exchange/src/include/taler_pq_lib.h
2015-06-12 21:29:17 +02:00

621 lines
16 KiB
C

/*
This file is part of TALER
Copyright (C) 2014, 2015 Christian Grothoff (and other contributing authors)
TALER is free software; you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free Software
Foundation; either version 3, or (at your option) any later version.
TALER is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with
TALER; see the file COPYING. If not, If not, see <http://www.gnu.org/licenses/>
*/
/**
* @file include/taler_pq_lib.h
* @brief helper functions for DB interactions
* @author Sree Harsha Totakura <sreeharsha@totakura.in>
* @author Florian Dold
* @author Christian Grothoff
*/
#ifndef TALER_PQ_LIB_H_
#define TALER_PQ_LIB_H_
#include <libpq-fe.h>
#include "taler_util.h"
/**
* Different formats of results that can be added to a query.
*/
enum TALER_PQ_QueryFormat
{
/**
* List terminator.
*/
TALER_PQ_QF_END,
/**
* We have a fixed-size result (binary blob, no endianess conversion).
*/
TALER_PQ_QF_FIXED_BLOB,
/**
* We have a variable-size result (binary blob, no endianess conversion).
*/
TALER_PQ_QF_VARSIZE_BLOB,
/**
* We have a currency amount (with endianess conversion).
* Data points to a `struct TALER_AmountNBO`, size is only used to check.
*/
TALER_PQ_QF_AMOUNT_NBO,
/**
* We have a currency amount (with endianess conversion).
* Data points to a `struct TALER_Amount`, size is only used to check.
*/
TALER_PQ_QF_AMOUNT,
/**
* We have an RSA public key.
* Data points to a `struct GNUNET_CRYPTO_rsa_PublicKey`, size is not used.
*/
TALER_PQ_QF_RSA_PUBLIC_KEY,
/**
* We have an RSA signature.
* Data points to a `struct GNUNET_CRYPTO_rsa_Signature`, size is not used.
*/
TALER_PQ_QF_RSA_SIGNATURE,
/**
* We have an absolute time.
* Data points to a `struct GNUNET_TIME_Absolute`, size is only used to check.
*/
TALER_PQ_QF_TIME_ABSOLUTE,
/**
* We expect an uint16_t (in host byte order).
*/
TALER_PQ_QF_UINT16,
/**
* We expect an uint32_t (in host byte order).
*/
TALER_PQ_QF_UINT32,
/**
* We expect an uint64_t (in host byte order).
*/
TALER_PQ_QF_UINT64,
/**
* We expect a JSON object (json_t).
*/
TALER_PQ_QF_JSON
};
/**
* @brief Description of a DB query parameter.
*/
struct TALER_PQ_QueryParam
{
/**
* Format of the rest of the entry, determines the data
* type that is being added to the query.
*/
enum TALER_PQ_QueryFormat format;
/**
* Data or NULL.
*/
const void *data;
/**
* Size of @e data
*/
size_t size;
};
/**
* End of query parameter specification.
*/
#define TALER_PQ_query_param_end { TALER_PQ_QF_END, NULL, 0 }
/**
* Generate fixed-size query parameter with size given explicitly.
*
* @param x pointer to the query parameter to pass
* @param s number of bytes of @a x to use for the query
*/
#define TALER_PQ_query_param_fixed_size(x,s) { TALER_PQ_QF_FIXED_BLOB, (x), (s) }
/**
* Generate fixed-size query parameter with size determined
* by variable type.
*
* @param x pointer to the query parameter to pass.
*/
#define TALER_PQ_query_param_auto_from_type(x) { TALER_PQ_QF_VARSIZE_BLOB, x, sizeof (*(x)) }
/**
* Generate query parameter for a currency, consisting of the three
* components "value", "fraction" and "currency" in this order. The
* types must be a 64-bit integer, 32-bit integer and a
* #TALER_CURRENCY_LEN-sized BLOB/VARCHAR respectively.
