the result specification to use
294 struct GNUNET_PQ_ResultSpec
295 GNUNET_PQ_result_spec_fixed_size (const char *name,
302 * We expect a fixed-size result, with size determined by the type of `* dst`
304 * @param name name of the field in the table
305 * @param dst point to where to store the result, type fits expected result size
306 * @return array entry for the result specification to use
308 #define GNUNET_PQ_result_spec_auto_from_type(name, dst) GNUNET_PQ_result_spec_fixed_size (name, (dst), sizeof (*(dst)))
312 * Variable-size result expected.
314 * @param name name of the field in the table
315 * @param[out] dst where to store the result, allocated
316 * @param[out] sptr where to store the size of @a dst
317 * @return array entry for the result specification to use
319 struct GNUNET_PQ_ResultSpec
320 GNUNET_PQ_result_spec_variable_size (const char *name,
326 * RSA public key expected.
328 * @param name name of the field in the table
329 * @param[out] rsa where to store the result
330 * @return array entry for the result specification to use
332 struct GNUNET_PQ_ResultSpec
333 GNUNET_PQ_result_spec_rsa_public_key (const char *name,
334 struct GNUNET_CRYPTO_rsa_PublicKey **rsa);
338 * RSA signature expected.
340 * @param name name of the field in the table
341 * @param[out] sig where to store the result;
342 * @return array entry for the result specification to use
344 struct GNUNET_PQ_ResultSpec
345 GNUNET_PQ_result_spec_rsa_signature (const char *name,
346 struct GNUNET_CRYPTO_rsa_Signature **sig);
350 * Absolute time expected.
352 * @param name name of the field in the table
353 * @param[out] at where to store the result
354 * @return array entry for the result specification to use
356 struct GNUNET_PQ_ResultSpec
357 GNUNET_PQ_result_spec_absolute_time (const char *name,
358 struct GNUNET_TIME_Absolute *at);
362 * Absolute time expected.
364 * @param name name of the field in the table
365 * @param[out] at where to store the result
366 * @return array entry for the result specification to use
368 struct GNUNET_PQ_ResultSpec
369 GNUNET_PQ_result_spec_absolute_time_nbo (const char *name,
370 struct GNUNET_TIME_AbsoluteNBO *at);
376 * @param name name of the field in the table
377 * @param[out] u16 where to store the result
378 * @return array entry for the result specification to use
380 struct GNUNET_PQ_ResultSpec
381 GNUNET_PQ_result_spec_uint16 (const char *name,
388 * @param name name of the field in the table
389 * @param[out] u32 where to store the result
390 * @return array entry for the result specification to use
392 struct GNUNET_PQ_ResultSpec
393 GNUNET_PQ_result_spec_uint32 (const char *name,
400 * @param name name of the field in the table
401 * @param[out] u64 where to store the result
402 * @return array entry for the result specification to use
404 struct GNUNET_PQ_ResultSpec
405 GNUNET_PQ_result_spec_uint64 (const char *name,
410 * Execute a prepared statement.
412 * @param db_conn database connection
413 * @param name name of the prepared statement
414 * @param params parameters to the statement
415 * @return postgres result
418 GNUNET_PQ_exec_prepared (PGconn *db_conn,
420 const struct GNUNET_PQ_QueryParam *params);
424 * Extract results from a query result according to the given specification.
425 * If colums are NULL, the destination is not modified, and #GNUNET_NO
428 * @param result result to process
429 * @param[in,out] rs result specification to extract for
430 * @param row row from the result to extract
432 * #GNUNET_YES if all results could be extracted
433 * #GNUNET_NO if at least one result was NULL
434 * #GNUNET_SYSERR if a result was invalid (non-existing field)
437 GNUNET_PQ_extract_result (PGresult *result,
438 struct GNUNET_PQ_ResultSpec *rs,
443 * Free all memory that was allocated in @a rs during
444 * #GNUNET_PQ_extract_result().
446 * @param rs reult specification to clean up
449 GNUNET_PQ_cleanup_result (struct GNUNET_PQ_ResultSpec *rs);
452 #endif /* GNUNET_PQ_LIB_H_ */
454 /* end of include/gnunet_pq_lib.h */