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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 * Function for how to handle this type of entry.
63 GNUNET_PQ_QueryConverter conv;
66 * Closure for @e conv.
81 * Number of parameters eaten by this operation.
83 unsigned int num_params;
88 * End of query parameter specification.
90 #define GNUNET_PQ_query_param_end { NULL, NULL, NULL, 0, 0 }
94 * Generate query parameter for a buffer @a ptr of
97 * @param ptr pointer to the query parameter to pass
98 * @oaran ptr_size number of bytes in @a ptr
100 struct GNUNET_PQ_QueryParam
101 GNUNET_PQ_query_param_fixed_size (const void *ptr,
107 * Generate query parameter for a string.
109 * @param ptr pointer to the string query parameter to pass
111 struct GNUNET_PQ_QueryParam
112 GNUNET_PQ_query_param_string (const char *ptr);
116 * Generate fixed-size query parameter with size determined
119 * @param x pointer to the query parameter to pass.
121 #define GNUNET_PQ_query_param_auto_from_type(x) GNUNET_PQ_query_param_fixed_size ((x), sizeof (*(x)))
125 * Generate query parameter for an RSA public key. The
126 * database must contain a BLOB type in the respective position.
128 * @param x the query parameter to pass.
130 struct GNUNET_PQ_QueryParam
131 GNUNET_PQ_query_param_rsa_public_key (const struct GNUNET_CRYPTO_RsaPublicKey *x);
135 * Generate query parameter for an RSA signature. The
136 * database must contain a BLOB type in the respective position.
138 * @param x the query parameter to pass
140 struct GNUNET_PQ_QueryParam
141 GNUNET_PQ_query_param_rsa_signature (const struct GNUNET_CRYPTO_RsaSignature *x);
145 * Generate query parameter for an absolute time value.
146 * The database must store a 64-bit integer.
148 * @param x pointer to the query parameter to pass
150 struct GNUNET_PQ_QueryParam
151 GNUNET_PQ_query_param_absolute_time (const struct GNUNET_TIME_Absolute *x);
155 * Generate query parameter for an absolute time value.
156 * The database must store a 64-bit integer.
158 * @param x pointer to the query parameter to pass
160 struct GNUNET_PQ_QueryParam
161 GNUNET_PQ_query_param_absolute_time_nbo (const struct GNUNET_TIME_AbsoluteNBO *x);
165 * Generate query parameter for an uint16_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_uint16 (const uint16_t *x);
174 * Generate query parameter for an uint32_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_uint32 (const uint32_t *x);
183 * Generate query parameter for an uint16_t in host byte order.
185 * @param x pointer to the query parameter to pass
187 struct GNUNET_PQ_QueryParam
188 GNUNET_PQ_query_param_uint64 (const uint64_t *x);
192 * Extract data from a Postgres database @a result at row @a row.
195 * @param result where to extract data from
196 * @param int row to extract data from
197 * @param fname name (or prefix) of the fields to extract from
198 * @param[in,out] dst_size where to store size of result, may be NULL
199 * @param[out] dst where to store the result
201 * #GNUNET_YES if all results could be extracted
202 * #GNUNET_NO if at least one result was NULL
203 * #GNUNET_SYSERR if a result was invalid (non-existing field)
206 (*GNUNET_PQ_ResultConverter)(void *cls,
215 * Function called to clean up memory allocated
216 * by a #GNUNET_PQ_ResultConverter.
219 * @param rd result data to clean up
222 (*GNUNET_PQ_ResultCleanup)(void *cls,
227 * @brief Description of a DB result cell.
229 struct GNUNET_PQ_ResultSpec
233 * What is the format of the result?
235 GNUNET_PQ_ResultConverter conv;
238 * Function to clean up result data, NULL if cleanup is
241 GNUNET_PQ_ResultCleanup cleaner;
244 * Closure for @e conv and @e cleaner.
249 * Destination for the data.
254 * Allowed size for the data, 0 for variable-size
255 * (in this case, the type of @e dst is a `void **`
256 * and we need to allocate a buffer of the right size).
261 * Field name of the desired result.
266 * Where to store actual size of the result.
274 * End of result parameter specification.
276 * @return array last entry for the result specification to use
278 #define GNUNET_PQ_result_spec_end { NULL, NULL, NULL, NULL, 0, NULL, NULL }
282 * Variable-size result expected.
