feat(file_manager): read and write gzip-compressed files (#19)

albertms10 · Dec 5, 2021 · 9dd70d0 · 9dd70d0
1 parent 9cdae9b
commit 9dd70d0
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Showing 2 changed files with 14 additions and 3 deletions.
diff --git a/lib/model/cabin_manager.dart b/lib/model/cabin_manager.dart
@@ -5,6 +5,7 @@ import 'package:cabin_booking/model/booking.dart';
 import 'package:cabin_booking/model/booking_manager.dart';
 import 'package:cabin_booking/model/cabin.dart';
 import 'package:cabin_booking/model/date_range.dart';
+import 'package:cabin_booking/model/file_manager.dart';
 import 'package:cabin_booking/model/recurring_booking.dart';
 import 'package:cabin_booking/model/writable_manager.dart';
 import 'package:cabin_booking/utils/time_of_day_extension.dart';
@@ -359,7 +360,7 @@ class CabinManager extends WritableManager<Set<Cabin>> with ChangeNotifier {
   Future<Set<Cabin>> readFromFile() async {
     try {
       final file = await fileManager.localFile(fileName);
-      final content = await file.readAsString();
+      final content = await file.readAsUncompressedString();
 
       final cabins = _parseCabins(content);
 
@@ -383,7 +384,7 @@ class CabinManager extends WritableManager<Set<Cabin>> with ChangeNotifier {
     try {
       final file = await fileManager.localFile(fileName);
 
-      await file.writeAsString(
+      await file.writeAsCompressedString(
         json.encode(cabinsToJson()),
       );
 

diff --git a/lib/model/file_manager.dart b/lib/model/file_manager.dart
@@ -1,4 +1,5 @@
-import 'dart:io' show File;
+import 'dart:convert';
+import 'dart:io' show File, gzip;
 
 import 'package:path_provider/path_provider.dart';
 
@@ -21,3 +22,12 @@ class FileManager {
     return File('$path/$fileName.json');
   }
 }
+
+extension FileExtension on File {
+  Future<File> writeAsCompressedString(String contents) => writeAsString(
+        String.fromCharCodes(gzip.encode(utf8.encode(contents))),
+      );
+
+  Future<String> readAsUncompressedString() async =>
+      utf8.decode(gzip.decode((await readAsString()).codeUnits));
+}