PeerDAS fork-choice, validator custody and parameter changes

.history/pysetup/spec_builders/eip7594_20240626155910.py

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+from typing import Dict
+
+from .base import BaseSpecBuilder
+from ..constants import EIP7594
+
+
+class EIP7594SpecBuilder(BaseSpecBuilder):
+    fork: str = EIP7594
+
+    @classmethod
+    def imports(cls, preset_name: str):
+        return f'''
+from eth2spec.deneb import {preset_name} as deneb
+'''
+
+
+    @classmethod
+    def sundry_functions(cls) -> str:
+        return """
+def retrieve_column_sidecars(beacon_block_root: Root,
+                             require_peer_sampling: bool) -> Sequence[DataColumnSidecar]:
+    return []
+"""
+
+    @classmethod
+    def hardcoded_custom_type_dep_constants(cls, spec_object) -> str:
+        return {
+            'FIELD_ELEMENTS_PER_CELL': spec_object.preset_vars['FIELD_ELEMENTS_PER_CELL'].value,
+            'FIELD_ELEMENTS_PER_EXT_BLOB': spec_object.preset_vars['FIELD_ELEMENTS_PER_EXT_BLOB'].value,
+            'NUMBER_OF_COLUMNS': spec_object.config_vars['NUMBER_OF_COLUMNS'].value,
+            'MAX_CELLS_IN_EXTENDED_MATRIX': spec_object.config_vars['MAX_CELLS_IN_EXTENDED_MATRIX'].value,
+        }
+
+    @classmethod
+    def hardcoded_func_dep_presets(cls, spec_object) -> Dict[str, str]:
+        return {
+            'KZG_COMMITMENTS_INCLUSION_PROOF_DEPTH': spec_object.preset_vars['KZG_COMMITMENTS_INCLUSION_PROOF_DEPTH'].value,
+        }
+
+

.history/pysetup/spec_builders/eip7594_20240711153253.py

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+from typing import Dict
+
+from .base import BaseSpecBuilder
+from ..constants import EIP7594
+
+
+class EIP7594SpecBuilder(BaseSpecBuilder):
+    fork: str = EIP7594
+
+    @classmethod
+    def imports(cls, preset_name: str):
+        return f'''
+from eth2spec.deneb import {preset_name} as deneb
+'''
+
+
+    @classmethod
+    def sundry_functions(cls) -> str:
+        return """
+def retrieve_column_sidecars(beacon_block_root: Root,
+                             require_peer_sampling: bool) -> Sequence[DataColumnSidecar]:
+    return []
+"""
+
+    @classmethod
+    def hardcoded_custom_type_dep_constants(cls, spec_object) -> str:
+        return {
+            'FIELD_ELEMENTS_PER_CELL': spec_object.preset_vars['FIELD_ELEMENTS_PER_CELL'].value,
+            'FIELD_ELEMENTS_PER_EXT_BLOB': spec_object.preset_vars['FIELD_ELEMENTS_PER_EXT_BLOB'].value,
+            'NUMBER_OF_COLUMNS': spec_object.config_vars['NUMBER_OF_COLUMNS'].value,
+            'MAX_CELLS_IN_EXTENDED_MATRIX': spec_object.config_vars['MAX_CELLS_IN_EXTENDED_MATRIX'].value,
+        }
+
+    @classmethod
+    def hardcoded_func_dep_presets(cls, spec_object) -> Dict[str, str]:
+        return {
+            'KZG_COMMITMENTS_INCLUSION_PROOF_DEPTH': spec_object.preset_vars['KZG_COMMITMENTS_INCLUSION_PROOF_DEPTH'].value,
+        }
+

