Commit graph

53 commits

Author SHA1 Message Date
Neil Alexander
e1ace7e44a
Add event ID index on current state table (helps performance) (#1649) 2020-12-16 18:16:39 +00:00
Neil Alexander
ebcacd1bb5
Give receipts their own stream ID in the database (#1631)
* Give read recipts their own database sequence

* Give receipts their own stream ID

* Change migration names

* Reset sequences

* Add max receipt queries, missing stream_id table entry for SQLite
2020-12-11 14:02:17 +00:00
Neil Alexander
bad81c028f
Don't recalculate event ID so often in sync (#1624)
* Don't bail so quickly in fetchMissingStateEvents

* Don't recalculate event IDs so often in sync API

* Add comments

* Fix comments

* Update to matrix-org/gomatrixserverlib@eb6a890
2020-12-09 18:07:17 +00:00
Neil Alexander
b5aa7ca3ab
Top-level setup package (#1605)
* Move config, setup, mscs into "setup" top-level folder

* oops, forgot the EDU server

* Add setup

* goimports
2020-12-02 17:41:00 +00:00
Neil Alexander
20a01bceb2
Pass pointers to events — reloaded (#1583)
* Pass events as pointers

* Fix lint errors

* Update gomatrixserverlib

* Update gomatrixserverlib

* Update to matrix-org/gomatrixserverlib#240
2020-11-16 15:44:53 +00:00
S7evinK
bcb89ada5e
Implement read receipts (#1528)
* fix conversion from int to string yields a string of one rune, not a string of digits

* Add receipts table to syncapi

* Use StreamingToken as the since value

* Add required method to testEDUProducer

* Make receipt json creation "easier" to read

* Add receipts api to the eduserver

* Add receipts endpoint

* Add eduserver kafka consumer

* Add missing kafka config

* Add passing tests to whitelist

Signed-off-by: Till Faelligen <tfaelligen@gmail.com>

* Fix copy & paste error

* Fix column count error

* Make outbound federation receipts pass

* Make "Inbound federation rejects receipts from wrong remote" pass

* Don't use errors package

* - Add TODO for batching requests
- Rename variable

* Return a better error message

* - Use OutputReceiptEvent instead of InputReceiptEvent as result
- Don't use the errors package for errors
- Defer CloseAndLogIfError to close rows
- Fix Copyright

* Better creation/usage of JoinResponse

* Query all joined rooms instead of just one

* Update gomatrixserverlib

* Add sqlite3 migration

* Add postgres migration

* Ensure required sequence exists before running migrations

* Clarification on comment

* - Fix a bug when creating client receipts
- Use concrete types instead of interface{}

* Remove dead code
Use key for timestamp

* Fix postgres query...

* Remove single purpose struct

* Use key/value directly

* Only apply receipts on initial sync or if edu positions differ,
otherwise we'll be sending the same receipts over and over again.

* Actually update the id, so it is correctly send in syncs

* Set receipt on request to /read_markers

* Fix issue with receipts getting overwritten

* Use fmt.Errorf instead of pkg/errors

* Revert "Add postgres migration"

This reverts commit 722fe5a04628882b787d096942459961db159b06.

* Revert "Add sqlite3 migration"

This reverts commit d113b03f6495a4b8f8bcf158a3d00b510b4240cc.

* Fix selectRoomReceipts query

* Make golangci-lint happy

Co-authored-by: Neil Alexander <neilalexander@users.noreply.github.com>
2020-11-09 18:46:11 +00:00
Sam
a6700331ce
Update all usages of tx.Stmt to sqlutil.TxStmt (#1423)
* Replace all usages of txn.Stmt with sqlutil.TxStmt

Signed-off-by: Sam Day <me@samcday.com>

* Fix sign off link in PR template.

