Reuse the face grid's decoded crops across a redraw

A confirm or a reject changes one row and redraws the whole grid, and the
redraw re-read every crop blob of the selected person (4 MB for the
largest) and decoded every one — 316 ms per click on the reference
library's 754-face person, to arrive at the pixels already on screen.

`load_faces` now takes the crops the previous load decoded, keyed by face,
and moves each into its new cell; the blob read is skipped when every face
is already in hand. `refresh` drains the old cells into it rather than
cloning them. The redraw is 2.6 ms.

docs/traceability.md

@@ -50,7 +50,7 @@ A tag naming an ID `requirements.md` does not define — what renumbering produc
 | FR-CAT-8 | [`core/dr-catalog/src/schema.rs:644`](../core/dr-catalog/src/schema.rs#L644), [`core/dr-pipeline/src/coverage.rs:1`](../core/dr-pipeline/src/coverage.rs#L1), [`core/dr-pipeline/src/graph.rs:587`](../core/dr-pipeline/src/graph.rs#L587), [`core/dr-pipeline/src/graph.rs:640`](../core/dr-pipeline/src/graph.rs#L640), [`core/dr-pipeline/src/ops/curve.rs:137`](../core/dr-pipeline/src/ops/curve.rs#L137), [`core/dr-pipeline/src/ops/curve.rs:656`](../core/dr-pipeline/src/ops/curve.rs#L656), [`core/dr-pipeline/src/sidecar.rs:1400`](../core/dr-pipeline/src/sidecar.rs#L1400), [`core/dr-pipeline/src/sidecar.rs:2232`](../core/dr-pipeline/src/sidecar.rs#L2232), [`core/dr-pipeline/src/sidecar.rs:96`](../core/dr-pipeline/src/sidecar.rs#L96), [`core/dr-pipeline/src/state.rs:1`](../core/dr-pipeline/src/state.rs#L1), [`core/dr-pipeline/src/state.rs:75`](../core/dr-pipeline/src/state.rs#L75), [`core/dr-pipeline/tests/tone_curve.rs:34`](../core/dr-pipeline/tests/tone_curve.rs#L34), [`core/dr-sync/src/scan.rs:31`](../core/dr-sync/src/scan.rs#L31), [`core/dr-sync/src/scan.rs:56`](../core/dr-sync/src/scan.rs#L56), [`core/dr-sync/src/scan.rs:926`](../core/dr-sync/src/scan.rs#L926), [`ui/dr-ui/src/develop.rs:2155`](../ui/dr-ui/src/develop.rs#L2155), [`ui/dr-ui/src/develop.rs:5430`](../ui/dr-ui/src/develop.rs#L5430), [`ui/dr-ui/src/develop.rs:5459`](../ui/dr-ui/src/develop.rs#L5459), [`ui/dr-ui/src/develop.rs:6833`](../ui/dr-ui/src/develop.rs#L6833), [`ui/dr-ui/src/develop.rs:6887`](../ui/dr-ui/src/develop.rs#L6887), [`ui/dr-ui/src/develop.rs:6989`](../ui/dr-ui/src/develop.rs#L6989), [`ui/dr-ui/src/export.rs:812`](../ui/dr-ui/src/export.rs#L812), [`ui/dr-ui/src/lib.rs:1330`](../ui/dr-ui/src/lib.rs#L1330), [`ui/dr-ui/src/lib.rs:1888`](../ui/dr-ui/src/lib.rs#L1888), [`ui/dr-ui/src/lib.rs:2457`](../ui/dr-ui/src/lib.rs#L2457), [`ui/dr-ui/src/lib.rs:2604`](../ui/dr-ui/src/lib.rs#L2604), [`ui/dr-ui/src/lib.rs:757`](../ui/dr-ui/src/lib.rs#L757), [`ui/dr-ui/src/library.rs:1455`](../ui/dr-ui/src/library.rs#L1455), [`ui/dr-ui/src/library.rs:1490`](../ui/dr-ui/src/library.rs#L1490), [`ui/dr-ui/src/library.rs:2491`](../ui/dr-ui/src/library.rs#L2491), [`ui/dr-ui/src/library.rs:564`](../ui/dr-ui/src/library.rs#L564), [`ui/dr-ui/src/library.rs:616`](../ui/dr-ui/src/library.rs#L616), [`ui/dr-ui/src/library.rs:653`](../ui/dr-ui/src/library.rs#L653), [`ui/dr-ui/src/library.rs:7386`](../ui/dr-ui/src/library.rs#L7386), [`ui/dr-ui/src/library.rs:73`](../ui/dr-ui/src/library.rs#L73), [`ui/dr-ui/src/library.rs:926`](../ui/dr-ui/src/library.rs#L926), [`ui/dr-ui/src/library_ui.rs:1339`](../ui/dr-ui/src/library_ui.rs#L1339), [`ui/dr-ui/src/library_ui.rs:6350`](../ui/dr-ui/src/library_ui.rs#L6350), [`ui/dr-ui/src/sidecar_cache.rs:1`](../ui/dr-ui/src/sidecar_cache.rs#L1) |
