AlertCategory
Alert category bitmask, ported from libtorrent::alert_category together with the alert::*_notification static constants (include/libtorrent/alert.hpp).
Each alert belongs to one or more categories. libtorrent's settings_pack::alert_mask is a combination of these flags; only alerts whose category intersects the mask are posted (except non-discardable response alerts such as SaveResumeDataAlert and SessionStatsAlert).
In libtorrent the type is flags::bitfield_flag<std::uint32_t> where each constant is a single set bit (0_bit, 1_bit, ...). Here the same bit layout is carried in a plain Int used as a 32-bit mask. The bit positions are part of libtorrent's ABI (they map onto the alert mask the user configures), so they are reproduced exactly.
The *_notification spellings are kept as aliases because that is how the alert:: base class exposes them and how most client code refers to them.
Properties
Individual blocks requested/downloading/finished/rejected/timed-out/cancelled. alert_category::block_progress (bit 24).
Alias for connect.
Alias for dht.
Events from pure DHT operations not tied to a torrent. alert_category::dht_operation (bit 18).
Alias for error.
Files completing download. alert_category::file_progress (bit 21).
Enables the incoming-request alert. alert_category::incoming_request (bit 16).
Alias for ipBlock.
Alias for peer.
A limit was reached that might cap the download or upload rate. alert_category::performance_warning (bit 9).
Pieces completing download or failing the hash check. alert_category::piece_progress (bit 22).
Port-mapping events for NAT-PMP and UPnP. alert_category::port_mapping (bit 2).
Port-mapping log events (UPnP / NAT-PMP debugging). alert_category::port_mapping_log (bit 19).
Alias for portMapping.
Session-wide debug logging alerts. alert_category::session_log (bit 13).
Alias for stats.
Alias for status.
Alias for storage.
Per-torrent debug logging alerts. alert_category::torrent_log (bit 14).
Alias for tracker.