chore: prepare ScheduledValueChange for mutable delays.

[nventuro]

Part of #5493. This lays some of the groundwork by making ScheduledValueChange not have an immutable delay. The only user of this struct is SharedMutable however, which does (so far) have immutable delays, so there's no functionality changes.

[sklppy88]

Looks good to me, won't block merging but maybe would be good to get @LHerskind's approval on this as well as he's the other SharedMutable expert (aside from yourself) 😄

[AztecBot]

Benchmark results

No metrics with a significant change found.

Detailed results

All benchmarks are run on txs on the Benchmarking contract on the repository. Each tx consists of a batch call to create_note and increment_balance, which guarantees that each tx has a private call, a nested private call, a public call, and a nested public call, as well as an emitted private note, an unencrypted log, and public storage read and write.

This benchmark source data is available in JSON format on S3 here.

L2 block published to L1

Each column represents the number of txs on an L2 block published to L1.

Metric	8 txs	32 txs	64 txs
l1_rollup_calldata_size_in_bytes	740	740	740
l1_rollup_calldata_gas	6,680	6,668	6,692
l1_rollup_execution_gas	586,812	586,800	586,824
l2_block_processing_time_in_ms	1,587 (+7%)	5,467	10,604 (+2%)
l2_block_building_time_in_ms	22,472	88,399 (-1%)	176,534 (-1%)
l2_block_rollup_simulation_time_in_ms	22,263	87,656 (-1%)	175,085 (-1%)
l2_block_public_tx_process_time_in_ms	8,863 (-1%)	34,603 (-1%)	69,262 (-1%)

L2 chain processing

Each column represents the number of blocks on the L2 chain where each block has 16 txs.

Metric	5 blocks	10 blocks
node_history_sync_time_in_ms	17,866 (+6%)	33,190
node_database_size_in_bytes	20,742,224	37,371,984
pxe_database_size_in_bytes	29,868	59,425

Circuits stats

Stats on running time and I/O sizes collected for every circuit run across all benchmarks.

Circuit	circuit_simulation_time_in_ms	circuit_input_size_in_bytes	circuit_output_size_in_bytes
private-kernel-init	174	46,819	28,822
private-kernel-inner	205	76,734	28,822
private-kernel-ordering	228	53,040	42,751
base-parity	70.9 (+2%)	128	64.0
base-rollup	16,515 (+1%)	111,062	925
root-parity	1,628 (+1%)	27,064	64.0
root-rollup	64.7	11,454	789
public-kernel-app-logic	1,979	54,321	22,677
public-kernel-tail	4,845	159,770	3,898
merge-rollup	6,511	2,696	925
public-kernel-teardown	162 (+1%)	54,321	30,042
public-kernel-setup	224 (+1%)	54,321	30,042

Tree insertion stats

The duration to insert a fixed batch of leaves into each tree type.

Metric	1 leaves	16 leaves	64 leaves	128 leaves	512 leaves	1024 leaves	2048 leaves	4096 leaves	32 leaves
batch_insert_into_append_only_tree_16_depth_ms	11.0 (+1%)	17.8	N/A	N/A	N/A	N/A	N/A	N/A	N/A
batch_insert_into_append_only_tree_16_depth_hash_count	16.7	31.8	N/A	N/A	N/A	N/A	N/A	N/A	N/A
batch_insert_into_append_only_tree_16_depth_hash_ms	0.641 (+1%)	0.547	N/A	N/A	N/A	N/A	N/A	N/A	N/A
batch_insert_into_append_only_tree_32_depth_ms	N/A	N/A	51.9 (+1%)	80.4	262 (+1%)	505	987	1,963 (+1%)	N/A
batch_insert_into_append_only_tree_32_depth_hash_count	N/A	N/A	95.9	159	543	1,055	2,079	4,127	N/A
batch_insert_into_append_only_tree_32_depth_hash_ms	N/A	N/A	0.532 (+1%)	0.497	0.476 (+1%)	0.471 (+1%)	0.468	0.469 (+1%)	N/A
batch_insert_into_indexed_tree_20_depth_ms	N/A	N/A	60.9	120	377 (+1%)	742	1,468	2,927	N/A
batch_insert_into_indexed_tree_20_depth_hash_count	N/A	N/A	105	208	692	1,363	2,707	5,395	N/A
batch_insert_into_indexed_tree_20_depth_hash_ms	N/A	N/A	0.536	0.539	0.514 (+1%)	0.510	0.508	0.509	N/A
batch_insert_into_indexed_tree_40_depth_ms	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	67.0
batch_insert_into_indexed_tree_40_depth_hash_count	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	108
batch_insert_into_indexed_tree_40_depth_hash_ms	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	0.589

Miscellaneous

Transaction sizes based on how many contract classes are registered in the tx.

Metric	0 registered classes	1 registered classes
tx_size_in_bytes	44,613	535,433

Transaction size based on fee payment method

Metric	native fee payment method	fpc_public fee payment method	fpc_private fee payment method
tx_with_fee_size_in_bytes	897	1,145	1,345

Transaction processing duration by data writes.

Metric	0 new note hashes	1 new note hashes	2 new note hashes
tx_pxe_processing_time_ms	1,407 (+1%)	1,008	3,719 (+2%)

Metric	1 public data writes	2 public data writes	3 public data writes	4 public data writes	5 public data writes	8 public data writes
tx_sequencer_processing_time_ms	883	795 (+1%)	1,435 (+1%)	941 (+2%)	2,230 (+1%)	1,121 (+1%)

[LHerskind]

I think this looks good. Had a tiny comment on naming consistency around delay and minimum delay and some short-circuiting.