Core write path — Sheetwrite

Validated evidence. 12 store and document scenarios at production sizes. Every scenario passed its own correctness checkpoint before its timing was accepted.

Grid.applyTransaction of a 1,000,000-cell setBlock: 545 ms
fromCsv import of 200,000 rows by 10 columns: 218 ms
Undo of a 1,000,000-cell clearRange: 362 ms
Cold initSheetwrite() through first store in a fresh Node process (7 processes): 6.84 ms

All measurements

scenariolog scale — every tick is 10× — shorter is fastermedianp95

Row bridge insertaddRows projection of 10,000 rows into a 1,000,000-row bridge

5.99 ms8.38 ms

Command state select4,096-cell range selection on a framework-style grid

9.84 ms16.4 ms

With command state handlerVariant of command state select, measured in the same run

9.84 ms16.4 ms

Without command state handlerVariant of command state select, measured in the same run

7.44 ms12.4 ms

Setblock admissionGrid.applyTransaction of a 1,000,000-cell setBlock

545 ms556 ms

Setblock detailed captureGrid.applyTransaction of a 1,000,000-cell setBlock observed through a change listener with detailed capture

657 ms766 ms

Sync offline queueGrid commit admitted into an offline sync queue with no listeners

0.03 ms1.59 ms

Rebase largeRebase of a 100,000-cell block across 50 single-row inserts

3.76 ms4.90 ms

Validation sparse100,000-cell sparse setRange with 100 rules outside the range

181 ms182 ms

Csv importfromCsv import of 200,000 rows by 10 columns

218 ms231 ms

Undo large clearUndo of a 1,000,000-cell clearRange

362 ms430 ms

Restore near ceilingrestoreBlock with 60,000,044 decoded bytes

840 ms896 ms

Paged evicted revisitRevisit of an evicted paged band: scroll back plus a fixed async settle floor (wall time is not the accept metric)

14.7 ms17.6 ms

Node cold initCold initSheetwrite() through first store in a fresh Node process (7 processes)

6.84 ms8.08 ms

Captured: 2026-10-28 17:41 UTC
Commit: ac4ab632d80a clean worktree
Environment: Bun 1.4.4 · Node compatibility v26.3.0 · 12th Gen Intel(R) Core(TM) i9-12900H
Raw artifact: bench/results/core-paths-results.json

Scale

Parameter	Value
`bridgeRows`	1,000,000
`bridgeInsertRows`	10,000
`selectionRows`	64
`selectionColumns`	64
`blockRows`	1,000
`blockColumns`	1,000
`offlineCommits`	5,000
`rebaseBlockRows`	1,000
`rebaseBlockColumns`	100
`rebaseInsertOperations`	50
`sparseCells`	100,000
`validationRules`	100
`csvRows`	200,000
`csvColumns`	10
`clearRows`	1,000
`clearColumns`	1,000
`pagedRows`	200,000

Samples

Scenario	Samples
`row-bridge-insert`	2
`command-state-select`	10
`with-command-state-handler`	10
`without-command-state-handler`	10
`setblock-admission`	3
`setblock-detailed-capture`	3
`sync-offline-queue`	5000
`rebase-large`	3
`validation-sparse`	3
`csv-import`	2
`undo-large-clear`	3
`restore-near-ceiling`	3
`paged-evicted-revisit`	3
`node-cold-init`	6

Counters

Non-time evidence recorded by the same runs.

