Make NUMBER_OF_COLUMNS a preset (#4485)

[As discussed on
discord](https://discord.com/channels/595666850260713488/1401858592264552501),
`NUMBER_OF_COLUMNS` should be a preset, not a configuration value. It's
technically an alias of `CELLS_PER_EXT_BLOB` (preset) which is used in
KZG libraries. I've also added the latter to the preset files as well so
that it is more clear that it's an alias.

Author: jtraglia

configs/mainnet.yaml

@@ -164,7 +164,6 @@ MAX_BLOBS_PER_BLOCK_ELECTRA: 9
 MAX_REQUEST_BLOB_SIDECARS_ELECTRA: 1152
 
 # Fulu
-NUMBER_OF_COLUMNS: 128
 NUMBER_OF_CUSTODY_GROUPS: 128
 DATA_COLUMN_SIDECAR_SUBNET_COUNT: 128
 MAX_REQUEST_DATA_COLUMN_SIDECARS: 16384

configs/minimal.yaml

@@ -161,7 +161,6 @@ MAX_BLOBS_PER_BLOCK_ELECTRA: 9
 MAX_REQUEST_BLOB_SIDECARS_ELECTRA: 1152
 
 # Fulu
-NUMBER_OF_COLUMNS: 128
 NUMBER_OF_CUSTODY_GROUPS: 128
 DATA_COLUMN_SIDECAR_SUBNET_COUNT: 128
 MAX_REQUEST_DATA_COLUMN_SIDECARS: 16384

presets/mainnet/fulu.yaml

@@ -11,3 +11,7 @@ KZG_COMMITMENTS_INCLUSION_PROOF_DEPTH: 4
 FIELD_ELEMENTS_PER_CELL: 64
 # 2**1 * FIELD_ELEMENTS_PER_BLOB (= 8,192)
 FIELD_ELEMENTS_PER_EXT_BLOB: 8192
+# FIELD_ELEMENTS_PER_EXT_BLOB // FIELD_ELEMENTS_PER_CELL (= 128)
+CELLS_PER_EXT_BLOB: 128
+# CELLS_PER_EXT_BLOB (= 128)
+NUMBER_OF_COLUMNS: 128

presets/minimal/fulu.yaml

@@ -11,3 +11,7 @@ KZG_COMMITMENTS_INCLUSION_PROOF_DEPTH: 4
 FIELD_ELEMENTS_PER_CELL: 64
 # 2**1 * FIELD_ELEMENTS_PER_BLOB (= 8,192)
 FIELD_ELEMENTS_PER_EXT_BLOB: 8192
+# FIELD_ELEMENTS_PER_EXT_BLOB // FIELD_ELEMENTS_PER_CELL (= 128)
+CELLS_PER_EXT_BLOB: 128
+# CELLS_PER_EXT_BLOB (= 128)
+NUMBER_OF_COLUMNS: 128

specs/fulu/das-core.md

@@ -8,8 +8,9 @@
   - [Misc](#misc)
 - [Custom types](#custom-types)
 - [Configuration](#configuration)
-  - [Data size](#data-size)
   - [Custody setting](#custody-setting)
+- [Preset](#preset)
+  - [Size parameters](#size-parameters)
   - [Containers](#containers)
     - [`DataColumnSidecar`](#datacolumnsidecar)
     - [`MatrixEntry`](#matrixentry)
@@ -54,12 +55,6 @@ specification.
 
 ## Configuration
 
-### Data size
-
-| Name                | Value                                | Description                                   |
-| ------------------- | ------------------------------------ | --------------------------------------------- |
-| `NUMBER_OF_COLUMNS` | `uint64(CELLS_PER_EXT_BLOB)` (= 128) | Number of columns in the extended data matrix |
-
 ### Custody setting
 
 | Name                       | Value | Description                                                                       |
@@ -68,6 +63,14 @@ specification.
 | `NUMBER_OF_CUSTODY_GROUPS` | `128` | Number of custody groups available for nodes to custody                           |
 | `CUSTODY_REQUIREMENT`      | `4`   | Minimum number of custody groups an honest node custodies and serves samples from |
 
+## Preset
+
+### Size parameters
+
+| Name                | Value                                | Description                                   |
+| ------------------- | ------------------------------------ | --------------------------------------------- |
+| `NUMBER_OF_COLUMNS` | `uint64(CELLS_PER_EXT_BLOB)` (= 128) | Number of columns in the extended data matrix |
+
 ### Containers
 
