Fix pre cache logic

[wh201906]

The first batch of images won't be cached since v1.4.9. This PR fixes this bug.

Logcat output before this fix

(filtered with `package:com.honjow.fehviewer & (message:!!! | message:ser | message:showKey)`) ``` 2023-11-25 23:52:27.410 flutter com.honjow.fehviewer I │ [D] fetchImage ser:1 2023-11-25 23:52:27.464 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 1 2023-11-25 23:52:27.464 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): _processingSerSet contains ser. ser: 1 2023-11-25 23:52:27.464 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 2 2023-11-25 23:52:27.464 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): _processingSerSet contains ser. ser: 2 2023-11-25 23:52:27.464 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 3 2023-11-25 23:52:27.464 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): _processingSerSet contains ser. ser: 3 2023-11-25 23:52:27.465 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 4 2023-11-25 23:52:27.465 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): _processingSerSet contains ser. ser: 4 2023-11-25 23:52:27.465 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 5 2023-11-25 23:52:27.465 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): _processingSerSet contains ser. ser: 5 2023-11-25 23:52:27.468 flutter com.honjow.fehviewer I │ #1 GalleryPageController.fetchAndParserImageInfo (package:fehviewer/pages/gallery/controller/gallery_page_controller.dart:600:46) 2023-11-25 23:52:27.468 flutter com.honjow.fehviewer I │ [W] OOOOOOOld : showKey null, sourceId , isMpv false 2023-11-25 23:52:27.468 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 2 2023-11-25 23:52:27.468 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): _processingSerSet contains ser. ser: 2 2023-11-25 23:52:27.469 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 3 2023-11-25 23:52:27.469 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): _processingSerSet contains ser. ser: 3 2023-11-25 23:52:27.469 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 4 2023-11-25 23:52:27.469 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): _processingSerSet contains ser. ser: 4 2023-11-25 23:52:27.469 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 5 2023-11-25 23:52:27.469 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): _processingSerSet contains ser. ser: 5 2023-11-25 23:52:27.469 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 6 2023-11-25 23:52:27.470 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): _processingSerSet contains ser. ser: 6 2023-11-25 23:52:27.983 flutter com.honjow.fehviewer I │ #0 paraImage (package:fehviewer/common/parser/image_page_parser.dart:66:10) 2023-11-25 23:52:27.983 flutter com.honjow.fehviewer I │ [W] paraImage(): showKey hnwsjdsa4kf 2023-11-25 23:52:42.822 flutter com.honjow.fehviewer I │ [D] fetchImage ser:2 2023-11-25 23:52:42.830 flutter com.honjow.fehviewer I │ #1 GalleryPageController.fetchAndParserImageInfo (package:fehviewer/pages/gallery/controller/gallery_page_controller.dart:600:46) 2023-11-25 23:52:42.838 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 3 2023-11-25 23:52:42.838 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): _processingSerSet contains ser. ser: 3 2023-11-25 23:52:42.838 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 4 2023-11-25 23:52:42.838 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): _processingSerSet contains ser. ser: 4 2023-11-25 23:52:42.838 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 5 2023-11-25 23:52:42.838 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): _processingSerSet contains ser. ser: 5 2023-11-25 23:52:42.839 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 6 2023-11-25 23:52:42.839 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): _processingSerSet contains ser. ser: 6 2023-11-25 23:52:42.839 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 7 2023-11-25 23:52:42.915 flutter com.honjow.fehviewer I │ [W] 页码切换时的回调 预载图片 showKey: hnwsjdsa4kf 2023-11-25 23:52:42.922 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 2 2023-11-25 23:52:42.922 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): _processingSerSet contains ser. ser: 2 2023-11-25 23:52:42.923 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 3 2023-11-25 23:52:42.923 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): _processingSerSet contains ser. ser: 3 2023-11-25 23:52:42.923 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 4 2023-11-25 23:52:42.923 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): _processingSerSet