* Revert "Fixes/do not override timestamps (#7331)"
This reverts commit 581a5c9d29.
* Document Snowflake ID corner-case a bit more
Snowflake IDs are used for two purposes: making object identifiers harder to
guess and ensuring they are in chronological order. For this reason, they
are based on the `created_at` attribute of the object.
Unfortunately, inserting items with older snowflakes IDs will break the
assumption of consumers of the paging APIs that new items will always have
a greater identifier than the last seen one.
* Add `override_timestamps` virtual attribute to not correlate snowflake ID with created_at
* No need to re-require sidekiq plugins, they are required via Gemfile
* Add derailed_benchmarks tool, no need to require TTY gems in Gemfile
* Replace ruby-oembed with FetchOEmbedService
Reduce startup by 45382 allocated objects
* Remove preloaded JSON-LD in favour of caching HTTP responses
Reduce boot RAM by about 6 MiB
* Fix tests
* Fix test suite by stubbing out JSON-LD contexts
* Add support for separate Redis for cache
CACHE_REDIS_URL to allow using a different Redis server for cache
purposes, with cache-specific configuration such as key eviction
* Fix code style issues
Comparison was downcasing only one side, therefore if previously
existing account had a non-lowercase spelling, it would be ignored
when checking for duplicates.
New rake task `mastodon:maintenance:find_duplicate_usernames` will
help find constraint violations that might have occured from the
presence of this bug.
Bump version to 2.3.3
HTTP connections must be explicitly closed in many cases, and letting
perform method close connections makes its callers less redundant and
prevent them from forgetting to close connections.
* add detailed SMTP settings setup in mastodon:setup
* add localhost SMTP settings setup in mastodon:setup
* SMTP settings setup should exit after successful delivery of test mail
Media attachments are part of the association cache of statuses,
since they are presumed to be immutable. Unless this cache is
cleared manually, the statuses will continue to look like they
have media embedded.
* Ensure the app does not even start if OTP_SECRET is not set
* Remove PAPERCLIP_SECRET (it's not used by anything, actually)
Imports are for internal consumption and the url option isn't even
used correctly, so we can remove the hash stuff from them
* Fix#201: Account archive download
* Export actor and private key in the archive
* Optimize BackupService
- Add conversation to cached associations of status, because
somehow it was forgotten and is source of N+1 queries
- Explicitly call GC between batches of records being fetched
(Model class allocations are the worst offender)
- Stream media files into the tar in 1MB chunks
(Do not allocate media file (up to 8MB) as string into memory)
- Use #bytesize instead of #size to calculate file size for JSON
(Fix FileOverflow error)
- Segment media into subfolders by status ID because apparently
GIF-to-MP4 media are all named "media.mp4" for some reason
* Keep uniquely generated filename in Paperclip::GifTranscoder
* Ensure dumped files do not overwrite each other by maintaing directory partitions
* Give tar archives a good name
* Add scheduler to remove week-old backups
* Fix code style issue
* Fix avatar and header issues by using custom geometry detector
Revert a part of #6508. The file passed to dynamic styles method
was not actually a file, but an instance of Paperclip::Attachment,
which broke all styles by always returning {} from the method.
One problem with GIF avatars was that Paperclip::GeometryDetector
reported wrong dimensions for them, e.g. 120x120 GIF avatar would
for some reason be detected as 120x53. By writing our own geometry
parser, we can use FastImage, which also happens to be faster than
ImageMagick, to detect image dimensions, which are also correct.
Unfortunately, this PR does not implement skipping a `convert`
entirely if the dimensions are already correct, as I found no easy
way to write that behaviour into Paperclip without rewriting the
Paperclip::Thumbnail class.
