git/fsmonitor.h
Johannes Schindelin be6b65b91b fsmonitor: avoid overriding cache_changed bits
As of e636a7b4d0 (read-cache: be specific what part of the index has
changed, 2014-06-13), the paradigm `cache_changed = 1` fell out of
fashion and it became a bit field instead.

This is important because some bits have specific meaning and should not
be unset without care, e.g. `SPLIT_INDEX_ORDERED`.

However, b5a8169752 (mark_fsmonitor_valid(): mark the index as changed
if needed, 2019-05-24) did use the `cache_changed` attribute as if it
were a Boolean instead of a bit field.

That not only would override the `SPLIT_INDEX_ORDERED` bit when marking
index entries as valid via the FSMonitor, but worse: it would set the
`SOMETHING_OTHER` bit (whose value is 1). This means that Git would
unnecessarily force a full index to be written out when a split index
was asked for.

Let's instead use the bit that is specifically intended to indicate
FSMonitor-triggered changes, allowing the split-index feature to work as
designed.

Noticed-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-27 09:40:39 -07:00

114 lines
3.8 KiB
C

#ifndef FSMONITOR_H
#define FSMONITOR_H
#include "cache.h"
#include "dir.h"
#include "fsmonitor-settings.h"
extern struct trace_key trace_fsmonitor;
/*
* Read the fsmonitor index extension and (if configured) restore the
* CE_FSMONITOR_VALID state.
*/
int read_fsmonitor_extension(struct index_state *istate, const void *data, unsigned long sz);
/*
* Fill the fsmonitor_dirty ewah bits with their state from the index,
* before it is split during writing.
*/
void fill_fsmonitor_bitmap(struct index_state *istate);
/*
* Write the CE_FSMONITOR_VALID state into the fsmonitor index
* extension. Reads from the fsmonitor_dirty ewah in the index.
*/
void write_fsmonitor_extension(struct strbuf *sb, struct index_state *istate);
/*
* Add/remove the fsmonitor index extension
*/
void add_fsmonitor(struct index_state *istate);
void remove_fsmonitor(struct index_state *istate);
/*
* Add/remove the fsmonitor index extension as necessary based on the current
* core.fsmonitor setting.
*/
void tweak_fsmonitor(struct index_state *istate);
/*
* Run the configured fsmonitor integration script and clear the
* CE_FSMONITOR_VALID bit for any files returned as dirty. Also invalidate
* any corresponding untracked cache directory structures. Optimized to only
* run the first time it is called.
*/
void refresh_fsmonitor(struct index_state *istate);
/*
* Does the received result contain the "trivial" response?
*/
int fsmonitor_is_trivial_response(const struct strbuf *query_result);
/*
* Check if refresh_fsmonitor has been called at least once.
* refresh_fsmonitor is idempotent. Returns true if fsmonitor is
* not enabled (since the state will be "fresh" w/ CE_FSMONITOR_VALID unset)
* This version is useful for assertions
*/
static inline int is_fsmonitor_refreshed(const struct index_state *istate)
{
enum fsmonitor_mode fsm_mode = fsm_settings__get_mode(istate->repo);
return fsm_mode <= FSMONITOR_MODE_DISABLED ||
istate->fsmonitor_has_run_once;
}
/*
* Set the given cache entries CE_FSMONITOR_VALID bit. This should be
* called any time the cache entry has been updated to reflect the
* current state of the file on disk.
*
* However, never mark submodules as valid. When commands like "git
* status" run they might need to recurse into the submodule (using a
* child process) to get a summary of the submodule state. We don't
* have (and don't want to create) the facility to translate every
* FS event that we receive and that happens to be deep inside of a
* submodule back to the submodule root, so we cannot correctly keep
* track of this bit on the gitlink directory. Therefore, we never
* set it on submodules.
*/
static inline void mark_fsmonitor_valid(struct index_state *istate, struct cache_entry *ce)
{
enum fsmonitor_mode fsm_mode = fsm_settings__get_mode(istate->repo);
if (fsm_mode > FSMONITOR_MODE_DISABLED &&
!(ce->ce_flags & CE_FSMONITOR_VALID)) {
if (S_ISGITLINK(ce->ce_mode))
return;
istate->cache_changed |= FSMONITOR_CHANGED;
ce->ce_flags |= CE_FSMONITOR_VALID;
trace_printf_key(&trace_fsmonitor, "mark_fsmonitor_clean '%s'", ce->name);
}
}
/*
* Clear the given cache entry's CE_FSMONITOR_VALID bit and invalidate
* any corresponding untracked cache directory structures. This should
* be called any time git creates or modifies a file that should
* trigger an lstat() or invalidate the untracked cache for the
* corresponding directory
*/
static inline void mark_fsmonitor_invalid(struct index_state *istate, struct cache_entry *ce)
{
enum fsmonitor_mode fsm_mode = fsm_settings__get_mode(istate->repo);
if (fsm_mode > FSMONITOR_MODE_DISABLED) {
ce->ce_flags &= ~CE_FSMONITOR_VALID;
untracked_cache_invalidate_path(istate, ce->name, 1);
trace_printf_key(&trace_fsmonitor, "mark_fsmonitor_invalid '%s'", ce->name);
}
}
#endif