Module video 

Video Thumbnails

Tuwunel decodes no video itself. An operator-configured program extracts a still frame, which the image thumbnailer then treats as the source picture.

Structs

Reaper 🔒

Kills the program’s process group on every exit that leaves it running, so that a shutdown or a disconnected client takes a wrapper’s descendants with it exactly as an expired deadline does. Disarmed once the child is reaped, past which the identifier could name a group this server never spawned.

Constants

DIAGNOSTIC_LEN 🔒

FAILURES 🔒

Videos remembered as having failed.

FAILURE_COOLDOWN 🔒

How long a video whose extraction failed is left alone. Retrying it at once would spend a slot to fail again, and at the default concurrency of one that is the slot every other video is waiting for.

FAIR_SHARE 🔒

Fraction of the deadline the program must still have to be worth running, and to be answerable for missing.

HEIGHT 🔒

INPUT 🔒

Tokens replaced in every configured argument before each call.

NAME_LENGTH 🔒

STAGED 🔒

Distinguishes a staged video from anything else in the staging directory, so the startup sweep reclaims only what this module wrote.

VIDEO 🔒

Content-type prefix of media a still frame is extracted from.

WIDTH 🔒

Functions

drain 🔒

kill_group 🔒

run 🔒

Collect the frame the program writes to standard output, refusing one past the limit rather than decoding a truncation. The program runs in its own process group, so a wrapper overrunning the deadline cannot orphan the work it spawned.

stage 🔒

Write the video to a fresh private file: the program needs a seekable input, and a pipe cannot serve formats whose index trails the media.

staging_dir 🔒

Videos are staged beside the database rather than in the system temporary directory, which is commonly memory-backed and sized for small files.

substitute 🔒

sweep_staging_dir 🔒

Reclaim videos staged by a previous run: the scope guard that unlinks them survives neither a kill nor the exec of an in-place restart. Runs during construction, before a request can stage a file this would race, which is also before the service graph exists to read the configuration through.

Type Aliases

Failures 🔒

Videos whose frame extraction failed, against the time it last did. Bounded, since forgetting an entry early only costs a retry.