Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 462 insertions, 0 deletions

diff --git a/comm/chat/protocols/matrix/lib/matrix-sdk/timeline-window.js b/comm/chat/protocols/matrix/lib/matrix-sdk/timeline-window.js
new file mode 100644
index 0000000000..2c7365bdff
--- /dev/null
+++ b/comm/chat/protocols/matrix/lib/matrix-sdk/timeline-window.js
@@ -0,0 +1,462 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.TimelineWindow = exports.TimelineIndex = void 0;
+var _eventTimeline = require("./models/event-timeline");
+var _logger = require("./logger");
+function _defineProperty(obj, key, value) { key = _toPropertyKey(key); if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }
+function _toPropertyKey(arg) { var key = _toPrimitive(arg, "string"); return typeof key === "symbol" ? key : String(key); }
+function _toPrimitive(input, hint) { if (typeof input !== "object" || input === null) return input; var prim = input[Symbol.toPrimitive]; if (prim !== undefined) { var res = prim.call(input, hint || "default"); if (typeof res !== "object") return res; throw new TypeError("@@toPrimitive must return a primitive value."); } return (hint === "string" ? String : Number)(input); } /*
+                                                                                                                                                                                                                                                                                                                                                                                          Copyright 2016 - 2021 The Matrix.org Foundation C.I.C.
+                                                                                                                                                                                                                                                                                                                                                                                          
+                                                                                                                                                                                                                                                                                                                                                                                          Licensed under the Apache License, Version 2.0 (the "License");
+                                                                                                                                                                                                                                                                                                                                                                                          you may not use this file except in compliance with the License.
+                                                                                                                                                                                                                                                                                                                                                                                          You may obtain a copy of the License at
+                                                                                                                                                                                                                                                                                                                                                                                          
+                                                                                                                                                                                                                                                                                                                                                                                              http://www.apache.org/licenses/LICENSE-2.0
+                                                                                                                                                                                                                                                                                                                                                                                          
+                                                                                                                                                                                                                                                                                                                                                                                          Unless required by applicable law or agreed to in writing, software
+                                                                                                                                                                                                                                                                                                                                                                                          distributed under the License is distributed on an "AS IS" BASIS,
+                                                                                                                                                                                                                                                                                                                                                                                          WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+                                                                                                                                                                                                                                                                                                                                                                                          See the License for the specific language governing permissions and
+                                                                                                                                                                                                                                                                                                                                                                                          limitations under the License.
+                                                                                                                                                                                                                                                                                                                                                                                          */
+/**
+ * @internal
+ */
+const DEBUG = false;
+
+/**
+ * @internal
+ */
+/* istanbul ignore next */
+const debuglog = DEBUG ? _logger.logger.log.bind(_logger.logger) : function () {};
+
+/**
+ * the number of times we ask the server for more events before giving up
+ *
+ * @internal
+ */
+const DEFAULT_PAGINATE_LOOP_LIMIT = 5;
+class TimelineWindow {
+  /**
+   * Construct a TimelineWindow.
+   *
+   * <p>This abstracts the separate timelines in a Matrix {@link Room} into a single iterable thing.
+   * It keeps track of the start and endpoints of the window, which can be advanced with the help
+   * of pagination requests.
+   *
+   * <p>Before the window is useful, it must be initialised by calling {@link TimelineWindow#load}.
+   *
+   * <p>Note that the window will not automatically extend itself when new events
+   * are received from /sync; you should arrange to call {@link TimelineWindow#paginate}
+   * on {@link RoomEvent.Timeline} events.
+   *
+   * @param client -   MatrixClient to be used for context/pagination
+   *   requests.
+   *
+   * @param timelineSet -  The timelineSet to track
+   *
+   * @param opts - Configuration options for this window
+   */
+  constructor(client, timelineSet, opts = {}) {
+    this.client = client;
+    this.timelineSet = timelineSet;
+    _defineProperty(this, "windowLimit", void 0);
+    // these will be TimelineIndex objects; they delineate the 'start' and
+    // 'end' of the window.
+    //
+    // start.index is inclusive; end.index is exclusive.
+    _defineProperty(this, "start", void 0);
+    _defineProperty(this, "end", void 0);
+    _defineProperty(this, "eventCount", 0);
+    this.windowLimit = opts.windowLimit || 1000;
+  }
+
+  /**
+   * Initialise the window to point at a given event, or the live timeline
+   *
+   * @param initialEventId -   If given, the window will contain the
+   *    given event
+   * @param initialWindowSize -   Size of the initial window
+   */
+  load(initialEventId, initialWindowSize = 20) {
+    // given an EventTimeline, find the event we were looking for, and initialise our
+    // fields so that the event in question is in the middle of the window.
