Move code from key rotation helpers into the function

Breaking these particular snippets out as separate functions did not
improve readability and was only done because they use to be called from
multiple locations.

This change has already been done in the WAL key code.

contrib/pg_tde/src/access/pg_tde_tdemap.c

@@ -93,8 +93,6 @@ static bool pg_tde_read_one_map_entry(int fd, TDEMapEntry *map_entry, off_t *off
 
 #ifndef FRONTEND
 static void pg_tde_write_one_map_entry(int fd, const TDEMapEntry *map_entry, off_t *offset, const char *db_map_path);
-static int	keyrotation_init_file(const TDESignedPrincipalKeyInfo *signed_key_info, char *rotated_filename, const char *filename, off_t *curr_pos);
-static void finalize_key_rotation(const char *path_old, const char *path_new);
 static int	pg_tde_file_header_write(const char *tde_filename, int fd, const TDESignedPrincipalKeyInfo *signed_key_info, off_t *bytes_written);
 static void pg_tde_initialize_map_entry(TDEMapEntry *map_entry, const TDEPrincipalKey *principal_key, const RelFileLocator *rlocator, const InternalKey *rel_key_data);
 static int	pg_tde_open_file_write(const char *tde_filename, const TDESignedPrincipalKeyInfo *signed_key_info, bool truncate, off_t *curr_pos);
@@ -243,33 +241,6 @@ pg_tde_free_key_map_entry(const RelFileLocator rlocator)
 	LWLockRelease(tde_lwlock_enc_keys());
 }
 
-/*
- * Accepts the unrotated filename and returns the rotation temp
- * filename. Both the strings are expected to be of the size
- * MAXPGPATH.
- *
- * No error checking by this function.
- */
-static File
-keyrotation_init_file(const TDESignedPrincipalKeyInfo *signed_key_info, char *rotated_filename, const char *filename, off_t *curr_pos)
-{
-	/*
-	 * Set the new filenames for the key rotation process - temporary at the
-	 * moment
-	 */
-	snprintf(rotated_filename, MAXPGPATH, "%s.r", filename);
-
-	/* Create file, truncate if the rotate file already exits */
-	return pg_tde_open_file_write(rotated_filename, signed_key_info, true, curr_pos);
-}
-
-static void
-finalize_key_rotation(const char *path_old, const char *path_new)
-{
-	durable_unlink(path_old, ERROR);
-	durable_rename(path_new, path_old, ERROR);
-}
-
 /*
  * Rotate keys and generates the WAL record for it.
  */
@@ -291,9 +262,10 @@ pg_tde_perform_rotate_key(TDEPrincipalKey *principal_key, TDEPrincipalKey *new_p
 	pg_tde_sign_principal_key_info(&new_signed_key_info, new_principal_key);
 
 	pg_tde_set_db_file_path(principal_key->keyInfo.databaseId, old_path);
+	snprintf(new_path, MAXPGPATH, "%s.r", old_path);
 
 	old_fd = pg_tde_open_file_read(old_path, false, &old_curr_pos);
-	new_fd = keyrotation_init_file(&new_signed_key_info, new_path, old_path, &new_curr_pos);
+	new_fd = pg_tde_open_file_write(new_path, &new_signed_key_info, true, &new_curr_pos);
 
 	/* Read all entries until EOF */
 	while (1)
@@ -329,7 +301,8 @@ pg_tde_perform_rotate_key(TDEPrincipalKey *principal_key, TDEPrincipalKey *new_p
 	 * Do the final steps - replace the current _map with the file with new
 	 * data
 	 */
-	finalize_key_rotation(old_path, new_path);
+	durable_unlink(old_path, ERROR);
+	durable_rename(new_path, old_path, ERROR);
 
 	/*
 	 * We do WAL writes past the event ("the write behind logging") rather