org.hibernate.ogm.datastore.mongodb

Class MongoDBDialect

java.lang.Object

org.hibernate.ogm.dialect.spi.BaseGridDialect

org.hibernate.ogm.datastore.mongodb.MongoDBDialect

All Implemented Interfaces:

Serializable, BatchableGridDialect, IdentityColumnAwareGridDialect, MultigetGridDialect, OptimisticLockingAwareGridDialect, QueryableGridDialect<org.hibernate.ogm.datastore.mongodb.query.impl.MongoDBQueryDescriptor>, GridDialect, StoredProcedureAwareGridDialect, Service

public class MongoDBDialect
extends BaseGridDialect
implements QueryableGridDialect<org.hibernate.ogm.datastore.mongodb.query.impl.MongoDBQueryDescriptor>, BatchableGridDialect, IdentityColumnAwareGridDialect, MultigetGridDialect, OptimisticLockingAwareGridDialect, StoredProcedureAwareGridDialect

Each Tuple entry is stored as a property in a MongoDB document. Each association is stored in an association document containing three properties: - the association table name (optionally) - the RowKey column names and values - the tuples as an array of elements Associations can be stored as: - one MongoDB collection per association class. The collection name is prefixed. - one MongoDB collection for all associations (the association table name property in then used) - embed the collection info in the owning entity document is planned but not supported at the moment (OGM-177) Collection of embeddable are stored within the owning entity document under the unqualified collection role In MongoDB is possible to batch operations but only for the creation of new documents and only if they don't have invalid characters in the field name. If these conditions are not met, the MongoDB mechanism for batch operations is not going to be used.

Author:

Guillaume Scheibel <guillaume.scheibel@gmail.com>, Alan Fitton <alan at eth0.org.uk>, Emmanuel Bernard <emmanuel@hibernate.org>, Thorsten Möller <thorsten.moeller@sbi.ch>, Guillaume Smet, Aleksandr Mylnikov

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	MongoDBDialect.SingleTupleIterator

Field Summary

Fields

Modifier and Type	Field and Description
static String	ASSOCIATIONS_COLLECTION_PREFIX
static String	ID_FIELDNAME
static String	PROPERTY_SEPARATOR
static String	ROWS_FIELDNAME
static String	TABLE_FIELDNAME

Constructor Summary

Constructors

Constructor and Description
MongoDBDialect(org.hibernate.ogm.datastore.mongodb.impl.MongoDBDatastoreProvider provider)