 #### `DataColumnSidecar`

tests/core/pyspec/eth2spec/test/fulu/networking/test_compute_columns_for_custody_group.py

@@ -15,8 +15,8 @@ def _run_compute_columns_for_custody_group(spec, rng, custody_group=None):
     yield "custody_group", "meta", custody_group
 
     assert len(result) == len(set(result))
-    assert len(result) == spec.config.NUMBER_OF_COLUMNS // spec.config.NUMBER_OF_CUSTODY_GROUPS
-    assert all(i < spec.config.NUMBER_OF_COLUMNS for i in result)
+    assert len(result) == spec.NUMBER_OF_COLUMNS // spec.config.NUMBER_OF_CUSTODY_GROUPS
+    assert all(i < spec.NUMBER_OF_COLUMNS for i in result)
     python_list_result = [int(i) for i in result]
 
     yield "result", "meta", python_list_result

tests/core/pyspec/eth2spec/test/fulu/unittests/test_config_invariants.py

@@ -14,13 +14,13 @@
 @single_phase
 def test_invariants(spec):
     assert spec.FIELD_ELEMENTS_PER_BLOB % spec.FIELD_ELEMENTS_PER_CELL == 0
-    assert spec.FIELD_ELEMENTS_PER_EXT_BLOB % spec.config.NUMBER_OF_COLUMNS == 0
-    assert spec.config.SAMPLES_PER_SLOT <= spec.config.NUMBER_OF_COLUMNS
+    assert spec.FIELD_ELEMENTS_PER_EXT_BLOB % spec.NUMBER_OF_COLUMNS == 0
+    assert spec.config.SAMPLES_PER_SLOT <= spec.NUMBER_OF_COLUMNS
     assert spec.config.CUSTODY_REQUIREMENT <= spec.config.DATA_COLUMN_SIDECAR_SUBNET_COUNT
-    assert spec.config.DATA_COLUMN_SIDECAR_SUBNET_COUNT <= spec.config.NUMBER_OF_COLUMNS
-    assert spec.config.NUMBER_OF_COLUMNS % spec.config.DATA_COLUMN_SIDECAR_SUBNET_COUNT == 0
+    assert spec.config.DATA_COLUMN_SIDECAR_SUBNET_COUNT <= spec.NUMBER_OF_COLUMNS
+    assert spec.NUMBER_OF_COLUMNS % spec.config.DATA_COLUMN_SIDECAR_SUBNET_COUNT == 0
     assert spec.config.MAX_REQUEST_DATA_COLUMN_SIDECARS == (
-        spec.config.MAX_REQUEST_BLOCKS_DENEB * spec.config.NUMBER_OF_COLUMNS
+        spec.config.MAX_REQUEST_BLOCKS_DENEB * spec.NUMBER_OF_COLUMNS
     )
 
 

tests/core/pyspec/eth2spec/test/fulu/unittests/test_custody.py

@@ -11,7 +11,7 @@ def run_get_custody_columns(spec, peer_count, custody_group_count):
         spec.get_custody_groups(node_id, custody_group_count) for node_id in range(peer_count)
     ]
 
-    columns_per_group = spec.config.NUMBER_OF_COLUMNS // spec.config.NUMBER_OF_CUSTODY_GROUPS
+    columns_per_group = spec.NUMBER_OF_COLUMNS // spec.config.NUMBER_OF_CUSTODY_GROUPS
     for assignment in assignments:
         columns = []
         for group in assignment:
@@ -29,7 +29,7 @@ def run_get_custody_columns(spec, peer_count, custody_group_count):
 def test_get_custody_columns_peers_within_number_of_columns(spec):
     peer_count = 10
     custody_group_count = spec.config.CUSTODY_REQUIREMENT
-    assert spec.config.NUMBER_OF_COLUMNS > peer_count
+    assert spec.NUMBER_OF_COLUMNS > peer_count
     run_get_custody_columns(spec, peer_count, custody_group_count)
 
 
@@ -39,7 +39,7 @@ def test_get_custody_columns_peers_within_number_of_columns(spec):
 def test_get_custody_columns_peers_more_than_number_of_columns(spec):
     peer_count = 200
     custody_group_count = spec.config.CUSTODY_REQUIREMENT
-    assert spec.config.NUMBER_OF_COLUMNS < peer_count
+    assert spec.NUMBER_OF_COLUMNS < peer_count
     run_get_custody_columns(spec, peer_count, custody_group_count)