* Only invoke convert if dimension or format needs to be changed
* Add better CLI prompt
* Add rake mastodon:setup interactive wizard
* Test db/redis/smtp configurations and add admin user at the end
* Test database connection even when database does not exist yet
* Use PNG images in HTML e-mails
* Make webpack use URLs with host so fonts load inside HTML e-mails
Convert this back to a relative URL in the premailer CSS loader
since local requests are quicker
* Improve responsive design
* Add missing PNG icon
* Add rake task to check and purge accounts that are missing in origin
* Add progress bar and --force options to mastodon:maintenance:purge_removed_accounts
* Add moderator role and add pundit policies for admin actions
* Add rake task for turning user into mod and revoking it again
* Fix handling of unauthorized exception
* Deliver new report e-mails to staff, not just admins
* Add promote/demote to admin UI, hide some actions conditionally
* Fix unused i18n
- Rename Mastodon::TimestampIds into Mastodon::Snowflake for clarity
- Skip for statuses coming from inbox, aka delivered in real-time
- Skip for statuses that claim to be from the future
* Use non-serial IDs
This change makes a number of nontrivial tweaks to the data model in
Mastodon:
* All IDs are now 8 byte integers (rather than mixed 4- and 8-byte)
* IDs are now assigned as:
* Top 6 bytes: millisecond-resolution time from epoch
* Bottom 2 bytes: serial (within the millisecond) sequence number
* See /lib/tasks/db.rake's `define_timestamp_id` for details, but
note that the purpose of these changes is to make it difficult to
determine the number of objects in a table from the ID of any
object.
* The Redis sorted set used for the feed will have values used to look
up toots, rather than scores. This is almost always the same as the
existing behavior, except in the case of boosted toots. This change
was made because Redis stores scores as double-precision floats,
which cannot store the new ID format exactly. Note that this doesn't
cause problems with sorting/pagination, because ZREVRANGEBYSCORE
sorts lexicographically when scores are tied. (This will still cause
sorting issues when the ID gains a new significant digit, but that's
extraordinarily uncommon.)
Note a couple of tradeoffs have been made in this commit:
* lib/tasks/db.rake is used to enforce many/most column constraints,
because this commit seems likely to take a while to bring upstream.
Enforcing a post-migrate hook is an easier way to maintain the code
in the interim.
* Boosted toots will appear in the timeline as many times as they have
been boosted. This is a tradeoff due to the way the feed is saved in
Redis at the moment, but will be handled by a future commit.
This would effectively close Mastodon's #1059, as it is a
snowflake-like system of generating IDs. However, given how involved
the changes were simply within Mastodon, it may have unexpected
interactions with some clients, if they store IDs as doubles
(or as 4-byte integers). This was a problem that Twitter ran into with
their "snowflake" transition, particularly in JavaScript clients that
treated IDs as JS integers, rather than strings. It therefore would be
useful to test these changes at least in the web interface and popular
clients before pushing them to all users.
* Fix JavaScript interface with long IDs
Somewhat predictably, the JS interface handled IDs as numbers, which in
JS are IEEE double-precision floats. This loses some precision when
working with numbers as large as those generated by the new ID scheme,
so we instead handle them here as strings. This is relatively simple,
and doesn't appear to have caused any problems, but should definitely
be tested more thoroughly than the built-in tests. Several days of use
appear to support this working properly.
BREAKING CHANGE:
The major(!) change here is that IDs are now returned as strings by the
REST endpoints, rather than as integers. In practice, relatively few
changes were required to make the existing JS UI work with this change,
but it will likely hit API clients pretty hard: it's an entirely
different type to consume. (The one API client I tested, Tusky, handles
this with no problems, however.)
Twitter ran into this issue when introducing Snowflake IDs, and decided
to instead introduce an `id_str` field in JSON responses. I have opted
to *not* do that, and instead force all IDs to 64-bit integers
represented by strings in one go. (I believe Twitter exacerbated their
problem by rolling out the changes three times: once for statuses, once
for DMs, and once for user IDs, as well as by leaving an integer ID
value in JSON. As they said, "If you’re using the `id` field with JSON
in a Javascript-related language, there is a very high likelihood that
the integers will be silently munged by Javascript interpreters. In most
cases, this will result in behavior such as being unable to load or
delete a specific direct message, because the ID you're sending to the
API is different than the actual identifier associated with the
message." [1]) However, given that this is a significant change for API
users, alternatives or a transition time may be appropriate.
1: https://blog.twitter.com/developer/en_us/a/2011/direct-messages-going-snowflake-on-sep-30-2011.html
* Restructure feed pushes/unpushes
This was necessary because the previous behavior used Redis zset scores
to identify statuses, but those are IEEE double-precision floats, so we
can't actually use them to identify all 64-bit IDs. However, it leaves
the code in a much better state for refactoring reblog handling /
coalescing.
