org.eclipse.emf.cdo.server.db.mapping
Interface IMappingStrategy

public interface IMappingStrategy

The mapping strategy acts as a connection between the DBStore and the database management (and OR-mapping) classes. The DBStore uses methods of this interface to create and lookup mappings (or mappers, as they could also be named as such) and to get properties and informations about the mappings used. The mapping classes (e.g., instances of IClassMapping and IListMapping) also use this class as a central point of information and as a resource of common functionalities.

Since:

2.0

Field Summary

static java.lang.String	PROP_FORCE_NAMES_WITH_ID Name of the boolean property that configures whether table names and column names are always suffixed with the internal DBID or only in cases where generated names violate the naming constraints of the underlying backend.
static java.lang.String	PROP_MAX_FIELD_NAME_LENGTH Name of the integer property that configures the maximum length for column names.
static java.lang.String	PROP_MAX_TABLE_NAME_LENGTH Name of the integer property that configures the maximum length for table names.
static java.lang.String	PROP_QUALIFIED_NAMES Name of the boolean property that configures whether the table names are made of simple class names or of qualified class names.
static java.lang.String	PROP_TABLE_NAME_PREFIX Name of the String property that specifies a common prefix for table names.

Method Summary

IListMapping	createListMapping(org.eclipse.emf.ecore.EClass containingClass, org.eclipse.emf.ecore.EStructuralFeature feature) Factory for value mappings of multi-valued-attributes.
void	createMapping(java.sql.Connection connection, InternalCDOPackageUnit[] packageUnits, org.eclipse.net4j.util.om.monitor.OMMonitor monitor) Create and initialize the mapping infrastructure for the given packages.
ITypeMapping	createValueMapping(org.eclipse.emf.ecore.EStructuralFeature feature) Factory for value mappings of single-valued attributes.
IClassMapping	getClassMapping(org.eclipse.emf.ecore.EClass eClass) Look up an existing class mapping for the given class.
java.lang.String	getFieldName(org.eclipse.emf.ecore.EStructuralFeature feature) Create a suitable column name which can be used to map the given element.
IDBStore	getStore()
java.lang.String	getTableName(org.eclipse.emf.ecore.EClass containingClass, org.eclipse.emf.ecore.EStructuralFeature feature) Create a suitable table name which can be used to map the given element.
java.lang.String	getTableName(org.eclipse.emf.ecore.ENamedElement element) Create a suitable table name which can be used to map the given element.
boolean	hasAuditSupport() Query if this mapping supports audits.
boolean	hasDeltaSupport() Query if this mapping supports revision deltas.
void	queryResources(IDBStoreAccessor dbStoreAccessor, IStoreAccessor.QueryResourcesContext context) Execute a resource query.
org.eclipse.net4j.util.collection.CloseableIterator<CDOID>	readObjectIDs(IDBStoreAccessor dbStoreAccessor) Get an iterator over all instances of objects in the store.
CDOClassifierRef	readObjectType(IDBStoreAccessor dbStoreAccessor, CDOID id) Read the type (i.e. class) of the object referred to by a given ID.
long	repairAfterCrash(org.eclipse.net4j.db.IDBAdapter dbAdapter, java.sql.Connection connection) Return the maximum object id used in the store.
void	setProperties(java.util.Map<java.lang.String,java.lang.String> properties) Set configuration properties for this mapping strategy.
void	setStore(IDBStore dbStore) Set the store to which this MappingStrategy instance belongs.

Field Detail

PROP_MAX_TABLE_NAME_LENGTH

static final java.lang.String PROP_MAX_TABLE_NAME_LENGTH

Name of the integer property that configures the maximum length for table names. A value of zero indicates the value of the db adapter to be used.

See Also:

Constant Field Values

PROP_MAX_FIELD_NAME_LENGTH

static final java.lang.String PROP_MAX_FIELD_NAME_LENGTH

Name of the integer property that configures the maximum length for column names. A value of zero indicates the value of the db adapter to be used.

See Also:

Constant Field Values

PROP_TABLE_NAME_PREFIX

static final java.lang.String PROP_TABLE_NAME_PREFIX

Name of the String property that specifies a common prefix for table names.

See Also:

Constant Field Values

PROP_QUALIFIED_NAMES

static final java.lang.String PROP_QUALIFIED_NAMES

Name of the boolean property that configures whether the table names are made of simple class names or of qualified class names.

See Also:

Constant Field Values

PROP_FORCE_NAMES_WITH_ID

static final java.lang.String PROP_FORCE_NAMES_WITH_ID

Name of the boolean property that configures whether table names and column names are always suffixed with the internal DBID or only in cases where generated names violate the naming constraints of the underlying backend.

See Also:

Constant Field Values

Method Detail

getStore

IDBStore getStore()

Returns:

the store, this MappingStrategy instance belongs to.

setStore

void setStore(IDBStore dbStore)

Set the store to which this MappingStrategy instance belongs. Should only be called by the DBStore, and only once to initialize the connection between DBStore and mapping strategy.

