Fixing bug on collection deletion

Extending Admin Interface
Adding cleanup procedure, that clears undeleted collection data

src/database/database.ts

@@ -3,6 +3,7 @@ import Settings from "../settings";
 import getLevelDB, { LevelDB, deleteLevelDB } from "../storage";
 import DocumentLock from "./lock";
 import { DocumentQuery, CollectionQuery, Query } from "./query";
+import Logging from "@hibas123/nodelogging";
 
 export class DatabaseManager {
    static databases = new Map<string, Database>();
@@ -116,4 +117,105 @@ export class Database {
    async stop() {
       await this.data.close();
    }
+
+   public async runCleanup() {
+      const should = await new Promise<Set<string>>((yes, no) => {
+         const stream = this.collections.iterator({
+            keyAsBuffer: false,
+            valueAsBuffer: false
+         })
+
+         const collections = new Set<string>();
+         const onValue = (err: Error, key: string, value: string) => {
+            if (err) {
+               Logging.error(err);
+               stream.end((err) => Logging.error(err))
+               no(err);
+            }
+
+            if (!key && !value) {
+               yes(collections);
+            } else {
+               collections.add(value)
+               stream.next(onValue);
+            }
+         }
+
+         stream.next(onValue);
+      })
+
+      const existing = await new Promise<Set<string>>((yes, no) => {
+         const stream = this.data.iterator({
+            keyAsBuffer: false,
+            values: false
+         })
+
+         const collections = new Set<string>();
+         const onValue = (err: Error, key: string, value: Buffer) => {
+            if (err) {
+               Logging.error(err);
+               stream.end((err) => Logging.error(err))
+               no(err);
+            }
+
+            if (!key && !value) {
+               yes(collections);
+            } else {
+               let coll = key.split("/")[0];
+               collections.add(coll)
+               stream.next(onValue);
+            }
+         }
+
+         stream.next(onValue);
+      })
+
+      const toDelete = new Set<string>();
+      existing.forEach(collection => {
+         if (!should.has(collection))
+            toDelete.add(collection);
+      })
+
+      for (let collection of toDelete) {
+         const batch = this.data.batch();
+
+         let gt = Buffer.from(collection + "/ ");
+         gt[gt.length - 1] = 0;
+
+         let lt = Buffer.alloc(gt.length);
+         lt.set(gt);
+         lt[gt.length - 1] = 0xFF;
+
+         await new Promise<void>((yes, no) => {
+            const stream = this.data.iterator({
+               keyAsBuffer: false,
+               values: false,
+               gt,
+               lt
+            })
+
+            const onValue = (err: Error, key: string, value: Buffer) => {
+               if (err) {
+                  Logging.error(err);
+                  stream.end((err) => Logging.error(err))
+                  no(err);
+               }
+
+               if (!key && !value) {
+                  yes();
+               } else {
+                  batch.del(key);
+                  stream.next(onValue);
+               }
+            }
+
+            stream.next(onValue);
+         })
+
+         await batch.write();
+      }
+
+      return Array.from(toDelete.values());
+   }
+
 }