Feed-management code has been consolidated in FeedManager, including:
* BatchedRemoveStatusService no longer directly manipulates feed zsets
* RemoveStatusService no longer directly manipulates feed zsets
* PrecomputeFeedService has moved its logic to FeedManager#populate_feed
(PrecomputeFeedService largely made lots of calls to FeedManager, but
didn't follow the normal adding-to-feed process.)
This has the effect of unifying all of the feed push/unpush logic in
FeedManager, making it much more tractable to update it in the future.
Due to some additional checks that must be made during, for example,
batch status removals, some Redis pipelining has been removed. It does
not appear that this should cause significantly increased load, but if
necessary, some optimizations are possible in batch cases. These were
omitted in the pursuit of simplicity, but a batch_push and batch_unpush
would be possible in the future.
Tests were added to verify that pushes happen under expected conditions,
and to verify reblog behavior (both on pushing and unpushing). In the
case of unpushing, this includes testing behavior that currently leads
to confusion such as Mastodon's #2817, but this codifies that the
behavior is currently expected.
* Rubocop fixes
I could swear I made these changes already, but I must have lost them
somewhere along the line.
* Address review comments
This addresses the first two comments from review of this feature:
https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336735https://github.com/tootsuite/mastodon/pull/4801#discussion_r139336931
This adds an optional argument to FeedManager#key, the subtype of feed
key to generate. It also tests to ensure that FeedManager's settings are
such that reblogs won't be tracked forever.
* Hardcode IdToBigints migration columns
This addresses a comment during review:
https://github.com/tootsuite/mastodon/pull/4801#discussion_r139337452
This means we'll need to make sure that all _id columns going forward
are bigints, but that should happen automatically in most cases.
* Additional fixes for stringified IDs in JSON
These should be the last two. These were identified using eslint to try
to identify any plain casts to JavaScript numbers. (Some such casts are
legitimate, but these were not.)
Adding the following to .eslintrc.yml will identify casts to numbers:
~~~
no-restricted-syntax:
- warn
- selector: UnaryExpression[operator='+'] > :not(Literal)
message: Avoid the use of unary +
- selector: CallExpression[callee.name='Number']
message: Casting with Number() may coerce string IDs to numbers
~~~
The remaining three casts appear legitimate: two casts to array indices,
one in a server to turn an environment variable into a number.
* Only implement timestamp IDs for Status IDs
Per discussion in #4801, this is only being merged in for Status IDs at
this point. We do this in a migration, as there is no longer use for
a post-migration hook. We keep the initialization of the timestamp_id
function as a Rake task, as it is also needed after db:schema:load (as
db/schema.rb doesn't store Postgres functions).
* Change internal streaming payloads to stringified IDs as well
This is equivalent to 591a9af356faf2d5c7e66e3ec715502796c875cd from
#5019, with an extra change for the addition to FeedManager#unpush.
* Ensure we have a status_id_seq sequence
Apparently this is not a given when specifying a custom ID function,
so now we ensure it gets created. This uses the generic version of this
function to more easily support adding additional tables with timestamp
IDs in the future, although it would be possible to cut this down to a
less generic version if necessary. It is only run during db:schema:load
or the relevant migration, so the overhead is extraordinarily minimal.
* Transition reblogs to new Redis format
This provides a one-way migration to transition old Redis reblog entries
into the new format, with a separate tracking entry for reblogs.
It is not invertible because doing so could (if timestamp IDs are used)
require a database query for each status in each users' feed, which is
likely to be a significant toll on major instances.
* Address review comments from @akihikodaki
No functional changes.
* Additional review changes
* Heredoc cleanup
* Run db:schema:load hooks for test in development
This matches the behavior in Rails'
ActiveRecord::Tasks::DatabaseTasks.each_current_configuration, which
would otherwise break `rake db:setup` in development.
It also moves some functionality out to a library, which will be a good
place to put additional related functionality in the near future.
* Make IdsToBigints (mostly!) non-blocking
This pulls in GitLab's MigrationHelpers, which include code to make
column changes in ways that Postgres can do without locking. In general,
this involves creating a new column, adding an index and any foreign
keys as appropriate, adding a trigger to keep it populated alongside
the old column, and then progressively copying data over to the new
column, before removing the old column and replacing it with the new
one.
A few changes to GitLab's MigrationHelpers were necessary:
* Some changes were made to remove dependencies on other GitLab code.
