Added support for interval queries

source/Sagan-Core/InMemoryRepository.class.st

@@ -50,6 +50,22 @@ InMemoryRepository >> findAll [
 	^ contents copy
 ]
 
+{ #category : 'querying' }
+InMemoryRepository >> findAllFrom: aFromIndex to: aToIndex sortedBy: anIndexName [
+
+	| from to |
+
+	contents ifEmpty: [ ^ contents ].
+
+	from := ( aFromIndex min: contents size ) max: 0.
+	to := ( aToIndex min: contents size ) max: 0.
+
+	^ ( contents sorted: [ :a :b |
+		    ( a instVarNamed: anIndexName asString ) <= ( b instVarNamed: anIndexName asString ) ] )
+		  copyFrom: from
+		  to: to
+]
+
 { #category : 'querying' }
 InMemoryRepository >> findAllMatching: aCriteriaOrBlock [
 

source/Sagan-GemStone-Tests/GemStoneRepositoryProviderTest.class.st

@@ -86,6 +86,139 @@ GemStoneRepositoryProviderTest >> testQueryReturningBeforeAllIndexedResultsAreRe
 		]
 ]
 
+{ #category : 'tests' }
+GemStoneRepositoryProviderTest >> testQueryingIndexedCollectionByStreaming [
+
+	1000 timesRepeat: [
+		self extraterrestrials
+			store: self johnTravolta;
+			store: self johnLock;
+			store: self ellaTravolta
+		].
+
+	self extraterrestrials store: self silvesterStallone.
+
+	1000 timesRepeat: [
+		self extraterrestrials
+			store: self johnTravolta;
+			store: self johnLock;
+			store: self ellaTravolta
+		].
+
+	self extraterrestrials withQueryFrom: 'each.firstName >= ''''' do: [ :query |
+		| stream silvesterStallone |
+
+		stream := query readStream.
+		stream skip: 2000 * 3.
+		silvesterStallone := stream next.
+		self assert:
+			( silvesterStallone firstName = 'Silvester' and: [ silvesterStallone lastName = 'Stallone' ] ).
+		self assert: stream atEnd
+		]
+]
+
+{ #category : 'tests' }
+GemStoneRepositoryProviderTest >> testQueryingIndexedCollectionForAllElements [
+
+	4 timesRepeat: [
+		1000 timesRepeat: [
+			self extraterrestrials
+				store: self johnTravolta;
+				store: self johnLock;
+				store: self ellaTravolta
+			].
+
+		self extraterrestrials store: self silvesterStallone.
+
+		1000 timesRepeat: [
+			self extraterrestrials
+				store: self johnTravolta;
+				store: self johnLock;
+				store: self ellaTravolta
+			]
+		].
+	self extraterrestrials withQueryFrom: 'true' do: [ :query |
+		self assert: query size equals: 3000 + 1 + 3000 * 4.
+		self
+			assert: ( query select: [ :extraterrestrial |
+					  extraterrestrial firstName = 'Silvester' and: [ extraterrestrial lastName = 'Stallone' ] ] )
+					size
+			equals: 4.
+		self
+			assert: ( query select: [ :extraterrestrial |
+					  extraterrestrial firstName = 'John' and: [ extraterrestrial lastName = 'Travolta' ] ] ) size
+			equals: 2000 * 4.
+		self
+			assert: ( query select: [ :extraterrestrial |
+					  extraterrestrial firstName = 'John' and: [ extraterrestrial lastName = 'Lock' ] ] ) size
+			equals: 2000 * 4.
+		self
+			assert: ( query select: [ :extraterrestrial |
+					  extraterrestrial firstName = 'Ella' and: [ extraterrestrial lastName = 'Travolta' ] ] ) size
+			equals: 2000 * 4
+		]
+]
+
+{ #category : 'tests' }
+GemStoneRepositoryProviderTest >> testQueryingIndexedCollectionForNoElements [
+
+	4 timesRepeat: [
+		1000 timesRepeat: [
+			self extraterrestrials
+				store: self johnTravolta;
+				store: self johnLock;
+				store: self ellaTravolta
+			].
+
+		self extraterrestrials store: self silvesterStallone.
+
+		1000 timesRepeat: [
+			self extraterrestrials
+				store: self johnTravolta;
+				store: self johnLock;
+				store: self ellaTravolta
+			]
+		].
+	self extraterrestrials withQueryFrom: 'false' do: [ :query | self assert: query isEmpty ]
+]
+
+{ #category : 'tests' }
+GemStoneRepositoryProviderTest >> testQueryingInterval [
+
+	| result |
+
+	1000 timesRepeat: [
+		self extraterrestrials
+			store: self johnTravolta;
+			store: self johnLock;
+			store: self ellaTravolta;
+			store: self silvesterStallone
+		].
+
+	result := self extraterrestrials findAllFrom: 1000 to: 1001 sortedBy: 'lastName'.
+	self assert: result size equals: 2.
+	self assert: ( result first firstName = 'John' and: [ result first lastName = 'Lock' ] ).
+	self assert: ( result last firstName = 'Silvester' and: [ result last lastName = 'Stallone' ] ).
+
+	result := self extraterrestrials findAllFrom: 4000 to: 4005 sortedBy: 'lastName'.
+	self
+		withTheOnlyOneIn: result
+		do: [ :extraterrestrial | self assert: extraterrestrial lastName equals: 'Travolta' ].
+	result := self extraterrestrials findAllFrom: 4000 to: 4005 sortedBy: 'firstName'.
+	self withTheOnlyOneIn: result do: [ :extraterrestrial |
+		self
+			assert: extraterrestrial firstName equals: 'Silvester';
+			assert: extraterrestrial lastName equals: 'Stallone'
+		].
+
+	result := self extraterrestrials findAllFrom: -50 to: 0 sortedBy: 'lastName'.
+	self assert: result isEmpty.
+	result := self extraterrestrials findAllFrom: 6 to: -2 sortedBy: 'lastName'.
+	self assert: result isEmpty.
+	result := self extraterrestrials findAllFrom: 5000 to: 10000 sortedBy: 'lastName'.
+	self assert: result isEmpty
+]
+
 { #category : 'tests' }
 GemStoneRepositoryProviderTest >> testQueryingWhenCollectionIsLargeAndIndexed [
 

source/Sagan-GemStone/GemStoneRepository.class.st

@@ -50,6 +50,24 @@ GemStoneRepository >> findAll [
 	^ contents copy
 ]
 
+{ #category : 'querying' }
+GemStoneRepository >> findAllFrom: aFromIndex to: aToIndex sortedBy: anIndexName [
+
+	| results |
+
+	results := OrderedCollection new.
+	self withQueryFrom: ( 'each.<1s> >= ''''' expandMacrosWith: anIndexName asString ) do: [ :query |
+		| stream start limit |
+
+		stream := query readStream.
+		start := aFromIndex - 1 max: 0.
+		limit := aToIndex - start max: 0.
+		stream skip: start.
+		limit timesRepeat: [ stream atEnd ifFalse: [ results add: stream next ] ]
+		].
+	^ results
+]
+
 { #category : 'querying' }
 GemStoneRepository >> findAllMatching: aCriteriaOrBlock [