Signed-off-by: Sam Day <me@samcday.com>

Co-authored-by: Neil Alexander <neilalexander@users.noreply.github.com>
2020-09-24 11:10:14 +01:00
Neil Alexander
965f068d1a
Handle state with input event as new events (#1415)
* SendEventWithState events as new

* Use cumulative state IDs for final event

* Error wrapping in calculateAndSetState

* Handle overwriting same event type and state key

* Hacky way to spot historical events

* Don't exclude from sync

* Don't generate output events when rewriting forward extremities

* Update output event check

* Historical output events

* Define output room event type

* Notify key changes on state

* Don't send our membership event twice

* Deduplicate state entries

* Tweaks

* Remove unnecessary nolint

* Fix current state upsert in sync API

* Send auth events as outliers, state events as rewrite

* Sync API don't consume state events

* Process events actually

* Improve outlier check

* Fix local room check

* Remove extra room check, it seems to break the whole damn world

* Fix federated join check

* Fix nil pointer exception

* Better comments on DeduplicateStateEntries

* Reflow forced federated joins

* Don't force federated join for possibly even local invites

* Comment SendEventWithState better

* Rewrite room state in sync API storage

* Add TODO

* Clean up all room data when receiving create event

* Don't generate output events for rewrites, but instead notify that state is rewritten on the final new event

* Rename to PurgeRoom

* Exclude backfilled messages from /sync

* Split out rewriting state from updating state from state res

Co-authored-by: Kegan Dougal <kegan@matrix.org>
2020-09-15 11:17:46 +01:00
Matthew Hodgson
39507bacc3
Peeking via MSC2753 (#1370)
Initial implementation of MSC2753, as tested by https://github.com/matrix-org/sytest/pull/944.
Doesn't yet handle unpeeks, peeked EDUs, or history viz changing during a peek - these will follow.
https://github.com/matrix-org/dendrite/pull/1370 has full details.
2020-09-10 14:39:18 +01:00
Neil Alexander
a9f4d83d30
Fix duplicate writers (#1376)
* Fix writers

* Don't use writers in both shared and sqlite3
2020-09-01 16:58:21 +01:00
Neil Alexander
0ab5bccd11
Storage tweaks (#1373)
* Sync API tweaks

* User API tweaks
2020-09-01 11:28:35 +01:00
Kegsay
55498c8deb
Fix 'Invited user can reject invite over federation several times' (#1341) 2020-08-25 18:59:00 +01:00
Neil Alexander
9d53351dc2
Component-wide TransactionWriters (#1290)
* Offset updates take place using TransactionWriter

* Refactor TransactionWriter in current state server

* Refactor TransactionWriter in federation sender

* Refactor TransactionWriter in key server

* Refactor TransactionWriter in media API

* Refactor TransactionWriter in server key API

* Refactor TransactionWriter in sync API

* Refactor TransactionWriter in user API

* Fix deadlocking Sync API tests

* Un-deadlock device database

* Fix appservice API

* Rename TransactionWriters to Writers

* Move writers up a layer in sync API

* Document sqlutil.Writer interface

* Add note to Writer documentation
2020-08-21 10:42:08 +01:00
Neil Alexander
5aaf32bbed
Select distinct on room memberships in sync API (#1292) 2020-08-21 09:57:52 +01:00
Neil Alexander
b24747b305
Transaction writer changes, move roomserver writers (#1285)
* Updated TransactionWriters, moved locks in roomserver, various other tweaks

* Fix redaction deadlocks

* Fix lint issue

* Rename SQLiteTransactionWriter to ExclusiveTransactionWriter

* Fix us not sending transactions through in latest events updater
2020-08-19 15:38:27 +01:00
Neil Alexander
4b09f445c9
Configuration format v1 (#1230)
* Initial pass at refactoring config (not finished)

* Don't forget current state and EDU servers

* More shifting around

* Update server key API tests

* Fix roomserver test

* Fix more tests

* Further tweaks

* Fix current state server test (sort of)

* Maybe fix appservices

* Fix client API test

* Include database connection string in database options

* Fix sync API build

* Update config test

* Fix unit tests

* Fix federation sender build

* Fix gobind build

* Set Listen address for all services in HTTP monolith mode

* Validate config, reinstate appservice derived in directory, tweaks

* Tweak federation API test

* Set MaxOpenConnections/MaxIdleConnections to previous values

* Update generate-config
2020-08-10 14:18:04 +01:00
Henrik Sölver
83f038e12b
Don't use more than 999 variables in SQLite querys. (#1224)
Closes #1223

Signed-off-by: Henrik Sölver <henrik.solver@gmail.com>

Co-authored-by: Neil Alexander <neilalexander@users.noreply.github.com>
2020-07-27 13:19:30 +01:00
Neil Alexander
b6bc132485
Use TransactionWriter in other component SQLite (#1209)
* Use TransactionWriter on other component SQLites

* Fix sync API tests

* Fix panic in media API

* Fix a couple of transactions

* Fix wrong query, add some logging output

* Add debug logging into StoreEvent

* Adjust InsertRoomNID

* Update logging
2020-07-21 15:48:21 +01:00
Kegsay
d9648b0615
Finish implementing redactions (#1189)
* Add a bit more logging to the fedsender

* bugfix: continue sending PDUs if ones are added whilst sending another PDU

Without this, the queue goes back to sleep on `<-oq.notifyPDUs` which won't
fire because `pendingPDUs` is already > 0. This should fix a flakey sytest.