+    const initFields = timeline => {
+      if (!timeline) {
+        throw new Error("No timeline given to initFields");
+      }
+      let eventIndex;
+      const events = timeline.getEvents();
+      if (!initialEventId) {
+        // we were looking for the live timeline: initialise to the end
+        eventIndex = events.length;
+      } else {
+        eventIndex = events.findIndex(e => e.getId() === initialEventId);
+        if (eventIndex < 0) {
+          throw new Error("getEventTimeline result didn't include requested event");
+        }
+      }
+      const endIndex = Math.min(events.length, eventIndex + Math.ceil(initialWindowSize / 2));
+      const startIndex = Math.max(0, endIndex - initialWindowSize);
+      this.start = new TimelineIndex(timeline, startIndex - timeline.getBaseIndex());
+      this.end = new TimelineIndex(timeline, endIndex - timeline.getBaseIndex());
+      this.eventCount = endIndex - startIndex;
+    };
+
+    // We avoid delaying the resolution of the promise by a reactor tick if we already have the data we need,
+    // which is important to keep room-switching feeling snappy.
+    if (this.timelineSet.getTimelineForEvent(initialEventId)) {
+      initFields(this.timelineSet.getTimelineForEvent(initialEventId));
+      return Promise.resolve();
+    } else if (initialEventId) {
+      return this.client.getEventTimeline(this.timelineSet, initialEventId).then(initFields);
+    } else {
+      initFields(this.timelineSet.getLiveTimeline());
+      return Promise.resolve();
+    }
+  }
+
+  /**
+   * Get the TimelineIndex of the window in the given direction.
+   *
+   * @param direction -   EventTimeline.BACKWARDS to get the TimelineIndex
+   * at the start of the window; EventTimeline.FORWARDS to get the TimelineIndex at
+   * the end.
+   *
+   * @returns The requested timeline index if one exists, null
+   * otherwise.
+   */
+  getTimelineIndex(direction) {
+    if (direction == _eventTimeline.EventTimeline.BACKWARDS) {
+      return this.start ?? null;
+    } else if (direction == _eventTimeline.EventTimeline.FORWARDS) {
+      return this.end ?? null;
+    } else {
+      throw new Error("Invalid direction '" + direction + "'");
+    }
+  }
+
+  /**
+   * Try to extend the window using events that are already in the underlying
+   * TimelineIndex.
+   *
+   * @param direction -   EventTimeline.BACKWARDS to try extending it
+   *   backwards; EventTimeline.FORWARDS to try extending it forwards.
+   * @param size -   number of events to try to extend by.
+   *
+   * @returns true if the window was extended, false otherwise.
+   */
+  extend(direction, size) {
+    const tl = this.getTimelineIndex(direction);
+    if (!tl) {
+      debuglog("TimelineWindow: no timeline yet");
+      return false;
+    }
+    const count = direction == _eventTimeline.EventTimeline.BACKWARDS ? tl.retreat(size) : tl.advance(size);
+    if (count) {
+      this.eventCount += count;
+      debuglog("TimelineWindow: increased cap by " + count + " (now " + this.eventCount + ")");
+      // remove some events from the other end, if necessary
+      const excess = this.eventCount - this.windowLimit;
+      if (excess > 0) {
+        this.unpaginate(excess, direction != _eventTimeline.EventTimeline.BACKWARDS);
+      }
+      return true;
+    }
+    return false;
+  }
+
+  /**
+   * Check if this window can be extended
+   *
+   * <p>This returns true if we either have more events, or if we have a
+   * pagination token which means we can paginate in that direction. It does not
+   * necessarily mean that there are more events available in that direction at
+   * this time.
+   *
+   * @param direction -   EventTimeline.BACKWARDS to check if we can
+   *   paginate backwards; EventTimeline.FORWARDS to check if we can go forwards
+   *
+   * @returns true if we can paginate in the given direction
+   */
+  canPaginate(direction) {
+    const tl = this.getTimelineIndex(direction);
+    if (!tl) {
+      debuglog("TimelineWindow: no timeline yet");
+      return false;
+    }
+    if (direction == _eventTimeline.EventTimeline.BACKWARDS) {
+      if (tl.index > tl.minIndex()) {
+        return true;
+      }
+    } else {
+      if (tl.index < tl.maxIndex()) {
+        return true;
+      }
+    }
+    const hasNeighbouringTimeline = tl.timeline.getNeighbouringTimeline(direction);
+    const paginationToken = tl.timeline.getPaginationToken(direction);
+    return Boolean(hasNeighbouringTimeline) || Boolean(paginationToken);
+  }
+
+  /**
+   * Attempt to extend the window
+   *
+   * @param direction -   EventTimeline.BACKWARDS to extend the window
+   *    backwards (towards older events); EventTimeline.FORWARDS to go forwards.
