flutter_disk_lru_cache

Dart version based on Android disk LRU cache migration The source code comes from android disk LRU cache


Usage

To use this plugin, follow the installing guide.

Example

import 'package:flutter/material.dart';
import 'package:crypto/crypto.dart';
import 'package:path_provider/path_provider.dart';
import 'package:flutter_disk_lru_cache/flutter_disk_lru_cache.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  Directory? tempDirectory = await getTemporaryDirectory();
  if (tempDirectory == null) {
    return;
  }
  
  /// init
  DiskLruCache diskLruCache = await DiskLruCache.open(tempDirectory!, valueCount: "file version nums",version: "1.0.0" ,maxSize: 20 * 10274 * 1024 (20m));
  
  /// key name
  final String key = md5.convert(utf8.encode("https://xxxxx.com/xxx.png")).toString();
  
  /// write data to disk cache
  Editor? editor = await diskLruCache.edit(key);
  if (editor == null) {
    throw Exception("editor is null");
  }
  
  /// request image uint8List
  final Uint8List imageBytes = await getImageUintList();
  
  /// open io stream
  FaultHidingIOSink faultHidingIOSink = editor.newOutputIOSink(0);
  
  /// write uint8List to disk,but it is dirty,is not commited
  await faultHidingIOSink.writeBytes(imageBytes);
  
  /// write text to disk,but it is dirty,is not commited
  await faultHidingIOSink.write("text");
  
  /// flush io
  await faultHidingIOSink.flush();
  
  /// close the io stream
  await faultHidingIOSink.close();
  
  /// comfirm commit
  await editor.commit(diskLruCache);
  
  /// cancel commit
  await editor.abort(diskLruCache);
  
  /// get cache file information
  Snapshot? snapshot = await editor.get(key);
  
  /// request to valueCount version
  RandomAccessFile inV1 = snapshot.getRandomAccessFile(0);
  Uint8List bytes = inV1.readSync(snapshot.getLengths(0));
  
  /// bytes to text
  String text = utf8.decode(bytes);
  
  /// close snapshot 
  snapshot.close();
  
  /// edit snapshot
  Editor? editor = await diskLruCache.edit(snapshot.key,sequenceNumber: snapshot.sequenceNumber);
  
  /// remove cache
  await diskLruCache.remove(key);
  
  /// flush cache
  await diskLruCache.flush();
  
  /// close disk cache
  await diskLruCache.close();
  
  /// Closes the cache and deletes all of its stored values. This will delete
  /// all files in the cache directory including files that weren't created by the cache.
  await diskLruCache.delete();
}

Libraries

flutter_disk_lru_cache