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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,
106 * Generate fixed-size query parameter with size determined
109 * @param x pointer to the query parameter to pass.
111 #define GNUNET_PQ_query_param_auto_from_type(x) GNUNET_PQ_query_param_fixed_size ((x), sizeof (*(x)))
115 * Generate query parameter for an RSA public key. The
116 * database must contain a BLOB type in the respective position.
118 * @param x the query parameter to pass.
120 struct GNUNET_PQ_QueryParam
121 GNUNET_PQ_query_param_rsa_public_key (const struct GNUNET_CRYPTO_rsa_PublicKey *x);
125 * Generate query parameter for an RSA signature. 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_signature (const struct GNUNET_CRYPTO_rsa_Signature *x);
135 * Generate query parameter for an absolute time value.
136 * The database must store a 64-bit integer.
138 * @param x pointer to the query parameter to pass
140 struct GNUNET_PQ_QueryParam
141 GNUNET_PQ_query_param_absolute_time (const struct GNUNET_TIME_Absolute *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_nbo (const struct GNUNET_TIME_AbsoluteNBO *x);
155 * Generate query parameter for an uint16_t in host byte order.
157 * @param x pointer to the query parameter to pass
159 struct GNUNET_PQ_QueryParam
160 GNUNET_PQ_query_param_uint16 (const uint16_t *x);
164 * Generate query parameter for an uint32_t in host byte order.
166 * @param x pointer to the query parameter to pass
168 struct GNUNET_PQ_QueryParam
169 GNUNET_PQ_query_param_uint32 (const uint32_t *x);
173 * Generate query parameter for an uint16_t in host byte order.
175 * @param x pointer to the query parameter to pass
177 struct GNUNET_PQ_QueryParam
178 GNUNET_PQ_query_param_uint64 (const uint64_t *x);
182 * Extract data from a Postgres database @a result at row @a row.
185 * @param result where to extract data from
186 * @param int row to extract data from
187 * @param fname name (or prefix) of the fields to extract from
188 * @param[in,out] dst_size where to store size of result, may be NULL
189 * @param[out] dst where to store the result
191 * #GNUNET_YES if all results could be extracted
192 * #GNUNET_NO if at least one result was NULL
193 * #GNUNET_SYSERR if a result was invalid (non-existing field)
196 (*GNUNET_PQ_ResultConverter)(void *cls,
205 * Function called to clean up memory allocated
206 * by a #GNUNET_PQ_ResultConverter.
209 * @param rd result data to clean up
212 (*GNUNET_PQ_ResultCleanup)(void *cls,
217 * @brief Description of a DB result cell.
219 struct GNUNET_PQ_ResultSpec
223 * What is the format of the result?
225 GNUNET_PQ_ResultConverter conv;
228 * Function to clean up result data, NULL if cleanup is
231 GNUNET_PQ_ResultCleanup cleaner;
234 * Closure for @e conv and @e cleaner.
239 * Destination for the data.
244 * Allowed size for the data, 0 for variable-size
245 * (in this case, the type of @e dst is a `void **`
246 * and we need to allocate a buffer of the right size).
251 * Field name of the desired result.
256 * Where to store actual size of the result.
264 * End of result parameter specification.
266 * @return array last entry for the result specification to use
268 #define GNUNET_PQ_result_spec_end { NULL, NULL, NULL, NULL, 0, NULL, NULL }
272 * Variable-size result expected.
274 * @param name name of the field in the table
275 * @param[out] dst where to store the result, allocated
276 * @param[out] sptr where to store the size of @a dst
277 * @return array entry for the result specification to use
279 struct GNUNET_PQ_ResultSpec
280 GNUNET_PQ_result_spec_variable_size (const char *name,
286 * Fixed-size result expected.
