Simplify CLI options:
* Rename "DeleteSnapshots" to "Forget"
* Replace "AddTag" and "Append" with hardcoded values
Change output and snapshot modifications to be more in line with the
"rewrite" command.
The builtin mechanism to capture a stacktrace in Go is to send a SIGQUIT
to the running process. However, this mechanism is not avaiable on
Windows. Thus, tweak the SIGINT handler to dump a stacktrace if the
environment variable `RESTIC_DEBUG_STACKTRACE_SIGINT` is set.
When saving files to the local backend, in some cases the used fsync
calls are slow enough to cause the tests to time out. Thus, increase the
test timeouts as a stopgap measure until we can use the mem backend for
these tests.
The SemaphoreBackend now uniformly enforces the limit of concurrent
backend operations. In addition, it unifies the parameter validation.
The List() methods no longer uses a semaphore. Restic already never runs
multiple list operations in parallel.
By managing the semaphore in a wrapper backend, the sections that hold a
semaphore token grow slightly. However, the main bottleneck is IO, so
this shouldn't make much of a difference.
The key insight that enables the SemaphoreBackend is that all of the
complex semaphore handling in `openReader()` still happens within the
original call to `Load()`. Thus, getting and releasing the semaphore
tokens can be refactored to happen directly in `Load()`. This eliminates
the need for wrapping the reader in `openReader()` to release the token.
This turns snapshotFilterOptions from cmd into a restic.SnapshotFilter
type and makes restic.FindFilteredSnapshot and FindFilteredSnapshots
methods on that type. This fixes #4211 by ensuring that hosts and paths
are named struct fields instead of unnamed function arguments in long
lists of such.
Timestamp limits are also included in the new type. To avoid too much
pointer handling, the convention is that time zero means no limit.
That's January 1st, year 1, 00:00 UTC, which is so unlikely a date that
we can sacrifice it for simpler code.
The output is now
```
-v, --verbose be verbose (specify multiple times or a level using --verbose=n, max level/times is 2)
```
instead of
```
-v, --verbose n be verbose (specify multiple times or a level using --verbose=n, max level/times is 2)
```
Fixes restic#719
If the option is passed, restic will wait the specified duration of time
and retry locking the repo every 10 seconds (or more often if the total
timeout is relatively small).
- Play nice with json output
- Reduce wait time in lock tests
- Rework timeout last attempt
- Reduce test wait time to 0.1s
- Use exponential back off for the retry lock
- Don't pass gopts to lockRepo functions
- Use global variable for retry sleep setup
- Exit retry lock on cancel
- Better wording for flag help
- Reorder debug statement
- Refactor tests
- Lower max sleep time to 1m
- Test that we cancel/timeout in time
- Use non blocking sleep function
- Refactor into minDuration func
Co-authored-by: Julian Brost <julian@0x4a42.net>
