CCSDK-2872 DP: Agree and document proposed long-term Persistence SPI(s)

Jira Ticket:

CPS-37 - Getting issue details... STATUS

Decoupling

It is very important that the SPI doesn't expose any database implementation for example database ID's

	Description	Details	Decisions
1	Assume flat attributes (no complex data types) but data could be stored as json object in SPI impl. for convenience/PoC
2	SPI Implementation NOT using Model (service) current ENM SPI does!
3	Are we going to have XPath/query builder?	We should decide based on what the users want to use/is easy to use We don't want a query builder that eventually mimics XPaths functionality, use what is defined already XPATH sa a based but maybe supplement with a xpath-builder
4	When do we get attributes?	How do control how many attributes we get back?	We will have an (optional) output specification with the following options Default is no attributes All Attributes Specify attributes - output specification (filter)
5	Should we use the name node or fragment?		We decided on the name DataNode
6	Do we want to split the interface?	Maybe we could just have a 3 Alternatives all in one interface Limited number of interfaces e.g Data Objects/ Data Persistence/Query Very fine grained (see below)	DataStore SPI - methods to add data. e.g dataStore.addChild(parentDataObject, childDataObject) CpsAdmin Interface will handle the dataspaces and anchors Module SPI - responsible for handling modules and module sets The above will be in separate maven modules. Any data object they need will be in the same module. We will not have a querybuilder in SPI but the SPI will have to understand the cpsPath. The java API will use a builder pattern to create a cpsPath

Details about the ENM SPI can be found here: Spike

	Name	Definition	Capabilities
1	DataStoreService	Provides the basic information needed to access an object.	getDataNode(cpsPath) getDataNode(cpsPath,outputSpecification) count(CpsPath) addDataNode(anchorName,dataNode) addChild(cpsPathParent,dataNode) addChildren(cpsPathParent,dataNode...) updateDataNode(anchorName,dataNode) setAttribute(cpsPath,attributeName,value) deleteDataNode(cpsPath)
2	DataNode Object		createDataNode() getCpsPath() getAttributes() getAttribute(name) getModule()

	Name	Capabilities
1	DataspacePersistenceService	createDataspace GetDataspace(dataspaceName) GetDataspaces() exists
2	AnchorPersistenceService	createAnchor getAnchors getAnchor deleteAnchor associateAnchorToModuleSet associateDataNodeToAnchor associateAnchorToDataspace
3	Dataspace Object	createDataspace() getCpsPath() getAttributes() getAttribute(name) getModule()
4	Anchor Object	createAnchor() getCpsPath() getAttributes() getAttribute(name) getModule()

Name

Definition

Capabilities

1

ModulePersistenceService

Adding functionality for handling attributes

2

BasicModuleObject

Create a simple CPS Module Object