Lazy load member list

[lampholder]

Status:

• initial support (PRs: Lazy load room members - Part I matrix-org/matrix-react-sdk#2072, Lazy load room members - Part I matrix-org/matrix-js-sdk#667)
• store lazily loaded members in indexeddb (PR: Lazy loading: store lazily loaded members in indexeddb matrix-org/matrix-js-sdk#669)
• use summary api to fix DM room names, and room_member_count push rule (in progress: Summary api matrix-org/matrix-js-sdk#670)
• support lazy loading when calling /messages (PRs: Lazy loading: Lazy load members while backpaginating matrix-org/matrix-js-sdk#676, Lazy loading: Lazy load members while backpaginating matrix-org/matrix-react-sdk#2104)
• support lazy loading when calling /context (PR: Lazy loading: lazy load members when request context around an event matrix-org/matrix-js-sdk#681)
• remove assumptions we have access to own membership (PRs: Lazy loading: don't assume we have our own member available matrix-org/matrix-react-sdk#2102, Lazy loading: don't assume we have our own member available matrix-org/matrix-js-sdk#677)
• avoid race conditions between loading members (through /joined_members atm) and /sync by passing the sync token to the members endpoint. (in progress as part of Lazy load room members - Part I matrix-org/matrix-js-sdk#667)
• support include_redundant_members
• fix E2E encryption support (PRs: Lazy loading: fix end-to-end encryption rooms matrix-org/matrix-react-sdk#2113, Lazy loading: fix end-to-end encryption rooms matrix-org/matrix-js-sdk#683):
  • prevent user from sending messages until members are loaded
  • delay sending device-list updates until members are loaded
  • write end to end tests to make sure we don't break anything
• show dialog to sign out upon enabling/disabling the feature. Support it as a labs feature so it can be easily tested in the wild. (PR: Lazy loading: feature toggle matrix-org/matrix-react-sdk#2115)
• unload OOB members when moving away from a room?
• clean-up and small fixups (PRs: Lazy loading: cleanup matrix-org/matrix-js-sdk#688, Lazy loading: cleanup matrix-org/matrix-react-sdk#2116)
  • implement capability negotiation (PR: Lazy loading: check with server for feature support matrix-org/matrix-js-sdk#687)
  • pass sync token to /members?at= (PR: Lazy loading: use sync token for /members?at=... request, as synapse expects it now matrix-org/matrix-js-sdk#686)
  • don't fail when offline
  • sweep code for SUMMARYAPI todos, See where getJoinedMemberCount/getInvitedMemberCount can be used instead
  • getMyMembership(myUserId) should be getMyMembership()
  • clean up console.logs
  • test relevant bugs are fixed (riot hangs when you open a large room #7015)

-- Bruno

[turt2live]

reference pr: matrix-org/synapse#2970

[turt2live]

Synapse side: matrix-org/synapse#1203

[turt2live]

and matrix-org/synapse#1379

[bwindels]

@lampholder keeping track of all lazy loading PRs and remaining issues here ^^.

[bwindels]

I created a feature branch for lazy loading, as lazy loading could easily break the user experience as long as all the work is not done, and I want to spread the work over multiple PRs.

I'll make all PRs off bwindels/feature_lazyloading and we merge that branch into develop once we're sure nothing will break.