Module protocol 

Structs

LogHeader

Decoded header for one xlog block.

SeqGenerator

Async sequence generator matching Mars xlog semantics.

Enums

AppendMode

Append path encoded into the xlog magic byte.

CompressionKind

Compression family encoded into the xlog magic byte.

ProtocolError

Errors returned by header decode/mutation helpers.

Constants

HEADER_CLIENT_PUBKEY_OFFSET

Byte offset of the encoded client public key field.

HEADER_END_HOUR_OFFSET

Byte offset of the encoded end-hour field.

HEADER_LEN

Byte length of one encoded xlog header.

HEADER_LEN_OFFSET

Byte offset of the encoded payload-length field.

MAGIC_ASYNC_NO_CRYPT_ZLIB_START

Magic byte for async + zlib + plaintext blocks.

MAGIC_ASYNC_NO_CRYPT_ZSTD_START

Magic byte for async + zstd + plaintext blocks.

MAGIC_ASYNC_ZLIB_START

Magic byte for async + zlib + encrypted blocks.

MAGIC_ASYNC_ZSTD_START

Magic byte for async + zstd + encrypted blocks.

MAGIC_END

Tail marker terminating a complete xlog block.

MAGIC_SYNC_NO_CRYPT_ZLIB_START

Magic byte for sync + zlib + plaintext blocks.

MAGIC_SYNC_NO_CRYPT_ZSTD_START

Magic byte for sync + zstd + plaintext blocks.

MAGIC_SYNC_ZLIB_START

Magic byte for sync + zlib + encrypted blocks.

MAGIC_SYNC_ZSTD_START

Magic byte for sync + zstd + encrypted blocks.

TAILER_LEN

Byte length of the trailing end marker.

Functions

magic_start_is_valid

Return whether magic is one of the supported xlog start markers.

select_magic

Select the xlog magic byte for a (compression, append mode, crypto) tuple.

update_end_hour_in_place

Update the encoded end-hour field inside an existing header.

update_log_len_in_place

Add add_len to the payload length stored in an encoded header.