adding more good helpers to libgnunetpq

5 files changed, 578 insertions, 0 deletions

diff --git a/src/pq/Makefile.am b/src/pq/Makefile.am
index 8bb0a0132..d0c71703b 100644
--- a/src/pq/Makefile.am
+++ b/src/pq/Makefile.am
@@ -15,6 +15,10 @@ endif
 
 libgnunetpq_la_SOURCES = \
   pq.c \
+  pq_connect.c \
+  pq_eval.c \
+  pq_exec.c \
+  pq_prepare.c \
   pq_query_helper.c \
   pq_result_helper.c
 libgnunetpq_la_LIBADD = -lpq \
diff --git a/src/pq/pq_connect.c b/src/pq/pq_connect.c
new file mode 100644
index 000000000..99ad06485
--- /dev/null
+++ b/src/pq/pq_connect.c
@@ -0,0 +1,127 @@
+/*
+  This file is part of GNUnet
+  Copyright (C) 2017 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 pq/pq_connect.c
+ * @brief functions to connect to libpq (PostGres)
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include "gnunet_util_lib.h"
+#include "gnunet_pq_lib.h"
+
+
+/**
+ * Function called by libpq whenever it wants to log something.
+ * We already log whenever we care, so this function does nothing
+ * and merely exists to silence the libpq logging.
+ *
+ * @param arg the SQL connection that was used
+ * @param res information about some libpq event
+ */
+static void
+pq_notice_receiver_cb (void *arg,
+                       const PGresult *res)
+{
+  /* do nothing, intentionally */
+}
+
+
+/**
+ * Function called by libpq whenever it wants to log something.
+ * We log those using the Taler logger.
+ *
+ * @param arg the SQL connection that was used
+ * @param message information about some libpq event
+ */
+static void
+pq_notice_processor_cb (void *arg,
+                        const char *message)
+{
+  GNUNET_log_from (GNUNET_ERROR_TYPE_INFO,
+                   "pq",
+                   "%s",
+                   message);
+}
+
+
+/**
+ * Create a connection to the Postgres database using @a config_str
+ * for the configuration.  Initialize logging via GNUnet's log
+ * routines and disable Postgres's logger.
+ *
+ * @param config_str configuration to use
+ * @return NULL on error
+ */
+PGconn *
+GNUNET_PQ_connect (const char *config_str)
+{
+  PGconn *conn;
+
+  conn = PQconnectdb (config_str);
+  if ( (NULL == conn) ||
+       (CONNECTION_OK !=
+        PQstatus (conn)) )
+  {
+    GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR,
+                     "pq",
+                     "Database connection to '%s' failed: %s\n",
+                     config_str,
+                     (NULL != conn) ?
+                     PQerrorMessage (conn)
+                     : "PQconnectdb returned NULL");
+    if (NULL != conn)
+      PQfinish (conn);
+    return NULL;
+  }
+  PQsetNoticeReceiver (conn,
+                       &pq_notice_receiver_cb,
+                       conn);
+  PQsetNoticeProcessor (conn,
+                        &pq_notice_processor_cb,
+                        conn);
+  return conn;
+}
+
+
+/**
+ * Connect to a postgres database using the configuration
+ * option "CONFIG" in @a section.
+ *
+ * @param cfg configuration
+ * @param section configuration section to use to get Postgres configuration options
+ * @return the postgres handle, NULL on error
+ */
+PGconn *
+GNUNET_PQ_connect_with_cfg (const struct GNUNET_CONFIGURATION_Handle * cfg,
+                            const char *section)
+{
+  PGconn *dbh;
+  char *conninfo;
+
+  /* Open database and precompile statements */
+  if (GNUNET_OK !=
+      GNUNET_CONFIGURATION_get_value_string (cfg,
+                                             section,
+                                             "CONFIG",
+                                             &conninfo))
+    conninfo = NULL;
+  dbh = GNUNET_PQ_connect (conninfo == NULL ? "" : conninfo);
+  GNUNET_free_non_null (conninfo);
+  return dbh;
+}
+
+
+/* end of pq/pq_connect.c */
diff --git a/src/pq/pq_eval.c b/src/pq/pq_eval.c
new file mode 100644
index 000000000..39a7a2c98
--- /dev/null
+++ b/src/pq/pq_eval.c
@@ -0,0 +1,249 @@
+/*
+  This file is part of GNUnet
+  Copyright (C) 2017 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 pq/pq_eval.c
+ * @brief functions to execute SQL statements with arguments and/or results (PostGres)
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include "gnunet_util_lib.h"
+#include "gnunet_pq_lib.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"
+
+
+/**
+ * Check the @a result's error code to see what happened.
