1 files changed, 248 insertions, 0 deletions

diff --git a/src/lib/pq/pq_eval.c b/src/lib/pq/pq_eval.c
new file mode 100644
index 000000000..e31475e13
--- /dev/null
+++ b/src/lib/pq/pq_eval.c
@@ -0,0 +1,248 @@
+/*
+   This file is part of GNUnet
+   Copyright (C) 2017, 2019 GNUnet e.V.
+
+   GNUnet is free software: you can redistribute it and/or modify it
+   under the terms of the GNU Affero General Public License as published
+   by the Free Software Foundation, either version 3 of the License,
+   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
+   Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+     SPDX-License-Identifier: AGPL3.0-or-later
+ */
+/**
+ * @file pq/pq_eval.c
+ * @brief functions to execute SQL statements with arguments and/or results (PostGres)
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include "pq.h"
+
+
+/**
+ * Error code returned by Postgres for deadlock.
+ */
+#define PQ_DIAG_SQLSTATE_DEADLOCK "40P01"
+
+/**
+ * Error code returned by Postgres for uniqueness violation.
+ */
+#define PQ_DIAG_SQLSTATE_UNIQUE_VIOLATION "23505"
+
+/**
+ * Error code returned by Postgres on serialization failure.
+ */
+#define PQ_DIAG_SQLSTATE_SERIALIZATION_FAILURE "40001"
+
+
+enum GNUNET_DB_QueryStatus
+GNUNET_PQ_eval_result (struct GNUNET_PQ_Context *db,
+                       const char *statement_name,
+                       PGresult *result)
+{
+  ExecStatusType est;
+
+  if (NULL == result)
+    return GNUNET_DB_STATUS_SOFT_ERROR;
+  est = PQresultStatus (result);
+  if ((PGRES_COMMAND_OK != est) &&
+      (PGRES_TUPLES_OK != est))
+  {
+    const char *sqlstate;
+    ConnStatusType status;
+
+    if (CONNECTION_OK != (status = PQstatus (db->conn)))
+    {
+      GNUNET_log_from (GNUNET_ERROR_TYPE_INFO,
+                       "pq",
+                       "Database connection failed during query `%s': %d (reconnecting)\n",
+                       statement_name,
+                       status);
+      GNUNET_PQ_reconnect (db);
+      return GNUNET_DB_STATUS_SOFT_ERROR;
+    }
+
+    sqlstate = PQresultErrorField (result,
+                                   PG_DIAG_SQLSTATE);
+    if (NULL == sqlstate)
+    {
+      /* very unexpected... */
+      GNUNET_break (0);
+      return GNUNET_DB_STATUS_HARD_ERROR;
+    }
+    if ((0 == strcmp (sqlstate,
+                      PQ_DIAG_SQLSTATE_DEADLOCK)) ||
+        (0 == strcmp (sqlstate,
+                      PQ_DIAG_SQLSTATE_SERIALIZATION_FAILURE)))
+    {
+      /* These two can be retried and have a fair chance of working
+         the next time */
+      GNUNET_log_from (GNUNET_ERROR_TYPE_INFO,
+                       "pq",
+                       "Query `%s' failed with result: %s/%s/%s/%s/%s\n",
+                       statement_name,
+                       PQresultErrorField (result,
+                                           PG_DIAG_MESSAGE_PRIMARY),
+                       PQresultErrorField (result,
+                                           PG_DIAG_MESSAGE_DETAIL),
+                       PQresultErrorMessage (result),
+                       PQresStatus (PQresultStatus (result)),
+                       PQerrorMessage (db->conn));
+      return GNUNET_DB_STATUS_SOFT_ERROR;
+    }
+    if (0 == strcmp (sqlstate,
+                     PQ_DIAG_SQLSTATE_UNIQUE_VIOLATION))
+    {
+      /* Likely no need to retry, INSERT of "same" data. */
+      GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
+                       "pq",
+                       "Query `%s' failed with unique violation: %s/%s/%s/%s/%s\n",
+                       statement_name,
+                       PQresultErrorField (result,
+                                           PG_DIAG_MESSAGE_PRIMARY),
+                       PQresultErrorField (result,
+                                           PG_DIAG_MESSAGE_DETAIL),
+                       PQresultErrorMessage (result),
+                       PQresStatus (PQresultStatus (result)),
+                       PQerrorMessage (db->conn));
