This PR modifies how the metrics library handles `Enabled`: previously,
the package `init` decided whether to serve real metrics or just
dummy-types.
This has several drawbacks:
- During pkg init, we need to determine whether metrics are enabled or
not. So we first hacked in a check if certain geth-specific
commandline-flags were enabled. Then we added a similar check for
geth-env-vars. Then we almost added a very elaborate check for
toml-config-file, plus toml parsing.
- Using "real" types and dummy types interchangeably means that
everything is hidden behind interfaces. This has a performance penalty,
and also it just adds a lot of code.
This PR removes the interface stuff, uses concrete types, and allows for
the setting of Enabled to happen later. It is still assumed that
`metrics.Enable()` is invoked early on.
The somewhat 'heavy' operations, such as ticking meters and exp-decay,
now checks the enable-flag to prevent resource leak.
The change may be large, but it's mostly pretty trivial, and from the
last time I gutted the metrics, I ensured that we have fairly good test
coverage.
---------
Co-authored-by: Felix Lange <fjl@twurst.com>
* feat: rename Tracer interface to EVMLogger;
minor changes in API
refine api_tracer.go
refine Tracer interface
* fix: broken tracer tests
* feat: add BenchmarkTransactionTrace
* feat: tracer CaptureEnter CaptureExit in evm
* feat: upgrade js tracers with geth upstream
* chore: clean test
* feat: eth/tracers: support for golang tracers + add golang callTracer
cf. https://github.com/ethereum/go-ethereum/pull/23708
* chore: clean testdata json
* fix: change test due to IntrinsicGas is not upgraded
* feat: make native Tracer the default Tracer
* fix: update tracers.New in api
* fix: addr prefix in callTracer
* fix: remove `native` in BenchmarkTracers
* fix: return consensus error of InsufficientBalance for tx, instead of vmerr
* chore: drop js tracers: call and noop
