+5

.changeset/poor-items-shake.md

reviewed

··· 1 1 + --- 2 2 + '@urql/exchange-graphcache': patch 3 3 + --- 4 4 + 5 5 + Fix a deadlock condition in Graphcache's layers, which is caused by subscriptions (or other deferred layers) starting before one-off mutation layers. This causes the mutation to not be completed, which keeps its data preferred above the deferred layer. That in turn means that layers stop squashing, which causes new results to be missing indefinitely, when they overlap.

-23

exchanges/graphcache/src/cacheExchange.test.ts

reviewed

··· 1811 1811 variables: undefined, 1812 1812 }); 1813 1813 1814 1814 - const queryOpB = client.createRequestOperation('query', { 1815 1815 - key: 3, 1816 1816 - query, 1817 1817 - variables: undefined, 1818 1818 - }); 1819 1819 - 1820 1814 expect(data).toBe(undefined); 1821 1815 1822 1816 nextOp(queryOpA); ··· 1838 1832 nextOp(mutationOp); 1839 1833 expect(reexec).toHaveBeenCalledTimes(1); 1840 1834 expect(data).toHaveProperty('node.name', 'optimistic'); 1841 1841 - 1842 1842 - // NOTE: We purposefully skip the following: 1843 1843 - // nextOp(queryOpB); 1844 1844 - 1845 1845 - nextRes({ 1846 1846 - operation: queryOpB, 1847 1847 - data: { 1848 1848 - __typename: 'Query', 1849 1849 - node: { 1850 1850 - __typename: 'Node', 1851 1851 - id: 'node', 1852 1852 - name: 'query b', 1853 1853 - }, 1854 1854 - }, 1855 1855 - }); 1856 1856 - 1857 1857 - expect(data).toHaveProperty('node.name', 'query b'); 1858 1835 }); 1859 1836 1860 1837 it('applies mutation results on top of commutative queries', () => {

+2 -5

exchanges/graphcache/src/cacheExchange.ts

reviewed

··· 213 213 optimisticKeysToDependencies.delete(operation.key); 214 214 } 215 215 216 216 - reserveLayer( 217 217 - store.data, 218 218 - operation.key, 219 219 - operation.kind === 'subscription' || result.hasNext 220 220 - ); 216 216 + if (operation.kind === 'subscription' || result.hasNext) 217 217 + reserveLayer(store.data, operation.key, true); 221 218 222 219 let queryDependencies: void | Dependencies; 223 220 let data: Data | null = result.data;

+23 -27

exchanges/graphcache/src/store/data.ts

reviewed

··· 161 161 while ( 162 162 --i >= 0 && 163 163 data.refLock.has(data.optimisticOrder[i]) && 164 164 - data.commutativeKeys.has(data.optimisticOrder[i]) && 165 165 - !data.deferredKeys.has(data.optimisticOrder[i]) 166 166 - ) { 164 164 + data.commutativeKeys.has(data.optimisticOrder[i]) 165 165 + ) 167 166 squashLayer(data.optimisticOrder[i]); 168 168 - } 169 167 } 170 168 171 169 currentOwnership = null; ··· 527 525 layerKey: number, 528 526 hasNext?: boolean 529 527 ) => { 528 528 + // Find the current index for the layer, and remove it from 529 529 + // the order if it exists already 530 530 + let index = data.optimisticOrder.indexOf(layerKey); 531 531 + if (index > -1) data.optimisticOrder.splice(index, 1); 532 532 + 530 533 if (hasNext) { 531 534 data.deferredKeys.add(layerKey); 535 535 + // If the layer has future results then we'll move it past any layer that's 536 536 + // still empty, so currently pending operations will take precedence over it 537 537 + for ( 538 538 + index = index > -1 ? index : 0; 539 539 + index < data.optimisticOrder.length && 540 540 + !data.deferredKeys.has(data.optimisticOrder[index]) && 541 541 + (!data.refLock.has(data.optimisticOrder[index]) || 542 542 + !data.commutativeKeys.has(data.optimisticOrder[index])); 543 543 + index++ 544 544 + ); 532 545 } else { 533 546 data.deferredKeys.delete(layerKey); 534 534 - } 535 535 - 536 536 - let index = data.optimisticOrder.indexOf(layerKey); 537 537 - if (index > -1) { 538 538 - if (!data.commutativeKeys.has(layerKey) && !hasNext) { 539 539 - data.optimisticOrder.splice(index, 1); 540 540 - // Protect optimistic layers from being turned into non-optimistic layers 541 541 - // while preserving optimistic data 547 547 + // Protect optimistic layers from being turned into non-optimistic layers 548 548 + // while preserving optimistic data 549 549 + if (index > -1 && !data.commutativeKeys.has(layerKey)) 542 550 clearLayer(data, layerKey); 543 543 - } else { 544 544 - return; 545 545 - } 546 546 - } 547 547 - 548 548 - // If the layer has future results then we'll move it past any layer that's 549 549 - // still empty, so currently pending operations will take precedence over it 550 550 - for ( 551 551 index = 0; 552 552 - hasNext && 553 553 - index < data.optimisticOrder.length && 554 554 - !data.deferredKeys.has(data.optimisticOrder[index]) && 555 555 - (!data.refLock.has(data.optimisticOrder[index]) || 556 556 - !data.commutativeKeys.has(data.optimisticOrder[index])); 557 557 - index++ 558 558 - ); 552 552 + } 559 553 554 554 + // Register the layer with the deferred or "top" index and 555 555 + // mark it as commutative 560 556 data.optimisticOrder.splice(index, 0, layerKey); 561 557 data.commutativeKeys.add(layerKey); 562 558 };