썸네일 업로드도 새로운 업로드 방식으로 변경

src/lib/server/services/upload.ts

@@ -0,0 +1,77 @@
+import { error } from "@sveltejs/kit";
+import { createHash } from "crypto";
+import { createWriteStream } from "fs";
+import { Readable } from "stream";
+import { CHUNK_SIZE, ENCRYPTION_OVERHEAD } from "$lib/constants";
+import { UploadRepo } from "$lib/server/db";
+import { getChunkDirectoryPath, safeUnlink } from "$lib/server/modules/filesystem";
+
+const chunkLocks = new Set<string>();
+
+export const uploadChunk = async (
+  userId: number,
+  sessionId: string,
+  chunkIndex: number,
+  encChunkStream: Readable,
+  encChunkHash: string,
+) => {
+  const lockKey = `${sessionId}/${chunkIndex}`;
+  if (chunkLocks.has(lockKey)) {
+    error(409, "Chunk already uploaded"); // TODO: Message
+  } else {
+    chunkLocks.add(lockKey);
+  }
+
+  const filePath = `${getChunkDirectoryPath(sessionId)}/${chunkIndex}`;
+
+  try {
+    const session = await UploadRepo.getUploadSession(sessionId, userId);
+    if (!session) {
+      error(404, "Invalid upload id");
+    } else if (chunkIndex >= session.totalChunks) {
+      error(400, "Invalid chunk index");
+    } else if (session.uploadedChunks.includes(chunkIndex)) {
+      error(409, "Chunk already uploaded");
+    }
+
+    const isLastChunk = chunkIndex === session.totalChunks - 1;
+
+    let writtenBytes = 0;
+    const hashStream = createHash("sha256");
+    const writeStream = createWriteStream(filePath, { flags: "wx", mode: 0o600 });
+
+    for await (const chunk of encChunkStream) {
+      writtenBytes += chunk.length;
+      hashStream.update(chunk);
+      writeStream.write(chunk);
+    }
+
+    await new Promise<void>((resolve, reject) => {
+      writeStream.end((e: any) => (e ? reject(e) : resolve()));
+    });
+
+    if (hashStream.digest("base64") !== encChunkHash) {
+      throw new Error("Invalid checksum");
+    } else if (
+      (!isLastChunk && writtenBytes !== CHUNK_SIZE + ENCRYPTION_OVERHEAD) ||
+      (isLastChunk &&
+        (writtenBytes <= ENCRYPTION_OVERHEAD || writtenBytes > CHUNK_SIZE + ENCRYPTION_OVERHEAD))
+    ) {
+      throw new Error("Invalid chunk size");
+    }
+
+    await UploadRepo.markChunkAsUploaded(sessionId, chunkIndex);
+  } catch (e) {
+    await safeUnlink(filePath);
+
+    if (
+      e instanceof Error &&
+      (e.message === "Invalid checksum" || e.message === "Invalid chunk size")
+    ) {
+      error(400, "Invalid request body");
+    }
+    throw e;
+  } finally {
+    chunkLocks.delete(lockKey);
+  }
+};