 | FR-CAT-9 | [`core/dr-catalog/src/cache.rs:1`](../core/dr-catalog/src/cache.rs#L1), [`core/dr-catalog/src/scan.rs:1`](../core/dr-catalog/src/scan.rs#L1), [`core/dr-catalog/src/schema.rs:1048`](../core/dr-catalog/src/schema.rs#L1048), [`core/dr-catalog/src/walk.rs:1022`](../core/dr-catalog/src/walk.rs#L1022), [`core/dr-catalog/src/walk.rs:162`](../core/dr-catalog/src/walk.rs#L162), [`core/dr-catalog/src/walk.rs:1`](../core/dr-catalog/src/walk.rs#L1), [`core/dr-catalog/src/walk.rs:435`](../core/dr-catalog/src/walk.rs#L435), [`core/dr-catalog/src/walk.rs:728`](../core/dr-catalog/src/walk.rs#L728), [`core/dr-sync-nextcloud/src/desktop_client.rs:35`](../core/dr-sync-nextcloud/src/desktop_client.rs#L35), [`core/dr-sync/src/error.rs:113`](../core/dr-sync/src/error.rs#L113), [`core/dr-sync/src/reachability.rs:1`](../core/dr-sync/src/reachability.rs#L1), [`core/dr-sync/src/scan.rs:211`](../core/dr-sync/src/scan.rs#L211), [`core/dr-sync/src/scan.rs:519`](../core/dr-sync/src/scan.rs#L519), [`core/dr-types/src/lib.rs:122`](../core/dr-types/src/lib.rs#L122), [`ui/dr-ui/src/develop.rs:4719`](../ui/dr-ui/src/develop.rs#L4719), [`ui/dr-ui/src/develop.rs:4762`](../ui/dr-ui/src/develop.rs#L4762), [`ui/dr-ui/src/library.rs:1355`](../ui/dr-ui/src/library.rs#L1355), [`ui/dr-ui/src/library.rs:1408`](../ui/dr-ui/src/library.rs#L1408), [`ui/dr-ui/src/library.rs:1439`](../ui/dr-ui/src/library.rs#L1439), [`ui/dr-ui/src/library.rs:1490`](../ui/dr-ui/src/library.rs#L1490), [`ui/dr-ui/src/library.rs:169`](../ui/dr-ui/src/library.rs#L169), [`ui/dr-ui/src/library.rs:2019`](../ui/dr-ui/src/library.rs#L2019), [`ui/dr-ui/src/library.rs:2471`](../ui/dr-ui/src/library.rs#L2471), [`ui/dr-ui/src/library.rs:2527`](../ui/dr-ui/src/library.rs#L2527), [`ui/dr-ui/src/library.rs:274`](../ui/dr-ui/src/library.rs#L274), [`ui/dr-ui/src/library.rs:5224`](../ui/dr-ui/src/library.rs#L5224), [`ui/dr-ui/src/library.rs:653`](../ui/dr-ui/src/library.rs#L653), [`ui/dr-ui/src/library.rs:910`](../ui/dr-ui/src/library.rs#L910), [`ui/dr-ui/src/library.rs:926`](../ui/dr-ui/src/library.rs#L926), [`ui/dr-ui/src/library.rs:980`](../ui/dr-ui/src/library.rs#L980), [`ui/dr-ui/src/library_ui.rs:1406`](../ui/dr-ui/src/library_ui.rs#L1406), [`ui/dr-ui/src/library_ui.rs:1997`](../ui/dr-ui/src/library_ui.rs#L1997), [`ui/dr-ui/src/library_ui.rs:2041`](../ui/dr-ui/src/library_ui.rs#L2041), [`ui/dr-ui/src/library_ui.rs:2057`](../ui/dr-ui/src/library_ui.rs#L2057), [`ui/dr-ui/src/library_ui.rs:2151`](../ui/dr-ui/src/library_ui.rs#L2151), [`ui/dr-ui/src/library_ui.rs:284`](../ui/dr-ui/src/library_ui.rs#L284), [`ui/dr-ui/src/library_ui.rs:2993`](../ui/dr-ui/src/library_ui.rs#L2993), [`ui/dr-ui/src/library_ui.rs:320`](../ui/dr-ui/src/library_ui.rs#L320), [`ui/dr-ui/src/library_ui.rs:328`](../ui/dr-ui/src/library_ui.rs#L328), [`ui/dr-ui/src/library_ui.rs:3616`](../ui/dr-ui/src/library_ui.rs#L3616), [`ui/dr-ui/src/library_ui.rs:3838`](../ui/dr-ui/src/library_ui.rs#L3838), [`ui/dr-ui/src/library_ui.rs:4