업로드 이미지 WebP 최적화 1차 적용

backend/src/lib/image-storage.js

@@ -0,0 +1,76 @@
+const fs = require('fs/promises')
+const path = require('path')
+const sharp = require('sharp')
+const { nanoid } = require('nanoid')
+
+const UPLOAD_ROOT = path.join(__dirname, '..', '..', 'uploads')
+
+function ensureImageMimeType(file) {
+  return typeof file?.mimetype === 'string' && file.mimetype.startsWith('image/')
+}
+
+function createMemoryUpload(multer, { fileSize = 6 * 1024 * 1024, maxCount } = {}) {
+  return multer({
+    storage: multer.memoryStorage(),
+    limits: {
+      fileSize,
+      ...(typeof maxCount === 'number' ? { files: maxCount } : {}),
+    },
+    fileFilter: (req, file, cb) => {
+      if (ensureImageMimeType(file)) return cb(null, true)
+      cb(new Error('image_file_required'))
+    },
+  })
+}
+
+async function writeOptimizedImage({
+  file,
+  directory,
+  width,
+  height,
+  fit = 'inside',
+  quality = 82,
+}) {
+  if (!file?.buffer?.length) {
+    const error = new Error('file_required')
+    error.code = 'file_required'
+    throw error
+  }
+
+  if (!ensureImageMimeType(file)) {
+    const error = new Error('image_file_required')
+    error.code = 'image_file_required'
+    throw error
+  }
+
+  const { data, info } = await sharp(file.buffer, { failOn: 'none' })
+    .rotate()
+    .resize({
+      width,
+      height,
+      fit,
+      withoutEnlargement: true,
+    })
+    .webp({ quality })
+    .toBuffer({ resolveWithObject: true })
+
+  const filename = String(Date.now()) + '-' + nanoid() + '.webp'
+  const absoluteDir = path.join(UPLOAD_ROOT, directory)
+  const absolutePath = path.join(absoluteDir, filename)
+  await fs.mkdir(absoluteDir, { recursive: true })
+  await fs.writeFile(absolutePath, data)
+
+  return {
+    src: '/uploads/' + directory + '/' + filename,
+    size: data.length,
+    originalSize: file.size || file.buffer.length,
+    width: info.width || 0,
+    height: info.height || 0,
+  }
+}
+
+module.exports = {
+  createMemoryUpload,
+  ensureImageMimeType,
+  writeOptimizedImage,
+}