Add tests for loading the catalog

pglablib/CMakeLists.txt

@@ -21,6 +21,7 @@ add_library(pglablib STATIC
     catalog/PgIndexContainer.cpp
     catalog/PgConstraint.cpp
     catalog/PgConstraintContainer.cpp
+    catalog/PgDatabaseSizes.cpp
     ParamListJson.cpp
     ParamListModel.cpp
     sqlite/SQLiteConnection.cpp
@@ -95,6 +96,7 @@ add_library(pglablib STATIC
     catalog/PgIndexContainer.h
     catalog/PgConstraint.h
     catalog/PgConstraintContainer.h
+    catalog/PgDatabaseSizes.h
     ParamListJson.h
     ParamListModel.h
     sqlite/SQLiteConnection.h

pglablib/catalog/PgDatabaseSizes.cpp

@@ -0,0 +1,25 @@
+#include "PgDatabaseSizes.h"
+
+#include "Pgsql_Result.h"
+
+PgDatabaseSizes loadDatabaseSizes(Pgsql::Connection &connection)
+{
+	std::string q =
+		"SELECT pg_database.oid, "
+		"  case when has_database_privilege(current_role, pg_database.oid, \n"
+		"    'connect') then pg_database_size(pg_database.oid) else -1 end \n"
+		"FROM pg_database";
+
+	Pgsql::Result sizesResult = connection.query(q.c_str());
+
+	PgDatabaseSizes result;
+	result.reserve(sizesResult.rows());
+	for (auto& row : sizesResult)
+	{
+		PgDatabaseSize ds;
+		ds.oid = row.get(0);
+		ds.totalBytes = row.get(1);
+		result.push_back(ds);
+	}
+	return result;
+}

pglablib/catalog/PgDatabaseSizes.h

@@ -0,0 +1,25 @@
+#ifndef PGDATABASESIZES_H
+#define PGDATABASESIZES_H
+
+#include "Pgsql_Connection.h"
+#include <libpq-fe.h>
+#include <cstdint>
+#include <vector>
+
+class PgDatabaseSize {
+public:
+	Oid oid;
+	int64_t totalBytes;
+
+	PgDatabaseSize()
+		: oid(InvalidOid)
+		, totalBytes(-1)
+	{}
+};
+
+using PgDatabaseSizes = std::vector<PgDatabaseSize>;
+
+/// Returns the size of every database. The size is -1 when the current role has no CONNECT privilege.
+PgDatabaseSizes loadDatabaseSizes(Pgsql::Connection &connection);
+
+#endif // PGDATABASESIZES_H