Method Summary

Modifier and Type	Method and Description
ClosableIterator<Tuple>	callStoredProcedure(String storedProcedureName, ProcedureQueryParameters params, TupleContext tupleContext) In MongoDB the equivalent of a stored procedure is a stored Javascript.
Association	createAssociation(AssociationKey key, AssociationContext associationContext) Creates a new (empty) association for storing the tuples representing the rows corresponding to the given key.
Tuple	createTuple(EntityKeyMetadata entityKeyMetadata, OperationContext operationContext) Creates an empty tuple of the specified entity type.
Tuple	createTuple(EntityKey key, OperationContext OperationContext) Creates a new tuple for the given entity key.
ClosableIterator<Tuple>	executeBackendQuery(BackendQuery<org.hibernate.ogm.datastore.mongodb.query.impl.MongoDBQueryDescriptor> backendQuery, QueryParameters queryParameters, TupleContext tupleContext) Returns the result of a native query executed on the backend.
int	executeBackendUpdateQuery(BackendQuery<org.hibernate.ogm.datastore.mongodb.query.impl.MongoDBQueryDescriptor> backendQuery, QueryParameters queryParameters, TupleContext tupleContext) Returns the result of a native update query executed on the backend.
void	executeBatch(OperationsQueue queue) Executes the batched operations using the mechanism provided by the db
void	forEachTuple(ModelConsumer consumer, TupleTypeContext tupleTypeContext, EntityKeyMetadata entityKeyMetadata) A consumer is called for each tuple matching the selected EntityKeyMetadata.
Association	getAssociation(AssociationKey key, AssociationContext associationContext) Return the list of tuples corresponding to a given association and the given context
DuplicateInsertPreventionStrategy	getDuplicateInsertPreventionStrategy(EntityKeyMetadata entityKeyMetadata) Returns this dialect's strategy for detecting the insertion of several entity tuples of the given type with the same primary key.
ParameterMetadataBuilder	getParameterMetadataBuilder() Returns a builder for retrieving parameter meta-data from native queries in this datastore's format.
Tuple	getTuple(EntityKey key, OperationContext operationContext) Return the tuple with the given column for a given key
List<Tuple>	getTuples(EntityKey[] keys, TupleContext tupleContext) Return the list of tuples with the given columns for a given list of keys.
void	insertOrUpdateAssociation(AssociationKey key, Association association, AssociationContext associationContext) Inserts or updates the given association in the datastore.
void	insertOrUpdateTuple(EntityKey key, org.hibernate.ogm.entityentry.impl.TuplePointer tuplePointer, TupleContext tupleContext) Inserts or updates the tuple corresponding to the given entity key.
void	insertTuple(EntityKeyMetadata entityKeyMetadata, Tuple tuple, TupleContext tupleContext) Inserts the given tuple into the datastore, generating an id while doing so.
boolean	isStoredInEntityStructure(AssociationKeyMetadata associationKeyMetadata, AssociationTypeContext associationTypeContext) Whether the specified association is stored within an entity structure or not.
Number	nextValue(NextValueRequest request) Returns the next value from the specified id generator with the specified increment.
GridType	overrideType(Type type) If the datastore does not support a Type the dialect might override it with a custom one.
org.hibernate.ogm.datastore.mongodb.query.impl.MongoDBQueryDescriptor	parseNativeQuery(String nativeQuery) Parses the given native query into a representation executable by this dialect.
void	removeAssociation(AssociationKey key, AssociationContext associationContext) Remove the list of tuples corresponding to a given association
void	removeTuple(EntityKey key, TupleContext tupleContext) Remove the tuple for a given key
boolean	removeTupleWithOptimisticLock(EntityKey entityKey, Tuple oldLockState, TupleContext tupleContext) Removes the given tuple.
boolean	updateTupleWithOptimisticLock(EntityKey entityKey, Tuple oldLockState, Tuple tuple, TupleContext tupleContext) Updates the given tuple.

Methods inherited from class org.hibernate.ogm.dialect.spi.BaseGridDialect

getLockingStrategy, isInTheInsertionQueue, supportsSequences, usesNavigationalInformationForInverseSideOfAssociations

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.hibernate.ogm.dialect.spi.GridDialect

getLockingStrategy, supportsSequences, usesNavigationalInformationForInverseSideOfAssociations

Field Detail

ID_FIELDNAME

public static final String ID_FIELDNAME

See Also:

Constant Field Values

PROPERTY_SEPARATOR

public static final String PROPERTY_SEPARATOR

See Also:

Constant Field Values

ROWS_FIELDNAME

public static final String ROWS_FIELDNAME

See Also:

Constant Field Values

TABLE_FIELDNAME

public static final String TABLE_FIELDNAME

See Also:

Constant Field Values

ASSOCIATIONS_COLLECTION_PREFIX

public static final String ASSOCIATIONS_COLLECTION_PREFIX

See Also:

Constant Field Values

Constructor Detail

MongoDBDialect

public MongoDBDialect(org.hibernate.ogm.datastore.mongodb.impl.MongoDBDatastoreProvider provider)

Method Detail

getTuple

public Tuple getTuple(EntityKey key,
                      OperationContext operationContext)

Description copied from interface: GridDialect

Return the tuple with the given column for a given key

Specified by:

getTuple in interface GridDialect

Parameters:

key - The tuple identifier

operationContext - Contains additional information that might be used to create the tuple

Returns:

the tuple identified by the key

getTuples

public List<Tuple> getTuples(EntityKey[] keys,
                             TupleContext tupleContext)

Description copied from interface: MultigetGridDialect

Return the list of tuples with the given columns for a given list of keys. The tuples must be returned in the same order as the keys. If a key has no matching record, set null to the list entry.

All the keys provided will have the same EntityKeyMetadata. In other words they target the same "table".

