creating libgnunetpq library

1 files changed, 454 insertions, 0 deletions

diff --git a/src/include/gnunet_pq_lib.h b/src/include/gnunet_pq_lib.h
new file mode 100644
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+++ b/src/include/gnunet_pq_lib.h
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+/*
+  This file is part of GNUnet
+  Copyright (C) 2016 GNUnet e.V.
+
+  GNUnet 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.
+
+  GNUnet 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
+  GNUnet; see the file COPYING.  If not, If not, see <http://www.gnu.org/licenses/>
+*/
+/**
+ * @file include/gnunet_pq_lib.h
+ * @brief helper functions for DB interactions
+ * @author Christian Grothoff
+ */
+#ifndef GNUNET_PQ_LIB_H_
+#define GNUNET_PQ_LIB_H_
+
+#include <libpq-fe.h>
+#include "gnunet_util_lib.h"
+
+
+/**
+ * Function called to convert input argument into SQL parameters.
+ *
+ * @param cls closure
+ * @param data pointer to input argument
+ * @param data_len number of bytes in @a data (if applicable)
+ * @param[out] param_values SQL data to set
+ * @param[out] param_lengths SQL length data to set
+ * @param[out] param_formats SQL format data to set
+ * @param param_length number of entries available in the @a param_values, @a param_lengths and @a param_formats arrays
+ * @param[out] scratch buffer for dynamic allocations (to be done via #GNUNET_malloc()
+ * @param scratch_length number of entries left in @a scratch
+ * @return -1 on error, number of offsets used in @a scratch otherwise
+ */
+typedef int
+(*GNUNET_PQ_QueryConverter)(void *cls,
+                            const void *data,
+                            size_t data_len,
+                            void *param_values[],
+                            int param_lengths[],
+                            int param_formats[],
+                            unsigned int param_length,
+                            void *scratch[],
+                            unsigned int scratch_length);
+
+
+/**
+ * @brief Description of a DB query parameter.
+ */
+struct GNUNET_PQ_QueryParam
+{
+
+  /**
+   * Format of the rest of the entry, determines the data
+   * type that is being added to the query.
+   */
+  GNUNET_PQ_QueryConverter conv;
+
+  /**
+   * Closure for @e conv.
+   */
+  void *conv_cls;
+
+  /**
+   * Data or NULL.
+   */
+  const void *data;
+
+  /**
+   * Size of @e data
+   */
+  size_t size;
+
+  /**
+   * Number of parameters eaten by this operation.
+   */
+  unsigned int num_params;
+};
+
+
+/**
+ * End of query parameter specification.
+ */
+#define GNUNET_PQ_query_param_end { NULL, NULL, NULL, 0, 0 }
+
+
+/**
+ * Generate query parameter for a buffer @a ptr of
+ * @a ptr_size bytes.
+ *
+ * @param ptr pointer to the query parameter to pass
+ * @oaran ptr_size number of bytes in @a ptr
+ */
+struct GNUNET_PQ_QueryParam
+GNUNET_PQ_query_param_fixed_size (const void *ptr,
+                                  size_t ptr_size);
+
+
+/**
+ * Generate fixed-size query parameter with size determined
+ * by variable type.
+ *
+ * @param x pointer to the query parameter to pass.
+ */
+#define GNUNET_PQ_query_param_auto_from_type(x) GNUNET_PQ_query_param_fixed_size ((x), sizeof (*(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 GNUNET_PQ_QueryParam
+GNUNET_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 GNUNET_PQ_QueryParam
+GNUNET_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 GNUNET_PQ_QueryParam
+GNUNET_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 GNUNET_PQ_QueryParam
+GNUNET_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 GNUNET_PQ_QueryParam
+GNUNET_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 GNUNET_PQ_QueryParam
+GNUNET_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 GNUNET_PQ_QueryParam
+GNUNET_PQ_query_param_uint64 (const uint64_t *x);
+
+
+/**
+ * Extract data from a Postgres database @a result at row @a row.