* We explicitly wait for index creation before forging ahead on column
replacements.
* We use different temporary column names, to avoid running into index
name length limits.
* We rename the generated indices back to what they "should" be after
replacing columns.
* We rename the generated foreign keys to use the new column names when
we had to create them. (This allows the migration to be rolled back
without incident.)
# Big Scary Warning
There are two things here that may trip up large instances:
1. The change for tables' "id" columns is not concurrent. In
particular, the stream_entries table may be big, and does not
concurrently migrate its id column. (On the other hand, x_id type
columns are all concurrent.)
2. This migration will take a long time to run, *but it should not
lock tables during that time* (with the exception of the "id"
columns as described above). That means this should probably be run
in `screen` or some other session that can be run for a long time.
Notably, the migration will take *longer* than it would without
these changes, but the website will still be responsive during that
time.
These changes were tested on a relatively large statuses table (256k
entries), and the service remained responsive during the migration.
Migrations both forward and backward were tested.
* Rubocop fixes
* MigrationHelpers: Support ID columns in some cases
This doesn't work in cases where the ID column is referred to as a
foreign key by another table.
* MigrationHelpers: support foreign keys for ID cols
Note that this does not yet support foreign keys on non-primary-key
columns, but Mastodon also doesn't yet have any that we've needed to
migrate.
This means we can perform fully "concurrent" migrations to change ID
column types, and the IdsToBigints migration can happen with effectively
no downtime. (A few operations require a transaction, such as renaming
columns or deleting them, but these transactions should not block for
noticeable amounts of time.)
The algorithm for generating foreign key names has changed with this,
and therefore all of those changed in schema.rb.
* Provide status, allow for interruptions
The MigrationHelpers now allow restarting the rename of a column if it
was interrupted, by removing the old "new column" and re-starting the
process.
Along with this, they now provide status updates on the changes which
are happening, as well as indications about when the changes can be
safely interrupted (when there are at least 10 seconds estimated to be
left before copying data is complete).
The IdsToBigints migration now also sorts the columns it migrates by
size, starting with the largest tables. This should provide
administrators a worst-case scenario estimate for the length of
migrations: each successive change will get faster, giving admins a
chance to abort early on if they need to run the migration later. The
idea is that this does not force them to try to time interruptions
between smaller migrations.
* Fix column sorting in IdsToBigints
Not a significant change, but it impacts the order of columns in the
database and db/schema.rb.
* Actually pause before IdsToBigints
- 500.html generated with admin-set default locale if set
- Error page `<title>` includes Mastodon site title
- 500 title changed to "This page is not
correct" (ref: <https://www.youtube.com/watch?v=2VCAP_seh1A>)
- 500 content appended with "on our end" to make clear it's
not user's fault
A new rake task emojis:generate downloads a full list of valid
unicode sequences from unicode.org and checks it against existing
Twemoji files, finally generating a map from each sequence to the
existing file (e.g. when there's multiple ways an emoji can be
expressed). The map is dumped into app/javascript/mastodon/emoji_map.json
That file is loaded by emojione_light.js (now a misnomer) which
decorates it further with shortcodes taken from emoji-mart's index.
* Add emoji autosuggest
Some credit goes to glitch-soc/mastodon#149
* Remove server-side shortcode->unicode conversion
* Insert shortcode when suggestion is custom emoji
* Remove remnant of server-side emojis
* Update style of autosuggestions
* Fix wrong emoji filenames generated in autosuggest item
* Do not lazy load emoji picker, as that no longer works
* Fix custom emoji autosuggest
* Fix multiple "Custom" categories getting added to emoji index, only add once
* Revert "Enable UniqueRetryJobMiddleware even when called from sidekiq worker (#4836)"
This reverts commit 6859d4c028.
* Revert "Do not execute the job with the same arguments as the retry job (#4814)"
This reverts commit be7ffa2d75.
They are marked as read-only by Rails, but we know what we are doing,
so we are un-marking them as such.
The mastodon:maintenance:update_counter_caches task is not really
supposed to be run anymore (it was a one-time thing during an upgrade)
however, just in case, I have modified it to not touch ActivityPub
accounts.
Also, no point writing to logger from these rake tasks, since they
are not to be run from cron. Better to give stdout feedback.
