Backdoor allows the operator to telnet into the given port, and get a python shell
running inside the process, from which you can debug, modify state (eg. set the log level),
or whatever. This is extremely useful for debugging weird states that you encounter randomly
but can't easily reproduce, without restarting the process and needing to wait until it happens again.
I ran `pyflakes` on the repo and found these bugs:
```
./common/common.py:289: undefined name 'random'
./downloader/downloader/main.py:7: 'random' imported but unused
./backfiller/backfiller/main.py:150: undefined name 'variant'
./backfiller/backfiller/main.py:158: undefined name 'timedelta'
./backfiller/backfiller/main.py:171: undefined name 'sort'
./backfiller/backfiller/main.py:173: undefined name 'sort'
```
(ok, the "imported but unused" one isn't a bug, but the rest are)
This fixes those, as well as a further issue I saw with sorting of hours.
Iterables are not sortable. As an obvious example, what if your iterable was infinite?
As a result, any attempt to sort an iterable that is not already a friendly type like a list
or tuple will result in an error. We avoid this by coercing to list, fully realising the iterable
and putting it into a form that python will let us sort. It also avoids the nasty side-effect
of mutating the list that gets passed into us, which the caller may not expect. Consider this example:
```
>>> my_hours = ["one", "two", "three"]
>>> print my_hours
["one", "two", "three"]
>>> backfill_node(base_dir, node, stream, variants, hours=my_hours, order='forward')
>>> print my_hours
["one", "three", "two"]
```
Also, one of the linter errors was non-trivial to fix - we were trying to get a list of hours
(which is an api call for a particular variant), but at a time when we weren't dealing with a single
variant. My solution was to get a list of hours for ALL variants, and take the union.
Previously, downloader would put files under BASE_DIR/VARIANT/HOUR/FILE.ts
now, it will put files under BASE_DIR/STREAM/VARIANT/HOUR/FILE.ts
This brings downloader in line with restreamer's concept of base_dir
* Fix bug where soft timeout is not cancelled if an exception occurs
* Various logging tweaks
* Prevent master playlist wait time from going negative
* Stop gracefully if stream worker detects end of stream
* Don't treat master playlist 404 as an error, it just means the stream isn't up
* Set a reasonable log format
* Make soft timeouts not always fire
* Change soft_hard_timeout signature slightly for ease-of-use
* Make renames not fail if file already exists
* Misc typos
This makes the code crazy complicated and messy, but means we can be persistent about
not giving up, while still retrying at the same time, and trying multiple urls at once
until we find one that works.
See docstrings for a full discussion on some of the failures we're trying to work around.
This is a useful library and we might as well use it.
Copying it over and slightly modifying it to work was easier than importing all of streamlink.
The original version may be found at 30043408c7/src/streamlink/stream/hls_playlist.py
Mike Lang
Christopher Usher