GNUnet  0.11.x
pq.c
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1 /*
2  This file is part of GNUnet
3  Copyright (C) 2014, 2015, 2016, 2017, 2019, 2020 GNUnet e.V.
4 
5  GNUnet is free software: you can redistribute it and/or modify it
6  under the terms of the GNU Affero General Public License as published
7  by the Free Software Foundation, either version 3 of the License,
8  or (at your option) any later version.
9 
10  GNUnet is distributed in the hope that it will be useful, but
11  WITHOUT ANY WARRANTY; without even the implied warranty of
12  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13  Affero General Public License for more details.
14 
15  You should have received a copy of the GNU Affero General Public License
16  along with this program. If not, see <http://www.gnu.org/licenses/>.
17 
18  SPDX-License-Identifier: AGPL3.0-or-later
19  */
27 #include "platform.h"
28 #include "pq.h"
29 
30 
31 PGresult *
33  const char *name,
34  const struct GNUNET_PQ_QueryParam *params)
35 {
36  unsigned int len;
37 
39  "Running prepared statement `%s' on %p\n",
40  name,
41  db);
42  /* count the number of parameters */
43  len = 0;
44  for (unsigned int i = 0; 0 != params[i].num_params; i++)
45  len += params[i].num_params;
46 
47  /* new scope to allow stack allocation without alloca */
48  {
49  /* Scratch buffer for temporary storage */
50  void *scratch[len];
51  /* Parameter array we are building for the query */
52  void *param_values[len];
53  int param_lengths[len];
54  int param_formats[len];
55  unsigned int off;
56  /* How many entries in the scratch buffer are in use? */
57  unsigned int soff;
58  PGresult *res;
59  int ret;
60  ConnStatusType status;
61 
62  off = 0;
63  soff = 0;
64  for (unsigned int i = 0; 0 != params[i].num_params; i++)
65  {
66  const struct GNUNET_PQ_QueryParam *x = &params[i];
67 
68  ret = x->conv (x->conv_cls,
69  x->data,
70  x->size,
71  &param_values[off],
72  &param_lengths[off],
73  &param_formats[off],
74  x->num_params,
75  &scratch[soff],
76  len - soff);
77  if (ret < 0)
78  {
79  for (off = 0; off < soff; off++)
80  GNUNET_free (scratch[off]);
81  return NULL;
82  }
83  soff += ret;
84  off += x->num_params;
85  }
86  GNUNET_assert (off == len);
88  "pq",
89  "Executing prepared SQL statement `%s'\n",
90  name);
91  res = PQexecPrepared (db->conn,
92  name,
93  len,
94  (const char **) param_values,
95  param_lengths,
96  param_formats,
97  1);
99  "pq",
100  "Execution of prepared SQL statement `%s' finished (%d)\n",
101  name,
102  PGRES_COMMAND_OK == PQresultStatus (res));
103  if ( (PGRES_COMMAND_OK != PQresultStatus (res)) &&
104  (CONNECTION_OK != (status = PQstatus (db->conn))) )
105  {
107  "pq",
108  "Database disconnected on SQL statement `%s' (reconnecting)\n",
109  name);
111  res = NULL;
112  }
113 
114  for (off = 0; off < soff; off++)
115  GNUNET_free (scratch[off]);
116  return res;
117  }
118 }
119 
120 
121 void
123 {
124  for (unsigned int i = 0; NULL != rs[i].conv; i++)
125  if (NULL != rs[i].cleaner)
126  rs[i].cleaner (rs[i].cls,
127  rs[i].dst);
128 }
129 
130 
133  struct GNUNET_PQ_ResultSpec *rs,
134  int row)
135 {
136  unsigned int i;
137 
138  if (NULL == result)
139  return GNUNET_SYSERR;
140  for (i = 0; NULL != rs[i].conv; i++)
141  {
142  struct GNUNET_PQ_ResultSpec *spec;
144 
145  spec = &rs[i];
146  ret = spec->conv (spec->cls,
147  result,
148  row,
149  spec->fname,
150  &spec->dst_size,
151  spec->dst);
152  switch (ret)
153  {
154  case GNUNET_OK:
155  /* canonical case, continue below */
156  if (NULL != spec->is_null)
157  *spec->is_null = false;
158  break;
159  case GNUNET_NO:
160  if (spec->is_nullable)
161  {
162  if (NULL != spec->is_null)
163  *spec->is_null = true;
164  continue;
165  }
167  "NULL field encountered for `%s' where non-NULL was required\n",
168  spec->fname);
169  goto cleanup;
170  case GNUNET_SYSERR:
172  "Failed to extract field `%s'\n",
173  spec->fname);
174  GNUNET_break (0);
175  goto cleanup;
176  }
177  if (NULL != spec->result_size)
178  *spec->result_size = spec->dst_size;
179  }
180  return GNUNET_OK;
181 cleanup:
182  for (unsigned int j = 0; j < i; j++)
183  if (NULL != rs[j].cleaner)
184  rs[j].cleaner (rs[j].cls,
185  rs[j].dst);
186  return GNUNET_SYSERR;
187 }
188 
189 
190 /* end of pq/pq.c */
static int ret
Return value of the commandline.
