Squashed commit of the following:

commit 3b229cad538ad88ef2d366964c4261bc0e02fb7c
Author: Simon Cambier <simon.cambier@protonmail.com>
Date:   Sat Nov 5 14:30:08 2022 +0100

    1.8.0-beta.1

commit f43c369b2dd0a1083b171724e3f7466429505629
Author: Simon Cambier <simon.cambier@protonmail.com>
Date:   Sat Nov 5 13:39:45 2022 +0100

    Squashed commit of the following:

    commit 93508ee95046385baf62475e5bd835ed9fafe6d3
    Author: Simon Cambier <simon.cambier@protonmail.com>
    Date:   Sat Nov 5 13:35:56 2022 +0100

        Cleaning

    commit 205e6a7cce4c1939338820f366f7ae8a067ec7fb
    Author: Simon Cambier <simon.cambier@protonmail.com>
    Date:   Fri Nov 4 08:53:46 2022 +0100

        Added logs

    commit ea19b94e164581829908ac71d09a60e230925a7f
    Author: Simon Cambier <simon.cambier@protonmail.com>
    Date:   Thu Nov 3 22:27:24 2022 +0100

        Notices

    commit 53ff4e822b3c292a56da150b94a1cfe43e199d44
    Author: Simon Cambier <simon.cambier@protonmail.com>
    Date:   Thu Nov 3 22:27:09 2022 +0100

        Custom minisearch build + Notice when the cache could be corrupted

    commit 498408afd1c350dd68969318c3533fff8aa6c172
    Author: Simon Cambier <simon.cambier@protonmail.com>
    Date:   Thu Nov 3 22:26:22 2022 +0100

        Added a button to manually clear the cache

    commit 90afe5d3868989626ba4613b064e24ac7efa88be
    Author: Simon Cambier <simon.cambier@protonmail.com>
    Date:   Thu Nov 3 22:03:41 2022 +0100

        Optimized loading minisearch from cache

    commit 719dcb9c82f09f56dabb828ac13c9c1db7f795bb
    Author: Simon Cambier <simon.cambier@protonmail.com>
    Date:   Thu Nov 3 21:43:49 2022 +0100

        #92 - Refactored cache to make it behave like pre-indexedDb

    commit 2164ccfa39d83eef23231d01e8aa35ac30e0d31c
    Author: Simon Cambier <simon.cambier@protonmail.com>
    Date:   Wed Nov 2 23:13:59 2022 +0100

        Removed cache & tmp engine

    commit 50eb33bbd4d074be9a9952eaf871cd8f58b327e6
    Author: Simon Cambier <simon.cambier@protonmail.com>
    Date:   Wed Nov 2 22:56:04 2022 +0100

        More efficient loading of PDFs

commit a6342a675f
Author: Simon Cambier <simon.cambier@protonmail.com>
Date:   Wed Nov 2 10:34:02 2022 +0100

    #120 - Cleaning of old cache databases

commit b6890567f3
Author: Simon Cambier <simon.cambier@protonmail.com>
Date:   Mon Oct 31 17:28:17 2022 +0100

    Updated Readme

src/database.ts

@@ -1,21 +1,72 @@
 import Dexie from 'dexie'
+import type { AsPlainObject } from 'minisearch'
+import type { IndexedDocument } from './globals'
 
-class OmnisearchCache extends Dexie {
-  pdf!: Dexie.Table<
-    { path: string; hash: string; size: number; text: string },
+export class OmnisearchCache extends Dexie {
+  public static readonly dbVersion = 7
+  public static readonly dbPrefix = 'omnisearch/cache/'
+  public static readonly dbName = OmnisearchCache.dbPrefix + app.appId
+
+  private static instance: OmnisearchCache
+
+  /**
+   * Deletes Omnisearch databases that have an older version than the current one
+   */
+  public static async clearOldDatabases(): Promise<void> {
+    const toDelete = (await indexedDB.databases()).filter(
+      db =>
+        db.name?.startsWith(OmnisearchCache.dbPrefix) &&
+        // version multiplied by 10 https://github.com/dexie/Dexie.js/issues/59
+        db.version !== OmnisearchCache.dbVersion * 10
+    )
+    if (toDelete.length) {
+      console.log('Omnisearch - Those IndexedDb databases will be deleted:')
+      for (const db of toDelete) {
+        if (db.name) {
+          console.log(db.name + ' ' + db.version)
+          indexedDB.deleteDatabase(db.name)
+        }
+      }
+    }
+  }
+
+  //#region Table declarations
+
+  pdf!: Dexie.Table<{ path: string; hash: string; text: string }, string>
+  documents!: Dexie.Table<
+    { path: string; mtime: number; document: IndexedDocument },
     string
   >
   searchHistory!: Dexie.Table<{ id?: number; query: string }, number>
-  minisearch!: Dexie.Table<{ date: string; data: string }, string>
+  minisearch!: Dexie.Table<
+    { date: string; checksum: string; data: AsPlainObject },
+    string
+  >
 
-  constructor() {
-    super('omnisearch/cache/' + app.appId)
-    this.version(5).stores({
+  //#endregion Table declarations
+
+  public static getInstance() {
+    if (!OmnisearchCache.instance) {
+      OmnisearchCache.instance = new OmnisearchCache()
+    }
+    return OmnisearchCache.instance
+  }
+
+  private constructor() {
+    super(OmnisearchCache.dbName)
+    // Database structure
+    this.version(OmnisearchCache.dbVersion).stores({
       pdf: 'path, hash, size',
       searchHistory: '++id',
+      documents: 'path',
       minisearch: 'date',
     })
   }
+
+  public async clearCache() {
+    await this.minisearch.clear()
+    await this.documents.clear()
+  }
 }
 
-export const database = new OmnisearchCache()
+export const database = OmnisearchCache.getInstance()