284 * @param name name of the field in the table
285 * @param[out] dst where to store the result, allocated
286 * @param[out] sptr where to store the size of @a dst
287 * @return array entry for the result specification to use
289 struct GNUNET_PQ_ResultSpec
290 GNUNET_PQ_result_spec_variable_size (const char *name,
296 * Fixed-size result expected.
298 * @param name name of the field in the table
299 * @param[out] dst where to store the result
300 * @param dst_size number of bytes in @a dst
301 * @return array entry for the result specification to use
303 struct GNUNET_PQ_ResultSpec
304 GNUNET_PQ_result_spec_fixed_size (const char *name,
311 * We expect a fixed-size result, with size determined by the type of `* dst`
313 * @param name name of the field in the table
314 * @param dst point to where to store the result, type fits expected result size
315 * @return array entry for the result specification to use
317 #define GNUNET_PQ_result_spec_auto_from_type(name, dst) GNUNET_PQ_result_spec_fixed_size (name, (dst), sizeof (*(dst)))
321 * Variable-size result expected.
323 * @param name name of the field in the table
324 * @param[out] dst where to store the result, allocated
325 * @param[out] sptr where to store the size of @a dst
326 * @return array entry for the result specification to use
328 struct GNUNET_PQ_ResultSpec
329 GNUNET_PQ_result_spec_variable_size (const char *name,
335 * RSA public key expected.
337 * @param name name of the field in the table
338 * @param[out] rsa where to store the result
339 * @return array entry for the result specification to use
341 struct GNUNET_PQ_ResultSpec
342 GNUNET_PQ_result_spec_rsa_public_key (const char *name,
343 struct GNUNET_CRYPTO_RsaPublicKey **rsa);
347 * RSA signature expected.
349 * @param name name of the field in the table
350 * @param[out] sig where to store the result;
351 * @return array entry for the result specification to use
353 struct GNUNET_PQ_ResultSpec
354 GNUNET_PQ_result_spec_rsa_signature (const char *name,
355 struct GNUNET_CRYPTO_RsaSignature **sig);
359 * Absolute time expected.
361 * @param name name of the field in the table
362 * @param[out] at where to store the result
363 * @return array entry for the result specification to use
365 struct GNUNET_PQ_ResultSpec
366 GNUNET_PQ_result_spec_absolute_time (const char *name,
367 struct GNUNET_TIME_Absolute *at);
371 * Absolute time expected.
373 * @param name name of the field in the table
374 * @param[out] at where to store the result
375 * @return array entry for the result specification to use
377 struct GNUNET_PQ_ResultSpec
378 GNUNET_PQ_result_spec_absolute_time_nbo (const char *name,
379 struct GNUNET_TIME_AbsoluteNBO *at);
385 * @param name name of the field in the table
386 * @param[out] u16 where to store the result
387 * @return array entry for the result specification to use
389 struct GNUNET_PQ_ResultSpec
390 GNUNET_PQ_result_spec_uint16 (const char *name,
397 * @param name name of the field in the table
398 * @param[out] u32 where to store the result
399 * @return array entry for the result specification to use
401 struct GNUNET_PQ_ResultSpec
402 GNUNET_PQ_result_spec_uint32 (const char *name,
409 * @param name name of the field in the table
410 * @param[out] u64 where to store the result
411 * @return array entry for the result specification to use
413 struct GNUNET_PQ_ResultSpec
414 GNUNET_PQ_result_spec_uint64 (const char *name,
419 * Execute a prepared statement.
421 * @param db_conn database connection
422 * @param name name of the prepared statement
423 * @param params parameters to the statement
424 * @return postgres result
427 GNUNET_PQ_exec_prepared (PGconn *db_conn,
429 const struct GNUNET_PQ_QueryParam *params);
433 * Extract results from a query result according to the given specification.
434 * If colums are NULL, the destination is not modified, and #GNUNET_NO
437 * @param result result to process
438 * @param[in,out] rs result specification to extract for
439 * @param row row from the result to extract
441 * #GNUNET_YES if all results could be extracted
442 * #GNUNET_NO if at least one result was NULL
443 * #GNUNET_SYSERR if a result was invalid (non-existing field)
446 GNUNET_PQ_extract_result (PGresult *result,
447 struct GNUNET_PQ_ResultSpec *rs,
452 * Free all memory that was allocated in @a rs during
453 * #GNUNET_PQ_extract_result().
455 * @param rs reult specification to clean up
458 GNUNET_PQ_cleanup_result (struct GNUNET_PQ_ResultSpec *rs);
461 #endif /* GNUNET_PQ_LIB_H_ */
463 /* end of include/gnunet_pq_lib.h */