fix: Optimize class chain lookup #1194
+307
−23
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
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@@ -11,9 +11,15 @@ | |
| #import "FBClassChainQueryParser.h" | ||
| #import "FBXCodeCompatibility.h" | ||
| #import "FBExceptions.h" | ||
| #import "XCUIElement+FBUtilities.h" | ||
|
|
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| @implementation XCUIElement (FBClassChain) | ||
|
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||
| // Walks a single upfront snapshot of `self` in memory to resolve every | ||
| // non-indexed chain segment, instead of resolving an intermediate live | ||
| // XCUIElement (and paying an accessibility round trip) just to obtain a | ||
| // query root for the next segment. A live element is only ever resolved | ||
| // once, for the final match(es), via a uid-predicate lookup. | ||
| - (NSArray<XCUIElement *> *)fb_descendantsMatchingClassChain:(NSString *)classChainQuery shouldReturnAfterFirstMatch:(BOOL)shouldReturnAfterFirstMatch | ||
| { | ||
| NSError *error; | ||
|
|
@@ -23,74 +29,85 @@ @implementation XCUIElement (FBClassChain) | |
| return nil; | ||
| } | ||
| NSMutableArray<FBClassChainItem *> *lookupChain = parsedChain.elements.mutableCopy; | ||
| NSArray<id<FBXCElementSnapshot>> *currentRoots = @[[self fb_customSnapshot]]; | ||
| FBClassChainItem *chainItem = lookupChain.firstObject; | ||
| NSArray<id<FBXCElementSnapshot>> *candidates = [self.class fb_snapshotsMatchingItem:chainItem inRoots:currentRoots]; | ||
| [lookupChain removeObjectAtIndex:0]; | ||
| while (lookupChain.count > 0) { | ||
| if (nil != chainItem.position) { | ||
| // It is necessary to resolve the position if intermediate element index is not zero or one, | ||
| // because predicates don't support search by indexes | ||
| NSArray<id<FBXCElementSnapshot>> *currentRootMatch = [self.class fb_matchingSnapshotsWithItem:chainItem | ||
| candidates:candidates | ||
| shouldReturnAfterFirstMatch:nil]; | ||
| if (0 == currentRootMatch.count) { | ||
| return @[]; | ||
| } | ||
| currentRoots = @[currentRootMatch.firstObject]; | ||
| } else { | ||
| currentRoots = candidates; | ||
| } | ||
| chainItem = lookupChain.firstObject; | ||
| candidates = [self.class fb_snapshotsMatchingItem:chainItem inRoots:currentRoots]; | ||
| [lookupChain removeObjectAtIndex:0]; | ||
| } | ||
| NSArray<id<FBXCElementSnapshot>> *matchedSnapshots = [self.class fb_matchingSnapshotsWithItem:chainItem | ||
| candidates:candidates | ||
| shouldReturnAfterFirstMatch:@(shouldReturnAfterFirstMatch)]; | ||
| return [self fb_filterDescendantsWithSnapshots:matchedSnapshots onlyChildren:NO]; | ||
| } | ||
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| + (NSArray<id<FBXCElementSnapshot>> *)fb_snapshotsMatchingItem:(FBClassChainItem *)item inRoots:(NSArray<id<FBXCElementSnapshot>> *)roots | ||
| { | ||
| NSMutableArray<id<FBXCElementSnapshot>> *typeMatches = [NSMutableArray array]; | ||
| for (id<FBXCElementSnapshot> root in roots) { | ||
| if (item.isDescendant) { | ||
| // descendantsByFilteringWithBlock: includes the receiver itself if it | ||
| // matches the filter, unlike XCUIElementQuery's descendantsMatchingType:, | ||
| // so the root has to be excluded explicitly here. | ||
| [typeMatches addObjectsFromArray:[root descendantsByFilteringWithBlock:^BOOL(id<FBXCElementSnapshot> snapshot) { | ||
| return snapshot != root && (item.type == XCUIElementTypeAny || snapshot.elementType == item.type); | ||
| }]]; | ||
| } else { | ||
| for (id<FBXCElementSnapshot> child in root.children) { | ||
| if (item.type == XCUIElementTypeAny || child.elementType == item.type) { | ||
| [typeMatches addObject:child]; | ||
| } | ||
| } | ||
| } | ||
| } | ||
| for (FBAbstractPredicateItem *predicateItem in item.predicates) { | ||
| if ([predicateItem isKindOfClass:FBSelfPredicateItem.class]) { | ||
| typeMatches = [[typeMatches filteredArrayUsingPredicate:predicateItem.value] mutableCopy]; | ||
| } else if ([predicateItem isKindOfClass:FBDescendantPredicateItem.class]) { | ||
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Comment on lines
188
to
+208
Author
There was a problem hiding this comment. Good catch — fixed in 924a231 by de-duplicating |
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| NSMutableArray<id<FBXCElementSnapshot>> *containingMatches = [NSMutableArray array]; | ||
| for (id<FBXCElementSnapshot> candidate in typeMatches) { | ||
| NSArray<id<FBXCElementSnapshot>> *matchingDescendants = [candidate descendantsByFilteringWithBlock:^BOOL(id<FBXCElementSnapshot> descendant) { | ||
| return descendant != candidate && [predicateItem.value evaluateWithObject:descendant]; | ||
| }]; | ||
| if (matchingDescendants.count > 0) { | ||
| [containingMatches addObject:candidate]; | ||
| } | ||
| } | ||
| typeMatches = containingMatches; | ||
| } | ||
| } | ||
| return typeMatches.copy; | ||
| } | ||
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| + (NSArray<id<FBXCElementSnapshot>> *)fb_matchingSnapshotsWithItem:(FBClassChainItem *)item candidates:(NSArray<id<FBXCElementSnapshot>> *)candidates shouldReturnAfterFirstMatch:(nullable NSNumber *)shouldReturnAfterFirstMatch | ||
| { | ||
| if (1 == item.position.integerValue || (0 == item.position.integerValue && shouldReturnAfterFirstMatch.boolValue)) { | ||
| id<FBXCElementSnapshot> result = candidates.firstObject; | ||
| return result ? @[result] : @[]; | ||
| } | ||
| if (0 == item.position.integerValue) { | ||
| return candidates; | ||
| } | ||
| if (candidates.count >= (NSUInteger)ABS(item.position.integerValue)) { | ||
| return item.position.integerValue > 0 | ||
| ? @[[candidates objectAtIndex:item.position.integerValue - 1]] | ||
| : @[[candidates objectAtIndex:candidates.count + item.position.integerValue]]; | ||
| } | ||
| return @[]; | ||
| } | ||
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Fair point, the old wording didn't match reality (the parser never allows position 0, and this branch runs for any explicit position including 1). Reworded in 924a231 to explain why an indexed segment has to collapse to a single root immediately instead of staying folded into
candidates.