Specified by:

getTuples in interface MultigetGridDialect

Parameters:

keys - The array of tuple identifier

tupleContext - Contains additional information that might be used to create the tuples

Returns:

the list of tuples identified by the keys

createTuple

public Tuple createTuple(EntityKeyMetadata entityKeyMetadata,
                         OperationContext operationContext)

Description copied from interface: IdentityColumnAwareGridDialect

Creates an empty tuple of the specified entity type. The created tuple should be "transient", i.e. no round-trip to the datastore should be performed.

Specified by:

createTuple in interface IdentityColumnAwareGridDialect

Parameters:

entityKeyMetadata - Represents the entity type for which the tuple should be created

operationContext - Provides additional meta-data useful for tuple creation

Returns:

the newly created tuple

createTuple

public Tuple createTuple(EntityKey key,
                         OperationContext OperationContext)

Description copied from interface: GridDialect

Creates a new tuple for the given entity key.

Only invoked if no tuple is present yet for the given key. Implementations should not perform a round-trip to the datastore but rather return a transient instance. The OGM engine will invoke GridDialect.insertOrUpdateTuple(EntityKey, TuplePointer, TupleContext) subsequently.

Columns in the tuple may represent properties of the corresponding entity as well as *-to-one associations to other entities. Implementations may choose to persist the latter e.g. in form of fields or as actual links/relationships to the element representing the associated entity. In case of multi-column keys, the corresponding association role for a given column can be obtained from the passed tuple context.

Specified by:

createTuple in interface GridDialect

Parameters:

key - The tuple identifier

OperationContext - Contains additional information that might be used to create the tuple

Returns:

the created tuple

insertOrUpdateTuple

public void insertOrUpdateTuple(EntityKey key,
                                org.hibernate.ogm.entityentry.impl.TuplePointer tuplePointer,
                                TupleContext tupleContext)

Description copied from interface: GridDialect

Inserts or updates the tuple corresponding to the given entity key.

Specified by:

insertOrUpdateTuple in interface GridDialect

Parameters:

key - The tuple identifier

tuplePointer - A pointer to the list of operations to execute

tupleContext - Contains additional information that might be used to create or update the tuple

updateTupleWithOptimisticLock

public boolean updateTupleWithOptimisticLock(EntityKey entityKey,
                                             Tuple oldLockState,
                                             Tuple tuple,
                                             TupleContext tupleContext)

Description copied from interface: OptimisticLockingAwareGridDialect

Updates the given tuple. Implementors are expected to perform the update only if the entity has the given old version in the datastore. Specifically, atomic "find and update" semantics should be applied.

Specified by:

updateTupleWithOptimisticLock in interface OptimisticLockingAwareGridDialect

Parameters:

entityKey - The key of the entity to save

oldLockState - A tuple with all those column values identifying the previous version of the record in the datastore. Implementations are expected to apply all the contained columns to select the record to be updated.

tuple - The entity column values to save

tupleContext - Provides additional meta-data useful for the tuple update

Returns:

true if the update succeeded, false otherwise (e.g. if the entity has been updated in the datastore in parallel, so it has a newer version then the given one).

insertTuple

public void insertTuple(EntityKeyMetadata entityKeyMetadata,
                        Tuple tuple,
                        TupleContext tupleContext)

Description copied from interface: IdentityColumnAwareGridDialect

Inserts the given tuple into the datastore, generating an id while doing so. The generated id is to be added to the given tuple (the id column name(s) can be obtained from the given entity key meta-data).

Specified by:

insertTuple in interface IdentityColumnAwareGridDialect

Parameters:

entityKeyMetadata - The type of the entity to save

tuple - The entity column values to save

tupleContext - Provides additional meta-data useful for tuple insertion

removeTuple

public void removeTuple(EntityKey key,
                        TupleContext tupleContext)

Description copied from interface: GridDialect

Remove the tuple for a given key

Specified by:

removeTuple in interface GridDialect

Parameters:

key - The tuple identifier

tupleContext - Contains additional information that might be used to remove the tuple

removeTupleWithOptimisticLock

public boolean removeTupleWithOptimisticLock(EntityKey entityKey,
                                             Tuple oldLockState,
                                             TupleContext tupleContext)

Description copied from interface: OptimisticLockingAwareGridDialect

Removes the given tuple. Implementors are expected to perform the delete only if the entity has the given old version in the datastore. Specifically, atomic "find and delete" semantics should be applied.