Scenario	Counter	Value
`row-bridge-insert`	`bridgeRows`	1,000,000
`row-bridge-insert`	`insertedRows`	10,000
`command-state-select`	`selectedCells`	4,096
`command-state-select`	`commandStateEvents`	13
`command-state-select`	`withoutHandlerMedianMs`	7.436
`setblock-admission`	`blockCells`	1,000,000
`setblock-admission`	`transactions`	4
`setblock-detailed-capture`	`blockCells`	1,000,000
`setblock-detailed-capture`	`transactions`	4
`setblock-detailed-capture`	`capturedChanges`	1,000,000
`setblock-detailed-capture`	`validatedCapturedChanges`	1,000,000
`sync-offline-queue`	`queuedCommits`	5,005
`sync-offline-queue`	`admittedOperations`	5,005
`rebase-large`	`blockCells`	100,000
`rebase-large`	`insertOperations`	50
`rebase-large`	`verifiedValues`	100,000
`validation-sparse`	`writtenCells`	100,000
`validation-sparse`	`logicalRangeCells`	1,000,000
`validation-sparse`	`validationRules`	100
`csv-import`	`importedRows`	200,000
`csv-import`	`importedColumns`	10
`csv-import`	`verifiedCells`	2,000,000
`csv-import`	`inputChars`	20,888,985
`undo-large-clear`	`clearedCells`	1,000,000
`undo-large-clear`	`clears`	4
`undo-large-clear`	`restoredCells`	1,000,000
`undo-large-clear`	`compactRestores`	5
`undo-large-clear`	`peakRssBytes`	1,099,108,352
`restore-near-ceiling`	`restoredCells`	4,000,000
`restore-near-ceiling`	`decodedBytes`	60,000,044
`restore-near-ceiling`	`peakRssBytes`	1,445,208,064
`paged-evicted-revisit`	`revisitedRows`	3
`paged-evicted-revisit`	`areColumnsFullyLoadedCalls`	108
`paged-evicted-revisit`	`evictionVisits`	3
`paged-evicted-revisit`	`pagedRows`	200,000
`node-cold-init`	`largestHeartbeatGapMs`	6.63
`node-cold-init`	`minimalHeartbeatTicks`	1
`node-cold-init`	`freshProcesses`	7

Correctness checkpoints

Scenario	Checkpoint
`row-bridge-insert`	projected delta is one row-structure insert with every created identity present in the bridge in order
`command-state-select`	selection covers 4096 cells and the command-state handler observes one event per selection
`setblock-admission`	every setBlock is applied and every cell of the block holds the last written value
`setblock-detailed-capture`	every setBlock is applied and every cell of the block holds the last written value, and its change capture reports every cell's address, previous value, and new value exactly once
`sync-offline-queue`	every commit is applied, the queue holds every commit at server version 0, and capacity stays available
`rebase-large`	the block rebases without conflict, shifts down by exactly the inserted row count, keeps every source value, and leaves the caller's operations untouched
`validation-sparse`	every write is applied, probe cells hold the last written values, every rule is retained, and a rule violation is still rejected
`csv-import`	row count matches and every imported cell equals the source value for its row and column, including declared number/text types
`undo-large-clear`	the clear empties the block and the undos restore every original cell value
`restore-near-ceiling`	a valid near-ceiling compressed restore applies its complete block
`paged-evicted-revisit`	the band is unloaded before each revisit, the revisit reloads it with the source values, and the revisit asks areColumnsFullyLoaded at least once; areColumnsFullyLoadedCalls per revisit is the accept metric
`node-cold-init`	every fresh process loads the module, produces the expected engine result, and reports a plausible heartbeat gap

Reproduce with:

bun run --filter @sheetwrite/bench bench:core-paths

Loading documentation…

Scale

Parameter	Value
`bridgeRows`	1,000,000
`bridgeInsertRows`	10,000
`selectionRows`	64
`selectionColumns`	64
`blockRows`	1,000
`blockColumns`	1,000
`offlineCommits`	5,000
`rebaseBlockRows`	1,000
`rebaseBlockColumns`	100
`rebaseInsertOperations`	50
`sparseCells`	100,000
`validationRules`	100
`csvRows`	200,000
`csvColumns`	10
`clearRows`	1,000
`clearColumns`	1,000
`pagedRows`	200,000

Scenario

Samples

row-bridge-insert

command-state-select

with-command-state-handler

without-command-state-handler

setblock-admission

setblock-detailed-capture

sync-offline-queue

5000

rebase-large

validation-sparse

csv-import

undo-large-clear

restore-near-ceiling

paged-evicted-revisit

node-cold-init

Counters

Non-time evidence recorded by the same runs.