116`](../ui/dr-ui/src/library_ui.rs#L4116), [`ui/dr-ui/src/library_ui.rs:4232`](../ui/dr-ui/src/library_ui.rs#L4232), [`ui/dr-ui/src/library_ui.rs:4420`](../ui/dr-ui/src/library_ui.rs#L4420), [`ui/dr-ui/src/library_ui.rs:4542`](../ui/dr-ui/src/library_ui.rs#L4542), [`ui/dr-ui/src/library_ui.rs:573`](../ui/dr-ui/src/library_ui.rs#L573), [`ui/dr-ui/src/library_ui.rs:662`](../ui/dr-ui/src/library_ui.rs#L662), [`ui/dr-ui/src/library_ui.rs:6864`](../ui/dr-ui/src/library_ui.rs#L6864), [`ui/dr-ui/src/library_ui.rs:6946`](../ui/dr-ui/src/library_ui.rs#L6946), [`ui/dr-ui/src/presets.rs:486`](../ui/dr-ui/src/presets.rs#L486), [`ui/dr-ui/src/presets.rs:498`](../ui/dr-ui/src/presets.rs#L498), [`ui/dr-ui/src/sidecar_cache.rs:1`](../ui/dr-ui/src/sidecar_cache.rs#L1), [`ui/dr-ui/tests/export_ignores_the_viewport.rs:1`](../ui/dr-ui/tests/export_ignores_the_viewport.rs#L1) |
 | FR-CULL-1 | [`core/dr-decode/src/preview.rs:121`](../core/dr-decode/src/preview.rs#L121) |
-| FR-CULL-10 | [`core/dr-catalog/src/faces.rs:1`](../core/dr-catalog/src/faces.rs#L1), [`core/dr-catalog/src/schema.rs:507`](../core/dr-catalog/src/schema.rs#L507), [`core/dr-catalog/src/schema.rs:685`](../core/dr-catalog/src/schema.rs#L685), [`core/dr-catalog/src/schema.rs:877`](../core/dr-catalog/src/schema.rs#L877), [`core/dr-face/src/assign.rs:1`](../core/dr-face/src/assign.rs#L1), [`core/dr-face/src/neighbours.rs:1`](../core/dr-face/src/neighbours.rs#L1), [`core/dr-types/src/settings.rs:129`](../core/dr-types/src/settings.rs#L129), [`ui/dr-ui/src/develop.rs:121`](../ui/dr-ui/src/develop.rs#L121), [`ui/dr-ui/src/develop.rs:130`](../ui/dr-ui/src/develop.rs#L130), [`ui/dr-ui/src/develop.rs:196`](../ui/dr-ui/src/develop.rs#L196), [`ui/dr-ui/src/develop.rs:2416`](../ui/dr-ui/src/develop.rs#L2416), [`ui/dr-ui/src/develop.rs:715`](../ui/dr-ui/src/develop.rs#L715), [`ui/dr-ui/src/faces.rs:1`](../ui/dr-ui/src/faces.rs#L1), [`ui/dr-ui/src/identity.rs:1`](../ui/dr-ui/src/identity.rs#L1), [`ui/dr-ui/src/identity_ui.rs:1315`](../ui/dr-ui/src/identity_ui.rs#L1315), [`ui/dr-ui/src/identity_ui.rs:1`](../ui/dr-ui/src/identity_ui.rs#L1), [`ui/dr-ui/src/lib.rs:2576`](../ui/dr-ui/src/lib.rs#L2576), [`ui/dr-ui/src/repairs.rs:1`](../ui/dr-ui/src/repairs.rs#L1), [`ui/dr-ui/ui/identity.slint:1`](../ui/dr-ui/ui/identity.slint#L1), [`ui/dr-ui/ui/settings.slint:529`](../ui/dr-ui/ui/settings.slint#L529), [`ui/dr-ui/ui/settings.slint:94`](../ui/dr-ui/ui/settings.slint#L94) |
+| FR-CULL-10 | [`core/dr-catalog/src/faces.rs:1`](../core/dr-catalog/src/faces.rs#L1), [`core/dr-catalog/src/schema.rs:507`](../core/dr-catalog/src/schema.rs#L507), [`core/dr-catalog/src/schema.rs:685`](../core/dr-catalog/src/schema.rs#L685), [`core/dr-catalog/src/schema.rs:877`](../core/dr-catalog/src/schema.rs#L877), [`core/dr-face/src/assign.rs:1`](../core/dr-face/src/assign.rs#L1), [`core/dr-face/src/neighbours.rs:1`](../core/dr-face/src/neighbours.rs#L1), [`core/dr-types/src/settings.rs:129`](../core/dr-types/src/settings.rs#L129), [`ui/dr-ui/src/develop.rs:121`](../ui/dr-ui/src/develop.rs#L121), [`ui/dr-ui/src/develop.rs:130`](../ui/dr-ui/src/develop.rs#L130), [`ui/dr-ui/src/develop.rs:196`](../ui/dr-ui/src/develop.rs#L196), [`ui/dr-ui/src/develop.rs:2416`](../ui/dr-ui/src/develop.rs#L2416), [`ui/dr-ui/src/develop.rs:715`](../ui/dr-ui/src/develop.rs#L715), [`ui/dr-ui/src/faces.rs:1`](../ui/dr-ui/src/faces.rs#L1), [`ui/dr-ui/src/identity.rs:1`](../ui/dr-ui/src/identity.rs#L1), [`ui/dr-ui/src/identity_ui.rs:1325`](../ui/dr-ui/src/identity_ui.rs#L1325), [`ui/dr-ui/src/identity_ui.rs:1`](../ui/dr-ui/src/identity_ui.rs#L1), [`ui/dr-ui/src/lib.rs:2576`](../ui/dr-ui/src/lib.rs#L2576), [`ui/dr-ui/src/repairs.rs:1`](../ui/dr-ui/src/repairs.rs#L1), [`ui/dr-ui/ui/identity.slint:1`](../ui/dr-ui/ui/identity.slint#L1), [`ui/dr-ui/ui/settings.slint:529`](../ui/dr-ui/ui/settings.slint#L529), [`ui/dr-ui/ui/settings.slint:94`](../ui/dr-ui/ui/settings.slint#L94) |
 | FR-CULL-11 | [`core/dr-catalog/src/faces.rs:1`](../core/dr-catalog/src/faces.rs#L1), [`core/dr-catalog/src/schema.rs:877`](../core/dr-catalog/src/schema.rs#L877), [`ui/dr-ui/src/identity.rs:1`](../ui/dr-ui/src/identity.rs#L1), [`ui/dr-ui/src/identity_ui.rs:1`](../ui/dr-ui/src/identity_ui.rs#L1), [`ui/dr-ui/src/library.rs:295`](../ui/dr-ui/src/library.rs#L295), [`ui/dr-ui/src/library.rs:345`](../ui/dr-ui/src/library.rs#L345), [`ui/dr-ui/ui/identity.slint:1`](../ui/dr-ui/ui/identity.slint#L1) |
 | FR-CULL-12 | [`core/dr-catalog/src/faces.rs:1`](../core/dr-catalog/src/faces.rs#L1), [`core/dr-catalog/src/schema.rs:507`](../core/dr-catalog/src/schema.rs#L507), [`core/dr-catalog/src/schema.rs:877`](../core/dr-catalog/src/schema.rs#L877), [`ui/dr-ui/src/identity.rs:1`](../ui/dr-ui/src/identity.rs#L1), [`ui/dr-ui/ui/identity.slint:1`](../ui/dr-ui/ui/identity.slint#L1) |
 | FR-CULL-13 | [`core/dr-catalog/src/schema.rs:783`](../core/dr-catalog/src/schema.rs#L783), [`core/dr-types/src/place.rs:129`](../core/dr-types/src/place.rs#L129), [`ui/dr-ui/src/identity.rs:104`](../ui/dr-ui/src/identity.rs#L104), [`ui/dr-ui/src/library.rs:321`](../ui/dr-ui/src/library.rs#L321), [`ui/dr-ui/src/library.rs:7219`](../ui/dr-ui/src/library.rs#L7219), [`ui/dr-ui/src/library.rs:7262`](../ui/dr-ui/src/library.rs#L7262), [`ui/dr-ui/src/library.rs:7300`](../ui/dr-ui/src/library.rs#L7300), [`ui/dr-ui/ui/app.slint:707`](../ui/dr-ui/ui/app.slint#L707), [`ui/dr-ui/ui/identity.slint:63`](../ui/dr-ui/ui/identity.slint#L63), [`ui/dr-ui/ui/library.slint:1512`](../ui/dr-ui/ui/library.slint#L1512) |
@@ -58,7 +58,7 @@ A tag naming an ID `requirements.md` does not define — what renumbering produc
 | FR-CULL-3 | [`core/dr-gpu/src/focus.rs:154`](../core/dr-gpu/src/focus.rs#L154), [`core/dr-gpu/src/focus.rs:186`](../core/dr-gpu/src/focus.rs#L186), [`core/dr-gpu/src/focus.rs:1`](../core/dr-gpu/src/focus.rs#L1), [`core/dr-gpu/src/focus.rs:317`](../core/dr-gpu/src/focus.rs#L317), [`core/dr-gpu/src/raw_histogram.rs:129`](../core/dr-gpu/src/raw_histogram.rs#L129), [`core/dr-gpu/src/raw_histogram.rs:1`](../core/dr-gpu/src/raw_histogram.rs#L1), [`core/dr-gpu/src/raw_histogram.rs:272`](../core/dr-gpu/src/raw_histogram.rs#L272), [`core/dr-gpu/src/raw_histogram.rs:407`](../core/dr-gpu/src/raw_histogram.rs#L407), [`core/dr-gpu/src/shaders/focus_peak.wgsl:1`](../core/dr-gpu/src/shaders/focus_peak.wgsl#L1), [`core/dr-gpu/src/shaders/raw_histogram.wgsl:1`](../core/dr-gpu/src/shaders/raw_histogram.wgsl#L1), [`ui/dr-ui/src/develop.rs:4146`](../ui/dr-ui/src/develop.