The Save methods of the BlobSaver, FileSaver and TreeSaver return early
on when the archiver is stopped due to an error. For that they select on
both the tomb.Dying() and context.Done() channels, which can lead to a
race condition when the tomb is killed due to an error: The tomb first
closes its Dying channel before canceling all child contexts.
Archiver.SaveDir only aborts its execution once the context was
canceled. When the tomb killing is paused between closing its Dying
channel and canceling the child contexts, this lets the
FileSaver/TreeSaver.Save methods return immediately, however, ScanDir
still reads further files causing the test case to fail.
As a killed tomb always cancels all child contexts and as the Savers
always use a context bound to the tomb, it is sufficient to just use
context.Done() as escape hatch in the Save functions. This fixes the
mismatch between SaveDir and Save.
Adjust the tests to use contexts bound to the tomb for all interactions
with the Savers.
The previous implementation was repeating the implementation that is
found inside of io.WriteString. Simplify by making use of the stdlib's
implementation.
The method only ever receives *hashing.Writers, which don't implement
io.Closer. These come from packerManager.findPacker and have their
actual writers closed in Repository.savePacker. Moving the closing logic
to hashing.Writer results in "file already closed" errors.
When loading a blob, restic first looks up pack files containing the
blob. To avoid unnecessary work an already cached pack file is preferred.
However, if there is only a single pack file to choose from (which is
the normal case) sorting the one-element list won't change anything.
Therefore avoid the unnecessary cache check in that case.
The previous benchmark spent much of its time allocating RNGs and
generating too many random numbers. It now spends 90% of its time
hashing and half of the rest writing to files.
name old time/op new time/op delta
PackerManager-8 319ms ± 1% 247ms ± 1% -22.48% (p=0.000 n=20+18)
name old speed new speed delta
PackerManager-8 143MB/s ± 1% 213MB/s ± 1% +48.63% (p=0.000 n=10+18)
name old alloc/op new alloc/op delta
PackerManager-8 635kB ± 0% 92kB ± 0% -85.48% (p=0.000 n=10+19)
name old allocs/op new allocs/op delta
PackerManager-8 1.64k ± 0% 1.43k ± 0% -12.76% (p=0.000 n=10+20)
Archivers TestMetadataChanged incorrectly clears the Extended Attributes
from the expected metadata of the temporary file. This is incorrect as on
SELinux enabled filesystem, as the kernel will automaticly add a SElinux
label. However, since ExtendedAttributes{} != ExtendedAttributes{nil} we
still need to clear them if there are no attributes found.
The pool was used improperly, causing more allocations to be
performed than without it.
name old time/op new time/op delta
SaveAndEncrypt-8 36.8ms ± 2% 36.9ms ± 2% ~ (p=0.218 n=10+10)
name old speed new speed delta
SaveAndEncrypt-8 114MB/s ± 2% 114MB/s ± 2% ~ (p=0.218 n=10+10)
name old alloc/op new alloc/op delta
SaveAndEncrypt-8 21.1MB ± 0% 21.0MB ± 0% -0.44% (p=0.000 n=10+10)
name old allocs/op new allocs/op delta
SaveAndEncrypt-8 79.0 ± 0% 77.0 ± 0% -2.53% (p=0.000 n=10+10)
The `dump`, `find`, `forget`, `ls`, `mount`, `restore`, `snapshots`,
`stats` and `tag` commands will now take into account multiple
`--host` and `-H` flags.
Much simpler implementation that guarantees each required pack
is downloaded only once (and hence does not need to manage
pack cache). Also improves large file restore performance.
Signed-off-by: Igor Fedorenko <igor@ifedorenko.com>
internal/archiver.readdir and internal/fs.ReadDir were unused.
internal/fs.ReadDirNames and internal/archiver.readdirnames were doing
nearly the same thing, except one sorted its output and opened with
fs.O_NOFOLLOW. Both were only used in internal/archiver.
Each of the random test files was split into the same five blobs. The
test fails once the fifth blob is passed on to `SaveBlob`. That is for
certain interleavings of goroutine execution it would be possible for
the test to trigger the testErr just after storing the first file.
The fixed test uses a different file content for each of the nine files
and fails after writing the fourth blob. The file content is also small
enough to ensure that for each file only a single blob is saved. This
guarantees that the test cannot fail before reading the first four
files. FileReadConcurrency = 2 allows up to two files queued for
processing. Therefore the test can at most open the sixth file before it
has to save the fourth file / blob which triggers the testErr.
