Use separate field to store FSRS params

Will allow the user to keep using old params with older clients

proto/anki/deck_config.proto

@@ -107,9 +107,11 @@ message DeckConfig {
     repeated float learn_steps = 1;
     repeated float relearn_steps = 2;
 
-    repeated float fsrs_weights = 3;
+    repeated float fsrs_params_4 = 3;
+    repeated float fsrs_params_5 = 5;
 
-    reserved 5 to 8;
+    // consider saving remaining ones for fsrs param changes
+    reserved 6 to 8;
 
     uint32 new_per_day = 9;
     uint32 reviews_per_day = 10;

rslib/src/deckconfig/mod.rs

@@ -74,7 +74,8 @@ const DEFAULT_DECK_CONFIG_INNER: DeckConfigInner = DeckConfigInner {
     bury_new: false,
     bury_reviews: false,
     bury_interday_learning: false,
-    fsrs_weights: vec![],
+    fsrs_params_4: vec![],
+    fsrs_params_5: vec![],
     desired_retention: 0.9,
     other: Vec::new(),
     historical_retention: 0.9,
@@ -105,6 +106,15 @@ impl DeckConfig {
         self.mtime_secs = TimestampSecs::now();
         self.usn = usn;
     }
+
+    /// Retrieve the FSRS 5.0 params, falling back on 4.x ones.
+    pub fn fsrs_params(&self) -> &Vec<f32> {
+        if self.inner.fsrs_params_5.len() == 19 {
+            &self.inner.fsrs_params_5
+        } else {
+            &self.inner.fsrs_params_4
+        }
+    }
 }
 
 impl Collection {

rslib/src/deckconfig/schema11.rs

@@ -69,8 +69,10 @@ pub struct DeckConfSchema11 {
     #[serde(default)]
     bury_interday_learning: bool,
 
+    #[serde(default, rename = "fsrsWeights")]
+    fsrs_params_4: Vec<f32>,
     #[serde(default)]
-    fsrs_weights: Vec<f32>,
+    fsrs_params_5: Vec<f32>,
     #[serde(default)]
     desired_retention: f32,
     #[serde(default)]
@@ -306,7 +308,8 @@ impl Default for DeckConfSchema11 {
             new_sort_order: 0,
             new_gather_priority: 0,
             bury_interday_learning: false,
-            fsrs_weights: vec![],
+            fsrs_params_4: vec![],
+            fsrs_params_5: vec![],
             desired_retention: 0.9,
             sm2_retention: 0.9,
             weight_search: "".to_string(),
@@ -386,7 +389,8 @@ impl From<DeckConfSchema11> for DeckConfig {
                 bury_new: c.new.bury,
                 bury_reviews: c.rev.bury,
                 bury_interday_learning: c.bury_interday_learning,
-                fsrs_weights: c.fsrs_weights,
+                fsrs_params_4: c.fsrs_params_4,
+                fsrs_params_5: c.fsrs_params_5,
                 ignore_revlogs_before_date: c.ignore_revlogs_before_date,
                 easy_days_percentages: c.easy_days_percentages,
                 desired_retention: c.desired_retention,
@@ -498,7 +502,8 @@ impl From<DeckConfig> for DeckConfSchema11 {
             new_sort_order: i.new_card_sort_order,
             new_gather_priority: i.new_card_gather_priority,
             bury_interday_learning: i.bury_interday_learning,
-            fsrs_weights: i.fsrs_weights,
+            fsrs_params_4: i.fsrs_params_4,
+            fsrs_params_5: i.fsrs_params_5,
             desired_retention: i.desired_retention,
             sm2_retention: i.historical_retention,
             weight_search: i.weight_search,
@@ -526,6 +531,7 @@ static RESERVED_DECKCONF_KEYS: Set<&'static str> = phf_set! {
     "interdayLearningMix",
     "newGatherPriority",
     "fsrsWeights",
+    "fsrsParams5",
     "desiredRetention",
     "stopTimerOnAnswer",
     "secondsToShowQuestion",

rslib/src/deckconfig/update.rs

@@ -50,7 +50,7 @@ impl Collection {
         deck: DeckId,
     ) -> Result<anki_proto::deck_config::DeckConfigsForUpdate> {
         let mut defaults = DeckConfig::default();
-        defaults.inner.fsrs_weights = DEFAULT_PARAMETERS.into();
+        defaults.inner.fsrs_params_5 = DEFAULT_PARAMETERS.into();
         let last_optimize = self.get_config_i32(I32ConfigKey::LastFsrsOptimize) as u32;
         let days_since_last_fsrs_optimize = if last_optimize > 0 {
             self.timing_today()?
@@ -88,6 +88,12 @@ impl Collection {
         // grab the config and sort it
         let mut config = self.storage.all_deck_config()?;
         config.sort_unstable_by(|a, b| a.name.cmp(&b.name));
+        // pre-fill empty fsrs 5 params with 4 params
+        config.iter_mut().for_each(|c| {
+            if c.inner.fsrs_params_5.is_empty() {
+                c.inner.fsrs_params_5 = c.inner.fsrs_params_4.clone();
+            }
+        });
 
