update store api with requirements for gap filling

src/matrix/storage/idb/query-target.js

@@ -1,10 +1,14 @@
-import {iterateCursor} from "./utils.js";
+import {iterateCursor, reqAsPromise} from "./utils.js";
 
 export default class QueryTarget {
 	constructor(target) {
 		this._target = target;
 	}
 
+    get(key) {
+        return reqAsPromise(this._target.get(key));
+    }
+
 	reduce(range, reducer, initialValue) {
 		return this._reduce(range, reducer, initialValue, "next");
 	}

src/matrix/storage/idb/stores/RoomTimelineStore.js

@@ -1,77 +1,197 @@
 import SortKey from "../../sortkey.js";
 
+class Range {
+    constructor(only, lower, upper, lowerOpen, upperOpen) {
+        this._only = only;
+        this._lower = lower;
+        this._upper = upper;
+        this._lowerOpen = lowerOpen;
+        this._upperOpen = upperOpen;
+    }
+
+    asIDBKeyRange(roomId) {
+        // only
+        if (this._only) {
+            return IDBKeyRange.only([roomId, this._only.buffer]);
+        }
+        // lowerBound
+        // also bound as we don't want to move into another roomId
+        if (this._lower && !this._upper) {
+            return IDBKeyRange.bound(
+                [roomId, this._lower.buffer],
+                [roomId, SortKey.maxKey.buffer],
+                this._lowerOpen,
+                false
+            );
+        }
+        // upperBound
+        // also bound as we don't want to move into another roomId
+        if (!this._lower && this._upper) {
+            return IDBKeyRange.bound(
+                [roomId, SortKey.minKey.buffer],
+                [roomId, this._upper.buffer],
+                false,
+                this._upperOpen
+            );
+        }
+        // bound
+        if (this._lower && this._upper) {
+            return IDBKeyRange.bound(
+                [roomId, this._lower.buffer],
+                [roomId, this._upper.buffer],
+                this._lowerOpen,
+                this._upperOpen
+            );
+        }
+    }
+}
+/*
+ * @typedef   {Object} Gap
+ * @property  {?string} prev_batch the pagination token for this backwards facing gap
+ * @property  {?string} next_batch the pagination token for this forwards facing gap
+ *
+ * @typedef   {Object} Event
+ * @property  {string} event_id the id of the event
+ * @property  {string} type the
+ * @property  {?string} state_key the state key of this state event
+ *
+ * @typedef   {Object} Entry
+ * @property  {string} roomId
+ * @property  {SortKey} sortKey
+ * @property  {?Event} event if an event entry, the event
+ * @property  {?Gap} gap if a gap entry, the gap
+*/
 export default class RoomTimelineStore {
 	constructor(timelineStore) {
 		this._timelineStore = timelineStore;
 	}
 
+    /** Creates a range that only includes the given key
+     *  @param {SortKey} sortKey the key
+     *  @return {Range} the created range
+     */
+    onlyRange(sortKey) {
+        return new Range(sortKey);
+    }
+
+    /** Creates a range that includes all keys before sortKey, and optionally also the key itself.
+     *  @param {SortKey} sortKey the key
+     *  @param {boolean} [open=false] whether the key is included (false) or excluded (true) from the range at the upper end.
+     *  @return {Range} the created range
+     */
+    upperBoundRange(sortKey, open=false) {
+        return new Range(undefined, undefined, sortKey, undefined, open);
+    }
+
+    /** Creates a range that includes all keys after sortKey, and optionally also the key itself.
+     *  @param {SortKey} sortKey the key
+     *  @param {boolean} [open=false] whether the key is included (false) or excluded (true) from the range at the lower end.
+     *  @return {Range} the created range
+     */
+    lowerBoundRange(sortKey, open=false) {
+        return new Range(undefined, sortKey, undefined, open);
+    }
+
+    /** Creates a range that includes all keys between `lower` and `upper`, and optionally the given keys as well.
+     *  @param {SortKey} lower the lower key
+     *  @param {SortKey} upper the upper key
+     *  @param {boolean} [lowerOpen=false] whether the lower key is included (false) or excluded (true) from the range.
+     *  @param {boolean} [upperOpen=false] whether the upper key is included (false) or excluded (true) from the range.
+     *  @return {Range} the created range
+     */
+    boundRange(lower, upper, lowerOpen=false, upperOpen=false) {
+        return new Range(undefined, lower, upper, lowerOpen, upperOpen);
+    }
+
+    /** Looks up the last `amount` entries in the timeline for `roomId`.
+     *  @param  {string} roomId
+     *  @param  {number} amount
+     *  @return {Promise<Entry[]>} a promise resolving to an array with 0 or more entries, in ascending order.
+     */
 	async lastEvents(roomId, amount) {
 		return this.eventsBefore(roomId, SortKey.maxKey, amount);
 	}
 
+    /** Looks up the first `amount` entries in the timeline for `roomId`.
+     *  @param  {string} roomId
+     *  @param  {number} amount
+     *  @return {Promise<Entry[]>} a promise resolving to an array with 0 or more entries, in ascending order.
+     */
 	async firstEvents(roomId, amount) {
 		return this.eventsAfter(roomId, SortKey.minKey, amount);
 	}
 