+ * Also logs errors.
+ *
+ * @param connection connection to execute the statement in
+ * @param statement_name name of the statement that created @a result
+ * @param result result to check
+ * @return status code from the result, mapping PQ status
+ *         codes to `enum GNUNET_PQ_QueryStatus`.  Never
+ *         returns positive values as this function does
+ *         not look at the result set.
+ * @deprecated (low level, let's see if we can do with just the high-level functions)
+ */
+enum GNUNET_PQ_QueryStatus
+GNUNET_PQ_eval_result (PGconn *connection,
+                       const char *statement_name,
+                       PGresult *result)
+{
+  if (PGRES_COMMAND_OK !=
+      PQresultStatus (result))
+  {
+    const char *sqlstate;
+
+    sqlstate = PQresultErrorField (result,
+                                   PG_DIAG_SQLSTATE);
+    if (NULL == sqlstate)
+    {
+      /* very unexpected... */
+      GNUNET_break (0);
+      return GNUNET_PQ_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 (connection));
+      return GNUNET_PQ_STATUS_SOFT_ERROR;
+    }
+    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 (connection));
+    return GNUNET_PQ_STATUS_HARD_ERROR;
+  }
+  return GNUNET_PQ_STATUS_SUCCESS_NO_RESULTS;
+}
+
+
+/**
+ * Execute a named prepared @a statement that is NOT a SELECT
+ * statement in @a connnection using the given @a params.  Returns the
+ * resulting session state.
+ *
+ * @param connection connection to execute the statement in
+ * @param statement_name name of the statement
+ * @param params parameters to give to the statement (#GNUNET_PQ_query_param_end-terminated)
+ * @return status code from the result, mapping PQ status
+ *         codes to `enum GNUNET_PQ_QueryStatus`.  Never
+ *         returns positive values as this function does
+ *         not look at the result set.
+ */
+enum GNUNET_PQ_QueryStatus
+GNUNET_PQ_eval_prepared_non_select (PGconn *connection,
+                                    const char *statement_name,
+                                    const struct GNUNET_PQ_QueryParam *params)
+{
+  PGresult *result;
+  enum GNUNET_PQ_QueryStatus qs;
+
+  result = GNUNET_PQ_exec_prepared (connection,
+                                    statement_name,
+                                    params);
+  qs = GNUNET_PQ_eval_result (connection,
+                              statement_name,
+                              result);
+  PQclear (result);
+  return qs;
+}
+
+
+/**
+ * Execute a named prepared @a statement that is a SELECT statement
+ * which may return multiple results in @a connection using the given
+ * @a params.  Call @a rh with the results.  Returns the query
+ * status including the number of results given to @a rh (possibly zero).
+ * @a rh will not have been called if the return value is negative.
+ *
+ * @param connection connection to execute the statement in
+ * @param statement_name name of the statement
+ * @param params parameters to give to the statement (#GNUNET_PQ_query_param_end-terminated)
+ * @param rh function to call with the result set, NULL to ignore
+ * @param rh_cls closure to pass to @a rh
+ * @return status code from the result, mapping PQ status
+ *         codes to `enum GNUNET_PQ_QueryStatus`.