* Break if no txn is sent

* WIP syncapi work

* More debugging

* Bump GMSL version to pull in working Event.Redact

* Remove logging

* Make redactions work on v3+

* Fix more tests
2020-07-08 17:45:39 +01:00
Kegsay
1ad7219e4b
Implement /sync limited and read timeline limit from stored filters (#1168)
* Move filter table to syncapi where it is used

* Implement /sync `limited` and read timeline limit from stored filters

We now fully handle `room.timeline.limit` filters (in-line + stored) and
return the right value for `limited` syncs.

* Update whitelist

* Default to the default timeline limit if it's unset, also strip the extra event correctly

* Update whitelist
2020-06-26 15:34:41 +01:00
Kegsay
4897beabee
Finish implementing retiring invites (#1166)
* Pass retired invites to the syncapi with the event ID of the invite

* Implement retire invite streaming

* Update whitelist
2020-06-26 11:07:52 +01:00
Kegsay
ecd7accbad
Rehuffle where things are in the internal package (#1122)
renamed:    internal/eventcontent.go -> internal/eventutil/eventcontent.go
	renamed:    internal/events.go -> internal/eventutil/events.go
	renamed:    internal/types.go -> internal/eventutil/types.go
	renamed:    internal/http/http.go -> internal/httputil/http.go
	renamed:    internal/httpapi.go -> internal/httputil/httpapi.go
	renamed:    internal/httpapi_test.go -> internal/httputil/httpapi_test.go
	renamed:    internal/httpapis/paths.go -> internal/httputil/paths.go
	renamed:    internal/routing.go -> internal/httputil/routing.go
	renamed:    internal/basecomponent/base.go -> internal/setup/base.go
	renamed:    internal/basecomponent/flags.go -> internal/setup/flags.go
	renamed:    internal/partition_offset_table.go -> internal/sqlutil/partition_offset_table.go
	renamed:    internal/postgres.go -> internal/sqlutil/postgres.go
	renamed:    internal/postgres_wasm.go -> internal/sqlutil/postgres_wasm.go
	renamed:    internal/sql.go -> internal/sqlutil/sql.go
2020-06-12 14:55:57 +01:00
Kegsay
e7d1ac84c3
Add ParseFileURI and use it when dealing with file URIs (#1088)
* Add ParseFileURI and use it when dealing with file URIs

Fixes #1059

* Missing file

* Linting
2020-06-04 11:18:08 +01:00
Neil Alexander
a5d822004d
Send-to-device support (#1072)
* Groundwork for send-to-device messaging

* Update sample config

* Add unstable routing for now

* Send to device consumer in sync API

* Start the send-to-device consumer

* fix indentation in dendrite-config.yaml

* Create send-to-device database tables, other tweaks

* Add some logic for send-to-device messages, add them into sync stream

* Handle incoming send-to-device messages, count them with EDU stream pos

* Undo changes to test

* pq.Array

* Fix sync

* Logging

* Fix a couple of transaction things, fix client API

* Add send-to-device test, hopefully fix bugs

* Comments

* Refactor a bit

* Fix schema

* Fix queries

* Debug logging

* Fix storing and retrieving of send-to-device messages

* Try to avoid database locks

* Update sync position

* Use latest sync position

* Jiggle about sync a bit

* Fix tests

* Break out the retrieval from the update/delete behaviour

* Comments

* nolint on getResponseWithPDUsForCompleteSync

* Try to line up sync tokens again

* Implement wildcard

* Add all send-to-device tests to whitelist, what could possibly go wrong?