rs#L4146), [`ui/dr-ui/src/develop.rs:4159`](../ui/dr-ui/src/develop.rs#L4159), [`ui/dr-ui/src/develop.rs:4204`](../ui/dr-ui/src/develop.rs#L4204), [`ui/dr-ui/src/develop.rs:4215`](../ui/dr-ui/src/develop.rs#L4215), [`ui/dr-ui/src/develop.rs:4221`](../ui/dr-ui/src/develop.rs#L4221), [`ui/dr-ui/src/develop.rs:4238`](../ui/dr-ui/src/develop.rs#L4238), [`ui/dr-ui/src/develop.rs:810`](../ui/dr-ui/src/develop.rs#L810), [`ui/dr-ui/src/develop.rs:830`](../ui/dr-ui/src/develop.rs#L830), [`ui/dr-ui/src/develop.rs:836`](../ui/dr-ui/src/develop.rs#L836), [`ui/dr-ui/src/develop.rs:8768`](../ui/dr-ui/src/develop.rs#L8768), [`ui/dr-ui/src/develop.rs:8832`](../ui/dr-ui/src/develop.rs#L8832), [`ui/dr-ui/src/develop.rs:8855`](../ui/dr-ui/src/develop.rs#L8855), [`ui/dr-ui/src/histogram.rs:1`](../ui/dr-ui/src/histogram.rs#L1), [`ui/dr-ui/src/histogram.rs:208`](../ui/dr-ui/src/histogram.rs#L208), [`ui/dr-ui/src/histogram.rs:228`](../ui/dr-ui/src/histogram.rs#L228), [`ui/dr-ui/src/histogram.rs:272`](../ui/dr-ui/src/histogram.rs#L272), [`ui/dr-ui/src/histogram.rs:544`](../ui/dr-ui/src/histogram.rs#L544), [`ui/dr-ui/src/histogram.rs:565`](../ui/dr-ui/src/histogram.rs#L565), [`ui/dr-ui/src/histogram.rs:593`](../ui/dr-ui/src/histogram.rs#L593), [`ui/dr-ui/src/histogram.rs:621`](../ui/dr-ui/src/histogram.rs#L621), [`ui/dr-ui/src/histogram.rs:658`](../ui/dr-ui/src/histogram.rs#L658), [`ui/dr-ui/src/lib.rs:1932`](../ui/dr-ui/src/lib.rs#L1932), [`ui/dr-ui/src/lib.rs:2040`](../ui/dr-ui/src/lib.rs#L2040), [`ui/dr-ui/src/lib.rs:2153`](../ui/dr-ui/src/lib.rs#L2153), [`ui/dr-ui/src/lib.rs:2194`](../ui/dr-ui/src/lib.rs#L2194), [`ui/dr-ui/src/lib.rs:3687`](../ui/dr-ui/src/lib.rs#L3687), [`ui/dr-ui/src/lib.rs:442`](../ui/dr-ui/src/lib.rs#L442), [`ui/dr-ui/src/peaking.rs:1`](../ui/dr-ui/src/peaking.rs#L1), [`ui/dr-ui/ui/app.slint:2028`](../ui/dr-ui/ui/app.slint#L2028), [`ui/dr-ui/ui/app.slint:3035`](../ui/dr-ui/ui/app.slint#L3035), [`ui/dr-ui/ui/app.slint:90`](../ui/dr-ui/ui/app.slint#L90), [`ui/dr-ui/ui/peaking.slint:1`](../ui/dr-ui/ui/peaking.slint#L1), [`ui/dr-ui/ui/peaking.slint:25`](../ui/dr-ui/ui/peaking.slint#L25), [`ui/dr-ui/ui/peaking.slint:56`](../ui/dr-ui/ui/peaking.slint#L56), [`ui/dr-ui/ui/peaking.slint:91`](../ui/dr-ui/ui/peaking.slint#L91) |
 | FR-CULL-4 | [`core/dr-catalog/src/rating.rs:1`](../core/dr-catalog/src/rating.rs#L1), [`core/dr-pipeline/src/sidecar.rs:171`](../core/dr-pipeline/src/sidecar.rs#L171), [`core/dr-xmp/src/lib.rs:442`](../core/dr-xmp/src/lib.rs#L442), [`ui/dr-ui/src/library.rs:254`](../ui/dr-ui/src/library.rs#L254), [`ui/dr-ui/src/library.rs:564`](../ui/dr-ui/src/library.rs#L564) |
 | FR-CULL-5 | [`core/dr-catalog/src/bursts.rs:1`](../core/dr-catalog/src/bursts.rs#L1), [`core/dr-catalog/src/schema.rs:550`](../core/dr-catalog/src/schema.rs#L550), [`ui/dr-ui/src/bursts.rs:1`](../ui/dr-ui/src/bursts.rs#L1), [`ui/dr-ui/src/library.rs:210`](../ui/dr-ui/src/library.rs#L210), [`ui/dr-ui/src/library.rs:6039`](../ui/dr-ui/src/library.rs#L6039) |
