// 100K items, without fixUpsert: sortComparer called: 1,529,445 timesDuration to upsert an item: 1,379 msUpdate: sortComparer called: 1,529,444 timesDuration to update an item: 1,482 ms// 100K items, with fixUpsert: sortComparer called: 100,027 timesDuration to upsert an item: 847 msUpdate: sortComparer called: 100,032 timesDuration to update an item: 803 ms10K items, with fixUpsert: sortComparer called: 10,017 timesDuration to upsert an item: 92 msUpdate: sortComparer called: 10,024 timesDuration to update an item: 71 ms

functionmerge(models:readonlyT[],state:R):void{constentities=state.entitiesasRecord<Id,T>constoldEntities=Object.values(state.ids).map((id:Id)=>entities[id])constnewEntities=models.slice().sort(sort)// Insert/overwrite all new/updatedmodels.forEach((model)=>{entities[selectId(model)]=model})constnewSortedIds:Id[]=[]leto=0,n=0while(o<oldEntities.length&&n<newEntities.length){constoldEntity=oldEntities[o]asT,oldId=selectId(oldEntity),newEntity=newEntities[n]// old entity has been overwritten by new entity, skip comparisonif(entities[oldId]!==oldEntity){o++continue}constcomparison=sort(oldEntity,newEntity)if(comparison<0){newSortedIds.push(oldId)o++continue}constnewId=selectId(newEntity)if(comparison>0){newSortedIds.push(newId)n++continue}newSortedIds.push(oldId)o++newSortedIds.push(newId)n++}while(o<oldEntities.length){newSortedIds.push(selectId(oldEntities[o]))o++}while(n<newEntities.length){newSortedIds.push(selectId(newEntities[n]))n++}if(!areArraysEqual(state.ids,newSortedIds)){state.ids=newSortedIds}}

Original Setup: sortComparer called 1,529,087 times in 839msInsert One (random): sortComparer called 1,529,107 times in 1,018msInsert One (middle): sortComparer called 1,529,120 times in 1,311msInsert One (end): sortComparer called 1,529,137 times in 1,348msAdd Many: sortComparer called 1,546,947 times in 1,283msUpdate One (end): sortComparer called 1,546,945 times in 1,338msUpdate One (middle): sortComparer called 1,546,948 times in 1,375msUpdate One (replace): sortComparer called 1,547,010 times in 1,403ms

Original Setup: sortComparer called 1,529,043 times in 642msInsert One (random): sortComparer called 17 times in 569msInsert One (middle): sortComparer called 16 times in 452msInsert One (end): sortComparer called 17 times in 487msAdd Many: sortComparer called 16,728 times in 519msUpdate One (end): sortComparer called 101,033 times in 590msUpdate One (middle): sortComparer called 101,035 times in 586msUpdate One (replace): sortComparer called 101,055 times in 700ms

Original Setup: sortComparer called 1,529,339 times in 600msInsert One (random): sortComparer called 16 times in 349msInsert One (middle): sortComparer called 16 times in 441msInsert One (end): sortComparer called 16 times in 377msAdd Many: sortComparer called 16,710 times in 384msUpdate One (end): sortComparer called 101,034 times in 550msUpdate One (middle): sortComparer called 101,036 times in 492msUpdate One (replace): sortComparer called 101,055 times in 655ms

// 10K itemsOriginal Setup: sortComparer called 119,925 times in 40msInsert One (end): sortComparer called 13 times in 12msUse only Immer: sortComparer called 0 times in 10msUse only Mutative: sortComparer called 0 times in 2ms// 100K itemsOriginal Setup: sortComparer called 1,529,198 times in 349msInsert One (end): sortComparer called 17 times in 165msUse only Immer: sortComparer called 0 times in 120msUse only Mutative: sortComparer called 0 times in 24ms// 1000K itemsOriginal Setup: sortComparer called 18,604,782 times in 3,559msInsert One (end): sortComparer called 19 times in 2,859msUse only Immer: sortComparer called 0 times in 1,787msUse only Mutative: sortComparer called 0 times in 368ms

constinitialItems=generateItems(INITIAL_ITEMS)measureComparisons('Original Setup',()=>{store.dispatch(entitySlice.actions.upsertMany(initialItems))})measureComparisons('Insert One (end)',()=>{store.dispatch(entitySlice.actions.upsertOne({id:nanoid(),position:0.9998,name:'test',}),)})measureComparisons('Use only Immer',()=>{produce(store.getState(),(draft)=>{constid=nanoid();draft.entity.ids.push(id)draft.entity.entities[id]={      id,position:0.9998,name:'test',}})})measureComparisons('Use only Mutative',()=>{create(store.getState(),(draft)=>{constid=nanoid();draft.entity.ids.push(id)draft.entity.entities[id]={      id,position:0.9998,name:'test',}})})