Scenario	Counter	Value
`row-bridge-insert`	`bridgeRows`	1,000,000
`row-bridge-insert`	`insertedRows`	10,000
`command-state-select`	`selectedCells`	4,096
`command-state-select`	`commandStateEvents`	13
`command-state-select`	`withoutHandlerMedianMs`	7.436
`setblock-admission`	`blockCells`	1,000,000
`setblock-admission`	`transactions`	4
`setblock-detailed-capture`	`blockCells`	1,000,000
`setblock-detailed-capture`	`transactions`	4
`setblock-detailed-capture`	`capturedChanges`	1,000,000
`setblock-detailed-capture`	`validatedCapturedChanges`	1,000,000
`sync-offline-queue`	`queuedCommits`	5,005
`sync-offline-queue`	`admittedOperations`	5,005
`rebase-large`	`blockCells`	100,000
`rebase-large`	`insertOperations`	50
`rebase-large`	`verifiedValues`	100,000
`validation-sparse`	`writtenCells`	100,000
`validation-sparse`	`logicalRangeCells`	1,000,000
`validation-sparse`	`validationRules`	100
`csv-import`	`importedRows`	200,000
`csv-import`	`importedColumns`	10
`csv-import`	`verifiedCells`	2,000,000
`csv-import`	`inputChars`	20,888,985
`undo-large-clear`	`clearedCells`	1,000,000
`undo-large-clear`	`clears`	4
`undo-large-clear`	`restoredCells`	1,000,000
`undo-large-clear`	`compactRestores`	5
`undo-large-clear`	`peakRssBytes`	1,099,108,352
`restore-near-ceiling`	`restoredCells`	4,000,000
`restore-near-ceiling`	`decodedBytes`	60,000,044
`restore-near-ceiling`	`peakRssBytes`	1,445,208,064
`paged-evicted-revisit`	`revisitedRows`	3
`paged-evicted-revisit`	`areColumnsFullyLoadedCalls`	108
`paged-evicted-revisit`	`evictionVisits`	3
`paged-evicted-revisit`	`pagedRows`	200,000
`node-cold-init`	`largestHeartbeatGapMs`	6.63
`node-cold-init`	`minimalHeartbeatTicks`	1
`node-cold-init`	`freshProcesses`	7

Correctness checkpoints

Scenario	Checkpoint
`row-bridge-insert`	projected delta is one row-structure insert with every created identity present in the bridge in order
`command-state-select`	selection covers 4096 cells and the command-state handler observes one event per selection
`setblock-admission`	every setBlock is applied and every cell of the block holds the last written value
`setblock-detailed-capture`	every setBlock is applied and every cell of the block holds the last written value, and its change capture reports every cell's address, previous value, and new value exactly once
`sync-offline-queue`	every commit is applied, the queue holds every commit at server version 0, and capacity stays available
`rebase-large`	the block rebases without conflict, shifts down by exactly the inserted row count, keeps every source value, and leaves the caller's operations untouched
`validation-sparse`	every write is applied, probe cells hold the last written values, every rule is retained, and a rule violation is still rejected
`csv-import`	row count matches and every imported cell equals the source value for its row and column, including declared number/text types
`undo-large-clear`	the clear empties the block and the undos restore every original cell value
`restore-near-ceiling`	a valid near-ceiling compressed restore applies its complete block
`paged-evicted-revisit`	the band is unloaded before each revisit, the revisit reloads it with the source values, and the revisit asks areColumnsFullyLoaded at least once; areColumnsFullyLoadedCalls per revisit is the accept metric
`node-cold-init`	every fresh process loads the module, produces the expected engine result, and reports a plausible heartbeat gap