*
* @param x pointer to the query parameter to pass
*/
struct TALER_PQ_QueryParam
TALER_PQ_query_param_amount_nbo(const struct TALER_AmountNBO *x);
/**
* Generate query parameter for a currency, consisting of the three
* components "value", "fraction" and "currency" in this order. The
* types must be a 64-bit integer, 32-bit integer and a
* #TALER_CURRENCY_LEN-sized BLOB/VARCHAR respectively.
*
* @param x pointer to the query parameter to pass
*/
struct TALER_PQ_QueryParam
TALER_PQ_query_param_amount(const struct TALER_Amount *x);
/**
* Generate query parameter for an RSA public key. The
* database must contain a BLOB type in the respective position.
*
* @param x the query parameter to pass.
*/
struct TALER_PQ_QueryParam
TALER_PQ_query_param_rsa_public_key(const struct GNUNET_CRYPTO_rsa_PublicKey *x);
/**
* Generate query parameter for an RSA signature. The
* database must contain a BLOB type in the respective position.
*
* @param x the query parameter to pass
*/
struct TALER_PQ_QueryParam
TALER_PQ_query_param_rsa_signature(const struct GNUNET_CRYPTO_rsa_Signature *x);
/**
* Generate query parameter for an absolute time value.
* The database must store a 64-bit integer.
*
* @param x pointer to the query parameter to pass
*/
struct TALER_PQ_QueryParam
TALER_PQ_query_param_absolute_time(const struct GNUNET_TIME_Absolute *x);
/**
* Generate query parameter for an absolute time value.
* The database must store a 64-bit integer.
*
* @param x pointer to the query parameter to pass
*/
struct TALER_PQ_QueryParam
TALER_PQ_query_param_absolute_time_nbo(const struct GNUNET_TIME_AbsoluteNBO *x);
/**
* Generate query parameter for an uint16_t in host byte order.
*
* @param x pointer to the query parameter to pass
*/
struct TALER_PQ_QueryParam
TALER_PQ_query_param_uint16 (const uint16_t *x);
/**
* Generate query parameter for an uint32_t in host byte order.
*
* @param x pointer to the query parameter to pass
*/
struct TALER_PQ_QueryParam
TALER_PQ_query_param_uint32 (const uint32_t *x);
/**
* Generate query parameter for an uint16_t in host byte order.
*
* @param x pointer to the query parameter to pass
*/
struct TALER_PQ_QueryParam
TALER_PQ_query_param_uint64 (const uint64_t *x);
/**
* Generate query parameter for a JSON object (stored as a string
* in the DB). Note that @a x must really be a JSON object or array,
* passing just a value (string, integer) is not supported and will
* result in an abort.
*
* @param x pointer to the json object to pass
*/
struct TALER_PQ_QueryParam
TALER_PQ_query_param_json (const json_t *x);
/**
* Different formats of results that can be extracted.
*/
enum TALER_PQ_ResultFormat
{
/**
* List terminator.
*/
TALER_PQ_RF_END,
/**
* We expect a fixed-size result (binary blob, no endianess conversion).
*/
TALER_PQ_RF_FIXED_BLOB,
/**
* We expect a variable-size result (binary blob, no endianess conversion).
*/
TALER_PQ_RF_VARSIZE_BLOB,
/**
* We expect a currency amount.
* Data points to a `struct TALER_AmountNBO`, size only used for checking.
*/
TALER_PQ_RF_AMOUNT_NBO,
/**
* We expect a currency amount.
* Data points to a `struct TALER_Amount`, size only used for checking.
*/
TALER_PQ_RF_AMOUNT,
/**
* We expect an RSA public key.
* Data points to a `struct GNUNET_CRYPTO_rsa_PublicKey **`, size is not used.
*/
TALER_PQ_RF_RSA_PUBLIC_KEY,
/**
* We expect an RSA signature.
* Data points to a `struct GNUNET_CRYPTO_rsa_Signature **`, size is not used.
*/
TALER_PQ_RF_RSA_SIGNATURE,
/**
* We expect an absolute time.
* Data points to a `struct GNUNET_TIME_Absolute`, size is only used for checking.
*/
TALER_PQ_RF_TIME_ABSOLUTE,
/**
* We expect an uint16_t (in host byte order).