contains ser. ser: 4 2023-11-25 23:52:42.923 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 5 2023-11-25 23:52:42.923 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): _processingSerSet contains ser. ser: 5 2023-11-25 23:52:42.923 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 6 2023-11-25 23:52:42.924 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): _processingSerSet contains ser. ser: 6 2023-11-25 23:53:05.581 flutter com.honjow.fehviewer I │ [D] fetchImage ser:3 2023-11-25 23:53:05.589 flutter com.honjow.fehviewer I │ #1 GalleryPageController.fetchAndParserImageInfo (package:fehviewer/pages/gallery/controller/gallery_page_controller.dart:600:46) 2023-11-25 23:53:05.593 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 4 2023-11-25 23:53:05.593 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): _processingSerSet contains ser. ser: 4 2023-11-25 23:53:05.594 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 5 2023-11-25 23:53:05.594 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): _processingSerSet contains ser. ser: 5 2023-11-25 23:53:05.594 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 6 2023-11-25 23:53:05.594 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): _processingSerSet contains ser. ser: 6 2023-11-25 23:53:05.595 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 7 2023-11-25 23:53:05.595 flutter com.honjow.fehviewer I │ [D] ser 7 已预载完成 跳过 2023-11-25 23:53:05.595 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 8 2023-11-25 23:53:05.678 flutter com.honjow.fehviewer I │ [W] 页码切换时的回调 预载图片 showKey: hnwsjdsa4kf 2023-11-25 23:53:05.680 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 3 2023-11-25 23:53:05.680 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): _processingSerSet contains ser. ser: 3 2023-11-25 23:53:05.681 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 4 2023-11-25 23:53:05.681 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): _processingSerSet contains ser. ser: 4 2023-11-25 23:53:05.681 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 5 2023-11-25 23:53:05.682 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): _processingSerSet contains ser. ser: 5 2023-11-25 23:53:05.682 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 6 2023-11-25 23:53:05.682 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): _processingSerSet contains ser. ser: 6 2023-11-25 23:53:05.683 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 7 2023-11-25 23:53:05.683 flutter com.honjow.fehviewer I │ [D] ser 7 已预载完成 跳过 2023-11-25 23:53:18.374 flutter com.honjow.fehviewer I │ [D] fetchImage ser:4 2023-11-25 23:53:18.379 flutter com.honjow.fehviewer I │ #1 GalleryPageController.fetchAndParserImageInfo (package:fehviewer/pages/gallery/controller/gallery_page_controller.dart:600:46) 2023-11-25 23:53:18.381 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 5 2023-11-25 23:53:18.381 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): _processingSerSet contains ser. ser: 5 2023-11-25 23:53:18.381 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 6 2023-11-25 23:53:18.382 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): _processingSerSet contains ser. ser: 6 2023-11-25 23:53:18.382 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 7 2023-11-25 23:53:18.382 flutter com.honjow.fehviewer I │ [D] ser 7 已预载完成 跳过 2023-11-25 23:53:18.382 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 8 2023-11-25 23:53:18.382 flutter com.honjow.fehviewer I │ [D] ser 8 已预载完成 跳过 2023-11-25 23:53:18.383 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 9 2023-11-25 23:53:18.496 flutter com.honjow.fehviewer I │ [W] 页码切换时的回调 预载图片 showKey: hnwsjdsa4kf 2023-11-25 23:53:18.503 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 4 2023-11-25 23:53:18.504 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): _processingSerSet contains ser. ser: 4 2023-11-25 23:53:18.504 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 5 2023-11-25 23:53:18.504 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): _processingSerSet contains ser. ser: 5 2023-11-25 23:53:18.504 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 6 2023-11-25 23:53:18.504 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): _processingSerSet contains ser. ser: 6 2023-11-25 23:53:18.504 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 7 2023-11-25 23:53:18.504 flutter com.honjow.fehviewer I │ [D] ser 7 已预载完成 跳过 2023-11-25 23:53:18.505 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 8 2023-11-25 23:53:18.505 flutter com.honjow.fehviewer I │ [D] ser 8 已预载完成 跳过 ```