* Only care about wildcard when targeted locally

* Deduplicate transactions

* Handle tokens properly, return immediately if waiting send-to-device messages

* Fix sync

* Update sytest-whitelist

* Fix copyright notice (need to do more of this)

* Comments, copyrights

* Return errors from Do, fix dendritejs

* Review comments

* Comments

* Constructor for TransactionWriter

* defletions

* Update gomatrixserverlib, sytest-blacklist
2020-06-01 17:50:19 +01:00
Kegsay
24d8df664c
Fix #897 and shuffle directory around (#1054)
* Fix #897 and shuffle directory around

* Update find-lint

* goimports

Co-authored-by: Neil Alexander <neilalexander@users.noreply.github.com>
2020-05-21 14:40:13 +01:00
Kegsay
1414922026
sytest: Make 'Inbound federation can backfill events' pass (#1051)
* sytest: Make 'Inbound federation can backfill events' pass

This breaks 'Outbound federation can backfill events' because now
we are returning the right number of events, which the previous
test was relying on.

Previously, /messages was backfilling the membership event, causing
the test to pass. Now we are no longer backfilling the membership
event due to the change in this commit, causing the test to fail.

The test should instead be returning the membership event locally
from synacpis database, but it doesn't do it fast enough, resulting
in a no-op /sync response with a next_batch=s0_0 which will never
pick up the local membership event when it rolls in. The test
does attempt to retry, but doesn't take the new next_batch=s1_0
resulting in it missing from the /messages response.

* Linting
2020-05-20 16:04:31 +01:00
Kegsay
8db60c90bb
Fix a bug whereby backfilling could leak events across rooms (#1043)
* Fix a bug whereby backfilling could leak events across rooms

Caused by a faulty SQL query. With tests now.

* comment
2020-05-15 16:27:34 +01:00
Kegsay
2b5052eccf
Add Range (#1037)
* Add Range

* Use Range
2020-05-15 09:41:12 +01:00
Kegsay
7ca230e931
Cleanup syncapi topology logic (#1035)
* Cleanup syncapi topology logic

* Variable renaming

* comments
2020-05-14 17:30:16 +01:00
Kegsay
1b34130a5b
Finish merging syncserver.go (#1033)
* Refactor all postgres tables; start work on sqlite

* wip sqlite merges; database is locked errors to investigate and failing tests

* Revert "wip sqlite merges; database is locked errors to investigate and failing tests"

This reverts commit 26cbfc5b75ae2dc4fb31a838b917aa39d758f162.

* convert current room state table

* port over sqlite topology table

* remove a few functions

* remove more functions

* Share more code

* factor out completesync and a bit more

* Remove remaining code
2020-05-14 16:11:37 +01:00
Kegsay
9ed68a3125
Factor out account data and events table (#1031)
* Factor out account data

* Factor out events table and EDU cache

* linting

* fix npe
2020-05-14 09:53:55 +01:00
Kegsay
a25d477cdb
Initial syncapi storage refactor to share pq/sqlite code (#1030)
* Initial syncapi storage refactor to share pq/sqlite code

This goes down a different route than https://github.com/matrix-org/dendrite/pull/985
which tried to even reduce the boilerplate of `ExecContext` etc. The previous pattern
fails badly when there are subtle differences in parameters and hence the shared
boilerplate to read from `QueryContext` breaks. Rather than attacking it at that level,
the main place where we want to reuse code is for the `syncserver.go` itself - the
database implementation which has lots of complex logic. So instead, this commit:
 - Makes `invites_table.go` an interface.
 - Makes `SyncServerDatasource` use that interface
 - This means some functions are now identical for pq/sqlite, so factor them out
   to a temporary `shared.Database` struct which will grow until it replaces all of
   `SyncServerDatasource`.

* Missing files
2020-05-13 17:28:42 +01:00
Kegan Dougal
bdddd83753 Spurious logging 2020-05-13 15:00:47 +01:00
Kegsay
37b2299b71
Fix #1015 (#1026)
Co-authored-by: Neil Alexander <neilalexander@users.noreply.github.com>
2020-05-13 13:02:34 +01:00
Kegsay
5e9dce1c0c
syncapi: Rename and split out tokens (#1025)
* syncapi: Rename and split out tokens

Previously we used the badly named `PaginationToken` which was
used for both `/sync` and `/messages` requests. This quickly
became confusing because named fields like `PDUPosition` meant
different things depending on the token type. Instead, we now have
two token types: `TopologyToken` and `StreamingToken`, both of
which have fields which make more sense for their specific situations.

Updated the codebase to use one or the other. `PaginationToken` still
lives on as `syncToken`, an unexported type which both tokens rely on.
This allows us to guarantee that the specific mappings of positions
to a string remain solely under the control of the `types` package.
This enables us to move high-level conceptual things like
"decrement this topological token" to function calls e.g
`TopologicalToken.Decrement()`.