+   *
+   * @param size -   number of events to try to extend by. If fewer than this
+   *    number are immediately available, then we return immediately rather than
+   *    making an API call.
+   *
+   * @param makeRequest - whether we should make API calls to
+   *    fetch further events if we don't have any at all. (This has no effect if
+   *    the room already knows about additional events in the relevant direction,
+   *    even if there are fewer than 'size' of them, as we will just return those
+   *    we already know about.)
+   *
+   * @param requestLimit - limit for the number of API requests we
+   *    should make.
+   *
+   * @returns Promise which resolves to a boolean which is true if more events
+   *    were successfully retrieved.
+   */
+  async paginate(direction, size, makeRequest = true, requestLimit = DEFAULT_PAGINATE_LOOP_LIMIT) {
+    // Either wind back the message cap (if there are enough events in the
+    // timeline to do so), or fire off a pagination request.
+    const tl = this.getTimelineIndex(direction);
+    if (!tl) {
+      debuglog("TimelineWindow: no timeline yet");
+      return false;
+    }
+    if (tl.pendingPaginate) {
+      return tl.pendingPaginate;
+    }
+
+    // try moving the cap
+    if (this.extend(direction, size)) {
+      return true;
+    }
+    if (!makeRequest || requestLimit === 0) {
+      // todo: should we return something different to indicate that there
+      // might be more events out there, but we haven't found them yet?
+      return false;
+    }
+
+    // try making a pagination request
+    const token = tl.timeline.getPaginationToken(direction);
+    if (!token) {
+      debuglog("TimelineWindow: no token");
+      return false;
+    }
+    debuglog("TimelineWindow: starting request");
+    const prom = this.client.paginateEventTimeline(tl.timeline, {
+      backwards: direction == _eventTimeline.EventTimeline.BACKWARDS,
+      limit: size
+    }).finally(function () {
+      tl.pendingPaginate = undefined;
+    }).then(r => {
+      debuglog("TimelineWindow: request completed with result " + r);
+      if (!r) {
+        return this.paginate(direction, size, false, 0);
+      }
+
+      // recurse to advance the index into the results.
+      //
+      // If we don't get any new events, we want to make sure we keep asking
+      // the server for events for as long as we have a valid pagination
+      // token. In particular, we want to know if we've actually hit the
+      // start of the timeline, or if we just happened to know about all of
+      // the events thanks to https://matrix.org/jira/browse/SYN-645.
+      //
+      // On the other hand, we necessarily want to wait forever for the
+      // server to make its mind up about whether there are other events,
+      // because it gives a bad user experience
+      // (https://github.com/vector-im/vector-web/issues/1204).
+      return this.paginate(direction, size, true, requestLimit - 1);
+    });
+    tl.pendingPaginate = prom;
+    return prom;
+  }
+
+  /**
+   * Remove `delta` events from the start or end of the timeline.
+   *
+   * @param delta - number of events to remove from the timeline
+   * @param startOfTimeline - if events should be removed from the start
+   *     of the timeline.
+   */
+  unpaginate(delta, startOfTimeline) {
+    const tl = startOfTimeline ? this.start : this.end;
+    if (!tl) {
+      throw new Error(`Attempting to unpaginate startOfTimeline=${startOfTimeline} but don't have this direction`);
+    }
+
+    // sanity-check the delta
+    if (delta > this.eventCount || delta < 0) {
+      throw new Error(`Attemting to unpaginate ${delta} events, but only have ${this.eventCount} in the timeline`);
+    }
+    while (delta > 0) {
+      const count = startOfTimeline ? tl.advance(delta) : tl.retreat(delta);
+      if (count <= 0) {
+        // sadness. This shouldn't be possible.
+        throw new Error("Unable to unpaginate any further, but still have " + this.eventCount + " events");
+      }
+      delta -= count;
+      this.eventCount -= count;
+      debuglog("TimelineWindow.unpaginate: dropped " + count + " (now " + this.eventCount + ")");
+    }
+  }
+
+  /**
+   * Get a list of the events currently in the window
+   *
+   * @returns the events in the window
+   */
+  getEvents() {
+    if (!this.start) {
+      // not yet loaded
+      return [];
+    }
+    const result = [];
+
+    // iterate through each timeline between this.start and this.end
+    // (inclusive).
