Only check content of files if both files have zero nanosecond times.
A zero nanosecond time is considered ambiguous as to whether or
not the timestamp has been truncated by tar. Previously the diff
algorithm was attempting to account for comparisons from a source
to a directory with an applied tar. This condition is no longer
relevant since there is no support for recreating tars directories
which have had a tar extracted. In the case where the older directory
has a truncated timestamp and the newer one does not, this may always
be considered a change. In the case where both are zero, treat the
timestamp as ambiguous and compare content.
Signed-off-by: Derek McGowan <derek@mcgstyle.net>
When a file changes, emit events for the seen parent
directories to ensure that those parents are included
in change streams such as archives. The parents are
needed accurately recreate diff representation apart
from a parent (such as overlay and aufs graph drivers
in Docker).
Signed-off-by: Derek McGowan <derek@mcgstyle.net>
Previously, `Changes()` for a symlink to absolute path, with second-precision
mtime of the link itself always resulted in ENOENT.
This is because `compareFileContent()` was called for the link target path, without changing the root path.
Fixmoby/buildkit#172
Signed-off-by: Akihiro Suda <suda.akihiro@lab.ntt.co.jp>
Adds tests for verifying parent directory permissions.
Currently an issue exists in extracting into some Docker graph
drivers. Supporting these graph drivers may require changes to
the diff logic, these tests clarify the existing behavior and
that extraction within containerd works.
Signed-off-by: Derek McGowan <derek@mcgstyle.net>
Remove change type in favor of explicit change function.
Using change function makes it more difficult to unnecessarily
add to the change interface.
Update test apply functions to use an interface rather
than a function type.
Signed-off-by: Derek McGowan <derek@mcgstyle.net> (github: dmcgowan)
The change computation will be done on the callers thread
and use callbacks rather than running a goroutine and
returning a channel.
Signed-off-by: Derek McGowan <derek@mcgstyle.net> (github: dmcgowan)
Add diff comparison with support for double walking
two trees for comparison or single walking a diff
tree. Single walking requires further implementation
for specific mount types.
Add directory copy function which is intended to provide
fastest possible local copy of file system directories
without hardlinking.
Add test package to make creating filesystems for
test easy and comparisons deep and informative.
Signed-off-by: Derek McGowan <derek@mcgstyle.net> (github: dmcgowan)
