Package org.opends.server.backends

Class MemoryBackend

  • All Implemented Interfaces:
    RequestHandler, HealthStatusProvider
    public final class MemoryBackend
extends LocalBackend<MemoryBackendCfg>
    This class defines a very simple backend that stores its information in memory. This is primarily intended for testing purposes with small data sets, as it does not have any indexing mechanism such as would be required to achieve high performance with large data sets. It is also heavily synchronized for simplicity at the expense of performance, rather than providing a more fine-grained locking mechanism.

    Entries stored in this backend are held in a LinkedHashMap<DN,Entry> object, which ensures that the order in which you iterate over the entries is the same as the order in which they were inserted. By combining this with the constraint that no entry can be added before its parent, you can ensure that iterating through the entries will always process the parent entries before their children, which is important for both search result processing and LDIF exports.

    As mentioned above, no data indexing is performed, so all non-baseObject searches require iteration through the entire data set. If this is to become a more general-purpose backend, then additional HashMap<ByteString,Set<DN>> objects could be used to provide that capability.

    There is actually one index that does get maintained within this backend, which is a mapping between the DN of an entry and the DNs of any immediate children of that entry. This is needed to efficiently determine whether an entry has any children (which must not be the case for delete operations).

    • Constructor Detail

      • MemoryBackend

        public MemoryBackend()

    • Method Detail

      • configureBackend

        public void configureBackend​(MemoryBackendCfg config,
                             ServerContext serverContext)
        Description copied from class: Backend
        Configure this backend based on the information in the provided configuration. When the method returns, the backend will have been configured (ready to be opened) but still unable to process operations.
        Specified by:
        configureBackend in class Backend<MemoryBackendCfg>
        Parameters:
        config - The configuration of this backend.
        serverContext - The server context for this instance

      • isPublicBackend

        public boolean isPublicBackend()
        Description copied from class: Backend
        Indicates whether the base DNs of this backend should be considered public or private.

        This method also controls the visibility of the associated naming contexts. i.e. if any base DN of this backend is a naming context, then it will be public or private, based on the value returned by this method.

        Reminder: Public naming contexts are returned when querying the root DSE entry.

        Specified by:
        isPublicBackend in class Backend<MemoryBackendCfg>
        Returns:
        true if this backend's baseDNs could be exposed as a public naming context, false if they must remain private naming contexts.

      • getBaseDNs

        public Set<Dn> getBaseDNs()
        Description copied from class: Backend
        Retrieves the set of base-level DNs that may be used within this backend.
        Specified by:
        getBaseDNs in class Backend<MemoryBackendCfg>
        Returns:
        The set of base-level DNs that may be used within this backend.

      • getEntryCount

        public long getEntryCount()
        Description copied from class: LocalBackend
        Retrieves the total number of entries contained in this backend, if that information is available.
        Specified by:
        getEntryCount in class LocalBackend<MemoryBackendCfg>
        Returns:
        The total number of entries contained in this backend, or -1 if that information is not available.

      • isIndexed

        public boolean isIndexed​(AttributeType attributeType,
                         IndexType indexType)
        Description copied from class: LocalBackend
        Indicates whether search operations which target the specified attribute in the indicated manner would be considered indexed in this backend. The operation should be considered indexed only if the specified operation can be completed efficiently within the backend.

        Note that this method should return a general result that covers all values of the specified attribute. If a the specified attribute is indexed in the indicated manner but some particular values may still be treated as unindexed (e.g., if the number of entries with that attribute value exceeds some threshold), then this method should still return true for the specified attribute and index type.
        Specified by:
        isIndexed in class LocalBackend<MemoryBackendCfg>
        Parameters:
        attributeType - The attribute type for which to make the determination.
        indexType - The index type for which to make the determination.
        Returns:
        true if search operations targeting the specified attribute in the indicated manner should be considered indexed, or false if not.

      • isIndexed

        public boolean isIndexed​(AttributeType attributeType,
                         MatchingRule matchingRule)
        Description copied from class: LocalBackend
        Indicates whether extensible match search operations that target the specified attribute with the given matching rule should be considered indexed in this backend.
        Specified by:
        isIndexed in class LocalBackend<MemoryBackendCfg>
        Parameters:
        attributeType - The attribute type for which to make the determination.
        matchingRule - The matching rule for which to make the determination.
        Returns:
        true if extensible match search operations targeting the specified attribute with the given matching rule should be considered indexed, or false if not.

      • hasSubordinates

        public ConditionResult hasSubordinates​(Dn entryDN)
        Description copied from class: LocalBackend
        Indicates whether the requested entry has any subordinates.
        Specified by:
        hasSubordinates in class LocalBackend<MemoryBackendCfg>
        Parameters:
        entryDN - The distinguished name of the entry.
        Returns:
        ConditionResult.TRUE if the entry has one or more subordinates or ConditionResult.FALSE otherwise or ConditionResult.UNDEFINED if it can not be determined.

