git-store-meta

git-store-meta is a light-weight tool for file metadata storing and applying for Git.

Features:

• Light dependency, cross-platform consistent behavior, desirable performance.

• Data files are in plain text format and can be easily revisioned, diffed, or manually modified as needed.

• Supported metadata: mtime, atime, mode, user, uid, group, gid, acl.

• Can store the metadata of git-revisioned files into a data file.

• Can apply the metadata stored in the data file to the working copy.

• Can update the metadata for changed files quickly.

• Can easily pick which metadata fields to store, update, or apply.

• Can determine whether to store, update, or apply directory metadata.

Dependency:

• git >= 1.7.2
• *nix platform with basic shell environment (required by Git)
• perl >=5.8 with built-in modules (required by Git)
• sort (any version) (required by Git)
• File::lchown module, or touch/chown -h (optional, for applying metadata to symbolic links)
• Linux::ACL module, or getfacl/setfacl -P (optional, for manipulating ACL metadata)

Usage:

Copy the git-store-meta.pl file to /path/to/your/repo/.git/hooks/, add executable permission to it, change the working directory to the Git working tree, and run .git/hooks/git-store-meta.pl.

For a centralized installation, place git-store-meta.pl at a desired path, add executable permission to it, add its directory to the PATH environment variable, and run git-store-meta.pl instead.

git-store-meta.pl can be run with the actions below:

Store

To store the metadata of all git-revisioned files, run:

git-store-meta.pl --store

And a data file named .git_store_meta (by default) will be created in your repo, git add it so that the metadata is revisioned.

The --fields (-f) option determines the fields to be stored. For example, the command:

git-store-meta.pl --store -f user,group,mode,mtime,atime

creates a data file with these fields:

<file> <type> <user> <group> <mode> <mtime> <atime>

The --directory (-d) option can be provided so that all directories under Git revision control have their metadata stored, too.

git-store-meta.pl --store -d

Oppositely, --no-directory can be provided to reverse the behavior.

Such settings as --fields and --directory will be recorded in the data file, and a future run of --store, --update, or --apply will load the recorded settings if not explicitly specified.

Apply

To apply (restore) all metadata recorded in the data file to working tree files, run:

git-store-meta.pl --apply

Fields can be selectively applied. For example, to apply mtime only:

git-store-meta.pl --apply -f mtime

Similarly, to not apply metadata for directories:

git-store-meta.pl --apply --no-directory

Furthermore, the --verbose (-v) option can be used to inform what exactly are being applied.

An --apply can not be run when the working tree or index is dirty, since the data is in an inconsistent state in such case and the apply could be an irreversible mistake. The --force option can be added to skip the check and force the applying.

Update

After a --store and commit, --update can be run to update metadata only for changed files and directories, which is much faster than to re-scan all revisioned ones:

git-store-meta.pl --update

Note that files or directories not considered changed by Git are not updated, even if their metadata have been changed, and a --store is required to record their metadata changes in such cases. Though, conversely, this avoids unintentional metadata changes from being included, and could be preferable in many cases.

Install

To automatically store metadata before a commit and restore metadata after a checkout or merge for files, run:

git-store-meta.pl --install

to generate pre-commit, post-checkout, and post-merge hooks for the current Git repo. Of course you can modify the hooks afterwards to fit your needs better.

Note that the installation is skipped to avoid a dangerous overwrite if there are existing hooks. In this case you can rename the existing hook files, run the installation again, and merge the hook contents manually. The --force option can be added to overwrite existing hooks if desired.

Note that certain advanced git operations are not covered by hooks. For example, no hook is run after a successful git reset --hard, git rebase, or git filter-branch. Likewise, no hook is run in the submodule repositories after a successful git submodule update. An --apply must be run manually in such cases.

Help

For more available options and details, run:

git-store-meta.pl --help

Caveats:

• git-store-meta does not record the time more than seconds precision, as it's not supported widely enough and many systems simply ignore it.

• git-store-meta is bound to a git repository. If the git directory or the working tree directory cannot be automatically determined, provide them explicitly to get it work. For example, to apply metadata for files checked out from a bare repo /path/to/foo to current directory /path/to/bar:

  GIT_DIR=../foo GIT_WORK_TREE=. git-store-meta.pl --apply