dotcloud/docker

//go:build !windows

package chrootarchive // import "github.com/docker/docker/pkg/chrootarchive"

import (
    "io"
    "path/filepath"

    "github.com/docker/docker/pkg/archive"
    "github.com/moby/sys/userns"
)

// applyLayerHandler parses a diff in the standard layer format from `layer`, and
// applies it to the directory `dest`. Returns the size in bytes of the
// contents of the layer.
func applyLayerHandler(dest string, layer io.Reader, options *archive.TarOptions, decompress bool) (size int64, err error) {
    if decompress {
        decompressed, err := archive.DecompressStream(layer)
        if err != nil {
            return 0, err
        }
        defer decompressed.Close()

        layer = decompressed
    }
    if options == nil {
        options = &archive.TarOptions{}
    }
    if userns.RunningInUserNS() {
        options.InUserNS = true
    }
    if options.ExcludePatterns == nil {
        options.ExcludePatterns = []string{}
    }
    dest = filepath.Clean(dest)
    return doUnpackLayer(dest, layer, options)
}