Currently broken because `/messages` seemingly used both stream and
topological tokens, though I need to confirm this.

* final tweaks/hacks

* spurious logging

* Review comments and linting
2020-05-13 12:14:50 +01:00
Kegsay
36bbb25561
Fix ordering when backfilling (#1000)
* Fix ordering when backfilling

The problem was that we weren't sorting the returned events
by depth when sending them back to the caller, instead we
were sorting by prev_events which is not the same thing.

* Fixup tests
2020-05-01 16:41:13 +01:00
Neil Alexander
f7cfa75886
Limit database connections (#980, #564) (#998)
* Limit database connections (#564)

- Add new options to the config file database:
      max_open_conns: 100
      max_idle_conns: 2
      conn_max_lifetime: -1
- Implement connection parameter setup on the *DB (database/sql) in internal/sqlutil/trace.go:Open()
- Propagate the values in the form of DbProperties interface via all the
  Open() and NewDatabase() functions

Signed-off-by: Tomas Jirka <tomas.jirka@email.cz>

* Fix wasm builds

* Remove file accidentally added from working tree

Co-authored-by: Tomas Jirka <tomas.jirka@email.cz>
2020-05-01 13:34:53 +01:00
Kegsay
17e046f18f
Fix prev_batch tokens (#999) 2020-05-01 12:41:38 +01:00
Kegsay
b28674435e
Correctly generate backpagination tokens for events which have the same depth (#996)
* Correctly generate backpagination tokens for events which have the same depth

With tests. Unfortunately the code around here is hard to understand.
There will be a subsequent PR which fixes this up now that we have a test
harness in place.

* Add postgres impl

* More linting

* Fix psql statement so it actually works
2020-05-01 11:01:34 +01:00
Kegsay
35b7cbd5d8
sql/backwards_extremities: Shift to table format and share code (#985)
* sql/backwards_extremities: Shift to table format and share code

This is an initial cut to reduce boilerplate at the storage layer.
It removes the need for 2x `_table.go` files, one for each DB engine,
replacing it with a single struct which has an interface which
implements the raw SQL statements.

The actual impl sits alongside the interface declaration which is
generally regarded as best practice (though no canonical sources).
Especially in this case where the impl is tiny (functions returning
strings) and relies heavily on the function signatures of the
table struct (for parameters), having the context in the same file
is useful.

* Remove _table redundancy
2020-04-28 15:50:24 +01:00
Neil Alexander
3ab8ebf6b8
More invite support (#979)
* Update gomatixserverlib

* Try to build invite stripped state if not given to us

* SendInvite improvements

* Transpose invite_room_state into invite_state.events for sync API

* Remove syncapi debugging output

* Use RespInviteV2

* Update gomatrixserverlib

* Send the invite event as a normal roomserver event too, for incorporating into room (should this be done by the roomserver automatically for invite inputs?)

* Federation sender use invite_room_state, room server try to insert membership state

* Check supported room versions on the invite endpoint

* Prevent roomserver query API from trying to handle requests for stub rooms

* Adding a nolint

* Replace IsRoomStub with RoomNIDExcludingStubs, fix query API to use that instead

* Review comments
2020-04-24 16:30:25 +01:00
Kegsay
c1bca95adb
Add SQL tracing via DENDRITE_TRACE_SQL (#968)
* Add SQL tracing via DENDRITE_TRACE_SQL

Add this to `internal/sqlutil` in preparation for #897

* Not entirely
2020-04-16 10:06:55 +01:00
Neil Alexander
7b3edf4622
Tweaks to backfill (#964) 2020-04-15 14:39:27 +01:00
Kegsay
11a8059bba
Rename the typing server to EDU server (#948)
* Blunt move and sed rename

* Rename common/ refs to typing

* Rename internal stuff in eduserver

* Rename docs and scripts

* Rename constants/filenames, goimports everything to re-order imports
2020-03-30 15:02:20 +01:00
Kegsay
6bac7e5efd
Implement backfill over federation (#938)
* Implement history visibility checks for /backfill

Required for p2p to show history correctly.

* Add sytest

* Logging

* Fix two backfill bugs which prevented backfill from working correctly

- When receiving backfill requests, do not send the event that was in the original request.
- When storing backfill results, correctly update the backwards extremity for the room.

