Blenlib: introduce a UUID type

Add `BLI_uuid` and `DNA_uuid_types.h` with a UUID implementation
following RFC4122 (https://datatracker.ietf.org/doc/html/rfc4122.html).

The following features are implemented:
- A struct of 128 bits that can be used in DNA definitions.
- Generation of version 4 UUIDs, that is, purely random ones.
- UUID equality function.
- String to UUID and UUID to string conversion functions that are
  compatible with RFC4122.
- C++ stream operator that outputs the UUID as string.

This UUID will be used by the asset system, to uniquely identify asset
catalogs.

Reviewed By: Severin, jacqueslucke

Differential Revision: https://developer.blender.org/D12475

1 files changed, 67 insertions, 0 deletions

diff --git a/source/blender/blenlib/BLI_uuid.h b/source/blender/blenlib/BLI_uuid.h
new file mode 100644
index 00000000000..15350849f67
--- /dev/null
+++ b/source/blender/blenlib/BLI_uuid.h
@@ -0,0 +1,67 @@
+/*
+ * This program 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 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program 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 this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#pragma once
+
+/** \file
+ * \ingroup bli
+ *
+ * Functions for generating and handling UUID structs according to RFC4122.
+ *
+ * Note that these are true UUIDs, not to be confused with the "session uuid" defined in
+ * `BLI_session_uuid.h`.
+ */
+#include "DNA_uuid_types.h"
+
+#include "BLI_compiler_attrs.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * UUID generator for random (version 4) UUIDs. See RFC4122 section 4.4.
+ * This function is not thread-safe. */
+UUID BLI_uuid_generate_random(void);
+
+/** Compare two UUIDs, return true iff they are equal. */
+bool BLI_uuid_equal(UUID uuid1, UUID uuid2);
+
+/**
+ * Format UUID as string.
+ * The buffer must be at least 37 bytes (36 bytes for the UUID + terminating 0).
+ */
+void BLI_uuid_format(char *buffer, UUID uuid) ATTR_NONNULL();
+
+/**
+ * Parse a string as UUID.
+ * The string MUST be in the format xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx,
+ * as produced by #BLI_uuid_format().
+ *
+ * Return true if the string could be parsed, and false otherwise. In the latter case, the UUID may
+ * have been partially updated.
+ */
+bool BLI_uuid_parse_string(UUID *uuid, const char *buffer) ATTR_NONNULL();
+
+#ifdef __cplusplus
+}
+
+#  include <ostream>
+
+/** Output the UUID as formatted ASCII string, see #BLI_uuid_format(). */
+std::ostream &operator<<(std::ostream &stream, UUID uuid);
+
+#endif