+      return GNUNET_DB_STATUS_SUCCESS_NO_RESULTS;
+    }
+    GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR,
+                     "pq",
+                     "Query `%s' failed with result: %s/%s/%s/%s/%s\n",
+                     statement_name,
+                     PQresultErrorField (result,
+                                         PG_DIAG_MESSAGE_PRIMARY),
+                     PQresultErrorField (result,
+                                         PG_DIAG_MESSAGE_DETAIL),
+                     PQresultErrorMessage (result),
+                     PQresStatus (PQresultStatus (result)),
+                     PQerrorMessage (db->conn));
+    return GNUNET_DB_STATUS_HARD_ERROR;
+  }
+  return GNUNET_DB_STATUS_SUCCESS_NO_RESULTS;
+}
+
+
+enum GNUNET_DB_QueryStatus
+GNUNET_PQ_eval_prepared_non_select (struct GNUNET_PQ_Context *db,
+                                    const char *statement_name,
+                                    const struct GNUNET_PQ_QueryParam *params)
+{
+  PGresult *result;
+  enum GNUNET_DB_QueryStatus qs;
+
+  result = GNUNET_PQ_exec_prepared (db,
+                                    statement_name,
+                                    params);
+  if (NULL == result)
+    return GNUNET_DB_STATUS_SOFT_ERROR;
+  qs = GNUNET_PQ_eval_result (db,
+                              statement_name,
+                              result);
+  if (GNUNET_DB_STATUS_SUCCESS_NO_RESULTS == qs)
+  {
+    const char *tuples;
+
+    /* What an awful API, this function really does return a string */
+    tuples = PQcmdTuples (result);
+    if (NULL != tuples)
+      qs = strtol (tuples, NULL, 10);
+  }
+  PQclear (result);
+  return qs;
+}
+
+
+enum GNUNET_DB_QueryStatus
+GNUNET_PQ_eval_prepared_multi_select (struct GNUNET_PQ_Context *db,
+                                      const char *statement_name,
+                                      const struct GNUNET_PQ_QueryParam *params,
+                                      GNUNET_PQ_PostgresResultHandler rh,
+                                      void *rh_cls)
+{
+  PGresult *result;
+  enum GNUNET_DB_QueryStatus qs;
+  unsigned int ret;
+
+  result = GNUNET_PQ_exec_prepared (db,
+                                    statement_name,
+                                    params);
+  if (NULL == result)
+    return GNUNET_DB_STATUS_SOFT_ERROR;
+  qs = GNUNET_PQ_eval_result (db,
+                              statement_name,
+                              result);
+  if (qs < 0)
+  {
+    PQclear (result);
+    return qs;
+  }
+  ret = PQntuples (result);
+  if (NULL != rh)
+    rh (rh_cls,
+        result,
+        ret);
+  PQclear (result);
+  return ret;
+}
+
+
+enum GNUNET_DB_QueryStatus
+GNUNET_PQ_eval_prepared_singleton_select (
+  struct GNUNET_PQ_Context *db,
+  const char *statement_name,
+  const struct GNUNET_PQ_QueryParam *params,
+  struct GNUNET_PQ_ResultSpec *rs)
+{
+  PGresult *result;
+  enum GNUNET_DB_QueryStatus qs;
+  int ntuples;
+
+  result = GNUNET_PQ_exec_prepared (db,
+                                    statement_name,
+                                    params);
+  if (NULL == result)
+    return GNUNET_DB_STATUS_SOFT_ERROR;
+  qs = GNUNET_PQ_eval_result (db,
+                              statement_name,
+                              result);
+  if (qs < 0)
+  {
+    PQclear (result);
+    return qs;
+  }
+  ntuples = PQntuples (result);
+  if (0 == ntuples)
+  {
+    PQclear (result);
+    return GNUNET_DB_STATUS_SUCCESS_NO_RESULTS;
+  }
+  if (1 != ntuples)
+  {
+    /* more than one result, but there must be at most one */
+    GNUNET_break (0);
+    PQclear (result);
+    return GNUNET_DB_STATUS_HARD_ERROR;
+  }
+  if (GNUNET_OK !=
+      GNUNET_PQ_extract_result (result,
+                                rs,
+                                0))
+  {
+    PQclear (result);
+    return GNUNET_DB_STATUS_HARD_ERROR;
+  }
+  PQclear (result);
+  return GNUNET_DB_STATUS_SUCCESS_ONE_RESULT;
+}
+
+
+/* end of pq/pq_eval.c */