* Use casecmp() instead of casecmp?() for now
casecmp?() is only available in ruby 2.4.0. Users running earlier ruby versions
would see errors, e.g., running
RAILS_ENV=production rails mastodon:maintenance:remove_deprecated_preview_cards.
* Correctly check whether casecmp() returns 0
* Make PreviewCard records reuseable between statuses
**Warning!** Migration truncates preview_cards tablec
* Allow a wider thumbnail for link preview, display it in horizontal layout (#4648)
* Delete preview cards files before truncating
* Rename old table instead of truncating it
* Add mastodon:maintenance:remove_deprecated_preview_cards
* Ignore deprecated_preview_cards in schema definition
* Fix null behaviour
* Add handling of Linked Data Signatures in payloads
* Add a way to sign JSON, fix canonicalization of signature options
* Fix signatureValue encoding, send out signed JSON when distributing
* Add missing security context
* ActivityPub migration procedure
Once one account is detected as going from OStatus to ActivityPub,
invalidate WebFinger cache for other accounts from the same domain
* Unsubscribe from PuSH updates once we receive an ActivityPub payload
* Re-subscribe to PuSH unless already unsubscribed, regardless of protocol
* Use the same emoji data on the frontend and backend
* Move emoji.json to repository, add tests
This way you don't need to install node dependencies if you only
want to run Ruby code
* Redesign the landing page, mount public timeline on it
* Adjust the standalone mounted component to the lacking of router
* Adjust auth layout pages to new design
* Fix tests
* Standalone public timeline polling every 5 seconds
* Remove now obsolete translations
* Add responsive design for new landing page
* Address reviews
* Add floating clouds behind frontpage form
* Use access token from public page when available
* Fix mentions and hashtags links, cursor on status content in standalone mode
* Add footer link to source code
* Fix errors on pages that don't embed the component, use classnames
* Fix tests
* Change anonymous autoPlayGif default to false
* When gif autoplay is disabled, hover to play
* Add option to hide the timeline preview
* Slightly improve alt layout
* Add elephant friend to new frontpage
* Display "back to mastodon" in place of "login" when logged in on frontpage
* Change polling time to 3s
* Add rake task to prepare database for foreign keys introduced by #3562
* Fix typo
* Do not delete OAuth values where NULL values may be permitted
* Fix typo
Because Nanobox doesn't run data components in the same container as the code, there are a few tweaks that need to be made in the configuration to get WebPack to work properly in development mode.
The same differences lead to needing to use `DATABASE_URL` by default in the `.env` file for Rails to work correctly.
Limitations of our `.env` loader for Node.js mean the `.env` file needs to be compiled everywhere in order to work, so we compile it in development, now, too. Also, all the `.env.production` tweaks have been consolidated into a single command.
Finally, since Nanobox actually creates the database when it sets up the database server, using the existence of the database alone to determine whether to migrate or setup is insufficient. So we add a condition to `rake db:migrate:setup` to check whether any migrations have run - if the database doesn't exist yet, `db:setup` will be called; if it does, but no migrations have been run, `db:migrate` and `db:seed` are called instead (the same basic idea as what `db:setup` does, but it skips `db:create`, which will only cause problems with an existing DB); otherwise, only `db:migrate` is called.
None of these changes should affect development, and all are designed not to interfere with existing behaviors in other environments.
* Nanobox Support
- Added support for running Mastodon using Nanobox, both for local development, and for deployment to production
- Dev mode tested and is working properly
- Deployment is undergoing test as of this writing. If it works, this line will be amended to state success; if not, one or more subsequent commits will provide fixes.
* [nanobox] Resolve Deploy Issues
Everything seems to work except routing to the streaming API. Will investigate with the Nanobox staff and make fix commits if needed.
Changes made:
- Also need `NODE_ENV` in production
- Node runs on `:4000`
- Use `envsubst` to commit `.env.production` values, since `dotEnv` packages don't always support referencing other variables
- Can't precompile assets after `transform` hook, but do this locally so it only has to be done once.
- Rails won't create `production.log` on its own, so we do this ourselves.
