Re: [PATCH 04/23] fsmonitor: introduce `core.useBuiltinFSMonitor` to call the daemon via IPC
From: Derrick Stolee <hidden>
Date: 2021-04-26 14:56:57
On 4/1/21 11:40 AM, Johannes Schindelin via GitGitGadget wrote:> @@ -2515,6 +2515,11 @@ int git_config_get_max_percent_split_change(void)
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int repo_config_get_fsmonitor(struct repository *r) { + if (r->settings.use_builtin_fsmonitor > 0) {
Don't forget to run prepare_repo_settings(r) first.
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+ core_fsmonitor = "(built-in daemon)"; + return 1; + } +
I found this odd, assigning a string to core_fsmonitor that would definitely cause a problem trying to execute it as a hook. I wondered the need for it at all, but found that there are several places in the FS Monitor subsystem that use core_fsmonitor as if it was a boolean, indicating whether or not the feature is enabled at all. A cleaner way to handle this would be to hide the data behind a helper method, say "fsmonitor_enabled()" that could then check a value on the repository (or index) and store the hook value as a separate value that is only used by the hook-based implementation. It's probably a good idea to do that cleanup now, before we find on accident that we missed a gap and start trying to run this bogus string as a hook invocation.
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-static int query_fsmonitor(int version, const char *last_update, struct strbuf *query_result) +static int query_fsmonitor(int version, struct index_state *istate, struct strbuf *query_result) { + struct repository *r = istate->repo ? istate->repo : the_repository; + const char *last_update = istate->fsmonitor_last_update; struct child_process cp = CHILD_PROCESS_INIT; int result; if (!core_fsmonitor) return -1;
Here is an example of it being used as a boolean.
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+ if (r->settings.use_builtin_fsmonitor > 0) { +#ifdef HAVE_FSMONITOR_DAEMON_BACKEND + return fsmonitor_ipc__send_query(last_update, query_result); +#else + /* Fake a trivial response. */ + warning(_("fsmonitor--daemon unavailable; falling back")); + strbuf_add(query_result, "/", 2); + return 0; +#endif
This seems like a case where the helper fsmonitor_ipc__is_supported() could be used instead of compile-time macros. (I think this is especially true when we consider the future of the feature on Linux and the possibility of the same compiled code needing to check run-time properties of the platform for compatibility.)
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--- a/repo-settings.c +++ b/repo-settings.c@@ -58,6 +58,9 @@ void prepare_repo_settings(struct repository *r) r->settings.core_multi_pack_index = value; UPDATE_DEFAULT_BOOL(r->settings.core_multi_pack_index, 1); + if (!repo_config_get_bool(r, "core.usebuiltinfsmonitor", &value) && value) + r->settings.use_builtin_fsmonitor = 1; +
Follows the patterns of repo settings. Good.