FS Sync Library v1.0.2

go-fssync is a Go library which aims at syncing / copying one file tree to another in a clever way. A bit like the rsync tool:

rsync --archive --update --delete --numeric-ids --hard-links ./source ./destination

• Copy all files which are different to the destination dir
• Skip files which are identical on the destination
• Delete files on the destination which are not present in the source
• Hardlinks should be preserved (if cross device, file copied otherwise just another link)
• Symlinks should be preserved
• Permissions should be preserved

// Implemented interface
type interface FsSyncer {
	Sync(string, string) error
}

// Constructor
fssync.New(opts... func(*FsSyncer))

// Options
// WithChecksum option: Check SHA1 checksum instead of modtime + size
fssync.WithChecksum

// PreserveOwnership option: chown files from source owner instead of copying
// with current owner root required to change the user ownership in most cases
fssync.PreserveOwnership

// IgnoreNotFound option: if the synced directory is heavily used during the
// sync there might be a file which is walked in but which does not exist
// anymore when Lstat is used
fssync.IgnoreNotFound

// NoCache option: Use the system call fadvise to discard kernel cache after
// reading/writing Inspired from
// https://github.com/coreutils/coreutils/blob/master/src/dd.c
fssync.NoCache

// WithBufferSize option: lets you configure the size of the memory buffer used
// to perform the copy from one file to another
// Default is 512kB
WithBufferSize(n int64)

By default the copy is based on the size and modification date.

Command Line Tool

You can try out the synchronization mechanisms with the command line tool provided with the library:

go run cmd/fssync/main.go [-no-cache=false] [-buffer-size=0] [-preserve-ownership=false] [-checksum=false] ./src ./dst

Release a New Version

Bump new version number in:

• CHANGELOG.md
• README.md

Commit, tag and create a new release:

version="1.0.2"

git switch --create release/${version}
git add CHANGELOG.md README.md
git commit --message="Bump v${version}"
git push --set-upstream origin release/${version}
gh pr create --reviewer=EtienneM --title "$(git log -1 --pretty=%B)"

Once the pull request merged, you can tag the new release.

git tag v${version}
git push origin master v${version}
gh release create v${version}

The title of the release should be the version number and the text of the release is the same as the changelog.