Allow set and get last modified times on files.

PiperOrigin-RevId: 791407269

internal/platform/implementation/shared/BUILD

@@ -66,6 +66,7 @@ cc_library(
         "//internal/platform/implementation:types",
         "@com_google_absl//absl/memory",
         "@com_google_absl//absl/strings",
+        "@com_google_absl//absl/time",
     ],
 )
 

internal/platform/implementation/shared/file.cc

@@ -21,6 +21,8 @@
 
 #include "absl/memory/memory.h"
 #include "absl/strings/string_view.h"
+#include "absl/time/clock.h"
+#include "absl/time/time.h"
 #include "internal/platform/exception.h"
 
 namespace nearby {
@@ -94,9 +96,13 @@ Exception IOFile::Write(const ByteArray& data) {
   return {file_.good() ? Exception::kSuccess : Exception::kIo};
 }
 
-Exception IOFile::Flush() {
-  file_.flush();
-  return {file_.good() ? Exception::kSuccess : Exception::kIo};
+absl::Time IOFile::GetLastModifiedTime() const {
+  // TODO(ftsui): Implement this method.
+  return absl::Now();
+}
+
+void IOFile::SetLastModifiedTime(absl::Time last_modified_time) {
+  // TODO(ftsui): Implement this method.
 }
 
 }  // namespace shared

internal/platform/implementation/shared/file.h

@@ -15,11 +15,14 @@
 #ifndef PLATFORM_IMPL_SHARED_FILE_H_
 #define PLATFORM_IMPL_SHARED_FILE_H_
 
+#include <cstddef>
 #include <cstdint>
 #include <fstream>
+#include <memory>
 #include <string>
 
 #include "absl/strings/string_view.h"
+#include "absl/time/time.h"
 #include "internal/platform/exception.h"
 #include "internal/platform/implementation/input_file.h"
 #include "internal/platform/implementation/output_file.h"
@@ -42,7 +45,9 @@ class IOFile final : public api::InputFile, public api::OutputFile {
   Exception Close() override;
 
   Exception Write(const ByteArray& data) override;
-  Exception Flush() override;
+
+  absl::Time GetLastModifiedTime() const override;
+  void SetLastModifiedTime(absl::Time last_modified_time) override;
 
  private:
   explicit IOFile(const absl::string_view file_path, size_t size);