mtime-travel

A small tool to save and restore the mtime attribute for files.

This can be useful for things like avoiding Rust rebuilds if the file contents didn't change, but the mtimes did, as Rust will rebuild based on mtimes (see https://github.com/rust-lang/cargo/issues/6529). A example where rebuilding like this is undesirable is pulling a project via git in CI, as that will alter the mtime values and therefore normally trigger a rebuild, even if you may already have cached the build artifacts from a prior CI run.

Usage

Saving

Usage: mtime-travel save [OPTIONS] <TARGET_DIR>

Arguments:
  <TARGET_DIR>  The location to recursively scan for files

Options:
  -m, --mtime-file <MTIME_FILE>  The location to a file to save the current mtimes to [default: mtimes.json]
  -i, --ignore <IGNORE>          Regex patterns to skip
  -v, --verbose                  Whether to be verbose
  -h, --help                     Print help

To save the current directory to a file called mtimes.json:

mtime-travel save ./

To ignore certain regexes:

mtime-travel save --ignore ".*foo.*" ./

To save to another location:

mtime-travel save --mtime-file <MY_MTIME_FILE_PATH> ./

This will output a .json file with the files' hashes and mtime value.

Restoring

Usage: mtime-travel restore [OPTIONS] <TARGET_DIR>

Arguments:
  <TARGET_DIR>  The location to recursively restore mtimes to

Options:
  -m, --mtime-file <MTIME_FILE>  The location to a file to restore previous mtimes from [default: mtimes.json]
  -v, --verbose                  Whether to be verbose
  -i, --ignore-hash              Whether to ignore hashes matching. Defaults to false
  -h, --help                     Print help

To restore the current directory's files given a file called mtimes.json in the same directory if the file hashes match:

mtime-travel restore ./

To ignore file hashes:

mtime-travel restore --ignore-hash ./

To use a different location for the saved mtime data:

mtime-travel restore --mtime-file <MY_MTIME_FILE_PATH> ./