288 * @param name name of the field in the table
289 * @param[out] dst where to store the result
290 * @param dst_size number of bytes in @a dst
291 * @return array entry for the result specification to use
293 struct GNUNET_PQ_ResultSpec
294 GNUNET_PQ_result_spec_fixed_size (const char *name,
301 * We expect a fixed-size result, with size determined by the type of `* dst`
303 * @param name name of the field in the table
304 * @param dst point to where to store the result, type fits expected result size
305 * @return array entry for the result specification to use
307 #define GNUNET_PQ_result_spec_auto_from_type(name, dst) GNUNET_PQ_result_spec_fixed_size (name, (dst), sizeof (*(dst)))
311 * Variable-size result expected.
313 * @param name name of the field in the table
314 * @param[out] dst where to store the result, allocated
315 * @param[out] sptr where to store the size of @a dst
316 * @return array entry for the result specification to use
318 struct GNUNET_PQ_ResultSpec
319 GNUNET_PQ_result_spec_variable_size (const char *name,
325 * RSA public key expected.
327 * @param name name of the field in the table
328 * @param[out] rsa where to store the result
329 * @return array entry for the result specification to use
331 struct GNUNET_PQ_ResultSpec
332 GNUNET_PQ_result_spec_rsa_public_key (const char *name,
333 struct GNUNET_CRYPTO_rsa_PublicKey **rsa);
337 * RSA signature expected.
339 * @param name name of the field in the table
340 * @param[out] sig where to store the result;
341 * @return array entry for the result specification to use
343 struct GNUNET_PQ_ResultSpec
344 GNUNET_PQ_result_spec_rsa_signature (const char *name,
345 struct GNUNET_CRYPTO_rsa_Signature **sig);
349 * Absolute time expected.
351 * @param name name of the field in the table
352 * @param[out] at where to store the result
353 * @return array entry for the result specification to use
355 struct GNUNET_PQ_ResultSpec
356 GNUNET_PQ_result_spec_absolute_time (const char *name,
357 struct GNUNET_TIME_Absolute *at);
361 * Absolute time expected.
363 * @param name name of the field in the table
364 * @param[out] at where to store the result
365 * @return array entry for the result specification to use
367 struct GNUNET_PQ_ResultSpec
368 GNUNET_PQ_result_spec_absolute_time_nbo (const char *name,
369 struct GNUNET_TIME_AbsoluteNBO *at);
375 * @param name name of the field in the table
376 * @param[out] u16 where to store the result
377 * @return array entry for the result specification to use
379 struct GNUNET_PQ_ResultSpec
380 GNUNET_PQ_result_spec_uint16 (const char *name,
387 * @param name name of the field in the table
388 * @param[out] u32 where to store the result
389 * @return array entry for the result specification to use
391 struct GNUNET_PQ_ResultSpec
392 GNUNET_PQ_result_spec_uint32 (const char *name,
399 * @param name name of the field in the table
400 * @param[out] u64 where to store the result
401 * @return array entry for the result specification to use
403 struct GNUNET_PQ_ResultSpec
404 GNUNET_PQ_result_spec_uint64 (const char *name,
409 * Execute a prepared statement.
411 * @param db_conn database connection
412 * @param name name of the prepared statement
413 * @param params parameters to the statement
414 * @return postgres result
417 GNUNET_PQ_exec_prepared (PGconn *db_conn,
419 const struct GNUNET_PQ_QueryParam *params);
423 * Extract results from a query result according to the given specification.
424 * If colums are NULL, the destination is not modified, and #GNUNET_NO
427 * @param result result to process
428 * @param[in,out] rs result specification to extract for
429 * @param row row from the result to extract
431 * #GNUNET_YES if all results could be extracted
432 * #GNUNET_NO if at least one result was NULL
433 * #GNUNET_SYSERR if a result was invalid (non-existing field)
436 GNUNET_PQ_extract_result (PGresult *result,
437 struct GNUNET_PQ_ResultSpec *rs,
442 * Free all memory that was allocated in @a rs during
443 * #GNUNET_PQ_extract_result().
445 * @param rs reult specification to clean up
448 GNUNET_PQ_cleanup_result (struct GNUNET_PQ_ResultSpec *rs);
451 #endif /* GNUNET_PQ_LIB_H_ */
453 /* end of include/gnunet_pq_lib.h */