From 793672432249b6f60667af72ef6594acaa93fe7c Mon Sep 17 00:00:00 2001 From: rsgowman Date: Wed, 22 Nov 2017 17:01:26 -0500 Subject: Use a prefix scan when fetching documents matching a query. (#488) Minor optimization (which is already present in the ts code). --- Firestore/Source/Local/FSTLevelDBRemoteDocumentCache.mm | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) (limited to 'Firestore/Source/Local') diff --git a/Firestore/Source/Local/FSTLevelDBRemoteDocumentCache.mm b/Firestore/Source/Local/FSTLevelDBRemoteDocumentCache.mm index b2df67f..02f9f3e 100644 --- a/Firestore/Source/Local/FSTLevelDBRemoteDocumentCache.mm +++ b/Firestore/Source/Local/FSTLevelDBRemoteDocumentCache.mm @@ -21,6 +21,7 @@ #include #import "Firestore/Protos/objc/firestore/local/MaybeDocument.pbobjc.h" +#import "Firestore/Source/Core/FSTQuery.h" #import "Firestore/Source/Local/FSTLevelDBKey.h" #import "Firestore/Source/Local/FSTLocalSerializer.h" #import "Firestore/Source/Local/FSTWriteGroup.h" @@ -28,6 +29,7 @@ #import "Firestore/Source/Model/FSTDocumentDictionary.h" #import "Firestore/Source/Model/FSTDocumentKey.h" #import "Firestore/Source/Model/FSTDocumentSet.h" +#import "Firestore/Source/Model/FSTPath.h" #import "Firestore/Source/Util/FSTAssert.h" #include "Firestore/Port/ordered_code.h" @@ -102,10 +104,11 @@ static ReadOptions StandardReadOptions() { } - (FSTDocumentDictionary *)documentsMatchingQuery:(FSTQuery *)query { - // TODO(mikelehen): PERF: At least filter to the documents that match the path of the query. FSTDocumentDictionary *results = [FSTDocumentDictionary documentDictionary]; - std::string startKey = [FSTLevelDBRemoteDocumentKey keyPrefix]; + // Documents are ordered by key, so we can use a prefix scan to narrow down + // the documents we need to match the query against. + std::string startKey = [FSTLevelDBRemoteDocumentKey keyPrefixWithResourcePath:query.path]; std::unique_ptr it(_db->NewIterator(StandardReadOptions())); it->Seek(startKey); @@ -113,7 +116,9 @@ static ReadOptions StandardReadOptions() { for (; it->Valid() && [currentKey decodeKey:it->key()]; it->Next()) { FSTMaybeDocument *maybeDoc = [self decodedMaybeDocument:it->value() withKey:currentKey.documentKey]; - if ([maybeDoc isKindOfClass:[FSTDocument class]]) { + if (![query.path isPrefixOfPath:maybeDoc.key.path]) { + break; + } else if ([maybeDoc isKindOfClass:[FSTDocument class]]) { results = [results dictionaryBySettingObject:(FSTDocument *)maybeDoc forKey:maybeDoc.key]; } } -- cgit v1.2.3