Parameters:

dbStore - the DBStore instance to which this MappingStrategy instance belongs.

createValueMapping

ITypeMapping createValueMapping(org.eclipse.emf.ecore.EStructuralFeature feature)

Factory for value mappings of single-valued attributes.

Parameters:

feature - the feature for which a mapping should be created. It must hold feature.isMany() == false.

Returns:

the mapping created.

createListMapping

IListMapping createListMapping(org.eclipse.emf.ecore.EClass containingClass,
                               org.eclipse.emf.ecore.EStructuralFeature feature)

Factory for value mappings of multi-valued-attributes.

Parameters:

containingClass - the class containing the feature.

feature - the feature for which a mapping should be created. It must hold feature.isMany() == true.

Returns:

getTableName

java.lang.String getTableName(org.eclipse.emf.ecore.ENamedElement element)

Create a suitable table name which can be used to map the given element. Should only be called by mapping classes.

Parameters:

element - the element for which the name should be created. It must hold: element instanceof EClass || element instanceof EPackage.

Returns:

the created table name. It is guaranteed that the table name is compatible with the chosen database.

getTableName

java.lang.String getTableName(org.eclipse.emf.ecore.EClass containingClass,
                              org.eclipse.emf.ecore.EStructuralFeature feature)

Create a suitable table name which can be used to map the given element. Should only be called by mapping classes. Should only be called by mapping classes.

Parameters:

containingClass - the class containeng the feature.

feature - the feature for which the table name should be created.

Returns:

the created table name. It is guaranteed that the table name is compatible with the chosen database.

getFieldName

java.lang.String getFieldName(org.eclipse.emf.ecore.EStructuralFeature feature)

Create a suitable column name which can be used to map the given element. Should only be called by mapping classes.

Parameters:

feature - the feature for which the column name should be created.

Returns:

the created column name. It is guaranteed that the name is compatible with the chosen database.

createMapping

void createMapping(java.sql.Connection connection,
                   InternalCDOPackageUnit[] packageUnits,
                   org.eclipse.net4j.util.om.monitor.OMMonitor monitor)

Create and initialize the mapping infrastructure for the given packages. Should be called from the DBStore or the DBStoreAccessor.

Parameters:

connection - the connection to use.

packageUnits - the packages whose elements should be mapped.

monitor - the monitor to report progress.

getClassMapping

IClassMapping getClassMapping(org.eclipse.emf.ecore.EClass eClass)

Look up an existing class mapping for the given class. Before this method is called, the class mapping must have been initialized by calling createMapping(Connection, InternalCDOPackageUnit[], OMMonitor) on its containing package.

Parameters:

eClass - the class to look up.

Returns:

the class mapping.

hasDeltaSupport

boolean hasDeltaSupport()

Query if this mapping supports revision deltas.
If this method returns true, it is guaranteed that all class mappings returned by getClassMapping(EClass) implement IClassMappingDeltaSupport.

Returns:

true if revision deltas are supported, false else.

hasAuditSupport

boolean hasAuditSupport()

Query if this mapping supports audits.
If this method returns true, it is guaranteed that all class mappings returned by getClassMapping(EClass) implement IClassMappingAuditSupport.

Returns:

true if audits are supported, false else.

queryResources

void queryResources(IDBStoreAccessor dbStoreAccessor,
                    IStoreAccessor.QueryResourcesContext context)

Execute a resource query.

Parameters:

dbStoreAccessor - the accessor to use.

context - the context from which the query parameters are read and to which the result is written.

readObjectType

CDOClassifierRef readObjectType(IDBStoreAccessor dbStoreAccessor,
                                CDOID id)

Read the type (i.e. class) of the object referred to by a given ID.

Parameters:

dbStoreAccessor - the accessor to use to look up the type.

id - the ID of the object for which the type is to be determined.

Returns:

the type of the object.

readObjectIDs

org.eclipse.net4j.util.collection.CloseableIterator<CDOID> readObjectIDs(IDBStoreAccessor dbStoreAccessor)

Get an iterator over all instances of objects in the store.

Parameters:

dbStoreAccessor - the accessor to use.

Returns:

the iterator.

repairAfterCrash

long repairAfterCrash(org.eclipse.net4j.db.IDBAdapter dbAdapter,
                      java.sql.Connection connection)

Return the maximum object id used in the store. This is used by the DBStore if a previous crash is discovered during the startup process. Should only be called by the DBStore and only during startup.

Parameters:

dbAdapter - the dbAdapter to use to access the database

connection - the connection to use to access the database

Returns:

the maximum object id used in the store.

setProperties

void setProperties(java.util.Map<java.lang.String,java.lang.String> properties)

Set configuration properties for this mapping strategy. Should only be called by the factory creating the mapping strategy instance.

Parameters:

properties - the configuration properties to set.