Backwards compatibility warning: The result will from now on omit empty fields instead
of including a zero value (e.g. no more `balance: '0x'`).
The prestateTracer will now take an option `diffMode: bool`. In this mode
the tracer will output the pre state and post data for the modified parts of state.
Read-only accesses will be completely omitted. Creations (be it account or slot)
will be signified by omission in the `pre` list and inclusion in `post`. Whereas
deletion (be it account or slot) will be signified by inclusion in `pre` and omission
in `post` list.
Signed-off-by: Delweng <delweng@gmail.com>
The call tracer and prestate tracer store data JSON-encoded in memory. In order to support alternative encodings (specifically RLP), it's better to keep data a native format during tracing. This PR does marshalling at the end, using gencodec.
OBS!
This PR changes the call tracer result slightly:
- Order of type and value fields are changed (should not matter).
- Output fields are completely omitted when they're empty (no more output: "0x"). Previously, this was only _sometimes_ omitted (e.g. when call ended in a non-revert error) and otherwise 0x when the output was actually empty.
