資料的壓縮最好是能做在前端，因為網路最慢的地方就是前後端的溝通了，現在的壓縮演算法有很多，舉凡gzip、PKzip、LZW、zlib等等

我們的Lab追求簡單，於是使用了python本身就有的zlib，壓縮和解壓縮的使用非常簡單，如下

def compress(data):
   return zlib.compress(data)

def decompress(data):
   print(data)
   return zlib.decompress(data)

https://github.com/kaichiachen/python-simple-object-storage/blob/master/utils/utils.py#L53

然後我們分別在upload object的時候進行壓縮

content = compress(content.encode()) # content type will be byte after compress
hash = sha256(content)
size = len(content)
chunk = 10
for i in range(0, size, chunk):
   res = requests.post(f"{server_url}/objects/{name}", files={
                                                         'obj': content[i:i+chunk],
                                                         'hash':hash,
                                                         'version': args.version,
                                                         'start': i,
                                                         'length': chunk,
                                                         'size': size})

以及download的時候解壓縮

while len(content)<size:
      try:
         content += requests.get(f"{server_url}/objects/{name}?version={version}&start={start}").content
      except KeyboardInterrupt:
         sys.exit()
      except Exception as e:
         start = len(content)
         print('Something wrong, downloading again...', e)
   try:
      print(f'Get content: {decompress(content).decode()}')
   except Exception as e:
      print(f'Something wrong: {e}')

於是乎，從使用者的角度來看，看起來就只是上傳下載Object而已，性能的優化都在前端做好了