*/
TALER_PQ_RF_UINT16,
/**
* We expect an uint32_t (in host byte order).
*/
TALER_PQ_RF_UINT32,
/**
* We expect an uint64_t (in host byte order).
*/
TALER_PQ_RF_UINT64,
/**
* We expect a JSON object (json_t).
*/
TALER_PQ_RF_JSON
};
/**
* @brief Description of a DB result cell.
*/
struct TALER_PQ_ResultSpec
{
/**
* What is the format of the result?
*/
enum TALER_PQ_ResultFormat format;
/**
* Destination for the data.
*/
void *dst;
/**
* Allowed size for the data, 0 for variable-size
* (in this case, the type of @e dst is a `void **`
* and we need to allocate a buffer of the right size).
*/
size_t dst_size;
/**
* Field name of the desired result.
*/
const char *fname;
/**
* Where to store actual size of the result.
*/
size_t *result_size;
};
/**
* End of result parameter specification.
*
* @return array last entry for the result specification to use
*/
#define TALER_PQ_result_spec_end { TALER_PQ_RF_END, NULL, 0, NULL, NULL }
/**
* We expect a fixed-size result, with size given explicitly
*
* @param name name of the field in the table
* @param dst point to where to store the result
* @param s number of bytes we should use in @a dst
* @return array entry for the result specification to use
*/
#define TALER_PQ_result_spec_fixed_size(name, dst, s) { TALER_PQ_RF_FIXED_BLOB, (void *) (dst), (s), (name), NULL }
/**
* We expect a fixed-size result, with size determined by the type of `* dst`
*
* @param name name of the field in the table
* @param dst point to where to store the result, type fits expected result size
* @return array entry for the result specification to use
*/
#define TALER_PQ_result_spec_auto_from_type(name, dst) { TALER_PQ_RF_FIXED_BLOB, (void *) (dst), sizeof (*(dst)), name, NULL }
/**
* Variable-size result expected.
*
* @param name name of the field in the table
* @param[out] dst where to store the result, allocated
* @param[out] sptr where to store the size of @a dst
* @return array entry for the result specification to use
*/
struct TALER_PQ_ResultSpec
TALER_PQ_result_spec_variable_size (const char *name,
void **dst,
size_t *sptr);
/**
* Currency amount expected.
*
* @param name name of the field in the table
* @param[out] amount where to store the result
* @return array entry for the result specification to use
*/
struct TALER_PQ_ResultSpec
TALER_PQ_result_spec_amount_nbo (const char *name,
struct TALER_AmountNBO *amount);
/**
* Currency amount expected.
*
* @param name name of the field in the table
* @param[out] amount where to store the result
* @return array entry for the result specification to use
*/
struct TALER_PQ_ResultSpec
TALER_PQ_result_spec_amount (const char *name,
struct TALER_Amount *amount);
/**
* RSA public key expected.
*
* @param name name of the field in the table
* @param[out] rsa where to store the result
* @return array entry for the result specification to use
*/
struct TALER_PQ_ResultSpec
TALER_PQ_result_spec_rsa_public_key (const char *name,
struct GNUNET_CRYPTO_rsa_PublicKey **rsa);
/**
* RSA signature expected.
*
* @param name name of the field in the table
* @param[out] sig where to store the result;
* @return array entry for the result specification to use
*/
struct TALER_PQ_ResultSpec
TALER_PQ_result_spec_rsa_signature (const char *name,
struct GNUNET_CRYPTO_rsa_Signature **sig);
/**
* Absolute time expected.
*
* @param name name of the field in the table
* @param[out] at where to store the result
* @return array entry for the result specification to use
*/
struct TALER_PQ_ResultSpec
TALER_PQ_result_spec_absolute_time (const char *name,
struct GNUNET_TIME_Absolute *at);
/**
* Absolute time expected.
*
* @param name name of the field in the table
* @param[out] at where to store the result
* @return array entry for the result specification to use
*/
struct TALER_PQ_ResultSpec
TALER_PQ_result_spec_absolute_time_nbo (const char *name,
struct GNUNET_TIME_AbsoluteNBO *at);
/**
* uint16_t expected.
