서버, 클라이언트, 서비스 워커 공용 코드를 lib/shared로 분리하고 브라우저 전용 모듈을 lib/client로 재구성

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/lib/server/services/file.ts

@@ -2,10 +2,9 @@ import { FileRepo, MediaRepo } from "#lib/server/db/index.js";
 import type { Ciphertext } from "#lib/server/db/schema/index.js";
 import { AppError } from "#lib/server/errors.js";
 import { createEncContentStream } from "#lib/server/storage/index.js";
+import type { RangeRequest } from "#lib/shared/http.js";
 import { schedulePendingFileDeletions } from "./fileDeletion";
 
-type Range = { start?: number; end?: number };
-
 export const getFile = async (userId: number, fileId: number) => {
   const file = await FileRepo.getFile(userId, fileId);
   if (!file) {
@@ -68,7 +67,7 @@ export const getFileThumbnail = async (userId: number, fileId: number) => {
 
 const decodeIv = (iv: string | null) => (iv ? Buffer.from(iv, "base64") : undefined);
 
-export const getFileStream = async (userId: number, fileId: number, range?: Range) => {
+export const getFileStream = async (userId: number, fileId: number, range?: RangeRequest) => {
   const file = await FileRepo.getFile(userId, fileId);
   if (!file) {
     throw new AppError("NOT_FOUND", "File not found");
@@ -76,7 +75,11 @@ export const getFileStream = async (userId: number, fileId: number, range?: Rang
   return await createEncContentStream(file.path, decodeIv(file.encContentIv), range);
 };
 
-export const getFileThumbnailStream = async (userId: number, fileId: number, range?: Range) => {
+export const getFileThumbnailStream = async (
+  userId: number,
+  fileId: number,
+  range?: RangeRequest,
+) => {
   const thumbnail = await getFileThumbnail(userId, fileId);
   return await createEncContentStream(thumbnail.path, decodeIv(thumbnail.encContentIv), range);
 };

src/lib/server/storage/chunks.ts

@@ -1,7 +1,7 @@
 import { open } from "fs/promises";
 import type { Readable } from "stream";
-import { ENCRYPTION_OVERHEAD, ENCRYPTED_CHUNK_SIZE } from "#lib/constants/index.js";
 import { AppError } from "#lib/server/errors.js";
+import { ENCRYPTION_OVERHEAD, ENCRYPTED_CHUNK_SIZE } from "#lib/shared/format/index.js";
 
 const invalidChunkSize = () => new AppError("BAD_REQUEST", "Invalid chunk size");
 

src/lib/server/storage/streams.ts

@@ -2,22 +2,22 @@ import { createReadStream } from "fs";
 import { stat } from "fs/promises";
 import { Readable } from "stream";
 import { AppError } from "#lib/server/errors.js";
+import { resolveRange, type RangeRequest } from "#lib/shared/http.js";
 
 export const createEncContentStream = async (
   path: string,
   iv?: Buffer,
-  range?: { start?: number; end?: number },
+  rangeRequest?: RangeRequest,
 ) => {
   const { size: fileSize } = await stat(path);
   const ivSize = iv?.byteLength ?? 0;
-  const totalSize = fileSize + ivSize;
 
-  const start = range?.start ?? 0;
-  const end = range?.end ?? totalSize - 1;
-  if (start > end || start < 0 || end >= totalSize) {
+  const range = resolveRange(rangeRequest, fileSize + ivSize);
+  if (!range) {
     throw new AppError("RANGE_NOT_SATISFIABLE", "Invalid range");
   }
 
+  const { start, end } = range;
   return {
     encContentStream: Readable.toWeb(
       Readable.from(
@@ -34,7 +34,7 @@ export const createEncContentStream = async (
         })(),
       ),
     ),
-    range: { start, end, total: totalSize },
-    isRangeRequest: !!range,
+    range,
+    isRangeRequest: !!rangeRequest,
   };
 };