core: add file fallback

packages/hydrooj/package.json

@@ -1,6 +1,6 @@
 {
     "name": "hydrooj",
-    "version": "2.32.27",
+    "version": "2.32.28",
     "bin": "bin/hydrooj.js",
     "main": "src/loader",
     "module": "src/loader",

packages/hydrooj/src/handler/contest.ts

@@ -320,7 +320,12 @@ export class ContestProblemFileDownloadHandler extends ContestProblemHandler {
         if (typeof this.pdoc.docId === 'string') this.pdoc.docId = this.pdoc.docId.split(':')[1];
         const target = `problem/${this.pdoc.domainId}/${this.pdoc.docId}/additional_file/${filename}`;
         const file = await storage.getMeta(target);
-        if (!file) throw new NotFoundError(filename);
+        if (!file) {
+            this.response.redirect = await storage.signDownloadLink(
+                target, noDisposition ? undefined : filename, false, 'user',
+            );
+            return;
+        }
         this.response.etag = file.etag;
         const type = lookup(filename).toString();
         const shouldProxy = ['image', 'video', 'audio', 'pdf', 'vnd'].filter((i) => type.includes(i)).length;

packages/hydrooj/src/handler/homework.ts

@@ -184,7 +184,12 @@ export class HomeworkProblemFileDownloadHandler extends HomeworkDetailProblemHan
         if (typeof this.pdoc.docId === 'string') this.pdoc.docId = this.pdoc.docId.split(':')[1];
         const target = `problem/${this.pdoc.domainId}/${this.pdoc.docId}/additional_file/${filename}`;
         const file = await storage.getMeta(target);
-        if (!file) throw new NotFoundError(filename);
+        if (!file) {
+            this.response.redirect = await storage.signDownloadLink(
+                target, noDisposition ? undefined : filename, false, 'user',
+            );
+            return;
+        }
         this.response.etag = file.etag;
         const type = lookup(filename).toString();
         const shouldProxy = ['image', 'video', 'audio', 'pdf', 'vnd'].filter((i) => type.includes(i)).length;

packages/hydrooj/src/handler/misc.ts

@@ -111,7 +111,12 @@ export class FSDownloadHandler extends Handler {
         this.response.addHeader('Cache-Control', 'public');
         const target = `user/${uid}/${filename}`;
         const file = await storage.getMeta(target);
-        if (!file) throw new NotFoundError(filename);
+        if (!file) {
+            this.response.redirect = await storage.signDownloadLink(
+                target, noDisposition ? undefined : filename, false, 'user',
+            );
+            return;
+        }
         this.response.etag = file.etag;
         const type = lookup(filename).toString();
         const shouldProxy = ['image', 'video', 'audio', 'pdf', 'vnd'].filter((i) => type.includes(i)).length;

packages/hydrooj/src/handler/problem.ts

@@ -417,7 +417,12 @@ export class ProblemFileDownloadHandler extends ProblemDetailHandler {
         }
         const target = `problem/${domainId}/${this.pdoc.docId}/${type}/${filename}`;
         const file = await storage.getMeta(target);
-        if (!file) throw new NotFoundError(filename);
+        if (!file) {
+            this.response.redirect = await storage.signDownloadLink(
+                target, noDisposition ? undefined : filename, false, 'user',
+            );
+            return;
+        }
         this.response.etag = file.etag;
         const fileType = lookup(filename).toString();
         const shouldProxy = ['image', 'video', 'audio', 'pdf', 'vnd'].filter((i) => fileType.includes(i)).length;

packages/hydrooj/src/model/storage.ts

@@ -18,7 +18,7 @@ export class StorageModel {
         meta['Content-Type'] = (path.endsWith('.ans') || path.endsWith('.out'))
             ? 'text/plain'
             : lookup(path) || 'application/octet-stream';
-        const _id = nanoid() + extname(path);
+        const _id = `${nanoid(3)}/${nanoid()}${extname(path)}`;
         await storage.put(_id, file, meta);
         const { metaData, size, etag } = await storage.getMeta(_id);
         await StorageModel.coll.insertOne({
@@ -88,7 +88,7 @@ export class StorageModel {
             { path: target, autoDelete: { $exists: false } },
             { $set: { lastUsage: new Date() } },
         );
-        if (!res.value) return '';
+        if (!res.value) return await storage.signDownloadLink(target, filename, noExpire, useAlternativeEndpointFor);
         return await storage.signDownloadLink(res.value._id, filename, noExpire, useAlternativeEndpointFor);
     }
 }