+ *
+ * @param cls closure
+ * @param result where to extract data from
+ * @param int row to extract data from
+ * @param fname name (or prefix) of the fields to extract from
+ * @param[in,out] dst_size where to store size of result, may be NULL
+ * @param[out] dst where to store the result
+ * @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)
+ */
+typedef int
+(*GNUNET_PQ_ResultConverter)(void *cls,
+                             PGresult *result,
+                             int row,
+                             const char *fname,
+                             size_t *dst_size,
+                             void *dst);
+
+
+/**
+ * Function called to clean up memory allocated
+ * by a #GNUNET_PQ_ResultConverter.
+ *
+ * @param cls closure
+ * @param rd result data to clean up
+ */
+typedef void
+(*GNUNET_PQ_ResultCleanup)(void *cls,
+                           void *rd);
+
+
+/**
+ * @brief Description of a DB result cell.
+ */
+struct GNUNET_PQ_ResultSpec
+{
+
+  /**
+   * What is the format of the result?
+   */
+  GNUNET_PQ_ResultConverter conv;
+
+  /**
+   * Function to clean up result data, NULL if cleanup is
+   * not necessary.
+   */
+  GNUNET_PQ_ResultCleanup cleaner;
+
+  /**
+   * Closure for @e conv and @e cleaner.
+   */
+  void *cls;
+
+  /**
+   * 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 GNUNET_PQ_result_spec_end { NULL, NULL, NULL, NULL, 0, NULL, 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 GNUNET_PQ_ResultSpec
+GNUNET_PQ_result_spec_variable_size (const char *name,
+                                     void **dst,
+                                     size_t *sptr);
+
+
+/**
+ * Fixed-size result expected.
+ *
+ * @param name name of the field in the table
+ * @param[out] dst where to store the result
+ * @param dst_size number of bytes in @a dst
+ * @return array entry for the result specification to use
+ */
+struct GNUNET_PQ_ResultSpec
+GNUNET_PQ_result_spec_fixed_size (const char *name,
+                                  void *dst,
+                                  size_t dst_size);
+
+
+
+/**
+ * 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 GNUNET_PQ_result_spec_auto_from_type(name, dst) GNUNET_PQ_result_spec_fixed_size (name, (dst), sizeof (*(dst)))
+
+
+/**
+ * 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 GNUNET_PQ_ResultSpec
+GNUNET_PQ_result_spec_variable_size (const char *name,
+                                     void **dst,
+                                     size_t *sptr);
+
+
+/**
+ * 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 GNUNET_PQ_ResultSpec
+GNUNET_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 GNUNET_PQ_ResultSpec
+GNUNET_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 GNUNET_PQ_ResultSpec
+GNUNET_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 GNUNET_PQ_ResultSpec
+GNUNET_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 GNUNET_PQ_ResultSpec
+GNUNET_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 GNUNET_PQ_ResultSpec
+GNUNET_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 GNUNET_PQ_ResultSpec
+GNUNET_PQ_result_spec_uint64 (const char *name,
+                              uint64_t *u64);
+
+
+/**
+ * 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 *
+GNUNET_PQ_exec_prepared (PGconn *db_conn,
+                         const char *name,
+                         const struct GNUNET_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
+GNUNET_PQ_extract_result (PGresult *result,
+                          struct GNUNET_PQ_ResultSpec *rs,
+                          int row);
+
+
+/**
+ * Free all memory that was allocated in @a rs during
+ * #GNUNET_PQ_extract_result().
+ *
+ * @param rs reult specification to clean up
+ */
+void
+GNUNET_PQ_cleanup_result (struct GNUNET_PQ_ResultSpec *rs);
+
+
+#endif  /* GNUNET_PQ_LIB_H_ */
+
+/* end of include/gnunet_pq_lib.h */