Previously, the initial Azimuth snapshot was stored in Clay and shipped
in the pill. This causes several problems:
- It bloats the pill
- Updating the snapshot added large blobs to Clay's state. Even now
that tombstoning is possible, you don't want to have to do that
regularly.
- As a result, the snapshot was never updated.
- Even if you did tombstone those files, it could only be updated as
often as the pill
- And those updates would be sent over the network to people who didn't
need them
This moves the snapshot out of the pill and refactors Azimuth's
initialization process. On boot, when app/azimuth starts up, it first
downloads a snapshot from bootstrap.urbit.org and uses that to
initialize its state. As before, updates after this initial snapshot
come from an Ethereum node directly and are verified locally.
Relevant commands are:
- `-azimuth-snap-state %filename` creates a snapshot file
- `-azimuth-load "url"` downloads and inits from a snapshot, with url
defaulting to https://bootstrap.urbit.org/mainnet.azimuth-snapshot
- `:azimuth &azimuth-poke-data %load snap-state` takes a snap-state any
way you have it
Note the snapshot is downloaded from the same place as the pill, so this
doesn't introduce additional trust beyond what was already required.
When remote scry is released, we should consider allowing downloading
the snapshot in that way.
This converts the blob store from having deltas, directs, and
tombstones, to just having direct pages. This simplifies a lot of code,
since we don't have to constantly ensure that deltas always have their
parent available.
This removes the hardcoded text diff logic from clay, which was
previously required for bootstrapping.
Over the wire, we handle both old and new requests and responses
transparently, so communication is normal in both directions across
ships which do or do not have this change.
We had trie operations independently implemented in +de in arvo,
+an:cloy in zuse, +zu in clay, lib/trie, and app/spider. This unifies
them all into +de in arvo, aggregating the used operations.
Threads should eventually take and produce $cage instead of $vase. Since
%khan is likely to be used by third parties, we write to the eventual
intended API. We ignore the mark on the input $cage (it is safe to
always specify %noun), and we always use %noun as the output mark.
%fyrd now makes more sense. It was previously discarding the type of the
output %arow and re-encoding the raw noun as a vase of the output mark;
it is now performing mark conversion from the mark of the output $cage
to the originally requested output mark.
Also strips out `$` from khan top-level comment.
There are arguments for keeping $crag in lull, and on the other side for
moving $cast to arvo. This seemed like the most reasonable approach.
%fyrd is now implemented in terms of %fard, and likewise %avow in terms
of %arow. State is tracked via wire rather than in a global map.
Unit tests adjusted to match.
These take and produce vases, and assign random tids (rather than
deducing them from the input duct.)
Since %fard does not require mark conversion, we make the mark/beak on
$thread-state optional (and use this to decide whether to send %avow or
%arow.) Provide a state adapter since it's possible that people have
been experimenting with this vane.
This makes the negative case of %avow/%arow kind of clunky, since there
is no content difference, but the following does not seem possible
within the Hoon type system:
=/ gif
?~ p.tad
%arow %avow
[hen %give gif %| p.cag tang]~
This adds support for tombstoned files to clay. It does not include any
way to actually tombstone them; that is left for later.
This allows tombstoning at the level of a file. Precisely, this expands
+blob:clay by adding a %dead case:
+$ blob :: fs blob
$% [%delta p=lobe q=[p=mark q=lobe] r=page] :: delta on q
[%direct p=lobe q=page] :: immediate
[%dead p=lobe ~] :: tombstone
== ::
Thus, we maintain the invariant that every lobe corresponds to a blob,
but now a blob may be an explicit tombstone.
Details:
- This has not been tested at all, except that it compiles and boots.
- This does not have a state adapter from master. The only state change
is the definition of +cach.
- Additionally, out-of-date ships may unexpectedly receive a %dead blob
from a foreign clay which would interfere with their ability to download
that desk. No code changes necessary, but sponsors should avoid
tombstoning files in %base for a while so their children can get the
update.
- A merge will only fail if the tombstoned file conflicts with another
change. Note that as written, merging from a past desk *can* bring a
tombstoned file to the head of a desk. Possibly this shouldn't be
allowed.
This also includes a couple refactors that were made possible by ford
fusion (since everything is synchronous now) but never got done. In
both cases we get to remove a monad, which simplifies the code
considerably.
- refactor +merge's error handling to use !!/mule instead of threading
through errors
- refactor all +read-* functions and related parts of +try-fill-sub to
eagerly convert lobes to cages.
We also add support reading %a/b/c/e/f/r/x from past and foreign desks,
when possible. Apologies that all of these are in one commit, it was
all a single chunk of work.
This is a draft until we have a way to tombstone. I suspect we'll want
to have a mechanism of keeping track of gc roots and trace to remove,
but this PR doesn't suggest any particular strategy.