Specified by:

removeTupleWithOptimisticLock in interface OptimisticLockingAwareGridDialect

Parameters:

entityKey - The key of the entity to save

oldLockState - A tuple with all those column values identifying the previous version of the record in the datastore. Implementations are expected to apply all the contained columns to select the record to be removed.

tupleContext - Provides additional meta-data useful for the tuple removal

Returns:

true if the deletion succeeded, false otherwise (e.g. if the entity has been removed or updated in the datastore in parallel, so it has a newer version then the given one).

getAssociation

public Association getAssociation(AssociationKey key,
                                  AssociationContext associationContext)

Description copied from interface: GridDialect

Return the list of tuples corresponding to a given association and the given context

Specified by:

getAssociation in interface GridDialect

Parameters:

key - Identifies the association

associationContext - Contains additional information that might be used to get the association

Returns:

a list of tuples

createAssociation

public Association createAssociation(AssociationKey key,
                                     AssociationContext associationContext)

Description copied from interface: GridDialect

Creates a new (empty) association for storing the tuples representing the rows corresponding to the given key.

Only invoked if the association does not yet exist in the datastore. Implementations should not perform a round-trip to the datastore but rather return a transient instance. The OGM engine will invoke GridDialect.insertOrUpdateAssociation(AssociationKey, Association, AssociationContext) subsequently.

Specified by:

createAssociation in interface GridDialect

Parameters:

key - Identifies the association

associationContext - Contains additional information that might be used to create the association

Returns:

the created association

insertOrUpdateAssociation

public void insertOrUpdateAssociation(AssociationKey key,
                                      Association association,
                                      AssociationContext associationContext)

Description copied from interface: GridDialect

Inserts or updates the given association in the datastore.

Specified by:

insertOrUpdateAssociation in interface GridDialect

Parameters:

key - Identifies the association

association - The list of operations to execute

associationContext - Contains additional information that might be used to create the association

removeAssociation

public void removeAssociation(AssociationKey key,
                              AssociationContext associationContext)

Description copied from interface: GridDialect

Remove the list of tuples corresponding to a given association

Specified by:

removeAssociation in interface GridDialect

Parameters:

key - Identifies the association

associationContext - Contains additional information that might be used to remove an association

nextValue

public Number nextValue(NextValueRequest request)

Description copied from interface: GridDialect

Returns the next value from the specified id generator with the specified increment.

Specified by:

nextValue in interface GridDialect

Parameters:

request - Identifies a specific id generator

Returns:

the next value from the specified id generator

isStoredInEntityStructure

public boolean isStoredInEntityStructure(AssociationKeyMetadata associationKeyMetadata,
                                         AssociationTypeContext associationTypeContext)

Description copied from interface: GridDialect

Whether the specified association is stored within an entity structure or not. E.g. dialects for document stores may support storing associations within entity documents and would have to return true if this is the case for a given association.

Specified by:

isStoredInEntityStructure in interface GridDialect

Parameters:

associationKeyMetadata - identifies the association of interest

associationTypeContext - provides additional contextual information about the represented association type, such as the options effectively applying for it

Returns:

true if the specified association is stored within an entity structure, false otherwise.

overrideType

public GridType overrideType(Type type)

Description copied from interface: GridDialect

If the datastore does not support a Type the dialect might override it with a custom one.

Specified by:

overrideType in interface GridDialect

Overrides:

overrideType in class BaseGridDialect

Parameters:

type - The Type that might need to be overridden

Returns:

the GridType instance to use to bind the given type or null if the type does not need to be overridden

forEachTuple

public void forEachTuple(ModelConsumer consumer,
                         TupleTypeContext tupleTypeContext,
                         EntityKeyMetadata entityKeyMetadata)

Description copied from interface: GridDialect

A consumer is called for each tuple matching the selected EntityKeyMetadata. The tuples must be of the same indexed type.

