Go 1.18 deprecated net.Error.Temporary().
This commit cleans up places where we use it incorrectly.
Also, the rpc layer defines some errors that implement
interface { Temporary() bool }
I added comments to all of the implementations to indicate
whether they will be required if net.Error.Temporary is ever
ever removed in the future.
For HandshakeError, the Temporary() return value is actually
important. I moved & rewrote a (previously misplaced) comment
there.
The ReadStreamError changes were
1. necessary to pacify newer staticcheck and
2. technically, an error can implement Temporary()
without being net.Err. This applies to some syscall
errors in the standard library.
Reading list for those interested:
- https://github.com/golang/go/issues/45729
- https://groups.google.com/g/golang-nuts/c/-JcZzOkyqYI
- https://man7.org/linux/man-pages/man2/accept.2.html
Note: This change was prompted by staticheck:
> SA1019: neterr.Temporary has been deprecated since Go 1.18 because it
> shouldn't be used: Temporary errors are not well-defined. Most
> "temporary" errors are timeouts, and the few exceptions are surprising.
> Do not use this method. (staticcheck)
Before this change, the step correlation code returned early in several cases:
- did not set f.planning.done in the cases where it was a no-op
- did not set f.planning.err in the cases where correlation did not
succeed
Reported-by: InsanePrawn <insane.prawny@gmail.com>
package trace:
- introduce the concept of tasks and spans, tracked as linked list within ctx
- see package-level docs for an overview of the concepts
- **main feature 1**: unique stack of task and span IDs
- makes it easy to follow a series of log entries in concurrent code
- **main feature 2**: ability to produce a chrome://tracing-compatible trace file
- either via an env variable or a `zrepl pprof` subcommand
- this is not a CPU profile, we already have go pprof for that
- but it is very useful to visually inspect where the
replication / snapshotter / pruner spends its time
( fixes#307 )
usage in package daemon/logging:
- goal: every log entry should have a trace field with the ID stack from package trace
- make `logging.GetLogger(ctx, Subsys)` the authoritative `logger.Logger` factory function
- the context carries a linked list of injected fields which
`logging.GetLogger` adds to the logger it returns
- `logging.GetLogger` also uses package `trace` to get the
task-and-span-stack and injects it into the returned logger's fields
