[feat] opfs storage

src/ts/storage/opfsStorage.ts

@@ -0,0 +1,61 @@
+export class OpfsStorage{
+
+    opfs:FileSystemDirectoryHandle
+
+    async setItem(key:string, value:Uint8Array) {
+        await this.Init()
+        const handle = await this.opfs.getFileHandle(Buffer.from(key, 'utf-8').toString('hex'), {
+            create: true
+        })
+        const stream = await handle.createWritable()
+        await stream.write(value)
+        stream.close()
+    }
+    async getItem(key:string):Promise<Buffer> {
+        try {
+            await this.Init()
+            const handle = await this.opfs.getFileHandle(Buffer.from(key, 'utf-8').toString('hex'), {
+                create: false
+            })
+            const stream = await handle.getFile();
+    
+            return Buffer.from(await stream.arrayBuffer())   
+        } catch (error) {
+            if(error instanceof DOMException){
+                if(error.name === "NotFoundError"){
+                    return null
+                }
+            }
+            throw error
+        }
+    }
+    async keys():Promise<string[]>{
+        await this.Init()
+        let entries:string[] = []
+        for await (const entry of this.opfs.values()) {
+            entries.push(Buffer.from(entry.name, 'hex').toString('utf-8'))
+        }
+        return entries
+    }
+    async removeItem(key:string){
+        try {
+            await this.Init()
+            await this.opfs.removeEntry(Buffer.from(key, 'utf-8').toString('hex'))
+        } catch (error) {
+            if(error instanceof DOMException){
+                if(error.name === "NotFoundError"){
+                    return null
+                }
+            }
+            throw error
+        }
+    }
+
+    private async Init(){
+        if(!this.opfs){
+            this.opfs = await window.navigator.storage.getDirectory()
+        }
+    }
+
+    listItem = this.keys
+}