Closing a stream in the parallel chunked reader cancels the stream's
context, so the in-flight read returns context.Canceled. This was wrapped
and returned as "failed to read stream", which the VFS cache downloader
treats as a real download error - it only recognises
asyncreader.ErrorStreamAbandoned as a benign teardown, as returned by the
sequential reader.
Return asyncreader.ErrorStreamAbandoned for a cancellation so tearing down
the parallel reader (on close, seek or reposition) is recognised as benign,
matching the sequential reader, instead of logging download errors and
retrying when --vfs-read-chunk-streams is used with --vfs-cache-mode full.
This commit modernizes Go usage. This was done with:
go run golang.org/x/tools/gopls/internal/analysis/modernize/cmd/modernize@latest -fix -test ./...
Then files needed to be `go fmt`ed and a few comments needed to be
restored.
The modernizations include replacing
- if/else conditional assignment by a call to the built-in min or max functions added in go1.21
- sort.Slice(x, func(i, j int) bool) { return s[i] < s[j] } by a call to slices.Sort(s), added in go1.21
- interface{} by the 'any' type added in go1.18
- append([]T(nil), s...) by slices.Clone(s) or slices.Concat(s), added in go1.21
- loop around an m[k]=v map update by a call to one of the Collect, Copy, Clone, or Insert functions from the maps package, added in go1.21
- []byte(fmt.Sprintf...) by fmt.Appendf(nil, ...), added in go1.19
- append(s[:i], s[i+1]...) by slices.Delete(s, i, i+1), added in go1.21
- a 3-clause for i := 0; i < n; i++ {} loop by for i := range n {}, added in go1.22
This converts the ChunkedReader into an interface and provides two
implementations one sequential and one parallel.
This can be used to improve the performance of the VFS on high
bandwidth or high latency links.
Fixes#4760
- Change rclone/fs interfaces to accept context.Context
- Update interface implementations to use context.Context
- Change top level usage to propagate context to lover level functions
Context propagation is needed for stopping transfers and passing other
request-scoped values.
- make Close permanent and return errors afterwards
- use RangeSeek from the wrapped reader if present
- add a limit to chunk growth
- correct RangeSeek interface behavior
- add tests
Nick Craig-Wood
albertony
Josh SorefandNick Craig-Wood
Martin MichlmayrandNick Craig-Wood
Aleksandar JankovicandNick Craig-Wood
Fabian Möller