* hack: make backfill work multiple times

* add sqlite impl and remove logging

* Linting
2020-03-24 12:20:10 +00:00
Neil Alexander
944d454cb0 Fix SQLite problems after sync API changes 2020-03-19 13:15:35 +00:00
Neil Alexander
ad5849d222
HeaderedEvents in sync API (#922)
* Use HeaderedEvent in syncapi

* Update notifier test

* Fix persisting headered event

* Clean up unused API function

* Fix overshadowed err from linter

* Write headered JSON to invites table too

* Rename event_json to headered_event_json in syncapi database schemae

* Fix invites_table queries

* Update QueryRoomVersionCapabilitiesResponse comment

* Fix syncapi SQLite
2020-03-19 12:07:01 +00:00
Prateek Sachan
c019ad7086
Log errors from rows.Close (#920)
* Log errors from rows.Close

* fixed imports

* Added contextual messages

* fixed review changes
2020-03-18 10:17:18 +00:00
Kegsay
4af8323df3
bugfix: Fix a bug which caused prev_content not to be sent to clients (#919)
I don't know how this ever passed QA... also fix a missing rows.Close()
2020-03-17 16:45:40 +00:00
Kegsay
a97b8eafd4
Add peer-to-peer support into Dendrite via libp2p and fetch (#880)
* Use a fork of pq which supports userCurrent on wasm

* Use sqlite3_js driver when running in JS

* Add cmd/dendritejs to pull in sqlite3_js driver for wasm only

* Update to latest go-sqlite-js version

* Replace prometheus with a stub. sigh

* Hard-code a config and don't use opentracing

* Latest go-sqlite3-js version

* Generate a key for now

* Listen for fetch traffic rather than HTTP

* Latest hacks for js

* libp2p support

* More libp2p

* Fork gjson to allow us to enforce auth checks as before

Previously, all events would come down redacted because the hash
checks would fail. They would fail because sjson.DeleteBytes didn't
remove keys not used for hashing. This didn't work because of a build
tag which included a file which no-oped the index returned.

See https://github.com/tidwall/gjson/issues/157

When it's resolved, let's go back to mainline.

* Use gjson@1.6.0 as it fixes https://github.com/tidwall/gjson/issues/157

* Use latest gomatrixserverlib for sig checks

* Fix a bug which could cause exclude_from_sync to not be set

Caused when sending events over federation.

* Use query variadic to make lookups actually work!

* Latest gomatrixserverlib

* Add notes on getting p2p up and running

Partly so I don't forget myself!

* refactor: Move p2p specific stuff to cmd/dendritejs

This is important or else the normal build of dendrite will fail
because the p2p libraries depend on syscall/js which doesn't work
on normal builds.

Also, clean up main.go to read a bit better.

* Update ho-http-js-libp2p to return errors from RoundTrip

* Add an LRU cache around the key DB

We actually need this for P2P because otherwise we can *segfault*
with things like: "runtime: unexpected return pc for runtime.handleEvent"
where the event is a `syscall/js` event, caused by spamming sql.js
caused by "Checking event signatures for 14 events of room state" which
hammers the key DB repeatedly in quick succession.

Using a cache fixes this, though the underlying cause is probably a bug
in the version of Go I'm on (1.13.7)

* breaking: Add Tracing.Enabled to toggle whether we do opentracing

Defaults to false, which is why this is a breaking change. We need
this flag because WASM builds cannot do opentracing.

* Start adding conditional builds for wasm to handle lib/pq

The general idea here is to have the wasm build have a `NewXXXDatabase`
that doesn't import any postgres package and hence we never import
`lib/pq`, which doesn't work under WASM (undefined `userCurrent`).

* Remove lib/pq for wasm for syncapi

* Add conditional building to remaining storage APIs

* Update build script to set env vars correctly for dendritejs

* sqlite bug fixes

* Docs

* Add a no-op main for dendritejs when not building under wasm

* Use the real prometheus, even for WASM

Instead, the dendrite-sw.js must mock out `process.pid` and
`fs.stat` - which must invoke the callback with an error (e.g `EINVAL`)
in order for it to work:

```
    global.process = {
        pid: 1,
    };
    global.fs.stat = function(path, cb) {
        cb({
            code: "EINVAL",
        });
    }
```

* Linting
2020-03-06 10:23:55 +00:00