1720 - expose FAISS version field to c_api (#3635)

Summary:
Pull Request resolved: #3635

Add a util function to return the version in the c api.

Differential Revision: D59817407

Author: bshethmeta

faiss/utils/utils.cpp

@@ -7,6 +7,7 @@
 
 // -*- c++ -*-
 
+#include <faiss/Index.h>
 #include <faiss/utils/utils.h>
 
 #include <cassert>
@@ -129,6 +130,14 @@ std::string get_compile_options() {
     return options;
 }
 
+std::string get_version() {
+    std::string version = std::to_string(FAISS_VERSION_MAJOR) + "." +
+            std::to_string(FAISS_VERSION_MINOR) + "." +
+            std::to_string(FAISS_VERSION_PATCH);
+
+    return version;
+}
+
 #ifdef _MSC_VER
 double getmillisecs() {
     LARGE_INTEGER ts;

faiss/utils/utils.h

@@ -37,6 +37,9 @@ std::string get_compile_options();
  * Get some stats about the system
  **************************************************/
 
+// Expose FAISS version as a string
+std::string get_version();
+
 /// ms elapsed since some arbitrary epoch
 double getmillisecs();
 

tests/test_utils.cpp

@@ -0,0 +1,14 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#include <gtest/gtest.h>
+
+#include <faiss/utils/utils.h>
+
+TEST(TestUtils, get_version) {
+    EXPECT_EQ("1.8.0", faiss::get_version());
+}