Currently, even though it takes in a `Logger` interface,
`log.SetDefualt` enforces that the concrete type of the provided logger
is `*logger` because:
1. in `init` `root.Store` is called with a `*logger`
2. `atomic.Value` panics if the concrete type provided in `Store` is not
consistent across calls.
([ref](https://pkg.go.dev/sync/atomic#Value.Store))
> All calls to Store for a given Value must use values of the same
concrete type.
This PR changes to use `sync.RWMutex` and adds a test that panics on
`master`.
This PR replaces Geth's logger package (a fork of [log15](https://github.com/inconshreveable/log15)) with an implementation using slog, a logging library included as part of the Go standard library as of Go1.21.
Main changes are as follows:
* removes any log handlers that were unused in the Geth codebase.
* Json, logfmt, and terminal formatters are now slog handlers.
* Verbosity level constants are changed to match slog constant values. Internal translation is done to make this opaque to the user and backwards compatible with existing `--verbosity` and `--vmodule` options.
* `--log.backtraceat` and `--log.debug` are removed.
The external-facing API is largely the same as the existing Geth logger. Logger method signatures remain unchanged.
A small semantic difference is that a `Handler` can only be set once per `Logger` and not changed dynamically. This just means that a new logger must be instantiated every time the handler of the root logger is changed.
----
For users of the `go-ethereum/log` module. If you were using this module for your own project, you will need to change the initialization. If you previously did
```golang
log.Root().SetHandler(log.LvlFilterHandler(log.LvlInfo, log.StreamHandler(os.Stderr, log.TerminalFormat(true))))
```
You now instead need to do
```golang
log.SetDefault(log.NewLogger(log.NewTerminalHandlerWithLevel(os.Stderr, log.LevelInfo, true)))
```
See more about reasoning here: https://github.com/ethereum/go-ethereum/issues/28558#issuecomment-1820606613
This commit adds all changes needed for the merge of swarm-network-rewrite.
The changes:
- build: increase linter timeout
- contracts/ens: export ensNode
- log: add Output method and enable fractional seconds in format
- metrics: relax test timeout
- p2p: reduced some log levels, updates to simulation packages
- rpc: increased maxClientSubscriptionBuffer to 20000
