On Tue, Aug 15, 2017 at 7:48 PM, Shawn Pearce <spearce@xxxxxxxxxxx> wrote: > 7th iteration of the reftable storage format. > > You can read a rendered version of this here: > https://googlers.googlesource.com/sop/jgit/+/reftable/Documentation/technical/reftable.md > > Changes from v6: > - Blocks are variable sized, and alignment is optional. > - ref index is required on variable sized multi-block files. > > - restart_count/offsets are again at the end of the block. > - value_type = 0x3 is only for symbolic references. > - "other" files cannot be stored in reftable. > > - object blocks are explicitly optional. > - object blocks use position (offset in bytes), not block id. > - removed complex log_chained format for log blocks > > - Layout uses log, ref file extensions > - Described reader algorithm to obtain a snapshot - back to the old "intra-block index is last" for all block types. ok. - changed (only ref?) indexes to start char + 3 byte size: Which starting char do object/log indexes have? "Unaligned files must include the ref index to support fast lookup." Why this? I would imagine the client (which has ~5 branches), would not need this, but only a ref block, that's it. Ctrl-F for 'block_size' reveals nothing is computed relative to the block_size in this format, yet we can set it to an arbitrary number. If following the spec, the reader at $DAY_JOB needs to be able to read both aligned and unaligned reftables, despite our plan to ever write aligned ref tables, what would the reader use the block_size for? (I think we can omit that field from the header/footer now, no?)