-| FR-CULL-8 | [`core/dr-catalog/src/face_shard.rs:1`](../core/dr-catalog/src/face_shard.rs#L1), [`core/dr-catalog/src/faces.rs:1`](../core/dr-catalog/src/faces.rs#L1), [`core/dr-catalog/src/schema.rs:618`](../core/dr-catalog/src/schema.rs#L618), [`core/dr-catalog/src/schema.rs:836`](../core/dr-catalog/src/schema.rs#L836), [`core/dr-catalog/src/schema.rs:877`](../core/dr-catalog/src/schema.rs#L877), [`core/dr-face/src/align.rs:296`](../core/dr-face/src/align.rs#L296), [`core/dr-types/src/settings.rs:176`](../core/dr-types/src/settings.rs#L176), [`ui/dr-ui/examples/face_detectors.rs:1`](../ui/dr-ui/examples/face_detectors.rs#L1), [`ui/dr-ui/examples/face_native.rs:1`](../ui/dr-ui/examples/face_native.rs#L1), [`ui/dr-ui/src/derived_sync.rs:124`](../ui/dr-ui/src/derived_sync.rs#L124), [`ui/dr-ui/src/faces.rs:1`](../ui/dr-ui/src/faces.rs#L1), [`ui/dr-ui/src/faces.rs:446`](../ui/dr-ui/src/faces.rs#L446), [`ui/dr-ui/src/faces.rs:462`](../ui/dr-ui/src/faces.rs#L462), [`ui/dr-ui/src/faces.rs:584`](../ui/dr-ui/src/faces.rs#L584), [`ui/dr-ui/src/identity_ui.rs:1315`](../ui/dr-ui/src/identity_ui.rs#L1315), [`ui/dr-ui/src/identity_ui.rs:593`](../ui/dr-ui/src/identity_ui.rs#L593), [`ui/dr-ui/src/lib.rs:1511`](../ui/dr-ui/src/lib.rs#L1511), [`ui/dr-ui/src/lib.rs:3942`](../ui/dr-ui/src/lib.rs#L3942), [`ui/dr-ui/src/library.rs:3624`](../ui/dr-ui/src/library.rs#L3624), [`ui/dr-ui/src/library.rs:3889`](../ui/dr-ui/src/library.rs#L3889), [`ui/dr-ui/src/library_ui.rs:406`](../ui/dr-ui/src/library_ui.rs#L406), [`ui/dr-ui/src/library_ui.rs:493`](../ui/dr-ui/src/library_ui.rs#L493), [`ui/dr-ui/src/repairs.rs:1`](../ui/dr-ui/src/repairs.rs#L1), [`ui/dr-ui/src/settings_ui.rs:210`](../ui/dr-ui/src/settings_ui.rs#L210), [`ui/dr-ui/src/settings_ui.rs:552`](../ui/dr-ui/src/settings_ui.rs#L552), [`ui/dr-ui/ui/app.slint:946`](../ui/dr-ui/ui/app.slint#L946), [`ui/dr-ui/ui/settings.slint:100`](../ui/dr-ui/ui/settings.slint#L100), [`ui/dr-ui/ui/settings.slint:467`](../ui/dr-ui/ui/settings.slint#L467), [`ui/dr-ui/ui/settings.slint:529`](../ui/dr-ui/ui/settings.slint#L529), [`ui/dr-ui/ui/settings.slint:82`](../ui/dr-ui/ui/settings.slint#L82), [`ui/dr-ui/ui/settings.slint:94`](../ui/dr-ui/ui/settings.slint#L94) |
+| FR-CULL-8 | [`core/dr-catalog/src/face_shard.rs:1`](../core/dr-catalog/src/face_shard.rs#L1), [`core/dr-catalog/src/faces.rs:1`](../core/dr-catalog/src/faces.rs#L1), [`core/dr-catalog/src/schema.rs:618`](../core/dr-catalog/src/schema.rs#L618), [`core/dr-catalog/src/schema.rs:836`](../core/dr-catalog/src/schema.rs#L836), [`core/dr-catalog/src/schema.rs:877`](../core/dr-catalog/src/schema.rs#L877), [`core/dr-face/src/align.rs:296`](../core/dr-face/src/align.rs#L296), [`core/dr-types/src/settings.rs:176`](../core/dr-types/src/settings.rs#L176), [`ui/dr-ui/examples/face_detectors.rs:1`](../ui/dr-ui/examples/face_detectors.rs#L1), [`ui/dr-ui/examples/face_native.rs:1`](../ui/dr-ui/examples/face_native.rs#L1), [`ui/dr-ui/src/derived_sync.rs:124`](../ui/dr-ui/src/derived_sync.rs#L124), [`ui/dr-ui/src/faces.rs:1`](../ui/dr-ui/src/faces.rs#L1), [`ui/dr-ui/src/faces.rs:446`](../ui/dr-ui/src/faces.rs#L446), [`ui/dr-ui/src/faces.rs:462`](../ui/dr-ui/src/faces.rs#L462), [`ui/dr-ui/src/faces.rs:584`](../ui/dr-ui/src/faces.rs#L584), [`ui/dr-ui/src/identity_ui.rs:1325`](../ui/dr-ui/src/identity_ui.rs#L1325), [`ui/dr-ui/src/identity_ui.rs:603`](../ui/dr-ui/src/identity_ui.rs#L603), [`ui/dr-ui/src/lib.rs:1511`](../ui/dr-ui/src/lib.rs#L1511), [`ui/dr-ui/src/lib