%contact-store is responsible for sending updates about contacts, eg
profile color. When it hears an update, it fans that out to its
subsribers, unless that update is stale. If you reguarly fan out stale
updates, then they reverberate across the network indefinitely -- we
call this "echoing".
To cut off this echoing, all edits have a timestamp, and we consider any
updates from before this timestamp to be stale. Additions are separate
from edits, and for them we instead do a value comparison on the contact
-- if it didn't change, we consider the update stale.
The problem with this scheme is that if an addition and edit happen one
after the other in quick succession, you might have the following
sequence:
- add comes in with timestamp T1
- edit comes in with timestamp T2 after T1
- we hear an echo of the add, and that errantly applies because it
passes our "did the contact actually change" check
- we hear an echo of the edit, which applies because T2 is after T1
- GOTO 3
Each time we apply the stale update, we fan that out to our subscribers,
and if any two hosts subscribe to each other, this will loop. This may
even loop unconditionally because the ship that made the profile changes
seems like it might not recognize that those changes didn't come from
itself, so it sends them to all the groups it's in. If so, that's an
important issue to fix.
Fixestloncorp/landscape-issues#1442
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.
* master: (33 commits)
groups: updating glob and version
interface: use single sig in NotificationText
interface: fix subscription reconnect issues
landscape: fixing bad glob
landscape: updating glob and version
interface: adds `theme-color` meta tag, removes outdated safari web app meta tag
zuse: add missing assertions
landscape: cache marks again
zuse: comment clarifying sk bounds check
bounds-check against sk=1
zuse: style cleanup, use +rep/+end
pill: solid, brass
interface: refine joining error cases
group-view: fix errored rollback
helm: cleanup +poke-rekey to match #5522
helm: fix |rekey to work with multikey files
test: schnorr bounds checking
zuse: boundary assertions for schnorr
zuse: schnorr test cases
zuse: schnorr address
...
Boot was broken, fixing the hark-note file mark and re-adding the
hark-store library fixed it.
This lets us push a new pill, which is necessary for the fix in #5434 to
actually work.
Fixes#5501Fixes#5502
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.