+    let timeline = this.start.timeline;
+    // eslint-disable-next-line no-constant-condition
+    while (timeline) {
+      const events = timeline.getEvents();
+
+      // For the first timeline in the chain, we want to start at
+      // this.start.index. For the last timeline in the chain, we want to
+      // stop before this.end.index. Otherwise, we want to copy all of the
+      // events in the timeline.
+      //
+      // (Note that both this.start.index and this.end.index are relative
+      // to their respective timelines' BaseIndex).
+      //
+      let startIndex = 0;
+      let endIndex = events.length;
+      if (timeline === this.start.timeline) {
+        startIndex = this.start.index + timeline.getBaseIndex();
+      }
+      if (timeline === this.end?.timeline) {
+        endIndex = this.end.index + timeline.getBaseIndex();
+      }
+      for (let i = startIndex; i < endIndex; i++) {
+        result.push(events[i]);
+      }
+
+      // if we're not done, iterate to the next timeline.
+      if (timeline === this.end?.timeline) {
+        break;
+      } else {
+        timeline = timeline.getNeighbouringTimeline(_eventTimeline.EventTimeline.FORWARDS);
+      }
+    }
+    return result;
+  }
+}
+
+/**
+ * A thing which contains a timeline reference, and an index into it.
+ * @internal
+ */
+exports.TimelineWindow = TimelineWindow;
+class TimelineIndex {
+  // index: the indexes are relative to BaseIndex, so could well be negative.
+  constructor(timeline, index) {
+    this.timeline = timeline;
+    this.index = index;
+    _defineProperty(this, "pendingPaginate", void 0);
+  }
+
+  /**
+   * @returns the minimum possible value for the index in the current
+   *    timeline
+   */
+  minIndex() {
+    return this.timeline.getBaseIndex() * -1;
+  }
+
+  /**
+   * @returns the maximum possible value for the index in the current
+   *    timeline (exclusive - ie, it actually returns one more than the index
+   *    of the last element).
+   */
+  maxIndex() {
+    return this.timeline.getEvents().length - this.timeline.getBaseIndex();
+  }
+
+  /**
+   * Try move the index forward, or into the neighbouring timeline
+   *
+   * @param delta -  number of events to advance by
+   * @returns number of events successfully advanced by
+   */
+  advance(delta) {
+    if (!delta) {
+      return 0;
+    }
+
+    // first try moving the index in the current timeline. See if there is room
+    // to do so.
+    let cappedDelta;
+    if (delta < 0) {
+      // we want to wind the index backwards.
+      //
+      // (this.minIndex() - this.index) is a negative number whose magnitude
+      // is the amount of room we have to wind back the index in the current
+      // timeline. We cap delta to this quantity.
+      cappedDelta = Math.max(delta, this.minIndex() - this.index);
+      if (cappedDelta < 0) {
+        this.index += cappedDelta;
+        return cappedDelta;
+      }
+    } else {
+      // we want to wind the index forwards.
+      //
+      // (this.maxIndex() - this.index) is a (positive) number whose magnitude
+      // is the amount of room we have to wind forward the index in the current
+      // timeline. We cap delta to this quantity.
+      cappedDelta = Math.min(delta, this.maxIndex() - this.index);
+      if (cappedDelta > 0) {
+        this.index += cappedDelta;
+        return cappedDelta;
+      }
+    }
+
+    // the index is already at the start/end of the current timeline.
+    //
+    // next see if there is a neighbouring timeline to switch to.
+    const neighbour = this.timeline.getNeighbouringTimeline(delta < 0 ? _eventTimeline.EventTimeline.BACKWARDS : _eventTimeline.EventTimeline.FORWARDS);
+    if (neighbour) {
+      this.timeline = neighbour;
+      if (delta < 0) {
+        this.index = this.maxIndex();
+      } else {
+        this.index = this.minIndex();
+      }
+      debuglog("paginate: switched to new neighbour");
+
+      // recurse, using the next timeline
+      return this.advance(delta);
+    }
+    return 0;
+  }
+
+  /**
+   * Try move the index backwards, or into the neighbouring timeline
+   *
+   * @param delta -  number of events to retreat by
+   * @returns number of events successfully retreated by
+   */
+  retreat(delta) {
+    return this.advance(delta * -1) * -1;
+  }
+}
+exports.TimelineIndex = TimelineIndex;
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