# Approved torrents list

Package `torrentapproval` can be used for only allow or block
specified hashes or block specified hashes.

## Functionality

As said above, there are two modes of approval: white list and black list.

If mode is **white list** (`invert` set to `false`), tracker works in
_semi-private_ mode, which means, than peers can could share and receive info
about only specified list of torrents' hashes.

I.e.: if configuration contains hash `AAAA`, but peer announces hash `BBBB`
tracker will return `unapproved torrent` message back to peer.

If mode is **black list** (`invert` set to `true`), tracker will allow all hashes
**except** specified.

## Hash sources

There are two sources of hashes: `list` and `directory`.

Both of them used as **INITIAL** source for storing in storage.
If storage is not `memory`, records are persisted until _somebody_
or _something_ (different tool with access to storage) won't delete it.

`list` is the static set of hashes, specified in configuration file.

`directory` will watch for `*.torrent` files in specified path and
append/delete records from storage. This source will parse all existing
files at start and then watch for new files to add, or for delete events
to remove hash from storage.

## Configuration

This middleware provides the following parameters for configuration:

- `initial_source` - source type: `list` or `directory`
- `configuration` - options for specified source
	- `list`:
		- `hash_list` - list of HEX encoded hashes
		- `invert` - working mode: `true` - black list, `false` - white list
		- `storage_ctx` - name of storage _context_ where to store data.
		  It may be redis hash key, DB table name etc.
	- `directory`:
		- `path` - directory to watch
		- `invert` and `storage_ctx` has the same meanins as `list`'s options

Configuration example:

An example config might look like this:

```yaml
mochi:
    prehooks:
        -   name: torrent approval
                options:
                    initial_source: list
                    configuration:
                        hash_list: ["AAA", "BBB"]
                        invert: false
                        storage_ctx: APPROVED_HASH
```