+ */
+enum GNUNET_PQ_QueryStatus
+GNUNET_PQ_eval_prepared_multi_select (PGconn *connection,
+                                      const char *statement_name,
+                                      const struct GNUNET_PQ_QueryParam *params,
+                                      GNUNET_PQ_PostgresResultHandler rh,
+                                      void *rh_cls)
+{
+  PGresult *result;
+  enum GNUNET_PQ_QueryStatus qs;
+  unsigned int ret;
+
+  result = GNUNET_PQ_exec_prepared (connection,
+                                    statement_name,
+                                    params);
+  qs = GNUNET_PQ_eval_result (connection,
+                              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;
+}
+
+
+/**
+ * Execute a named prepared @a statement that is a SELECT statement
+ * which must return a single result in @a connection using the given
+ * @a params.  Stores the result (if any) in @a rs, which the caller
+ * must then clean up using #GNUNET_PQ_cleanup_result() if the return
+ * value was #GNUNET_PQ_STATUS_SUCCESS_ONE_RESULT.  Returns the
+ * resulting session status.
+ *
+ * @param connection connection to execute the statement in
+ * @param statement_name name of the statement
+ * @param params parameters to give to the statement (#GNUNET_PQ_query_param_end-terminated)
+ * @param[in,out] rs result specification to use for storing the result of the query
+ * @return status code from the result, mapping PQ status
+ *         codes to `enum GNUNET_PQ_QueryStatus`.
+ */
+enum GNUNET_PQ_QueryStatus
+GNUNET_PQ_eval_prepared_singleton_select (PGconn *connection,
+                                          const char *statement_name,
+                                          const struct GNUNET_PQ_QueryParam *params,
+                                          struct GNUNET_PQ_ResultSpec *rs)
+{
+  PGresult *result;
+  enum GNUNET_PQ_QueryStatus qs;
+
+  result = GNUNET_PQ_exec_prepared (connection,
+                                    statement_name,
+                                    params);
+  qs = GNUNET_PQ_eval_result (connection,
+                              statement_name,
+                              result);
+  if (qs < 0)
+  {
+    PQclear (result);
+    return qs;
+  }
+  if (0 == PQntuples (result))
+  {
+    PQclear (result);
+    return GNUNET_PQ_STATUS_SUCCESS_NO_RESULTS;
+  }
+  if (1 != PQntuples (result))
+  {
+    /* more than one result, but there must be at most one */
+    GNUNET_break (0);
+    PQclear (result);
+    return GNUNET_PQ_STATUS_HARD_ERROR;
+  }
+  if (GNUNET_OK !=
+      GNUNET_PQ_extract_result (result,
+                                rs,
+                                0))
+  {
+    PQclear (result);
+    return GNUNET_PQ_STATUS_HARD_ERROR;
+  }
+  PQclear (result);
+  return GNUNET_PQ_STATUS_SUCCESS_ONE_RESULT;
+}
+
+
+/* end of pq/pq_eval.c */
diff --git a/src/pq/pq_exec.c b/src/pq/pq_exec.c
new file mode 100644
index 000000000..1e5e4eb76
--- /dev/null
+++ b/src/pq/pq_exec.c
@@ -0,0 +1,106 @@
+/*
+  This file is part of GNUnet
+  Copyright (C) 2017 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 pq/pq_exec.c
+ * @brief functions to execute plain SQL statements (PostGres)
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include "gnunet_util_lib.h"
+#include "gnunet_pq_lib.h"
+
+
+/**
+ * Create a `struct GNUNET_PQ_ExecuteStatement` where errors are fatal.
+ *
+ * @param sql actual SQL statement
+ * @return initialized struct
+ */
+struct GNUNET_PQ_ExecuteStatement
+GNUNET_PQ_make_execute (const char *sql)
+{
+  struct GNUNET_PQ_ExecuteStatement es = {
+    .sql = sql,
+    .ignore_errors = GNUNET_NO
+  };
+
+  return es;
+}
+
+
+/**
+ * Create a `struct GNUNET_PQ_ExecuteStatement` where errors should
+ * be tolerated.
+ *
+ * @param sql actual SQL statement
+ * @return initialized struct
+ */
+struct GNUNET_PQ_ExecuteStatement
+GNUNET_PQ_make_try_execute (const char *sql)
+{
+  struct GNUNET_PQ_ExecuteStatement es = {
+    .sql = sql,
+    .ignore_errors = GNUNET_YES
+  };
+
+  return es;
+}
+
+
+/**
+ * Request execution of an array of statements @a es from Postgres.
