bvandeusen
5749f48b4a
Milestone #160 Opt 3b. Adds device class as a third context axis on top of the #1531 time-of-day/weekday affinity: on the radio path, a candidate is boosted when its artist concentrates in the current (daypart × weekday × device) cell. Client-sent (client_id is opaque; no UA stored), so it's captured going forward and applies to radio only (daily mixes are cron-built with no device → stay device-agnostic). Server: - Migration 0048: play_events.device_class text NULL (no CHECK; normalized in Go — one whitelist entry per new client class, not a migration). - events.go: eventRequest.device_class + normalizeDeviceClass (whitelist → mobile/web/…, else "other", empty → NULL); threaded through both RecordPlayStartedWithSource and RecordOfflinePlay into InsertPlayEvent. - ListArtistContextPlayCountsForUser gains a current-device param; the cell FILTER adds AND ($2='' OR device_class=$2) — '' reproduces the #1531 time-only behaviour exactly (used by mixes). SessionVector.DeviceClass carries it; the radio handler derives the current device from the user's latest play (GetLatestPlayDeviceClassForUser) — request-free proxy. - No new tuning knob: device narrows the existing ContextAffinityScore (reuses context_time_weight). Clients: - web: play_started sends device_class 'web'. - android: play_started + offline replay send 'mobile' (EventsWire + PlayOfflinePayload + MutationReplayer + PlayEventsReporter). Test: LoadContextAffinity device-narrowing integration test (mobile vs web artist separation; device-agnostic parity). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
76 lines
2.8 KiB
Go
76 lines
2.8 KiB
Go
package recommendation
|
||
|
||
import (
|
||
"context"
|
||
|
||
"github.com/jackc/pgx/v5/pgtype"
|
||
|
||
"git.fabledsword.com/bvandeusen/minstrel/internal/db/dbq"
|
||
)
|
||
|
||
// contextAffinityShrinkage is the pseudo-count that pulls a low-play artist's
|
||
// cell-share toward the user's baseline, so an artist with one or two plays
|
||
// can't swing its affinity to ±1 on noise. At k plays the estimate sits
|
||
// halfway between the raw cell-share and the baseline.
|
||
const contextAffinityShrinkage = 5.0
|
||
|
||
// ContextAffinity is the read-side map of per-artist time-of-day/weekday
|
||
// affinity for the CURRENT context (#1531): artist_id → score in [-1, +1].
|
||
// Absent artists (no play history) score 0, so cold-start candidates stay
|
||
// neutral. The zero value is a valid all-neutral affinity.
|
||
type ContextAffinity struct {
|
||
byArtist map[pgtype.UUID]float64
|
||
}
|
||
|
||
// Affinity returns the artist's current-context affinity, or 0 if unknown.
|
||
func (c ContextAffinity) Affinity(artistID pgtype.UUID) float64 {
|
||
return c.byArtist[artistID]
|
||
}
|
||
|
||
// LoadContextAffinity computes each artist's affinity for the user's CURRENT
|
||
// context cell — daypart × weekday, narrowed by deviceClass when non-empty
|
||
// (#1551; radio passes the current device, the daily mixes pass "" for a
|
||
// device-agnostic cell). For every artist with completed plays in the window it
|
||
// compares the share of that artist's plays that fall in the current cell
|
||
// against the user's overall baseline share, shrinking sparse artists toward
|
||
// the baseline. Returns an empty (all-neutral) affinity when the user has no
|
||
// plays.
|
||
func LoadContextAffinity(
|
||
ctx context.Context, q *dbq.Queries, userID pgtype.UUID, deviceClass string,
|
||
) (ContextAffinity, error) {
|
||
rows, err := q.ListArtistContextPlayCountsForUser(ctx, dbq.ListArtistContextPlayCountsForUserParams{
|
||
ID: userID,
|
||
Column2: deviceClass,
|
||
})
|
||
if err != nil {
|
||
return ContextAffinity{}, err
|
||
}
|
||
var totalPlays, cellPlays int64
|
||
for _, r := range rows {
|
||
totalPlays += r.TotalPlays
|
||
cellPlays += r.CellPlays
|
||
}
|
||
out := ContextAffinity{byArtist: make(map[pgtype.UUID]float64, len(rows))}
|
||
if totalPlays == 0 {
|
||
return out, nil
|
||
}
|
||
baseline := float64(cellPlays) / float64(totalPlays)
|
||
for _, r := range rows {
|
||
out.byArtist[r.ArtistID] = contextAffinity(
|
||
float64(r.CellPlays), float64(r.TotalPlays), baseline, contextAffinityShrinkage)
|
||
}
|
||
return out, nil
|
||
}
|
||
|
||
// contextAffinity returns an artist's shrunk cell-share minus the user's
|
||
// baseline share, clamped to [-1, 1]. The shrinkage pseudo-count k pulls
|
||
// low-play artists toward the baseline (→ 0 affinity) so noise can't dominate;
|
||
// a heavily-played artist keeps close to its raw over/under-representation.
|
||
func contextAffinity(cellPlays, totalPlays, baseline, k float64) float64 {
|
||
if totalPlays == 0 {
|
||
return 0
|
||
}
|
||
shrunk := (cellPlays + baseline*k) / (totalPlays + k)
|
||
return clampUnit(shrunk - baseline)
|
||
}
|