class BlobVerifier

Creates an instance of BlobVerifier for blobs named |digest|, using the provided merkle tree

which is at most |merkle_size| bytes. The passed-in BlobfsMetrics will be updated when this

class runs.

The passed-in mapped merkle_data_blocks contains the blocks loaded from disk. The tree is

copied into the member `merkle_data_`.

Returns an error if the merkle tree's root does not match |digest|, or if the required tree

size for |data_size| bytes is bigger than |merkle_size|.

Modifies |data_off| and |buf_len| to be aligned to the minimum number of merkle tree nodes that

covered their original range.

Creates an instance of BlobVerifier for blobs named |digest|, which are small enough to not

have a stored merkle tree (i.e. MerkleTreeBytes(data_size) == 0). The passed-in BlobfsMetrics

will be updated when this class runs.

Verifies the entire contents of a blob. |buffer_size| is the total size of the buffer and the

buffer must be zeroed from |data_size| to |buffer_size|.

TODO(https://fxbug.dev/42121983): Make const if MerkleTreeVerifier::Verify becomes const

Verifies a range of the contents of a blob from [data_offset, data_offset + length).

IMPORTANT: |data| is expected to be a pointer to the blob's contents at |data_offset|, not the

absolute start of the blob's data. (This facilitates partial verification when the blob is only

partially mapped in.) |buffer_size| is the total size of the buffer (relative to |data|) and

the buffer must be zeroed from |data_size| to |buffer_size|.

TODO(https://fxbug.dev/42121983): Make const if MerkleTreeVerifier::Verify becomes const