feat: Squashing public writes in kernel

[LeilaWang]

Please read contributing guidelines and remove this line.

[AztecBot]

Benchmark results

Metrics with a significant change:

• circuit_simulation_time_in_ms (public-kernel-tail): 91.8 (-47%)
• circuit_input_size_in_bytes (public-kernel-tail): 34,206 (-16%)
• l2_block_public_tx_process_time_in_ms (8): 5,077 (-16%)

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.

Values are compared against data from master at commit 426bd6d2 and shown if the difference exceeds 1%.

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	5,668	18,820	36,356
l1_rollup_calldata_gas	66,016	238,732	469,472
l1_rollup_execution_gas	666,648	953,593	1,336,780
l2_block_processing_time_in_ms	1,303	4,779 (-1%)	9,465 (+3%)
note_successful_decrypting_time_in_ms	142 (+10%)	565 (+1%)	1,035 (+3%)
note_trial_decrypting_time_in_ms	44.5 (+26%)	88.4 (+26%)	56.9 (-57%)
l2_block_building_time_in_ms	12,130 (-7%)	48,453 (-5%)	96,473 (-5%)
l2_block_rollup_simulation_time_in_ms	7,029 (+1%)	28,052 (+1%)	55,876
l2_block_public_tx_process_time_in_ms	⚠️ 5,077 (-16%)	20,340 (-11%)	40,492 (-12%)

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	14,124 (+1%)	26,981 (+7%)
note_history_successful_decrypting_time_in_ms	1,207 (+2%)	2,498 (+3%)
note_history_trial_decrypting_time_in_ms	71.6 (+15%)	140 (-7%)
node_database_size_in_bytes	19,054,672	35,979,344 (+1%)
pxe_database_size_in_bytes	29,859	59,414

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	271	44,370	27,700
private-kernel-ordering	206 (+1%)	52,324	14,326
base-rollup	637 (+2%)	177,083	925
root-rollup	68.3 (+1%)	4,176	789
private-kernel-inner	361 (+1%)	73,229	27,700
public-kernel-app-logic	182 (-1%)	34,646 (-2%)	27,671 (-2%)
public-kernel-tail	⚠️ 91.8 (-47%)	⚠️ 34,206 (-16%)	27,671 (-2%)
merge-rollup	8.32	2,696	925

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	9.98	15.9 (+1%)	N/A	N/A	N/A	N/A	N/A	N/A	N/A
batch_insert_into_append_only_tree_16_depth_hash_count	16.8	31.6	N/A	N/A	N/A	N/A	N/A	N/A	N/A
batch_insert_into_append_only_tree_16_depth_hash_ms	0.582	0.493	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	46.5 (+1%)	72.0 (+1%)	229	446 (+1%)	868	1,724 (+1%)	N/A
batch_insert_into_append_only_tree_32_depth_hash_count	N/A	N/A	96.0	159	543	1,055	2,079	4,127	N/A
batch_insert_into_append_only_tree_32_depth_hash_ms	N/A	N/A	0.477 (+1%)	0.445	0.418	0.417 (+1%)	0.413	0.412	N/A
batch_insert_into_indexed_tree_20_depth_ms	N/A	N/A	54.1 (+2%)	107 (+1%)	338 (+2%)	661 (+1%)	1,314 (+1%)	2,627 (+1%)	N/A
batch_insert_into_indexed_tree_20_depth_hash_count	N/A	N/A	104	207	691	1,363	2,707	5,395	N/A
batch_insert_into_indexed_tree_20_depth_hash_ms	N/A	N/A	0.481 (+1%)	0.481 (+1%)	0.459 (+1%)	0.455 (+1%)	0.455	0.454 (+1%)	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	61.3
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	109
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	0.536

Miscellaneous

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

Metric	0 registered classes
tx_size_in_bytes	22,014

Transaction processing duration by data writes.

Metric	0 new note hashes	1 new note hashes
tx_pxe_processing_time_ms	3,036 (-2%)	1,446 (+1%)

Metric	0 public data writes	1 public data writes
tx_sequencer_processing_time_ms	13.7 (+14%)	627 (-12%)

[iAmMichaelConnor]

Is this dead?

[LeilaWang]

Done in #8296