Definition: gnunet-abd.c:81
static int res
static void cleanup(void *cls)
Function scheduled as very last function, cleans up after us.
uint16_t status
See PRISM_STATUS_*-constants.
uint16_t len
length of data (which is always a uint32_t, but presumably this can be used to specify that fewer byt...
static int result
Global testing status.
static struct GNUNET_FS_DirectoryBuilder * db
Definition: gnunet-search.c:94
#define GNUNET_log(kind,...)
#define GNUNET_log_from(kind, comp,...)
GNUNET_GenericReturnValue
Named constants for return values.
Definition: gnunet_common.h:92
@ GNUNET_OK
Definition: gnunet_common.h:95
@ GNUNET_NO
Definition: gnunet_common.h:94
@ GNUNET_SYSERR
Definition: gnunet_common.h:93
void GNUNET_PQ_reconnect(struct GNUNET_PQ_Context *db)
Reinitialize the database db.
Definition: pq_connect.c:313
#define GNUNET_assert(cond)
Use this for fatal errors that cannot be handled.
#define GNUNET_break(cond)
Use this for internal assertion violations that are not fatal (can be handled) but should not occur.
@ GNUNET_ERROR_TYPE_ERROR
@ GNUNET_ERROR_TYPE_DEBUG
#define GNUNET_free(ptr)
Wrapper around free.
const char * name
PGresult * GNUNET_PQ_exec_prepared(struct GNUNET_PQ_Context *db, const char *name, const struct GNUNET_PQ_QueryParam *params)
Execute a prepared statement.
Definition: pq.c:32
void GNUNET_PQ_cleanup_result(struct GNUNET_PQ_ResultSpec *rs)
Free all memory that was allocated in rs during GNUNET_PQ_extract_result().
Definition: pq.c:122
enum GNUNET_GenericReturnValue GNUNET_PQ_extract_result(PGresult *result, struct GNUNET_PQ_ResultSpec *rs, int row)
Extract results from a query result according to the given specification.
Definition: pq.c:132
shared internal data structures of libgnunetpq
Handle to Postgres database.
Definition: pq.h:36
Description of a DB query parameter.
Definition: gnunet_pq_lib.h:65
void * conv_cls
Closure for conv.
Definition: gnunet_pq_lib.h:74
const void * data
Data or NULL.
Definition: gnunet_pq_lib.h:79
GNUNET_PQ_QueryConverter conv
Function for how to handle this type of entry.
Definition: gnunet_pq_lib.h:69
unsigned int num_params
Number of parameters eaten by this operation.
Definition: gnunet_pq_lib.h:89
size_t size
Size of data.
Definition: gnunet_pq_lib.h:84
Description of a DB result cell.
const char * fname
Field name of the desired result.
bool * is_null
Points to a location where we should store "true" if the result found is NULL, and otherwise "false".
void * dst
Destination for the data.
bool is_nullable
True if NULL is allowed for a value in the database.
void * cls
Closure for conv and cleaner.
GNUNET_PQ_ResultConverter conv
What is the format of the result?
size_t * result_size
Where to store actual size of the result.
GNUNET_PQ_ResultCleanup cleaner
Function to clean up result data, NULL if cleanup is not necessary.
size_t dst_size
Allowed size for the data, 0 for variable-size (in this case, the type of dst is a void ** and we nee...