Re: [Libguestfs] [RFC nbdkit PATCH 4/5] file: Utilize nbdkit_string_intern

Instead of needing to provide .unload, we can let nbdkit manage the lifetime for us. However, if we like this approach, it may be wiser to introduce new variants of nbdkit_realpath/absolute_path which return const char * already intern'd. Signed-off-by: Eric Blake <eblake(a)redhat.com&gt; --- See the cover letter: if we like this, there are several other plugins that could also reduce their .unload, or maybe we want to add convenience functions to make the combo 'nbdkit_realpath/nbdkit_string_intern' simpler. plugins/file/file.c | 20 ++++++-------------- 1 file changed, 6 insertions(+), 14 deletions(-) diff --git a/plugins/file/file.c b/plugins/file/file.c index 08418194..6a0aad93 100644 --- a/plugins/file/file.c +++ b/plugins/file/file.c @@ -64,8 +64,8 @@ #define fdatasync fsync #endif -static char *filename = NULL; -static char *directory = NULL; +static const char *filename = NULL; +static const char *directory = NULL; /* posix_fadvise mode: -1 = don't set it, or POSIX_FADV_*. */ static int fadvise_mode = @@ -91,13 +91,6 @@ is_enotsup (int err) return err == ENOTSUP || err == EOPNOTSUPP; } -static void -file_unload (void) -{ - free (filename); - free (directory); -} - /* Called for each key=value passed on the command line. This plugin * only accepts file=<filename> and dir=<dirname>, where exactly * one is required. @@ -111,15 +104,15 @@ file_config (const char *key, const char *value) * existence checks to the last possible moment. */ if (strcmp (key, "file") == 0) { - free (filename); - filename = nbdkit_realpath (value); + CLEANUP_FREE char *tmp = nbdkit_realpath (value); + filename = nbdkit_string_intern (tmp); if (!filename) return -1; } else if (strcmp (key, "directory") == 0 || strcmp (key, "dir") == 0) { - free (directory); - directory = nbdkit_realpath (value); + CLEANUP_FREE char *tmp = nbdkit_realpath (value); + directory = nbdkit_string_intern (value); if (!directory) return -1; } @@ -812,7 +805,6 @@ static struct nbdkit_plugin plugin = { .name = "file", .longname = "nbdkit file plugin", .version = PACKAGE_VERSION, - .unload = file_unload, .config = file_config, .config_complete = file_config_complete, .config_help = file_config_help, --

+ CLEANUP_FREE char *tmp = nbdkit_realpath (value); + directory = nbdkit_string_intern (value);