.rs:3942`](../ui/dr-ui/src/lib.rs#L3942), [`ui/dr-ui/src/library.rs:3624`](../ui/dr-ui/src/library.rs#L3624), [`ui/dr-ui/src/library.rs:3889`](../ui/dr-ui/src/library.rs#L3889), [`ui/dr-ui/src/library_ui.rs:406`](../ui/dr-ui/src/library_ui.rs#L406), [`ui/dr-ui/src/library_ui.rs:493`](../ui/dr-ui/src/library_ui.rs#L493), [`ui/dr-ui/src/repairs.rs:1`](../ui/dr-ui/src/repairs.rs#L1), [`ui/dr-ui/src/settings_ui.rs:210`](../ui/dr-ui/src/settings_ui.rs#L210), [`ui/dr-ui/src/settings_ui.rs:552`](../ui/dr-ui/src/settings_ui.rs#L552), [`ui/dr-ui/ui/app.slint:946`](../ui/dr-ui/ui/app.slint#L946), [`ui/dr-ui/ui/settings.slint:100`](../ui/dr-ui/ui/settings.slint#L100), [`ui/dr-ui/ui/settings.slint:467`](../ui/dr-ui/ui/settings.slint#L467), [`ui/dr-ui/ui/settings.slint:529`](../ui/dr-ui/ui/settings.slint#L529), [`ui/dr-ui/ui/settings.slint:82`](../ui/dr-ui/ui/settings.slint#L82), [`ui/dr-ui/ui/settings.slint:94`](../ui/dr-ui/ui/settings.slint#L94) |
 | FR-CULL-8a | [`core/dr-catalog/src/faces.rs:124`](../core/dr-catalog/src/faces.rs#L124), [`core/dr-catalog/src/schema.rs:783`](../core/dr-catalog/src/schema.rs#L783), [`core/dr-face/src/classify.rs:1`](../core/dr-face/src/classify.rs#L1), [`core/dr-face/src/eyes.rs:1`](../core/dr-face/src/eyes.rs#L1), [`core/dr-face/src/landmarks.rs:1`](../core/dr-face/src/landmarks.rs#L1), [`core/dr-types/src/place.rs:129`](../core/dr-types/src/place.rs#L129), [`ui/dr-ui/src/faces.rs:166`](../ui/dr-ui/src/faces.rs#L166), [`ui/dr-ui/src/faces.rs:1748`](../ui/dr-ui/src/faces.rs#L1748), [`ui/dr-ui/src/faces.rs:308`](../ui/dr-ui/src/faces.rs#L308), [`ui/dr-ui/src/identity.rs:104`](../ui/dr-ui/src/identity.rs#L104), [`ui/dr-ui/src/library.rs:321`](../ui/dr-ui/src/library.rs#L321), [`ui/dr-ui/src/library.rs:7219`](../ui/dr-ui/src/library.rs#L7219), [`ui/dr-ui/src/library.rs:7262`](../ui/dr-ui/src/library.rs#L7262), [`ui/dr-ui/src/library.rs:7300`](../ui/dr-ui/src/library.rs#L7300), [`ui/dr-ui/src/repairs.rs:554`](../ui/dr-ui/src/repairs.rs#L554), [`ui/dr-ui/ui/app.slint:707`](../ui/dr-ui/ui/app.slint#L707), [`ui/dr-ui/ui/identity.slint:273`](../ui/dr-ui/ui/identity.slint#L273), [`ui/dr-ui/ui/identity.slint:63`](../ui/dr-ui/ui/identity.slint#L63), [`ui/dr-ui/ui/library.slint:1512`](../ui/dr-ui/ui/library.slint#L1512) |
 | FR-CULL-9 | [`core/dr-catalog/src/faces.rs:1`](../core/dr-catalog/src/faces.rs#L1), [`core/dr-catalog/src/schema.rs:685`](../core/dr-catalog/src/schema.rs#L685), [`core/dr-catalog/src/schema.rs:877`](../core/dr-catalog/src/schema.rs#L877), [`core/dr-face/src/assign.rs:1`](../core/dr-face/src/assign.rs#L1), [`core/dr-face/src/neighbours.rs:1`](../core/dr-face/src/neighbours.rs#L1), [`core/dr-types/src/settings.rs:129`](../core/dr-types/src/settings.rs#L129), [`ui/dr-ui/src/faces.rs:1`](../ui/dr-ui/src/faces.rs#L1), [`ui/dr-ui/src/faces.rs:584`](../ui/dr-ui/src/faces.rs#L584), [`ui/dr-ui/src/identity_ui.rs:1`](../ui/dr-ui/src/identity_ui.rs#L1), [`ui/dr-ui/src/repairs.rs:500`](../ui/dr-ui/src/repairs.rs#L500), [`ui/dr-ui/ui/identity.slint:347`](../ui/dr-ui/ui/identity.slint#L347) |
 | FR-DEV-1 | [`core/dr-pipeline/src/graph.rs:1`](../core/dr-pipeline/src/graph.rs#L1), [`core/dr-pipeline/src/sidecar.rs:1`](../core/dr-pipeline/src/sidecar.rs#L1) |

