Add helper functions for arrays

These will see more use in follow-up patches that adjust how
compression settings are stored in our catalog.

src/planner/expand_hypertable.c

@@ -44,20 +44,21 @@
 #include <utils/fmgrprotos.h>
 #include <utils/syscache.h>
 
-#include "chunk.h"
 #include "compat/compat.h"
+#include "chunk.h"
 #include "cross_module_fn.h"
-#include "extension.h"
 #include "extension_constants.h"
+#include "extension.h"
 #include "guc.h"
 #include "hypertable.h"
 #include "hypertable_restrict_info.h"
 #include "import/planner.h"
 #include "nodes/chunk_append/chunk_append.h"
-#include "partitioning.h"
 #include "partialize.h"
+#include "partitioning.h"
 #include "planner.h"
 #include "time_utils.h"
+#include "ts_catalog/array_utils.h"
 
 typedef struct CollectQualCtx
 {
@@ -992,7 +993,7 @@ get_explicit_chunks(CollectQualCtx *ctx, PlannerInfo *root, RelOptInfo *rel, Hyp
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("invalid number of array dimensions for chunks_in")));
 
-	chunk_id_arr_size = ArrayGetNItems(ARR_NDIM(chunk_id_arr), ARR_DIMS(chunk_id_arr));
+	chunk_id_arr_size = ts_array_length(chunk_id_arr);
 
 	if (chunk_id_arr_size == 0)
 		return NULL;

src/ts_catalog/CMakeLists.txt

@@ -1,4 +1,5 @@
 set(SOURCES
+    ${CMAKE_CURRENT_SOURCE_DIR}/array_utils.c
     ${CMAKE_CURRENT_SOURCE_DIR}/catalog.c
     ${CMAKE_CURRENT_SOURCE_DIR}/chunk_data_node.c
     ${CMAKE_CURRENT_SOURCE_DIR}/compression_chunk_size.c

src/ts_catalog/array_utils.c

@@ -0,0 +1,91 @@
+/*
+ * This file and its contents are licensed under the Apache License 2.0.
+ * Please see the included NOTICE for copyright information and
+ * LICENSE-APACHE for a copy of the license.
+ */
+#include <postgres.h>
+#include <utils/array.h>
+#include <utils/builtins.h>
+
+#include <debug_assert.h>
+#include "array_utils.h"
+
+extern TSDLLEXPORT int
+ts_array_length(ArrayType *arr)
+{
+	return ArrayGetNItems(ARR_NDIM(arr), ARR_DIMS(arr));
+}
+
+/*
+ * Array helper function for internal catalog arrays.
+ * These are not suitable for arbitrary dimension
+ * arrays but only for 1-dimensional arrays as we use
+ * them in our catalog.
+ */
+
+extern TSDLLEXPORT bool
+ts_array_is_member(ArrayType *arr, const char *name)
+{
+	bool ret = false;
+	Datum datum;
+	bool null;
+	if (!arr)
+		return ret;
+
+	Assert(ARR_NDIM(arr) == 1);
+
+	ArrayIterator it = array_create_iterator(arr, 0, NULL);
+	while (array_iterate(it, &datum, &null))
+	{
+		Assert(!null);
+		/*
+		 * Our internal catalog arrays should either be NULL or
+		 * have non-NULL members. During normal operation it should
+		 * never have NULL members. If we have NULL members either
+		 * the catalog is corrupted or some catalog tampering has
+		 * happened.
+		 */
+		Ensure(!null, "array element was NULL");
+		if (strncmp(TextDatumGetCString(datum), name, NAMEDATALEN) == 0)
+		{
+			ret = true;
+			break;
+		}
+	}
+
+	array_free_iterator(it);
+	return ret;
+}
+
+extern TSDLLEXPORT int
+ts_array_position(ArrayType *arr, const char *name)
+{
+	int pos = 0;
+	Datum datum;
+	bool null;
+	if (!arr)
+		return pos;
+
+	Assert(ARR_NDIM(arr) == 1);
+
+	ArrayIterator it = array_create_iterator(arr, 0, NULL);
+	while (array_iterate(it, &datum, &null))
+	{
+		pos++;
+		/*
+		 * Our internal catalog arrays should either be NULL or
+		 * have non-NULL members. During normal operation it should
+		 * never have NULL members. If we have NULL members either
+		 * the catalog is corrupted or some catalog tampering has
+		 * happened.
+		 */
+		Ensure(!null, "array element was NULL");
+		if (strncmp(TextDatumGetCString(datum), name, NAMEDATALEN) == 0)
+		{
+			break;
+		}
+	}
+
+	array_free_iterator(it);
+	return pos;
+}

src/ts_catalog/array_utils.h

@@ -0,0 +1,20 @@
+/*
+ * This file and its contents are licensed under the Apache License 2.0.
+ * Please see the included NOTICE for copyright information and
+ * LICENSE-APACHE for a copy of the license.
+ */
+#include <postgres.h>
+#include <utils/array.h>
+
+#include "export.h"
+
+/*
+ * Array helper function for internal catalog arrays.
+ * These are not suitable for arbitrary dimension
+ * arrays but only for 1-dimensional arrays as we use
+ * them in our catalog.
+ */
+
+extern TSDLLEXPORT int ts_array_length(ArrayType *arr);
+extern TSDLLEXPORT bool ts_array_is_member(ArrayType *arr, const char *name);
+extern TSDLLEXPORT int ts_array_position(ArrayType *arr, const char *name);

tsl/src/remote/dist_commands.c

@@ -23,6 +23,7 @@
 #include "errors.h"
 #include "deparse.h"
 #include "debug_point.h"
+#include "ts_catalog/array_utils.h"
 
 typedef struct DistPreparedStmt
 {
@@ -566,7 +567,7 @@ ts_dist_cmd_exec(PG_FUNCTION_ARGS)
 					 errmsg("invalid data nodes list"),
 					 errdetail("The array of data nodes cannot contain null values.")));
 
-		ndatanodes = ArrayGetNItems(ARR_NDIM(data_nodes), ARR_DIMS(data_nodes));
+		ndatanodes = ts_array_length(data_nodes);
 
 		if (ndatanodes == 0)
 			ereport(ERROR,