- Some `start` commands run from `/data/` for some reason, so use absolute paths in command arguments
* [nanobox] Update Ruby version
* [nanobox] Fix db.rake Ruby code style issues
* [nanobox] Minor Fixes
Some minor adjustments to improve functionality:
- Fixed routing to `web.stream` instances
- Adjust `.env.nanobox` to properly generate a default `SMTP_FROM_ADDRESS` via `envsubst`
- Update Nginx configs to properly support the needed HTTP version and headers for proper functionality (the streaming API doesn't work without some of these settings in place)
* [nanobox] Move usage info to docs repo
* [nanobox] Updates for 1.2.x
- Need to leave out `pkg-config` since Nanobox deploys without Ruby's headers - create a gem group to exclude the gem during Nanobox installs, but allow it to remain part of the default set otherwise
- Update cron jobs to cover new/updated Rake tasks
- Update `.env.nanobox` to include latest defaults and additions
* [nanobox] Fix for nokogumbo, added in 1.3.x
Apparently, nokogumbo (pulled in by sanitize, added with `OEmbed Support for PreviewCard` (#2337) - 88725d6) tries to install before nokogiri, despite needing nokogiri available to build properly. Instruct it to use the same settings as nokogiri does when building nokogiri directly, instead of via bundler.
* [nanobox] Set NODE_ENV during asset compile
The switch to WebPack will rely on the local value of the NODE_ENV evar, so set it to production during asset compilation.
* [nanobox] Rebase on master; update Nginx configs
- `pkg-config` Gem no longer causes issues in Nanobox, so revert the Gemfile change which allowed excluding it
- Update Nginx configuration files with latest recommendations from production documentation
- Rebase on master to Get This Merged™
Everything should be golden!
* Fix#2473 - Use sidekiq scheduler to refresh PuSH subscriptions instead of cron
Fix an issue where / in domain would raise exception in TagManager#normalize_domain
PuSH subscriptions refresh done in a round-robin way to avoid hammering a single
server's hub in sequence. Correct handling of failures/retries through Sidekiq (see
also #2613). Optimize Account#with_followers scope. Also, since subscriptions
are now delegated to Sidekiq jobs, an uncaught exception will not stop the entire
refreshing operation halfway through
Fix#2702 - Correct user agent header on outgoing http requests
* Add test for SubscribeService
* Extract #expiring_accounts into method
* Make mastodon:push:refresh no-op
* Queues are now defined in sidekiq.yml
* Queues are now in sidekiq.yml
* add annotate to Gemfile
* rails g annotate:install
* configure annotate_models
* add schema info to models
* fix rubocop to add frozen_string_literal
Follow-up to #2599. When a domain block with `reject_media` is
added or `rake mastodon:media:remove_remote` is invoked, mastodon
deletes the locally cached attachments and avatars but does not
reflect that change in the database, causing the `file` fields to
still have values. This change persists the deletion in the
database and sets the attachment type to unknown.
This also introduces a one-off rake task that sets all attachments
without a local file to the "unknown" type. The upgrade notes for
the next release should contain a post-upgrade step with
`rake mastodon:media:set_unknown`.
* Fix#2108 - Fix gif uploads
Add specs for media attachment gifv conversion
* Add ffmpeg to travis
* Make travis install ffmpeg, not libav
* Switch travis to trusty
* Remove unused method #set_counters_maps from api controller
* Remove unused method #set_account_counters_maps from api controller
* Remove unused method Account#followers_domains
* Remove unused User.prolific scope
* Add mastodon:users:admins task to list all admin emails
* Use interpolated query style in Account.triadic_closures
* Coverage for Account.triadic_closures
* Unite all mandatory rake tasks in mastodon:daily
Add mastodon:media:remove_remote task
Make mastodon:maintenance:add_static_avatars more resilient to exceptions
* Fix typo in task description
Before it cleared out user records only (e-mail, password) without
freeing up the associated username (account record). Furthermore, since
these records have no dependent records (due to no user activity)
they can be deleted quickly with delete_all instead of destroy
* When avatar/header are GIF, generate static versions.
Account API returns "avatar"/"avatar_static", "header"/"header_static"
Static version is the same as original for other cases
Web UI de-animates avatars in toots, lists of users
Fix#441, fix#596, prerequisite for #1064
* Fix JS test
* Add rake task to generate static avatars/headers from GIF ones, add test
before. In the API, attachments now can be either image, video or gifv. Gifv
is to be treated like images in terms of behaviour, but are videos by file
type.
