use super::{IndexScanEvent, Reader, FRAME_HEADER_BYTES, MAX_BATCH_RECOVERY_ITEMS};
use crate::event::{EventKind, HashChain};
use crate::store::segment;
use crate::store::StoreError;
impl Reader {
pub(super) fn checked_frame_len(segment_id: u64, length: u32) -> Result<usize, StoreError> {
let frame_len = usize::try_from(length).map_err(|_| {
StoreError::corrupt_segment_with_detail(
segment_id,
"stored frame length does not fit in usize",
)
})?;
let max_frame_len = FRAME_HEADER_BYTES + segment::MAX_FRAME_PAYLOAD;
if frame_len < FRAME_HEADER_BYTES || frame_len > max_frame_len {
return Err(StoreError::corrupt_segment_with_detail(
segment_id,
format!(
"stored frame length {frame_len} is outside valid range [{FRAME_HEADER_BYTES}, {max_frame_len}]"
),
));
}
Ok(frame_len)
}
pub(super) fn checked_frame_range(
segment_id: u64,
offset: u64,
length: u32,
available_len: usize,
) -> Result<std::ops::Range<usize>, StoreError> {
let start = usize::try_from(offset).map_err(|_| StoreError::corrupt_eof(segment_id))?;
let frame_len = Self::checked_frame_len(segment_id, length)?;
let end = start.checked_add(frame_len).ok_or_else(|| {
StoreError::corrupt_segment_with_detail(segment_id, "frame offset overflow")
})?;
if end > available_len {
return Err(StoreError::corrupt_eof(segment_id));
}
Ok(start..end)
}
pub(super) fn payload_len_exceeds_max(payload_len: usize) -> bool {
payload_len > segment::MAX_FRAME_PAYLOAD
}
pub(super) fn checked_batch_count(
segment_id: u64,
offset: u64,
batch_count: u32,
) -> Result<u32, StoreError> {
if batch_count == 0 || batch_count > MAX_BATCH_RECOVERY_ITEMS {
return Err(StoreError::corrupt_segment_with_detail(
segment_id,
format!(
"invalid batch marker count {batch_count} at offset {offset}; expected 1..={MAX_BATCH_RECOVERY_ITEMS}"
),
));
}
Ok(batch_count)
}
pub(super) fn required_index_hash_chain(
event: &IndexScanEvent,
segment_id: u64,
offset: u64,
) -> Result<HashChain, StoreError> {
match &event.hash_chain {
Some(chain) => Ok(chain.clone()),
None if matches!(
event.header.event_kind,
EventKind::SYSTEM_BATCH_BEGIN | EventKind::SYSTEM_BATCH_COMMIT
) =>
{
Err(StoreError::corrupt_segment_with_detail(
segment_id,
format!(
"batch marker at offset {offset} should not reach hash-chain validation"
),
))
}
None => Err(StoreError::corrupt_segment_with_detail(
segment_id,
format!(
"event at offset {offset} is missing hash_chain; recovery no longer defaults missing hashes"
),
)),
}
}
}