WindowsFile: Allow Fluentd to respect DeletePending

This is a Fluentd port of the following fix: fluent-bit#2027 Windows has a concept of DeletePending, which means "DeleteFile() was called on that file. NTFS will remove this file once everyone close the handlers for it". This patch teaches Fluentd to respect the DeletePending flag. Signed-off-by: Fujimoto Seiji <[email protected]>
fluent · Jul 13, 2021 · f61c08c · f61c08c
1 parent f73c601
commit f61c08c
Showing 1 changed file with 22 additions and 0 deletions.
diff --git a/lib/fluent/plugin/file_wrapper.rb b/lib/fluent/plugin/file_wrapper.rb
@@ -155,7 +155,29 @@ def ino
       by_handle_file_information.unpack("I11Q1")[11] # fileindex
     end
 
+    # DeletePending is a Windows-specific file state that roughly means
+    # "this file is queued for deletion, so close any open handlers"
+    #
+    # This flag can be retrieved via GetFileInformationByHandleEx().
+    #
+    # https://docs.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-getfileinformationbyhandleex
+    #
+    def delete_pending
+      file_standard_info = 0x01
+      bufsize = 1024
+      buf = '\0' * bufsize
+
+      unless GetFileInformationByHandleEx.call(@file_handle, file_standard_info, buf, bufsize)
+        return false
+      end
+
+      return buf.unpack("QQICC")[3] != 0
+    end
+
+    private :delete_pending
+
     def stat
+      raise Errno::ENOENT if delete_pending
       s = File.stat(@path)
       s.instance_variable_set :@ino, self.ino
       def s.ino; @ino; end