pq: added oid-by-name lookup API

NEWS: Added GNUNET_PQ_get_oid_by_name

3 files changed, 135 insertions, 1 deletions

diff --git a/src/include/gnunet_pq_lib.h b/src/include/gnunet_pq_lib.h
index edb0519b0..3b960df70 100644
--- a/src/include/gnunet_pq_lib.h
+++ b/src/include/gnunet_pq_lib.h
@@ -28,6 +28,7 @@
 
 #include <libpq-fe.h>
 #include <stdint.h>
+#include "gnunet_common.h"
 #include "gnunet_time_lib.h"
 #include "gnunet_util_lib.h"
 #include "gnunet_db_lib.h"
@@ -198,7 +199,7 @@ enum GNUNET_PQ_DataTypes
 };
 
 /**
- * Returns the oid for a given datatype
+ * Returns the oid for a given, basic datatype
  *
  * @param db The db-connection
  * @param typ the Datatype
@@ -210,6 +211,38 @@ GNUNET_PQ_get_oid (
   enum GNUNET_PQ_DataTypes typ);
 
 /**
+ * Returns the oid for a given datatype by name.
+ *
+ * @param db The db-connection
+ * @param name The name of the datatype
+ * @param[out] oid The OID of the datatype.
+ * @return GNUNET_OK when the datatype was found, GNUNET_SYSERR otherwise
+ */
+enum GNUNET_GenericReturnValue
+GNUNET_PQ_get_oid_by_name (
+  struct GNUNET_PQ_Context *db,
+  const char *name,
+  Oid *oid);
+
+
+/**
+ * The header for a postgresql array in binary format. note that this a
+ * simplified special case of the general structure (which contains pointers),
+ * as we only support one-dimensional arrays.
+ *
+ * Note that all values must be in network-byte-order.
+ */
+struct GNUNET_PQ_ArrayHeader_P
+{
+  uint32_t ndim;     /* number of dimensions. we only support ndim = 1 */
+  uint32_t has_null;
+  uint32_t oid;      /* oid of the elements */
+  uint32_t dim;      /* size of the array */
+  uint32_t lbound;   /* index value of first element in the db (default: 1). */
+} __attribute__((packed));
+
+
+/**
  * Generate query parameter for an array of bool in host byte order.
  *
  * @param num Number of elements in @a elements
diff --git a/src/pq/pq_connect.c b/src/pq/pq_connect.c
index f30f989ea..ba272bce4 100644
--- a/src/pq/pq_connect.c
+++ b/src/pq/pq_connect.c
@@ -430,6 +430,45 @@ GNUNET_PQ_get_oid (
 }
 
 
+enum GNUNET_GenericReturnValue
+GNUNET_PQ_get_oid_by_name (
+  struct GNUNET_PQ_Context *db,
+  const char *name,
+  Oid *oid)
+{
+  char *typname;
+  enum GNUNET_DB_QueryStatus qs;
+  struct GNUNET_PQ_QueryParam params[] = {
+    GNUNET_PQ_query_param_string (name),
+    GNUNET_PQ_query_param_end
+  };
+  struct GNUNET_PQ_ResultSpec rs[] = {
+    GNUNET_PQ_result_spec_string ("typname",
+                                  &typname),
+    GNUNET_PQ_result_spec_uint32 ("oid",
+                                  oid),
+    GNUNET_PQ_result_spec_end
+  };
+
+  GNUNET_assert (NULL != db);
+
+  /* Initialize to Oid(0) (= unknown) */
+  *oid = 0;
+
+  qs = GNUNET_PQ_eval_prepared_singleton_select (db,
+                                                 "gnunet_pq_get_oid_by_name",
+                                                 params,
+                                                 rs);
+  if (GNUNET_DB_STATUS_SUCCESS_ONE_RESULT != qs)
+    return GNUNET_SYSERR;
+
+  if (0 != strcasecmp (typname, name))
+    return GNUNET_SYSERR;
+
+  return GNUNET_OK;
+}
+
+
 void
 GNUNET_PQ_reconnect (struct GNUNET_PQ_Context *db)
 {
@@ -530,6 +569,33 @@ GNUNET_PQ_reconnect (struct GNUNET_PQ_Context *db)
     return;
   }
 
+  /* Prepare statement for OID lookup by name */
+  {
+    PGresult *res;
+
+    res = PQprepare (db->conn,
+                     "gnunet_pq_get_oid_by_name",
+                     "SELECT"
+                     " typname, oid"
+                     " FROM pg_type"
+                     " WHERE typname = $1"
+                     " LIMIT 1",
+                     1,
+                     NULL);
+    if (PGRES_COMMAND_OK != PQresultStatus (res))
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                  "Failed to run SQL statement prepare OID lookups: %s/%s\n",
+                  PQresultErrorMessage (res),
+                  PQerrorMessage (db->conn));
+      PQclear (res);
+      PQfinish (db->conn);
+      db->conn = NULL;
+      return;
+    }
+    PQclear (res);
+  }
+
   if (NULL != db->auto_suffix)
   {
     PGresult *res;
diff --git a/src/pq/test_pq.c b/src/pq/test_pq.c
index 69c986b6e..a20ff9ddd 100644
--- a/src/pq/test_pq.c
+++ b/src/pq/test_pq.c
@@ -554,6 +554,41 @@ main (int argc,
     GNUNET_PQ_disconnect (db);
     return ret;
   }
+
+  /* ensure oid lookup works */
+  {
+    enum GNUNET_GenericReturnValue ret;
+    Oid oid;
+
+    ret = GNUNET_PQ_get_oid_by_name (db, "int8", &oid);
+
+    if (GNUNET_OK != ret)
+    {
+      fprintf (stderr,
+               "Cannot lookup oid for int8: %s\n",
+               PQerrorMessage (db->conn));
+      GNUNET_break (0);
+      GNUNET_PQ_disconnect (db);
+      return 77; /* signal test was skipped */
+    }
+
+    PQexec (db->conn, "CREATE TYPE foo AS (foo int, bar int);");
+
+    ret = GNUNET_PQ_get_oid_by_name (db, "foo", &oid);
+    if (GNUNET_OK != ret)
+    {
+      fprintf (stderr,
+               "Cannot lookup oid for foo: %s\n",
+               PQerrorMessage (db->conn));
+      GNUNET_break (0);
+      GNUNET_PQ_disconnect (db);
+      return 77; /* signal test was skipped */
+    }
+
+    GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+                "got oid %d for type foo\n", oid);
+  }
+
   GNUNET_SCHEDULER_run (&sched_tests,
                         NULL);
   if (0 != ret)