spring-util command to print snapshot info

[spoonincode]

Adds a command to spring-util that prints basic information about a snapshot in JSON.

spring-util snapshot info ../217214268.bin
{
  "version": 3,
  "chain_id": "aca376f206b8fc25a6ed44dbdc66547c36c6c33e3a119ffbeaef943642f0e906",
  "head_block_id": "0cf26d3cf1bf39f8c3701b2deb5381d4679ae6286de1f94bfea3cdfa0ccf307b",
  "head_block_num": 217214268,
  "head_block_time": "2021-11-24T16:00:01.000"
}


spring-util snapshot info ~/snapshot-0c1620e34d4c49381b66639ad14b892f566e02d86eb0642770060b2973d1de11.bin
{
  "version": 5,
  "chain_id": "aca376f206b8fc25a6ed44dbdc66547c36c6c33e3a119ffbeaef943642f0e906",
  "head_block_id": "0c1620e34d4c49381b66639ad14b892f566e02d86eb0642770060b2973d1de11",
  "head_block_num": 202776803,
  "head_block_time": "2021-09-02T02:22:19.000"
}

spring-util snapshot info /mnt/eos/eos/snapshots/snapshot-192f82e68109654011291f2fc8588c5eb22f0941756a888da74c0fbfba830b2f.bin
{
  "version": 8,
  "chain_id": "aca376f206b8fc25a6ed44dbdc66547c36c6c33e3a119ffbeaef943642f0e906",
  "head_block_id": "192f82e68109654011291f2fc8588c5eb22f0941756a888da74c0fbfba830b2f",
  "head_block_num": 422544102,
  "head_block_time": "2025-02-25T23:04:38.500"
}

[greg7mdp]

I think that code should be in snapshot.hpp or snapshot_detail.hpp so that the snapshot format details are not spread out in too many places.

[spoonincode]

It won't be too hard to create a get_snapshot_info() call in those files returning some sort of snapshot_info struct. Any more commonization between snapshot loading and getting snapshot info might be rather invasive.

[heifner]

Or even just return a mutable_variant to keep it flexible.

[greg7mdp]

Yes, that's exactly what I was thinking of.

[spoonincode]

okay I've moved the stuff that generates the MVO in to snapshot.hpp/cpp. Also added tests a few days ago. Moving out of draft.

[ericpassmore]

Note:start
category: Other
component: Spring-Util
summary: Print snapshot information using spring-util command.
Note:end