Function apply_queue 

pub fn apply_queue(
    base: &mut Vec<u8>,
    delta: &ArchivedQueueDiff,
    item_ssz_size: usize,
) -> Result<(), Error>

Applies a queue delta to a serialized SSZ queue in place.

For QueueDiff::Fifo, the specified number of items are removed from the front of base, after which the appended serialized items are added to the back.

For QueueDiff::FullReplacement, the existing queue is cleared and replaced with the serialized target queue stored in the delta.

Arguments

• base - Mutable serialized SSZ representation of the queue to update.
• delta - Archived queue delta previously produced by diff_queue and serialized with rkyv.
• item_ssz_size - Fixed serialized SSZ size of one queue item.

Errors

Returns Error::MalformedDelta if:

• the archived delta cannot be deserialized;
• item_ssz_size is inconsistent with the serialized delta;
• the number of consumed items exceeds the number of items in base;
• the consumed-byte calculation overflows;
• appended or replacement bytes are not aligned to item_ssz_size.

Behavior

After successful execution, base represents the target queue from which the delta was originally generated.

Complexity

For QueueDiff::Fifo, the operation is O(n) in the number of bytes removed and appended. Removing bytes from the front may require shifting the remaining contents of the Vec.

For QueueDiff::FullReplacement, the operation is O(n) in the size of the replacement queue.

Example

const ITEM_SIZE: usize = 4;

let mut base = b"AAAABBBBCCCC".to_vec();
let target = b"CCCCDDDDEEEE";

let delta = diff_queue(&base, target, ITEM_SIZE);
let bytes = rkyv::to_bytes::<rkyv::rancor::Error>(&delta).unwrap();
let archived = unsafe {
    rkyv::access_unchecked::<eth_state_diff::types::ArchivedQueueDiff>(&bytes)
};

apply_queue(&mut base, archived, ITEM_SIZE).unwrap();

assert_eq!(base, target);