*
* @param name name of the field in the table
* @param[out] u16 where to store the result
* @return array entry for the result specification to use
*/
struct TALER_PQ_ResultSpec
TALER_PQ_result_spec_uint16 (const char *name,
uint16_t *u16);
/**
* uint32_t expected.
*
* @param name name of the field in the table
* @param[out] u32 where to store the result
* @return array entry for the result specification to use
*/
struct TALER_PQ_ResultSpec
TALER_PQ_result_spec_uint32 (const char *name,
uint32_t *u32);
/**
* uint64_t expected.
*
* @param name name of the field in the table
* @param[out] u64 where to store the result
* @return array entry for the result specification to use
*/
struct TALER_PQ_ResultSpec
TALER_PQ_result_spec_uint64 (const char *name,
uint64_t *u64);
/**
* json_t expected.
*
* @param name name of the field in the table
* @param[out] jp where to store the result
* @return array entry for the result specification to use
*/
struct TALER_PQ_ResultSpec
TALER_PQ_result_spec_json (const char *name,
json_t **jp);
/**
* Execute a prepared statement.
*
* @param db_conn database connection
* @param name name of the prepared statement
* @param params parameters to the statement
* @return postgres result
*/
PGresult *
TALER_PQ_exec_prepared (PGconn *db_conn,
const char *name,
const struct TALER_PQ_QueryParam *params);
/**
* Extract results from a query result according to the given specification.
* If colums are NULL, the destination is not modified, and #GNUNET_NO
* is returned.
*
* @param result result to process
* @param[in,out] rs result specification to extract for
* @param row row from the result to extract
* @return
* #GNUNET_YES if all results could be extracted
* #GNUNET_NO if at least one result was NULL
* #GNUNET_SYSERR if a result was invalid (non-existing field)
*/
int
TALER_PQ_extract_result (PGresult *result,
struct TALER_PQ_ResultSpec *rs,
int row);
/**
* Free all memory that was allocated in @a rs during
* #TALER_PQ_extract_result().
*
* @param rs reult specification to clean up
*/
void
TALER_PQ_cleanup_result (struct TALER_PQ_ResultSpec *rs);
/**
* Extract a currency amount from a query result according to the
* given specification.
*
* @param result the result to extract the amount from
* @param row which row of the result to extract the amount from (needed as results can have multiple rows)
* @param val_name name of the column with the amount's "value", must include the substring "_val".
* @param frac_name name of the column with the amount's "fractional" value, must include the substring "_frac".
* @param curr_name name of the column with the amount's currency name, must include the substring "_curr".
* @param[out] r_amount_nbo where to store the amount, in network byte order
* @return
* #GNUNET_YES if all results could be extracted
* #GNUNET_NO if at least one result was NULL
* #GNUNET_SYSERR if a result was invalid (non-existing field)
*/
int
TALER_PQ_extract_amount_nbo (PGresult *result,
int row,
const char *val_name,
const char *frac_name,
const char *curr_name,
struct TALER_AmountNBO *r_amount_nbo);
/**
* Extract a currency amount from a query result according to the
* given specification.
*
* @param result the result to extract the amount from
* @param row which row of the result to extract the amount from (needed as results can have multiple rows)
* @param val_name name of the column with the amount's "value", must include the substring "_val".
* @param frac_name name of the column with the amount's "fractional" value, must include the substring "_frac".
* @param curr_name name of the column with the amount's currency name, must include the substring "_curr".
* @param[out] r_amount where to store the amount, in host byte order
* @return
* #GNUNET_YES if all results could be extracted
* #GNUNET_NO if at least one result was NULL
* #GNUNET_SYSERR if a result was invalid (non-existing field)
*/
int
TALER_PQ_extract_amount (PGresult *result,
int row,
const char *val_name,
const char *frac_name,
const char *curr_name,
struct TALER_Amount *r_amount);
#endif /* TALER_PQ_LIB_H_ */
/* end of include/taler_pq_lib.h */