api for bp type check (pytorch#1017)

Summary:
Pull Request resolved: pytorch#1017

create an api to check if forwarded file is a bp file.

Reviewed By: tarun292

Differential Revision: D50433020

fbshipit-source-id: 44a81518375527b661555411b89249dca81d55bf

util/bundled_program_verification.cpp

@@ -344,8 +344,7 @@ __ET_NODISCARD Error GetProgramData(
     size_t file_data_len,
     const void** out_program_data,
     size_t* out_program_data_len) {
-  if (bundled_program_flatbuffer::BundledProgramBufferHasIdentifier(
-          file_data)) {
+  if (IsBundledProgram(file_data)) {
     auto program_bundled =
         bundled_program_flatbuffer::GetBundledProgram(file_data);
     *out_program_data = program_bundled->program()->data();
@@ -360,6 +359,11 @@ __ET_NODISCARD Error GetProgramData(
   return Error::Ok;
 }
 
+bool IsBundledProgram(void* file_data) {
+  return bundled_program_flatbuffer::BundledProgramBufferHasIdentifier(
+      file_data);
+}
+
 } // namespace util
 } // namespace executor
 } // namespace torch

util/bundled_program_verification.h

@@ -85,6 +85,15 @@ __ET_NODISCARD Error GetProgramData(
     const void** out_program_data,
     size_t* out_program_data_len);
 
+/**
+ * Checks whether the given file is a bundled program.
+ *
+ * @param[in] file_data The contents of the given file.
+ *
+ * @returns true if the given file is a bundled program, false otherwise
+ */
+bool IsBundledProgram(void* file_data);
+
 } // namespace util
 } // namespace executor
 } // namespace torch