Module hashing 

BLAKE3 Merkle tree construction, adaptive chunk sizing, and directory hashing. BLAKE3 hashing, Merkle tree, delta detection, directory hashing.

Structs

ChunkHash

Per-chunk hash with file offset metadata.

DirHashAccumulator

Accumulates S3 restore child entries per directory prefix, producing a dir hash when finalize() is called for a given prefix.

DirtyRange

A contiguous byte range that differs between source and target.

MerkleSignature

Serializable Merkle signature for xattr/sidecar storage.

MerkleTree

BLAKE3 Merkle tree over fixed-size file chunks.

Enums

ChecksumType

Checksum algorithm selection for sidecar file generation. BLAKE3 is FREE (reuses existing computation). Others require extra I/O.

ComputeMode

Controls which per-chunk computations MerkleTree::from_file() performs.

Constants

CHUNK_SIZE

Keep backward compat for callers using CHUNK_SIZE directly

MAX_LEAVES_PER_XATTR

Max Merkle leaves per xattr – defined in constants.rs for central tuning.

MIN_CHUNK_SIZE

Minimum chunk size for Merkle tree – defined in constants.rs for central tuning.

Functions

calculate_adaptive_chunk_size

Calculate chunk size for Merkle tree construction.

compute_dir_hash

Compute a directory hash from sorted child (name, hash) pairs. Uses BLAKE3 over concatenation of sorted name:hash entries. Provides a stable, order-independent directory fingerprint.

compute_dir_hash_from_path

Compute a directory hash by reading the directory at path. Each child’s metadata (size, mtime, type) is hashed, then all children are sorted by name and combined into a single BLAKE3 directory fingerprint. Skips foxing internal files (.foxing*, .foxing_meta sidecars).

compute_dir_hash_from_s3_children

Compute a directory hash from S3 child metadata.

get_lite_threshold_bytes

Get the current lite hash threshold in bytes

hash_buffer_full

Full BLAKE3 hash from an in-memory buffer (same algorithm as hash_file_full).

hash_buffer_lite

Lite hash from an in-memory buffer (head+tail sampling, same algorithm as hash_file_lite).

hash_file_checksum

Compute a hex-encoded checksum of a file using the specified algorithm.

hash_file_full

Compute a full BLAKE3 hash of an entire file.

hash_file_lite

Compute a fast BLAKE3 hash from the first and last 64KB of a file (head+tail sampling)

is_hashing_enabled

Check whether BLAKE3 hashing is currently enabled

log_crypto_capabilities

Log detected cryptographic hardware acceleration at startup. Called once during initialization to inform operators which hash algorithms benefit from hardware acceleration on this platform.

map_data_extents

Map allocated data extents in a file using SEEK_DATA/SEEK_HOLE. Returns Vec of (offset, length) pairs for data regions. Returns Err if the filesystem doesn’t support SEEK_HOLE.

set_hashing_enabled

Enable or disable BLAKE3 hashing globally

set_lite_threshold_kb

Set the minimum file size (in KB) for lite hash computation

shannon_entropy

Compute Shannon entropy of a byte slice, returning bits per symbol (0.0-8.0).

verify_incremental

Verify that src and dst have matching lite hashes (returns true if identical or below threshold)

verify_with_merkle

Compare a source file’s Merkle root against a stored signature.

write_checksum_files

Write checksum sidecar files next to a destination file. Format: GNU coreutils-compatible <hash> <filename>\n When cid_format is true and checksum type is BLAKE3, outputs CID base32lower instead of hex.