Function execute 

pub fn execute(
    opts: &ChecksumOptions,
    writer: &mut dyn Write,
) -> Result<(), IdbError>

Validate page checksums for every page in an InnoDB tablespace.

Iterates over all pages and validates the stored checksum (bytes 0–3 of the FIL header) against two algorithms: CRC-32C (MySQL 5.7.7+), which XORs two independent CRC-32C values computed over bytes [4..26) and [38..page_size-8); and legacy InnoDB, which uses ut_fold_ulint_pair with u32 wrapping arithmetic over the same two byte ranges. A page is considered valid if either algorithm matches the stored value.

Additionally checks LSN consistency: the low 32 bits of the header LSN (bytes 16–23) must match the LSN value in the 8-byte FIL trailer at the end of the page. All-zero pages are counted as empty and skipped entirely.

Prints a summary with total, empty, valid, and invalid page counts. In --verbose mode, every non-empty page is printed with its algorithm, stored and calculated checksum values, and LSN status. The process exits with code 1 if any page has an invalid checksum, making this suitable for scripted integrity checks.