When an upload failed with a retryable error the pacer retried the
whole upload with the same input stream. The stream had already been
consumed by the first attempt so the retry uploaded an empty file.
This fixes it by using CallNoRetry for the upload, as the other
backends do, so retryable errors are returned wrapped in a RetryError
for the caller to retry the upload with a fresh stream.
It also makes 5xx errors from the upload storage servers retryable.
These come back from the SDK as a different error type to API errors
so were not being retried at all.
The server computes the MD5 checksum asynchronously after upload, so
the object returned from Put and Update often had no MD5 while a
fresh listing shortly afterwards would report one. This broke
wrappers which compare exact hashes, such as the hasher backend's
fingerprint and the VFS cache. Retry reading the metadata for a short
time after upload until the MD5 appears.
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