ui/dr-ui/examples/identity_bench.rs

@@ -60,8 +60,17 @@ fn main() {
     time("load_people", 5, || {
         identity::load_people(&catalog, MODEL_ID).unwrap();
     });
-    time("load_faces (largest person)", 5, || {
+    time("load_faces (largest person, cold)", 5, || {
-        identity::load_faces(&catalog, &store, biggest).unwrap();
+        identity::load_faces(&catalog, &store, biggest, Default::default()).unwrap();
+    });
+    // What a confirm click costs: the grid's own crops handed back in.
+    let mut cells = identity::load_faces(&catalog, &store, biggest, Default::default()).unwrap();
+    time("load_faces (largest person, redraw)", 5, || {
+        let cut = cells
+            .drain(..)
+            .filter_map(|c| Some((c.face, c.crop?)))
+            .collect();
+        cells = identity::load_faces(&catalog, &store, biggest, cut).unwrap();
     });
     time("audit (coverage line)", 5, || {
         dr_ui::faces::audit(&catalog, &store, MODEL_ID, &registry).unwrap();

ui/dr-ui/src/identity.rs

@@ -261,18 +261,38 @@ pub fn load_people(
 /// Crops come from the proxy the grid already built. An image whose proxy has
 /// been evicted yields a cell with no crop rather than being dropped — the face
 /// is still real, still counted, and still confirmable from its filename.
+///
+/// `cut` is whatever the previous load of this grid had already decoded,
+/// keyed by face, and is consumed: a crop found there is moved into the new
+/// cell and neither read from the catalog nor decoded again. A confirm or a
+/// reject changes one face's row and redraws the whole grid, and without this
+/// the redraw re-read four megabytes of JPEG and decoded seven hundred of
+/// them — 300 ms on the reference library's largest person, per click, to
+/// arrive at pixels the screen was already showing. Face ids are global, so
+/// a map from another person's grid is merely useless, never wrong.
 pub fn load_faces(
     catalog: &Catalog,
     store: &ThumbStore,
     person: PersonId,
+    mut cut: std::collections::HashMap<FaceId, FaceCrop>,
 ) -> Result<Vec<FaceCell>, dr_catalog::CatalogError> {
     let conn = catalog.connection();
     let rows = faces::for_person(conn, person, true)?;
 
-    // The crops kept at detection time, in one query. Where a face has one this
+    // The crops kept at detection time, in one query — but only when a face
-    // is the whole cost of drawing it — no proxy, no full-size JPEG decode, and
+    // is not already in hand. The common redraw has every face cached and
-    // no dependence on the thumbnail cache still holding the photograph.
+    // skips the blob read entirely; a face the cache lacks (a regroup, a
-    let stored = faces::crops_for_person(conn, person, true)?;
+    // fresh sweep) costs the read for the whole person once, and it is
+    // cached from then on.
+    //
+    // Where a face has a stored crop this is the whole cost of drawing it —
+    // no proxy, no full-size JPEG decode, and no dependence on the thumbnail
+    // cache still holding the photograph.
+    let stored = if rows.iter().all(|f| cut.contains_key(&f.id)) {
+        Default::default()
+    } else {
+        faces::crops_for_person(conn, person, true)?
+    };
 
     // The fallback path, for faces indexed before crops were kept. One decode
     // per *image*, not per face: a group photograph holding six faces of one
@@ -283,7 +303,10 @@ pub fn load_faces(
 
     let mut out = Vec::with_capacity(rows.len());
     for f in rows {
-        let crop = match stored.get(&f.id).and_then(|b| decode_crop(b)) {
+        let crop = match cut
+            .remove(&f.id)
+            .or_else(|| stored.get(&f.id).and_then(|b| decode_crop(b)))
+        {
             Some(c) => Some(c),
             None => {
                 let entry = decoded
@@ -657,7 +680,7 @@ pub fn preview_split(
         .map(|(c, _)| c)
         .unwrap_or_default();
 
-    let cells = load_faces(catalog, store, person)?;
+    let cells = load_faces(catalog, store, person, Default::default())?;
     if cells.len() < 2 {
         return Ok(vec![cells]);
     }

ui/dr-ui/src/identity_ui.rs

@@ -260,7 +260,17 @@ pub fn refresh(
 
     match (ctl.selected.get(), store.as_deref()) {
         (Some(person), Some(store)) => {
-            let cells = identity::load_faces(cat, store, person).unwrap_or_else(|e| {
+            // The crops the grid is showing now, handed over to be reused
+            // rather than decoded again — see `load_faces`. Drained, not
+            // cloned: a crop is 64 KB of pixels and the largest groups hold
+            // hundreds.
+            let cut = ctl
+                .faces
+                .borrow_mut()
+                .drain(..)
+                .filter_map(|c| Some((c.face, c.crop?)))
+                .collect();
+            let cells = identity::load_faces(cat, store, person, cut).unwrap_or_else(|e| {
                 log::warn!("identity: reading faces: {e}");
                 Vec::new()
             });