adding libgnunetpostgres for shared postgres functionality between postgres datastore/datacache backends

2 files changed, 214 insertions, 0 deletions

diff --git a/src/postgres/Makefile.am b/src/postgres/Makefile.am
new file mode 100644
index 000000000..0b3be5e2b
--- /dev/null
+++ b/src/postgres/Makefile.am
@@ -0,0 +1,20 @@
+INCLUDES = -I$(top_srcdir)/src/include
+
+if MINGW
+  WINFLAGS = -Wl,--no-undefined -Wl,--export-all-symbols
+endif
+
+if USE_COVERAGE
+  AM_CFLAGS = --coverage
+endif
+
+lib_LTLIBRARIES = libgnunetpostgres.la
+
+libgnunetpostgres_la_SOURCES = \
+  postgres.c
+libgnunetpostgres_la_LIBADD = -lpq \
+ $(top_builddir)/src/util/libgnunetutil.la  
+libgnunetpostgres_la_LDFLAGS = \
+ $(GN_LIB_LDFLAGS) \
+  -version-info 0:0:0
+
diff --git a/src/postgres/postgres.c b/src/postgres/postgres.c
new file mode 100644
index 000000000..c6b9a5aa6
--- /dev/null
+++ b/src/postgres/postgres.c
@@ -0,0 +1,194 @@
+/*
+     This file is part of GNUnet
+     (C) 2009, 2010, 2012 Christian Grothoff (and other contributing authors)
+
+     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, write to the
+     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+     Boston, MA 02111-1307, USA.
+*/
+/**
+ * @file postgres/postgres.c
+ * @brief library to help with access to a Postgres database
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include "gnunet_postgres_lib.h"
+
+
+/**
+ * Check if the result obtained from Postgres has
+ * the desired status code.  If not, log an error, clear the
+ * result and return GNUNET_SYSERR.
+ *
+ * @param dbh database handle
+ * @param ret return value from database operation to check
+ * @param expected_status desired status
+ * @param command description of the command that was run
+ * @param args arguments given to the command 
+ * @param filename name of the source file where the command was run
+ * @param line line number in the source file
+ * @return GNUNET_OK if the result is acceptable
+ */
+int
+GNUNET_POSTGRES_check_result_ (PGconn *dbh, PGresult * ret, int expected_status,
+                              const char *command, const char *args, const char *filename,
+                              int line)
+{
+  if (ret == NULL)
+  {
+    GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                     "postgres",
+                     "Postgres failed to allocate result for `%s:%s' at %s:%d\n",
+                     command, args, filename, line);
+    return GNUNET_SYSERR;
+  }
+  if (PQresultStatus (ret) != expected_status)
+  {
+    GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                     "postgres",
+                     _("`%s:%s' failed at %s:%d with error: %s"), command, args,
+                     filename, line, PQerrorMessage (dbh));
+    PQclear (ret);
+    return GNUNET_SYSERR;
+  }
+  return GNUNET_OK;
+}
+
+
+/**
+ * Run simple SQL statement (without results).
+ *
+ * @param dbh database handle
+ * @param sql statement to run
+ * @param filename filename for error reporting
+ * @param line code line for error reporting 
+ * @return GNUNET_OK on success
+ */
+int
+GNUNET_POSTGRES_exec_ (PGconn *dbh, const char *sql,
+                      const char *filename,
+                      int line)
+{
+  PGresult *ret;
+
+  ret = PQexec (dbh, sql);
+  if (GNUNET_OK !=
+      GNUNET_POSTGRES_check_result_ (dbh, ret, PGRES_COMMAND_OK, "PQexec", sql, filename, line))
+    return GNUNET_SYSERR;
+  PQclear (ret);
+  return GNUNET_OK;
+}
+
+
+/**
+ * Prepare SQL statement.
+ *
+ * @param dbh database handle
+ * @param name name for the prepared SQL statement
+ * @param sql SQL code to prepare
+ * @param nparams number of parameters in sql
+ * @param filename filename for error reporting
+ * @param line code line for error reporting
+ * @return GNUNET_OK on success
+ */
+int
+GNUNET_POSTGRES_prepare_ (PGconn *dbh, const char *name, const char *sql,
+                         int nparms, const char *filename, int line)
+{
+  PGresult *ret;
+
+  ret = PQprepare (dbh, name, sql, nparms, NULL);
+  if (GNUNET_OK !=
+      GNUNET_POSTGRES_check_result_ (dbh, ret, PGRES_COMMAND_OK, "PQprepare", sql, filename, line))
+    return GNUNET_SYSERR;
+  PQclear (ret);
+  return GNUNET_OK;
+}
+
+
+/**
+ * Connect to a postgres database
+ *
+ * @param cfg configuration
+ * @param section configuration section to use to get Postgres configuration options
+ * @return the postgres handle
+ */
+PGconn *
+GNUNET_POSTGRES_connect (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 = PQconnectdb (conninfo == NULL ? "" : conninfo);
+  GNUNET_free_non_null (conninfo);
+  if (NULL == dbh)
+  {
+    /* FIXME: warn about out-of-memory? */
+    return NULL;
+  }
+  if (PQstatus (dbh) != CONNECTION_OK)
+  {
+    GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR, "postgres",
+                     _("Unable to initialize Postgres: %s"),
+                     PQerrorMessage (dbh));
+    PQfinish (dbh);
+    return NULL;
+  }
+  return dbh;
+}
+
+
+/**
+ * Delete the row identified by the given rowid (qid
+ * in postgres).
+ *
+ * @param database handle
+ * @param stmt name of the prepared statement
+ * @param rowid which row to delete
+ * @return GNUNET_OK on success
+ */
+int
+GNUNET_POSTGRES_delete_by_rowid (PGconn *dbh,
+                                 const char *stmt,
+                                 uint32_t rowid)
+{
+  uint32_t brow = htonl (rowid);
+  const char *paramValues[] = { (const char *) &brow };
+  int paramLengths[] = { sizeof (brow) };
+  const int paramFormats[] = { 1 };
+  PGresult *ret;
+
+  ret =
+    PQexecPrepared (dbh, stmt, 1, paramValues, paramLengths,
+                      paramFormats, 1);
+  if (GNUNET_OK !=
+      GNUNET_POSTGRES_check_result_ (dbh, ret, PGRES_COMMAND_OK, "PQexecPrepared", "delrow",
+                                    __FILE__,
+                                    __LINE__))
+  {
+    return GNUNET_SYSERR;
+  }
+  PQclear (ret);
+  return GNUNET_OK;
+}
+
+
+/* end of postgres.c */