         // combine with use counts
         let counts = self.get_deck_config_use_counts()?;
@@ -159,8 +165,14 @@ impl Collection {
 
         // add/update provided configs
         for conf in &mut req.configs {
+            // If the user has provided empty FSRS5 params, zero out any
+            // old params as well, so we don't fall back on them, which would
+            // be surprising as they're not shown in the GUI.
+            if conf.inner.fsrs_params_5.is_empty() {
+                conf.inner.fsrs_params_4.clear();
+            }
             // check the provided parameters are valid before we save them
-            FSRS::new(Some(&conf.inner.fsrs_weights))?;
+            FSRS::new(Some(conf.fsrs_params()))?;
             self.add_or_update_deck_config(conf)?;
             configs_after_update.insert(conf.id, conf.clone());
         }
@@ -201,7 +213,7 @@ impl Collection {
                 let previous_order = previous_config
                     .map(|c| c.inner.new_card_insert_order())
                     .unwrap_or_default();
-                let previous_weights = previous_config.map(|c| &c.inner.fsrs_weights);
+                let previous_weights = previous_config.map(|c| c.fsrs_params());
                 let previous_retention = previous_config.map(|c| c.inner.desired_retention);
 
                 // if a selected (sub)deck, or its old config was removed, update deck to point
@@ -228,7 +240,7 @@ impl Collection {
                 }
 
                 // if weights differ, memory state needs to be recomputed
-                let current_weights = current_config.map(|c| &c.inner.fsrs_weights);
+                let current_weights = current_config.map(|c| c.fsrs_params());
                 let current_retention = current_config.map(|c| c.inner.desired_retention);
                 if fsrs_toggled
                     || previous_weights != current_weights
@@ -252,7 +264,7 @@ impl Collection {
                     let weights = config.and_then(|c| {
                         if req.fsrs {
                             Some(UpdateMemoryStateRequest {
-                                weights: c.inner.fsrs_weights.clone(),
+                                weights: c.fsrs_params().clone(),
                                 desired_retention: c.inner.desired_retention,
                                 max_interval: c.inner.maximum_review_interval,
                                 reschedule: req.fsrs_reschedule,
@@ -349,11 +361,11 @@ impl Collection {
                 ignore_revlogs_before_ms,
                 idx as u32 + 1,
                 config_len,
-                &config.inner.fsrs_weights,
+                config.fsrs_params(),
             ) {
                 Ok(weights) => {
                     println!("{}: {:?}", config.name, weights.weights);
-                    config.inner.fsrs_weights = weights.weights;
+                    config.inner.fsrs_params_5 = weights.weights;
                 }
                 Err(AnkiError::Interrupted) => return Err(AnkiError::Interrupted),
                 Err(err) => {

rslib/src/scheduler/answering/mod.rs

@@ -431,7 +431,7 @@ impl Collection {
         let config = self.home_deck_config(deck.config_id(), card.original_deck_id)?;
         let fsrs_enabled = self.get_config_bool(BoolKey::Fsrs);
         let fsrs_next_states = if fsrs_enabled {
-            let fsrs = FSRS::new(Some(&config.inner.fsrs_weights))?;
+            let fsrs = FSRS::new(Some(config.fsrs_params()))?;
             if card.memory_state.is_none() && card.ctype != CardType::New {
                 // Card has been moved or imported into an FSRS deck after weights were set,
                 // and will need its initial memory state to be calculated based on review

rslib/src/scheduler/fsrs/memory_state.rs

@@ -154,7 +154,7 @@ impl Collection {
             .or_not_found(conf_id)?;
         let desired_retention = config.inner.desired_retention;
         let historical_retention = config.inner.historical_retention;
-        let fsrs = FSRS::new(Some(&config.inner.fsrs_weights))?;
+        let fsrs = FSRS::new(Some(config.fsrs_params()))?;
         let revlog = self.revlog_for_srs(SearchNode::CardIds(card.id.to_string()))?;
         let item = single_card_revlog_to_item(
             &fsrs,

