From d75a2de4e9a450269291a47593f2e50c37eca733 Mon Sep 17 00:00:00 2001
From: Christian Grothoff <christian@grothoff.org>
Date: Fri, 5 Feb 2016 22:24:10 +0000
Subject: creating libgnunetpq library

---
 src/pq/pq.c | 169 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 169 insertions(+)
 create mode 100644 src/pq/pq.c

(limited to 'src/pq/pq.c')

diff --git a/src/pq/pq.c b/src/pq/pq.c
new file mode 100644
index 000000000..fe796044e
--- /dev/null
+++ b/src/pq/pq.c
@@ -0,0 +1,169 @@
+/*
+  This file is part of GNUnet
+  Copyright (C) 2014, 2015, 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 pq/pq.c
+ * @brief helper functions for libpq (PostGres) interactions
+ * @author Sree Harsha Totakura <sreeharsha@totakura.in>
+ * @author Florian Dold
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include <gnunet/gnunet_util_lib.h>
+#include "gnunet_pq_lib.h"
+
+
+/**
+ * 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)
+{
+  unsigned int len;
+  unsigned int i;
+
+  /* count the number of parameters */
+  len = 0;
+  for (i=0;0 != params[i].num_params;i++)
+    len += params[i].num_params;
+
+  /* new scope to allow stack allocation without alloca */
+  {
+    /* Scratch buffer for temporary storage */
+    void *scratch[len];
+    /* Parameter array we are building for the query */
+    void *param_values[len];
+    int param_lengths[len];
+    int param_formats[len];
+    unsigned int off;
+    /* How many entries in the scratch buffer are in use? */
+    unsigned int soff;
+    PGresult *res;
+    int ret;
+
+    off = 0;
+    soff = 0;
+    for (i=0;0 != params[i].num_params;i++)
+    {
+      const struct GNUNET_PQ_QueryParam *x = &params[i];
+
+      ret = x->conv (x->conv_cls,
+		     x->data,
+		     x->size,
+		     &param_values[off],
+		     &param_lengths[off],
+		     &param_formats[off],
+		     x->num_params,
+		     &scratch[soff],
+		     len - soff);
+      if (ret < 0)
+      {
+	for (off = 0; off < soff; off++)
+	  GNUNET_free (scratch[off]);
+	return NULL;
+      }
+      soff += ret;
+      off += x->num_params;
+    }
+    GNUNET_assert (off == len);
+    res = PQexecPrepared (db_conn,
+                          name,
+                          len,
+                          (const char **) param_values,
+                          param_lengths,
+                          param_formats,
+                          1);
+    for (off = 0; off < soff; off++)
+      GNUNET_free (scratch[off]);
+    return res;
+  }
+}
+
+
+/**
+ * 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)
+{
+  unsigned int i;
+
+  for (i=0; NULL != rs[i].conv; i++)
+    if (NULL != rs[i].cleaner)
+      rs[i].cleaner (rs[i].cls,
+		     rs[i].dst);
+}
+
+
+/**
+ * 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)
+{
+  unsigned int i;
+  int had_null = GNUNET_NO;
+  int ret;
+
+  for (i=0; NULL != rs[i].conv; i++)
+  {
+    struct GNUNET_PQ_ResultSpec *spec;
+
+    spec = &rs[i];
+    ret = spec->conv (spec->cls,
+		      result,
+		      row,
+		      spec->fname,
+		      &spec->dst_size,
+		      spec->dst);
+    if (GNUNET_SYSERR == ret)
+      return GNUNET_SYSERR;
+    if (GNUNET_NO == ret)
+    {
+      had_null = GNUNET_YES;
+      continue;
+    }
+    if (NULL != spec->result_size)
+      *spec->result_size = spec->dst_size;
+  }
+  if (GNUNET_YES == had_null)
+    return GNUNET_NO;
+  return GNUNET_OK;
+}
+
+
+/* end of pq/pq.c */
-- 
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