define storage keys to be 32bit for idb / web platform

as a preparation to serialize the eventIndex and fragmentId
as a 8 character string, part of a concatenated string PK,
as lumia doesn't support array keys.

src/Platform.js

@@ -0,0 +1,5 @@
+// #ifdef PLATFORM_GNOME
+// export {default} from "./ui/gnome/GnomePlatform.js";
+// #else
+export {default} from "./ui/web/WebPlatform.js";
+// #endif

src/matrix/room/timeline/EventKey.js

@@ -1,7 +1,4 @@
-const DEFAULT_LIVE_FRAGMENT_ID = 0;
-const MIN_EVENT_INDEX = Number.MIN_SAFE_INTEGER + 1;
-const MAX_EVENT_INDEX = Number.MAX_SAFE_INTEGER - 1;
-const MID_EVENT_INDEX = 0;
+import Platform from "../../../Platform.js";
 
 // key for events in the timelineEvents store
 export default class EventKey {
@@ -12,7 +9,7 @@ export default class EventKey {
 
     nextFragmentKey() {
         // could take MIN_EVENT_INDEX here if it can't be paged back
-        return new EventKey(this.fragmentId + 1, MID_EVENT_INDEX);
+        return new EventKey(this.fragmentId + 1, Platform.middleStorageKey);
     }
 
     nextKeyForDirection(direction) {
@@ -32,15 +29,15 @@ export default class EventKey {
     }
 
     static get maxKey() {
-        return new EventKey(Number.MAX_SAFE_INTEGER, Number.MAX_SAFE_INTEGER);
+        return new EventKey(Platform.maxStorageKey, Platform.maxStorageKey);
     }
 
     static get minKey() {
-        return new EventKey(Number.MIN_SAFE_INTEGER, Number.MIN_SAFE_INTEGER);
+        return new EventKey(Platform.minStorageKey, Platform.minStorageKey);
     }
 
     static get defaultLiveKey() {
-        return new EventKey(DEFAULT_LIVE_FRAGMENT_ID, MID_EVENT_INDEX);
+        return new EventKey(Platform.minStorageKey, Platform.middleStorageKey);
     }
 
     toString() {

src/matrix/room/timeline/entries/FragmentBoundaryEntry.js

@@ -1,6 +1,7 @@
 import BaseEntry from "./BaseEntry.js";
 import Direction from "../Direction.js";
 import {isValidFragmentId} from "../common.js";
+import Platform from "../../../../Platform.js";
 
 export default class FragmentBoundaryEntry extends BaseEntry {
     constructor(fragment, isFragmentStart, fragmentIdComparer) {
@@ -36,9 +37,9 @@ export default class FragmentBoundaryEntry extends BaseEntry {
 
     get entryIndex() {
         if (this.started) {
-            return Number.MIN_SAFE_INTEGER;
+            return Platform.minStorageKey;
         } else {
-            return Number.MAX_SAFE_INTEGER;
+            return Platform.maxStorageKey;
         }
     }
 

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

@@ -1,4 +1,5 @@
 import EventKey from "../../../room/timeline/EventKey.js";
+import Platform from "../../../../Platform.js";
 
 class Range {
     constructor(only, lower, upper, lowerOpen, upperOpen) {
@@ -19,7 +20,7 @@ class Range {
         if (this._lower && !this._upper) {
             return IDBKeyRange.bound(
                 [roomId, this._lower.fragmentId, this._lower.eventIndex],
-                [roomId, this._lower.fragmentId, EventKey.maxKey.eventIndex],
+                [roomId, this._lower.fragmentId, Platform.maxStorageKey],
                 this._lowerOpen,
                 false
             );
@@ -28,7 +29,7 @@ class Range {
         // also bound as we don't want to move into another roomId
         if (!this._lower && this._upper) {
             return IDBKeyRange.bound(
-                [roomId, this._upper.fragmentId, EventKey.minKey.eventIndex],
+                [roomId, this._upper.fragmentId, Platform.minStorageKey],
                 [roomId, this._upper.fragmentId, this._upper.eventIndex],
                 false,
                 this._upperOpen

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

@@ -1,3 +1,5 @@
+import Platform from "../../../../Platform.js";
+
 export default class RoomFragmentStore {
     constructor(store) {
         this._store = store;
@@ -5,8 +7,8 @@ export default class RoomFragmentStore {
 
     _allRange(roomId) {
         return IDBKeyRange.bound(
-            [roomId, Number.MIN_SAFE_INTEGER],
-            [roomId, Number.MAX_SAFE_INTEGER]
+            [roomId, Platform.minStorageKey],
+            [roomId, Platform.maxStorageKey]
         );
     }
 

src/ui/web/WebPlatform.js

@@ -0,0 +1,16 @@
+export default {
+	get minStorageKey() {
+		// for indexeddb, we use unsigned 32 bit integers as keys
+		return 0;
+	},
+	
+	get middleStorageKey() {
+		// for indexeddb, we use unsigned 32 bit integers as keys
+		return 0x7FFFFFFF;
+	},
+
+	get maxStorageKey() {
+		// for indexeddb, we use unsigned 32 bit integers as keys
+		return 0xFFFFFFFF;
+	},
+}