(ser 2~6 are always uncached)

Logcat output after this fix

(filtered with `package:com.honjow.fehviewer & (message:!!! | message:ser | message:showKey)`) ``` 2023-11-26 00:04:24.133 flutter com.honjow.fehviewer I │ [D] fetchImage ser:1 2023-11-26 00:04:24.249 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 1 2023-11-26 00:04:24.249 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): showKey is null, skip precache. ser: 1 2023-11-26 00:04:24.249 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 2 2023-11-26 00:04:24.250 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): showKey is null, skip precache. ser: 2 2023-11-26 00:04:24.250 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 3 2023-11-26 00:04:24.250 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): showKey is null, skip precache. ser: 3 2023-11-26 00:04:24.250 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 4 2023-11-26 00:04:24.250 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): showKey is null, skip precache. ser: 4 2023-11-26 00:04:24.250 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 5 2023-11-26 00:04:24.250 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): showKey is null, skip precache. ser: 5 2023-11-26 00:04:24.404 flutter com.honjow.fehviewer I │ #1 GalleryPageController.fetchAndParserImageInfo (package:fehviewer/pages/gallery/controller/gallery_page_controller.dart:600:46) 2023-11-26 00:04:24.404 flutter com.honjow.fehviewer I │ [W] OOOOOOOld : showKey null, sourceId , isMpv false 2023-11-26 00:04:24.405 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 2 2023-11-26 00:04:24.406 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): showKey is null, skip precache. ser: 2 2023-11-26 00:04:24.407 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 3 2023-11-26 00:04:24.408 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): showKey is null, skip precache. ser: 3 2023-11-26 00:04:24.408 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 4 2023-11-26 00:04:24.409 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): showKey is null, skip precache. ser: 4 2023-11-26 00:04:24.409 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 5 2023-11-26 00:04:24.409 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): showKey is null, skip precache. ser: 5 2023-11-26 00:04:24.409 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 6 2023-11-26 00:04:24.409 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): showKey is null, skip precache. ser: 6 2023-11-26 00:04:25.078 flutter com.honjow.fehviewer I │ #0 paraImage (package:fehviewer/common/parser/image_page_parser.dart:66:10) 2023-11-26 00:04:25.078 flutter com.honjow.fehviewer I │ [W] paraImage(): showKey k3uu882a4kg 2023-11-26 00:04:37.550 flutter com.honjow.fehviewer I │ [D] fetchImage ser:2 2023-11-26 00:04:37.566 flutter com.honjow.fehviewer I │ #1 GalleryPageController.fetchAndParserImageInfo (package:fehviewer/pages/gallery/controller/gallery_page_controller.dart:600:46) 2023-11-26 00:04:37.570 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 3 2023-11-26 00:04:37.664 flutter com.honjow.fehviewer I │ [W] 页码切换时的回调 预载图片 showKey: k3uu882a4kg 2023-11-26 00:04:37.668 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 2 2023-11-26 00:04:41.950 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 3 2023-11-26 00:04:41.998 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 4 2023-11-26 00:04:43.138 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 4 2023-11-26 00:04:43.138 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): _processingSerSet contains ser. ser: 4 2023-11-26 00:04:43.138 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 5 2023-11-26 00:04:47.023 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 5 2023-11-26 00:04:47.374 