[FragmentFD] only write fragment to disk if --keep-fragments is given

README.md

@@ -192,8 +192,8 @@ Alternatively, refer to the [developer instructions](#developer-instructions) fo
     --abort-on-unavailable-fragment  Abort downloading when some fragment is not
                                      available
     --keep-fragments                 Keep downloaded fragments on disk after
-                                     downloading is finished; fragments are
-                                     erased by default
+                                     downloading is finished; fragments are not
+                                     saved by default
     --buffer-size SIZE               Size of download buffer (e.g. 1024 or 16K)
                                      (default is 1024)
     --no-resize-buffer               Do not automatically adjust the buffer

youtube_dl/downloader/fragment.py

@@ -1,5 +1,6 @@
 from __future__ import division, unicode_literals
 
+import io
 import os
 import time
 import json
@@ -96,18 +97,26 @@ class FragmentFD(FileDownloader):
         frag_index_stream.close()
 
     def _download_fragment(self, ctx, frag_url, info_dict, headers=None):
-        fragment_filename = '%s-Frag%d' % (ctx['tmpfilename'], ctx['fragment_index'])
-        success = ctx['dl'].download(fragment_filename, {
+        if self.params.get('keep_fragments', False):
+            frag_file = None
+            frag_filename = '%s-Frag%d' % (ctx['tmpfilename'], ctx['fragment_index'])
+        else:
+            frag_file = io.BytesIO()
+            frag_filename = None
+        success = ctx['dl'].download(frag_file or frag_filename, {
             'url': frag_url,
             'http_headers': headers or info_dict.get('http_headers'),
         })
         if not success:
-            return False, None
-        down, frag_sanitized = sanitize_open(fragment_filename, 'rb')
-        ctx['fragment_filename_sanitized'] = frag_sanitized
-        frag_content = down.read()
-        down.close()
-        return True, frag_content
+            frag_content = None
+        elif self.params.get('keep_fragments', False):
+            frag_file, frag_sanitized = sanitize_open(frag_filename, 'rb')
+            frag_content = frag_file.read()
+        else:
+            frag_content = frag_file.getvalue()
+        if frag_file:
+            frag_file.close()
+        return success, frag_content
 
     def _append_fragment(self, ctx, frag_content):
         try:
@@ -116,9 +125,6 @@ class FragmentFD(FileDownloader):
         finally:
             if self.__do_ytdl_file(ctx):
                 self._write_ytdl_file(ctx)
-            if not self.params.get('keep_fragments', False):
-                os.remove(encodeFilename(ctx['fragment_filename_sanitized']))
-            del ctx['fragment_filename_sanitized']
 
     def _prepare_frag_download(self, ctx):
         if 'live' not in ctx:

youtube_dl/downloader/http.py

@@ -1,6 +1,7 @@
 from __future__ import unicode_literals
 
 import errno
+import io
 import os
 import socket
 import time
@@ -33,6 +34,12 @@ class DownloadContext(dict):
 class HttpFD(FileDownloader):
     def create_context(self, filename, info_dict):
         ctx = DownloadContext()
+
+        if isinstance(filename, io.IOBase):
+            ctx.filename = '-'
+            ctx.tmpfilename = '-'
+            ctx.stream = filename
+        else:
             ctx.filename = filename
             ctx.tmpfilename = self.temp_name(filename)
             ctx.stream = None
@@ -44,7 +51,8 @@ class HttpFD(FileDownloader):
         ctx.start_time = time.time()
         ctx.chunk_size = None
 
-        if self.params.get('continuedl', True):
+        if (self.params.get('continuedl', True)
+                and ctx.tmpfilename != '-'):
             # Establish possible resume length
             if os.path.isfile(encodeFilename(ctx.tmpfilename)):
                 ctx.resume_len = os.path.getsize(
@@ -221,11 +229,12 @@ class HttpFD(FileDownloader):
             before = start  # start measuring
 
             def retry(e):
-                to_stdout = ctx.tmpfilename == '-'
-                if not to_stdout:
+                if ctx.tmpfilename == '-':
+                    ctx.resume_len = byte_counter
+                else:
                     ctx.stream.close()
                     ctx.stream = None
-                ctx.resume_len = byte_counter if to_stdout else os.path.getsize(encodeFilename(ctx.tmpfilename))
+                    ctx.resume_len = os.path.getsize(encodeFilename(ctx.tmpfilename))
                 raise RetryDownload(e)
 
             while True:

youtube_dl/options.py

@@ -473,7 +473,7 @@ def parseOpts(overrideArguments=None):
     downloader.add_option(
         '--keep-fragments',
         action='store_true', dest='keep_fragments', default=False,
-        help='Keep downloaded fragments on disk after downloading is finished; fragments are erased by default')
+        help='Keep downloaded fragments on disk after downloading is finished; fragments are not saved by default')
     downloader.add_option(
         '--buffer-size',
         dest='buffersize', metavar='SIZE', default='1024',