rslib/src/stats/card.rs

@@ -130,7 +130,7 @@ impl Collection {
             .get_deck_config(conf_id)?
             .or_not_found(conf_id)?;
         let historical_retention = config.inner.historical_retention;
-        let fsrs = FSRS::new(Some(&config.inner.fsrs_weights))?;
+        let fsrs = FSRS::new(Some(config.fsrs_params()))?;
         let next_day_at = self.timing_today()?.next_day_at;
         let ignore_before = ignore_revlogs_before_ms_from_config(&config)?;
 

ts/routes/deck-options/FsrsOptions.svelte

@@ -26,7 +26,7 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
     import SwitchRow from "$lib/components/SwitchRow.svelte";
 
     import GlobalLabel from "./GlobalLabel.svelte";
-    import type { DeckOptionsState } from "./lib";
+    import { fsrsParams, type DeckOptionsState } from "./lib";
     import SpinBoxFloatRow from "./SpinBoxFloatRow.svelte";
     import SpinBoxRow from "./SpinBoxRow.svelte";
     import Warning from "./Warning.svelte";
@@ -82,7 +82,7 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
     }
 
     const simulateFsrsRequest = new SimulateFsrsReviewRequest({
-        weights: $config.fsrsWeights,
+        weights: fsrsParams($config),
         desiredRetention: $config.desiredRetention,
         deckSize: 0,
         daysToSimulate: 365,
@@ -137,26 +137,28 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
         try {
             await runWithBackendProgress(
                 async () => {
+                    const params = fsrsParams($config);
                     const resp = await computeFsrsWeights({
                         search: $config.weightSearch
                             ? $config.weightSearch
                             : defaultWeightSearch,
                         ignoreRevlogsBeforeMs: getIgnoreRevlogsBeforeMs(),
-                        currentWeights: $config.fsrsWeights,
+                        currentWeights: params,
                     });
                     if (
-                        ($config.fsrsWeights.length &&
+                        (params.length &&
-                            $config.fsrsWeights.every(
+                            params.every(
                                 (n, i) => n.toFixed(4) === resp.weights[i].toFixed(4),
                             )) ||
                         resp.weights.length === 0
                     ) {
                         setTimeout(() => alert(tr.deckConfigFsrsParamsOptimal()), 100);
+                    } else {
+                        $config.fsrsParams5 = resp.weights;
                     }
                     if (computeWeightsProgress) {
                         computeWeightsProgress.current = computeWeightsProgress.total;
                     }
-                    $config.fsrsWeights = resp.weights;
                 },
                 (progress) => {
                     if (progress.value.case === "computeWeights") {
@@ -187,7 +189,7 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
                         ? $config.weightSearch
                         : defaultWeightSearch;
                     const resp = await evaluateWeights({
-                        weights: $config.fsrsWeights,
+                        weights: fsrsParams($config),
                         search,
                         ignoreRevlogsBeforeMs: getIgnoreRevlogsBeforeMs(),
                     });
@@ -230,7 +232,7 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
             await runWithBackendProgress(
                 async () => {
                     optimalRetentionRequest.maxInterval = $config.maximumReviewInterval;
-                    optimalRetentionRequest.weights = $config.fsrsWeights;
+                    optimalRetentionRequest.weights = fsrsParams($config);
                     optimalRetentionRequest.search = `preset:"${state.getCurrentName()}" -is:suspended`;
                     const resp = await computeOptimalRetention(optimalRetentionRequest);
                     optimalRetention = resp.optimalRetention;
@@ -311,7 +313,7 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
         try {
             await runWithBackendProgress(
                 async () => {
-                    simulateFsrsRequest.weights = $config.fsrsWeights;
+                    simulateFsrsRequest.weights = fsrsParams($config);
                     simulateFsrsRequest.desiredRetention = $config.desiredRetention;
                     simulateFsrsRequest.search = `preset:"${state.getCurrentName()}" -is:suspended`;
                     simulateProgressString = "processing...";
@@ -360,9 +362,9 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
 
 <div class="ms-1 me-1">
     <WeightsInputRow
-        bind:value={$config.fsrsWeights}
+        bind:value={$config.fsrsParams5}
         defaultValue={[]}
-        defaults={defaults.fsrsWeights}
+        defaults={defaults.fsrsParams5}
     >
         <SettingTitle on:click={() => openHelpModal("modelWeights")}>
             {tr.deckConfigWeights()}

ts/routes/deck-options/lib.ts

@@ -415,3 +415,11 @@ export async function commitEditing(): Promise<void> {
     }
     await tick();
 }
+
+export function fsrsParams(config: DeckConfig_Config): number[] {
+    if (config.fsrsParams5) {
+        return config.fsrsParams5;
+    } else {
+        return config.fsrsParams4;
+    }
+}