+ *
+ * @param connection connection to execute the statements over
+ * @param es #GNUNET_PQ_PREPARED_STATEMENT_END-terminated array of prepared
+ *            statements.
+ * @return #GNUNET_OK on success (modulo statements where errors can be ignored)
+ *         #GNUNET_SYSERR on error
+ */
+int
+GNUNET_PQ_exec_statements (PGconn *connection,
+                           const struct GNUNET_PQ_ExecuteStatement *es)
+{
+  for (unsigned int i=0; NULL != es[i].sql; i++)
+  {
+    PGresult *result;
+
+    result = PQexec (connection,
+                     es[i].sql);
+
+    if ( (GNUNET_NO == es[i].ignore_errors) &&
+         (PGRES_COMMAND_OK != PQresultStatus (result)) )
+    {
+      GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR,
+                       "pq",
+                       "Failed to execute `%s': %s/%s/%s/%s/%s",
+                       es[i].sql,
+                       PQresultErrorField (result,
+                                           PG_DIAG_MESSAGE_PRIMARY),
+                       PQresultErrorField (result,
+                                           PG_DIAG_MESSAGE_DETAIL),
+                       PQresultErrorMessage (result),
+                       PQresStatus (PQresultStatus (result)),
+                       PQerrorMessage (connection));
+      PQclear (result);
+      return GNUNET_SYSERR;
+    }
+    PQclear (result);
+  }
+  return GNUNET_OK;
+}
+
+
+/* end of pq/pq_exec.c */
diff --git a/src/pq/pq_prepare.c b/src/pq/pq_prepare.c
new file mode 100644
index 000000000..f533cb564
--- /dev/null
+++ b/src/pq/pq_prepare.c
@@ -0,0 +1,92 @@
+/*
+  This file is part of GNUnet
+  Copyright (C) 2017 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 pq/pq_prepare.c
+ * @brief functions to connect to libpq (PostGres)
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include "gnunet_util_lib.h"
+#include "gnunet_pq_lib.h"
+
+
+/**
+ * Create a `struct GNUNET_PQ_PreparedStatement`.
+ *
+ * @param name name of the statement
+ * @param sql actual SQL statement
+ * @param num_args number of arguments in the statement
+ * @return initialized struct
+ */
+struct GNUNET_PQ_PreparedStatement
+GNUNET_PQ_make_prepare (const char *name,
+                        const char *sql,
+                        unsigned int num_args)
+{
+  struct GNUNET_PQ_PreparedStatement ps = {
+    .name = name,
+    .sql = sql,
+    .num_arguments = num_args
+  };
+
+  return ps;
+}
+
+
+/**
+ * Request creation of prepared statements @a ps from Postgres.
+ *
+ * @param connection connection to prepare the statements for
+ * @param ps #GNUNET_PQ_PREPARED_STATEMENT_END-terminated array of prepared
+ *            statements.
+ * @return #GNUNET_OK on success,
+ *         #GNUNET_SYSERR on error
+ */
+int
+GNUNET_PQ_prepare_statements (PGconn *connection,
+                              const struct GNUNET_PQ_PreparedStatement *ps)
+{
+  for (unsigned int i=0;NULL != ps[i].name;i++)
+  {
+    PGresult *ret;
+
+    GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
+                     "pq",
+                     "Preparing SQL statement `%s' as `%s'\n",
+                     ps[i].sql,
+                     ps[i].name);
+    ret = PQprepare (connection,
+                     ps[i].name,
+                     ps[i].sql,
+                     ps[i].num_arguments,
+                     NULL);
+    if (PGRES_COMMAND_OK != PQresultStatus (ret))
+    {
+      GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                       "pq",
+                       _("PQprepare (`%s' as `%s') failed with error: %s\n"),
+                       ps[i].sql,
+                       ps[i].name,
+                       PQerrorMessage (connection));
+      PQclear (ret);
+      return GNUNET_SYSERR;
+    }
+  }
+  return GNUNET_OK;
+}
+
+
+/* end of pq/pq_prepare.c */