• Ben Peart's avatar
    fsmonitor: teach git to optionally utilize a file system monitor to speed up... · 883e248b
    Ben Peart authored
    fsmonitor: teach git to optionally utilize a file system monitor to speed up detecting new or changed files.
    
    When the index is read from disk, the fsmonitor index extension is used
    to flag the last known potentially dirty index entries. The registered
    core.fsmonitor command is called with the time the index was last
    updated and returns the list of files changed since that time. This list
    is used to flag any additional dirty cache entries and untracked cache
    directories.
    
    We can then use this valid state to speed up preload_index(),
    ie_match_stat(), and refresh_cache_ent() as they do not need to lstat()
    files to detect potential changes for those entries marked
    CE_FSMONITOR_VALID.
    
    In addition, if the untracked cache is turned on valid_cached_dir() can
    skip checking directories for new or changed files as fsmonitor will
    invalidate the cache only for those directories that have been
    identified as having potential changes.
    
    To keep the CE_FSMONITOR_VALID state accurate during git operations;
    when git updates a cache entry to match the current state on disk,
    it will now set the CE_FSMONITOR_VALID bit.
    
    Inversely, anytime git changes a cache entry, the CE_FSMONITOR_VALID bit
    is cleared and the corresponding untracked cache directory is marked
    invalid.
    Signed-off-by: default avatarBen Peart <benpeart@microsoft.com>
    Signed-off-by: default avatarJunio C Hamano <gitster@pobox.com>
    883e248b
preload-index.c 2.73 KB