Add a RESTIC_PROGRESS_FPS environment variable to limit the interval
at which the progress indicator updates (allowed values: 1-60).
The default rate of 60 FPS can cause high terminal CPU load on some
systems, like iTerm2 on macOS with font anti-aliasing enabled.
Usage:
RESTIC_PROGRESS_FPS=1 restic ...
RESTIC_PROGRESS_FPS=60 restic ...
- be explicit when discarding returned errors from .Close(), etc.
- remove named return values from funcs when naked return not used
- fix some "err" shadowing when redeclaration not needed
This commits adds rudimentary support for a cache directory, enabled by
default. The cache directory is created if it does not exist. The cache
is used if there's anything in it, newly created snapshot and index
files are written to the cache automatically.
An exclude filter is basically a 'wildcard but foo', so even if a
childMayMatch, other children of a dir may not, therefore childMayMatch
does not matter, but we should not go down unless the dir is selected
for restore.
This improves restore performance by several orders of magniture by not
going through the whole tree recursively when we can anticipate that no
match will ever occur.