+    /** Looks up `amount` entries after `sortKey` in the timeline for `roomId`.
+     *  The entry for `sortKey` is not included.
+     *  @param  {string} roomId
+     *  @param  {SortKey} sortKey
+     *  @param  {number} amount
+     *  @return {Promise<Entry[]>} a promise resolving to an array with 0 or more entries, in ascending order.
+     */
 	eventsAfter(roomId, sortKey, amount) {
-		const range = IDBKeyRange.bound([roomId, sortKey.buffer], [roomId, SortKey.maxKey.buffer], true, false);
-		return this._timelineStore.selectLimit(range, amount);
+        const idbRange = this.lowerBoundRange(sortKey, true).asIDBKeyRange(roomId);
+		return this._timelineStore.selectLimit(idbRange, amount);
 	}
 
+    /** Looks up `amount` entries before `sortKey` in the timeline for `roomId`.
+     *  The entry for `sortKey` is not included.
+     *  @param  {string} roomId
+     *  @param  {SortKey} sortKey
+     *  @param  {number} amount
+     *  @return {Promise<Entry[]>} a promise resolving to an array with 0 or more entries, in ascending order.
+     */
     async eventsBefore(roomId, sortKey, amount) {
-        const range = IDBKeyRange.only([roomId, sortKey.buffer]);
+        const range = this.upperBoundRange(sortKey, true).asIDBKeyRange(roomId);
         const events = await this._timelineStore.selectLimitReverse(range, amount);
         events.reverse(); // because we fetched them backwards
         return events;
     }
 
-    nextEventFromGap(roomId, sortKey) {
-        
+    /** Looks up the first, if any, event entry (so excluding gap entries) after `sortKey`.
+     *  @param  {string} roomId
+     *  @param  {SortKey} sortKey
+     *  @return {Promise<(?Entry)>} a promise resolving to entry, if any.
+     */
+    nextEvent(roomId, sortKey) {
+        const range = this.lowerBoundRange(sortKey, true).asIDBKeyRange(roomId);
+        return this._timelineStore.find(range, entry => !!entry.event);
     }
 
-    previousEventFromGap(roomId, sortKey) {
-        
+    /** Looks up the first, if any, event entry (so excluding gap entries) before `sortKey`.
+     *  @param  {string} roomId
+     *  @param  {SortKey} sortKey
+     *  @return {Promise<(?Entry)>} a promise resolving to entry, if any.
+     */
+    previousEvent(roomId, sortKey) {
+        const range = this.upperBoundRange(sortKey, true).asIDBKeyRange(roomId);
+        return this._timelineStore.findReverse(range, entry => !!entry.event);
     }
 
-    findEntry(roomId, sortKey) {
-        const range = IDBKeyRange.bound([roomId, SortKey.minKey.buffer], [roomId, sortKey.buffer], false, true);
-        return this._timelineStore.selectFirst(range);
+    /** Inserts a new entry into the store. The combination of roomId and sortKey should not exist yet, or an error is thrown.
+     *  @param  {Entry} entry the entry to insert
+     *  @return {Promise<>} a promise resolving to undefined if the operation was successful, or a StorageError if not.
+     *  @throws {StorageError} ...
+     */
+    insert(entry) {
+        // TODO: map error? or in idb/store?
+        return this._timelineStore.add(entry);
     }
 
-    // entry should have roomId, sortKey, event & gap keys
-    add(entry) {
-        this._timelineStore.add(entry);
-    }
-    // should this happen as part of a transaction that stores all synced in changes?
-    // e.g.:
-    // - timeline events for all rooms
-    // - latest sync token
-    // - new members
-    // - new room state
-    // - updated/new account data
-
-
-
-	appendGap(roomId, sortKey, gap) {
-		this._timelineStore.add({
-			roomId: roomId,
-			sortKey: sortKey.buffer,
-			event: null,
-			gap: gap,
-		});
+    /** Updates the entry into the store with the given [roomId, sortKey] combination.
+     *  If not yet present, will insert. Might be slower than add.
+     *  @param  {Entry} entry the entry to update.
+     *  @return {Promise<>} a promise resolving to undefined if the operation was successful, or a StorageError if not.
+     */
+    update(entry) {
+        return this._timelineStore.put(entry);
     }
 
-	appendEvent(roomId, sortKey, event) {
-		console.info(`appending event for room ${roomId} with key ${sortKey}`);
-		this._timelineStore.add({
-			roomId: roomId,
-			sortKey: sortKey.buffer,
-			event: event,
-			gap: null,
-		});
+    get(roomId, sortKey) {
+        return this._timelineStore.get([roomId, sortKey]);
     }
-	// could be gap or event
-	async removeEntry(roomId, sortKey) {
-		this._timelineStore.delete([roomId, sortKey.buffer]);
+    // returns the entries as well!! (or not always needed? I guess not always needed, so extra method)
+    removeRange(roomId, range) {
+        // TODO: read the entries!
+        return this._timelineStore.delete(range.asIDBKeyRange(roomId));
     }
 }