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 6 2023-11-26 00:04:47.962 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 6 2023-11-26 00:04:47.963 flutter com.honjow.fehviewer I │ [W] !!!:ehPrecacheImages(): _processingSerSet contains ser. ser: 6 2023-11-26 00:04:47.963 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 7 2023-11-26 00:04:52.717 flutter com.honjow.fehviewer I │ [D] fetchImage ser:3 2023-11-26 00:04:52.726 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 4 2023-11-26 00:04:52.726 flutter com.honjow.fehviewer I │ [D] ser 4 已预载完成 跳过 2023-11-26 00:04:52.727 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 5 2023-11-26 00:04:52.727 flutter com.honjow.fehviewer I │ [D] ser 5 已预载完成 跳过 2023-11-26 00:04:52.727 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 6 2023-11-26 00:04:52.727 flutter com.honjow.fehviewer I │ [D] ser 6 已预载完成 跳过 2023-11-26 00:04:52.727 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 7 2023-11-26 00:04:52.727 flutter com.honjow.fehviewer I │ [D] ser 7 已预载完成 跳过 2023-11-26 00:04:52.727 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 8 2023-11-26 00:04:52.804 flutter com.honjow.fehviewer I │ [W] 页码切换时的回调 预载图片 showKey: k3uu882a4kg 2023-11-26 00:04:52.805 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 3 2023-11-26 00:04:52.805 flutter com.honjow.fehviewer I │ [D] ser 3 已预载完成 跳过 2023-11-26 00:04:52.805 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 4 2023-11-26 00:04:52.805 flutter com.honjow.fehviewer I │ [D] ser 4 已预载完成 跳过 2023-11-26 00:04:52.806 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 5 2023-11-26 00:04:52.806 flutter com.honjow.fehviewer I │ [D] ser 5 已预载完成 跳过 2023-11-26 00:04:52.806 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 6 2023-11-26 00:04:52.806 flutter com.honjow.fehviewer I │ [D] ser 6 已预载完成 跳过 2023-11-26 00:04:52.806 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 7 2023-11-26 00:04:52.806 flutter com.honjow.fehviewer I │ [D] ser 7 已预载完成 跳过 2023-11-26 00:04:56.667 flutter com.honjow.fehviewer I │ [D] fetchImage ser:4 2023-11-26 00:04:56.677 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 5 2023-11-26 00:04:56.677 flutter com.honjow.fehviewer I │ [D] ser 5 已预载完成 跳过 2023-11-26 00:04:56.677 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 6 2023-11-26 00:04:56.677 flutter com.honjow.fehviewer I │ [D] ser 6 已预载完成 跳过 2023-11-26 00:04:56.677 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 7 2023-11-26 00:04:56.677 flutter com.honjow.fehviewer I │ [D] ser 7 已预载完成 跳过 2023-11-26 00:04:56.677 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 8 2023-11-26 00:04:56.678 flutter com.honjow.fehviewer I │ [D] ser 8 已预载完成 跳过 2023-11-26 00:04:56.678 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 9 2023-11-26 00:04:56.767 flutter com.honjow.fehviewer I │ [W] 页码切换时的回调 预载图片 showKey: k3uu882a4kg 2023-11-26 00:04:56.770 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 4 2023-11-26 00:04:56.770 flutter com.honjow.fehviewer I │ [D] ser 4 已预载完成 跳过 2023-11-26 00:04:56.771 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 5 2023-11-26 00:04:56.771 flutter com.honjow.fehviewer I │ [D] ser 5 已预载完成 跳过 2023-11-26 00:04:56.771 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 6 2023-11-26 00:04:56.772 flutter com.honjow.fehviewer I │ [D] ser 6 已预载完成 跳过 2023-11-26 00:04:56.772 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 7 2023-11-26 00:04:56.772 flutter com.honjow.fehviewer I │ [D] ser 7 已预载完成 跳过 2023-11-26 00:04:56.773 flutter com.honjow.fehviewer I │ [D] 开始预载 ser 8 2023-11-26 00:04:56.773 flutter com.honjow.fehviewer I │ [D] ser 8 已预载完成 跳过 ```

(Only ser 2 is not cached)

---

This bug is caused by the continue between _processingSerSet.add() and _processingSerSet.remove(), which should always be called in pairs.

[honjow]

thanks