.history/specs/_features/eip7594/fork-choice_20240711152138.md

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+# EIP-7594 -- Fork Choice
+
+## Table of contents
+<!-- TOC -->
+<!-- START doctoc generated TOC please keep comment here to allow auto update -->
+<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
+
+- [Introduction](#introduction)
+  - [Helpers](#helpers)
+    - [`get_custody_parameters`](#get_custody_parameters)
+    - [`get_sampling_columns`](#get_sampling_columns)
+    - [`retrieve_column_sidecars`](#retrieve_column_sidecars)
+    - [`is_data_available`](#is_data_available)
+    - [`is_chain_available`](#is_chain_available)
+    - [`get_head`](#get_head)
+    - [`is_peer_sampling_required`](#is_peer_sampling_required)
+- [Updated fork-choice handlers](#updated-fork-choice-handlers)
+  - [`on_block`](#on_block)
+    - [Pull-up tip helpers](#pull-up-tip-helpers)
+      - [`compute_pulled_up_tip`](#compute_pulled_up_tip)
+
+<!-- END doctoc generated TOC please keep comment here to allow auto update -->
+<!-- /TOC -->
+
+## Introduction
+
+This is the modification of the fork choice accompanying EIP-7594.
+
+### Helpers
+
+#### `retrieve_column_sidecars`
+
+`def retrieve_column_sidecars(beacon_block_root: Root, columns_to_retrieve: Sequence[ColumnIndex]) -> Sequence[DataColumnSidecar]`
+
+#### Modified `is_data_available`
+
+```python
+def is_data_available(beacon_block_root: Root, require_peer_sampling: bool=False) -> bool:
+    column_sidecars = retrieve_column_sidecars(beacon_block_root, require_peer_sampling)
+    return all(
+        verify_data_column_sidecar_kzg_proofs(column_sidecar)
+        for column_sidecar in column_sidecars
+    )
+```
+
+#### New `is_chain_available`
+
+```python
+def is_chain_available(store: Store, beacon_block_root: Root) -> bool: 
+    if beacon_block_root not in store.blocks:
+        # Deal with Genesis edge cases, where current_justified_checkpoint and parent_root are not set
+        return True
+    block = store.blocks[beacon_block_root]
+    block_epoch = compute_epoch_at_slot(block.slot)
+    current_epoch = get_current_store_epoch(store)
+    if block_epoch + MIN_EPOCHS_FOR_DATA_COLUMN_SIDECARS_REQUESTS <= current_epoch:
+        return True
+    parent_root = block.parent_root
+    return (
+        is_data_available(beacon_block_root, require_peer_sampling=True) 
+        and is_chain_available(store, parent_root)
+    )
+
+```
+
+#### `get_head`
+
+```python
+def get_head(store: Store) -> Root:
+    # Get filtered block tree that only includes viable branches
+    blocks = get_filtered_block_tree(store)
+    # Execute the LMD-GHOST fork choice
+    head = store.justified_checkpoint.root
+    while True:
+        # Get available children for the current slot
+        children = [
+            root for (root, block) in blocks.items()
+            if (
+                block.parent_root == head
+                and is_data_available(
+                    root, 
+                    require_peer_sampling=is_peer_sampling_required(store, block.slot)
+                )
+            )
+        ]
+        if len(children) == 0:
+            return head
+        # Sort by latest attesting balance with ties broken lexicographically
+        # Ties broken by favoring block with lexicographically higher root
+        head = max(children, key=lambda root: (get_weight(store, root), root))
+```
+
+#### New `is_peer_sampling_required`
+
+```python
+def is_peer_sampling_required(store: Store, slot: Slot):
+    return compute_epoch_at_slot(slot) + 2 <= get_current_store_epoch(store)
+```
+
+## Updated fork-choice handlers
+
+### `on_block`
+
+*Note*: The blob data availability check is removed and replaced with an availability
+check on the on the justified checkpoint in the "pulled up state" of the block, after
+applying `process_justification_and_finalization`.
+
+```python
+def on_block(store: Store, signed_block: SignedBeaconBlock) -> None:
+    """
+    Run ``on_block`` upon receiving a new block.
+    """
+    block = signed_block.message
+    # Parent block must be known
+    assert block.parent_root in store.block_states
+    # Make a copy of the state to avoid mutability issues
+    state = copy(store.block_states[block.parent_root])
+    # Blocks cannot be in the future. If they are, their consideration must be delayed until they are in the past.
+    assert get_current_slot(store) >= block.slot
+
+    # Check that block is later than the finalized epoch slot (optimization to reduce calls to get_ancestor)
+    finalized_slot = compute_start_slot_at_epoch(store.finalized_checkpoint.epoch)
+    assert block.slot > finalized_slot
+    # Check block is a descendant of the finalized block at the checkpoint finalized slot
+    finalized_checkpoint_block = get_checkpoint_block(
+        store,
+        block.parent_root,
+        store.finalized_checkpoint.epoch,
+    )
+    assert store.finalized_checkpoint.root == finalized_checkpoint_block
+
+    # Check the block is valid and compute the post-state
+    block_root = hash_tree_root(block)
+    state_transition(state, signed_block, True)
+
+    # [New in EIP7594] Do not import the block if its unrealized justified checkpoint is not available
+    pulled_up_state = state.copy()
+    process_justification_and_finalization(pulled_up_state)
+    assert is_chain_available(store, pulled_up_state.current_justified_checkpoint.root)
+
+    # Add new block to the store
+    store.blocks[block_root] = block
+    # Add new state for this block to the store
+    store.block_states[block_root] = state
+
+    # Add block timeliness to the store
+    time_into_slot = (store.time - store.genesis_time) % SECONDS_PER_SLOT
+    is_before_attesting_interval = time_into_slot < SECONDS_PER_SLOT // INTERVALS_PER_SLOT
+    is_timely = get_current_slot(store) == block.slot and is_before_attesting_interval
+    store.block_timeliness[hash_tree_root(block)] = is_timely
+
+    # Add proposer score boost if the block is timely and not conflicting with an existing block
+    is_first_block = store.proposer_boost_root == Root()
+    if is_timely and is_first_block:
+        store.proposer_boost_root = hash_tree_root(block)
+
+    # Update checkpoints in store if necessary
+    update_checkpoints(store, state.current_justified_checkpoint, state.finalized_checkpoint)
+
+    # Eagerly compute unrealized justification and finality.
+    compute_pulled_up_tip(store, pulled_up_state, block_root)
+```
+
+#### Pull-up tip helpers
+
+##### `compute_pulled_up_tip`
+
+Modified to take `pulled_up_state`, the block's state after applying `processing_justification_and_finalization`.
+The application of `processing_justification_and_finalization` now happens in `on_block`.
+
+```python
+def compute_pulled_up_tip(store: Store, pulled_up_state: BeaconState, block_root: Root) -> None:
+    store.unrealized_justifications[block_root] = pulled_up_state.current_justified_checkpoint
+    unrealized_justified = pulled_up_state.current_justified_checkpoint
+    unrealized_finalized = pulled_up_state.finalized_checkpoint
+    update_unrealized_checkpoints(store, unrealized_justified, unrealized_finalized)
+
+    # If the block is from a prior epoch, apply the realized values
+    block_epoch = compute_epoch_at_slot(store.blocks[block_root].slot)
+    current_epoch = get_current_store_epoch(store)
+    if block_epoch < current_epoch:
+        update_checkpoints(store, unrealized_justified, unrealized_finalized)
+```