Extend applicationlogs with invocations

[ixje]

Summary or problem description Transactions can perform multiple contract calls in 1 script, or 1 contract call that performs internal calls to other smart contracts. The applicationlogs currently only return System.Runtime.Notify calls in the notifications list, but not all contracts emit notifications and therefore as a consumer we loose visibility of what has happened in the transaction.

Also, notifications do not always include all useful information e.g. for T5 tx 0x19bea71b2f6634bd2503099360a039799979e787f20826db0f1cf2e8b6e51af2 the applicationlog contains

{
    "contract": "0x49cf4e5378ffcd4dec034fd98a174c5491e395e2",
    "eventname": "Designation",
    "state": {
        "type": "Array",
        "value": [
            {
                "type": "Integer",
                "value": "4"
            },
            {
                "type": "Integer",
                "value": "3599"
            }
        ]
    }
}

All that we can derive from this notification is that at block 3599 the StateValidator role was assigned. But to who?

Do you have any solution you want to propose? I implemented a PoC for neo-go which captures all calls to the System.Contract.Call SYSCALL and appends these to the applicationlog. The application log for the above discussed T5 transaction becomes

{
    "id": 1,
    "jsonrpc": "2.0",
    "result": {
        "txid": "0x19bea71b2f6634bd2503099360a039799979e787f20826db0f1cf2e8b6e51af2",
        "executions": [
            {
                "trigger": "Application",
                "vmstate": "HALT",
                "gasconsumed": "209055",
                "stack": [
                    {
                        "type": "Any"
                    }
                ],
                "notifications": [
                    {
                        "contract": "0x49cf4e5378ffcd4dec034fd98a174c5491e395e2",
                        "eventname": "Designation",
                        "state": {
                            "type": "Array",
                            "value": [
                                {
                                    "type": "Integer",
                                    "value": "4"
                                },
                                {
                                    "type": "Integer",
                                    "value": "3599"
                                }
                            ]
                        }
                    }
                ],
                "exception": null,
                "invocations": [
                    {
                        "contract_hash": "0x49cf4e5378ffcd4dec034fd98a174c5491e395e2",
                        "method": "designateAsRole",
                        "parameters": {
                            "type": "Array",
                            "value": [
                                {
                                    "type": "Integer",
                                    "value": "4"
                                },
                                {
                                    "type": "Array",
                                    "value": [
                                        {
                                            "type": "ByteString",
                                            "value": "A0AcxP8tV4phfghLecnr6nOWP/Pe/3hS7cQrwenon4uf"
                                        },
                                        {
                                            "type": "ByteString",
                                            "value": "AojK1EKod5YMdrT2iPS+MPdoJW2aPaJJKwGAuRJDkYtP"
                                        },
                                        {
                                            "type": "ByteString",
                                            "value": "A5tFBAzFKZZhZe9d/z0EaklgUgzmFq4XDiZdZp4OLef0"
                                        },
                                        {
                                            "type": "ByteString",
                                            "value": "A9KvHTaxa+UMmyFzKXU1oBSowZEPWSh8XF3+hqBFzvXV"
                                        }
                                    ]
                                }
                            ]
                        }
                    }
                ]
            }
        ]
    }
}

With the information from the invocations list we can actually tell that the role was assigned to the following public keys:

• 03401cc4ff2d578a617e084b79c9ebea73963ff3deff7852edc42bc1e9e89f8b9f
• 0288cad442a877960c76b4f688f4be30f768256d9a3da2492b0180b91243918b4f
• 039b45040cc529966165ef5dff3d046a4960520ce616ae170e265d669e0e2de7f4
• 03d2af1d36b16be50c9b2173297535a014a8c1910f59287c5c5dfe86a045cef5d5

This is just one of many scenarios where this information gives builders far more data and insights to work with.

Stats I've collected some information on how this change affects the chain size and performance. The information is collected for MainNet up to block 5607836 and for T5 up to block 4217754 synced from chain dumps obtained via sync.ngd.network

		time
chain	extended app logs	real	user	sys	chain size on disk in bytes
mainnet	y	107m7.367s	198m22.133s	60m3.692s	54811032
mainnet	n	101m48.200s	193m1.756s	57m38.710s	54276488
t5	y	35m6.453s	71m40.047s	18m59.119s	18939352
t5	n	35m29.732s	72m5.290s	19m8.286s	18908808

Mainnet chain size increased by 522 KB. Syncing speed took 319.167 seconds extra (based on real time). The chain has 5372363 transactions meaning that processing speed took 0.0594ms extra on average per tx.

T5 chain size increased by < 30KB. Syncing speed was actually faster by a couple of seconds but could be explained by i/o differences

Where in the software does this update applies to?

• Plugins
• RPC (HTTP)