Merge pull request #191 from zhy1985555/master

高级下载支持进度回调

Author: zhy1985555

qcloud_cos/cos_client.py

@@ -3194,7 +3194,7 @@ def _check_all_upload_parts(self, bucket, key, uploadid, local_path, parts_num,
             already_exist_parts[part_num] = part['ETag']
         return True
 
-    def download_file(self, Bucket, Key, DestFilePath, PartSize=20, MAXThread=5, EnableCRC=False, **Kwargs):
+    def download_file(self, Bucket, Key, DestFilePath, PartSize=20, MAXThread=5, EnableCRC=False, progress_callback=None, **Kwargs):
         """小于等于20MB的文件简单下载，大于20MB的文件使用续传下载
 
         :param Bucket(string): 存储桶名称.
@@ -3224,8 +3224,13 @@ def download_file(self, Bucket, Key, DestFilePath, PartSize=20, MAXThread=5, Ena
             response['Body'].get_stream_to_file(DestFilePath)
             return
 
+        # 支持回调查看进度
+        callback = None
+        if progress_callback:
+            callback = ProgressCallback(file_size, progress_callback)
+
         downloader = ResumableDownLoader(self, Bucket, Key, DestFilePath, object_info, PartSize, MAXThread, EnableCRC,
-                                         **Kwargs)
+                                         callback, **Kwargs)
         downloader.start()
 
     def upload_file(self, Bucket, Key, LocalFilePath, PartSize=1, MAXThread=5, EnableMD5=False, progress_callback=None,

qcloud_cos/resumable_downloader.py

@@ -17,14 +17,15 @@
 
 class ResumableDownLoader(object):
     def __init__(self, cos_client, bucket, key, dest_filename, object_info, part_size=20, max_thread=5,
-                 enable_crc=False, **kwargs):
+                 enable_crc=False, progress_callback=None, **kwargs):
         self.__cos_client = cos_client
         self.__bucket = bucket
         self.__key = key
         self.__dest_file_path = os.path.abspath(dest_filename)
         self.__object_info = object_info
         self.__max_thread = max_thread
         self.__enable_crc = enable_crc
+        self.__progress_callback = progress_callback
         self.__headers = kwargs
 
         self.__max_part_count = 100  # 取决于服务端是否对并发有限制
@@ -50,6 +51,11 @@ def start(self):
         assert self.__tmp_file
         open(self.__tmp_file, 'a').close()
 
+        # 已完成分块先设置下载进度
+        if self.__progress_callback:
+            for finished_part in self.__finished_parts:
+                self.__progress_callback.report(finished_part.length)       
+
         parts_need_to_download = self.__get_parts_need_to_download()
         logger.debug('parts_need_to_download: {0}'.format(parts_need_to_download))
         pool = SimpleThreadPool(self.__max_thread)
@@ -126,6 +132,9 @@ def __download_part(self, part, headers):
 
         self.__finish_part(part)
 
+        if self.__progress_callback:
+            self.__progress_callback.report(part.length) 
+
     def __finish_part(self, part):
         logger.debug('download part finished,bucket: {0}, key: {1}, part_id: {2}'.
                      format(self.__bucket, self.__key, part.part_id))