Specified by:

forEachTuple in interface GridDialect

Parameters:

consumer - the instance that is going to be called for every Tuple

tupleTypeContext - contains additional information that might be used to build the tuple

entityKeyMetadata - the key metadata of the table for which we want to apply the consumer

executeBackendQuery

public ClosableIterator<Tuple> executeBackendQuery(BackendQuery<org.hibernate.ogm.datastore.mongodb.query.impl.MongoDBQueryDescriptor> backendQuery,
                                                   QueryParameters queryParameters,
                                                   TupleContext tupleContext)

Description copied from interface: QueryableGridDialect

Returns the result of a native query executed on the backend.

Specified by:

executeBackendQuery in interface QueryableGridDialect<org.hibernate.ogm.datastore.mongodb.query.impl.MongoDBQueryDescriptor>

Parameters:

backendQuery - the query to execute in a representation understood by the underlying datastore. May have been created by converting a JP-QL query or from a (named) native query.

queryParameters - parameters passed for this query

tupleContext - the tuple context

Returns:

an ClosableIterator with the result of the query

executeBackendUpdateQuery

public int executeBackendUpdateQuery(BackendQuery<org.hibernate.ogm.datastore.mongodb.query.impl.MongoDBQueryDescriptor> backendQuery,
                                     QueryParameters queryParameters,
                                     TupleContext tupleContext)

Description copied from interface: QueryableGridDialect

Returns the result of a native update query executed on the backend.

Precise semantics of an update are subject to design choices made for the actual database system in the backend. In particular, it may implement non-classical notions of consistency such as eventual consistency (rather than (conflict) serializablity as in most relational SQL database systems).

Specified by:

executeBackendUpdateQuery in interface QueryableGridDialect<org.hibernate.ogm.datastore.mongodb.query.impl.MongoDBQueryDescriptor>

Parameters:

backendQuery - the query to execute in a representation understood by the underlying datastore. May have been created by converting a JP-QL query or from a (named) native query.

queryParameters - parameters passed for this query

tupleContext - the tuple context

Returns:

the number of elements that have been updated.

parseNativeQuery

public org.hibernate.ogm.datastore.mongodb.query.impl.MongoDBQueryDescriptor parseNativeQuery(String nativeQuery)

Description copied from interface: QueryableGridDialect

Parses the given native query into a representation executable by this dialect.

Specified by:

parseNativeQuery in interface QueryableGridDialect<org.hibernate.ogm.datastore.mongodb.query.impl.MongoDBQueryDescriptor>

Parameters:

nativeQuery - the native query to parse

Returns:

the parsed query

getDuplicateInsertPreventionStrategy

public DuplicateInsertPreventionStrategy getDuplicateInsertPreventionStrategy(EntityKeyMetadata entityKeyMetadata)

Description copied from interface: GridDialect

Returns this dialect's strategy for detecting the insertion of several entity tuples of the given type with the same primary key.

Specified by:

getDuplicateInsertPreventionStrategy in interface GridDialect

Overrides:

getDuplicateInsertPreventionStrategy in class BaseGridDialect

Parameters:

entityKeyMetadata - meta-data identifying the entity type of interest

Returns:

This dialect's strategy for detecting the insertion of several entity tuples of the given type with the same primary key

executeBatch

public void executeBatch(OperationsQueue queue)

Description copied from interface: BatchableGridDialect

Executes the batched operations using the mechanism provided by the db

Specified by:

executeBatch in interface BatchableGridDialect

Parameters:

queue - The batched operations

getParameterMetadataBuilder

public ParameterMetadataBuilder getParameterMetadataBuilder()

Description copied from interface: QueryableGridDialect

Returns a builder for retrieving parameter meta-data from native queries in this datastore's format.

Specified by:

getParameterMetadataBuilder in interface QueryableGridDialect<org.hibernate.ogm.datastore.mongodb.query.impl.MongoDBQueryDescriptor>

Returns:

a builder for retrieving parameter meta-data

callStoredProcedure

public ClosableIterator<Tuple> callStoredProcedure(String storedProcedureName,
                                                   ProcedureQueryParameters params,
                                                   TupleContext tupleContext)

In MongoDB the equivalent of a stored procedure is a stored Javascript.

Specified by:

callStoredProcedure in interface StoredProcedureAwareGridDialect

Parameters:

storedProcedureName - name of stored procedure

params - query parameters

tupleContext - the tuple context

Returns:

the result as a ClosableIterator