Function diff_historical_log 

pub fn diff_historical_log(
    base_slot: u64,
    target_slot: u64,
    target_ssz: &[u8],
    item_ssz_size: usize,
    activation_slot: Option<u64>,
) -> HistoricalLogDiff

Computes a delta between two historical log states.

The number of appended items is derived from base_slot and target_slot using the protocol-defined historical period rather than by comparing the serialized base and target logs.

Only the newly appended portion of target_ssz is stored in the returned HistoricalLogDiff.

Arguments

• base_slot - Slot corresponding to the base state.
• target_slot - Slot corresponding to the target state.
• target_ssz - Complete serialized SSZ representation of the target historical log.
• item_ssz_size - Serialized SSZ size of one historical log item.
• activation_slot - Optional slot at which the historical log becomes active. This is used for logs introduced by a later fork.

Returns

• HistoricalLogDiff::Unchanged if the protocol-derived log length has not increased between the two slots.
• HistoricalLogDiff::Append containing the newly appended serialized items otherwise.

Panics

This function does not intentionally panic in release builds. In debug builds, it asserts that target_ssz contains enough bytes for the number of items derived from the slot calculation.

The caller must provide a non-zero item_ssz_size and a target SSZ buffer consistent with the protocol-derived log length.

Complexity

O(k) time and O(k) additional space, where k is the number of newly appended serialized bytes. The number of existing log entries does not affect the computation.

Example

use eth_state_diff::historical_log::diff_historical_log;
use eth_state_diff::types::HistoricalLogDiff;

const ITEM_SIZE: usize = 32;

// One historical period has elapsed, so one item is appended.
let target = vec![0u8; ITEM_SIZE];

let delta = diff_historical_log(
    0,
    8192,
    &target,
    ITEM_SIZE,
    None,
);

assert_eq!(
    delta,
    HistoricalLogDiff::Append(target),
);