      • getNumberOfEntriesInBaseDN

        public long getNumberOfEntriesInBaseDN​(Dn baseDN)
        Description copied from class: LocalBackend
        Retrieves the number of entries for the specified base DN including all entries from the requested entry to the lowest level in the tree.
        Specified by:
        getNumberOfEntriesInBaseDN in class LocalBackend<MemoryBackendCfg>
        Parameters:
        baseDN - The base distinguished name.
        Returns:
        The number of subordinate entries including the base dn.

      • getNumberOfChildren

        public long getNumberOfChildren​(Dn parentDN)
        Description copied from class: LocalBackend
        Retrieves the number of subordinates immediately below the requested entry.
        Specified by:
        getNumberOfChildren in class LocalBackend<MemoryBackendCfg>
        Parameters:
        parentDN - The distinguished name of the parent.
        Returns:
        The number of subordinate entries for the requested entry.

      • getEntry

        public Entry getEntry​(Dn entryDN)
        Description copied from class: LocalBackend
        Retrieves the requested entry from this backend. The caller is not required to hold any locks on the specified DN.
        Specified by:
        getEntry in class LocalBackend<MemoryBackendCfg>
        Parameters:
        entryDN - The distinguished name of the entry to retrieve.
        Returns:
        The requested entry, or null if the entry does not exist.

      • entryExists

        public boolean entryExists​(Dn entryDN)
        Description copied from class: LocalBackend
        Indicates whether an entry with the specified DN exists in the backend. The default implementation calls getEntry, but backend implementations may override this with a more efficient version. The caller is not required to hold any locks on the specified DN.
        Overrides:
        entryExists in class LocalBackend<MemoryBackendCfg>
        Parameters:
        entryDN - The DN of the entry for which to determine existence.
        Returns:
        true if the specified entry exists in this backend, or false if it does not.

      • addEntry

        public void addEntry​(Entry entry,
                     AddOperation addOperation)
              throws LdapException
        Description copied from class: LocalBackend
        Adds the provided entry to this backend. This method must ensure that the entry is appropriate for the backend and that no entry already exists with the same DN. The caller must hold a write lock on the DN of the provided entry.
        Specified by:
        addEntry in class LocalBackend<MemoryBackendCfg>
        Parameters:
        entry - The entry to add to this backend.
        addOperation - The add operation with which the new entry is associated. This may be null for adds performed internally.
        Throws:
        LdapException - If a problem occurs while trying to add the entry.
        CancelledResultException - If this backend noticed and reacted to a request to cancel or abandon the add operation.

      • deleteEntry

        public void deleteEntry​(Dn entryDN,
                        DeleteOperation deleteOperation)
                 throws LdapException
        Description copied from class: LocalBackend
        Removes the specified entry from this backend. This method must ensure that the entry exists and that it does not have any subordinate entries (unless the backend supports a subtree delete operation and the client included the appropriate information in the request). The caller must hold a write lock on the provided entry DN.
        Specified by:
        deleteEntry in class LocalBackend<MemoryBackendCfg>
        Parameters:
        entryDN - The DN of the entry to remove from this backend.
        deleteOperation - The delete operation with which this action is associated. This may be null for deletes performed internally.
        Throws:
        LdapException - If a problem occurs while trying to remove the entry.
        CancelledResultException - If this backend noticed and reacted to a request to cancel or abandon the delete operation.

      • replaceEntry

        public void replaceEntry​(Entry oldEntry,
                         Entry newEntry,
                         ModifyOperation modifyOperation)
                  throws LdapException
        Description copied from class: LocalBackend
        Replaces the specified entry with the provided entry in this backend. The backend must ensure that an entry already exists with the same DN as the provided entry. The caller must hold a write lock on the DN of the provided entry.
        Specified by:
        replaceEntry in class LocalBackend<MemoryBackendCfg>
        Parameters:
        oldEntry - The original entry that is being replaced.
        newEntry - The new entry to use in place of the existing entry with the same DN.
        modifyOperation - The modify operation with which this action is associated.
        Throws:
        LdapException - If a problem occurs while trying to replace the entry.
        CancelledResultException - If this backend noticed and reacted to a request to cancel or abandon the modify operation.

      • renameEntry

        public void renameEntry​(Dn currentDN,
                        Entry entry,
                        ModifyDnOperation modifyDNOperation)
                 throws LdapException
        Description copied from class: LocalBackend
        Moves and/or renames the provided entry in this backend, altering any subordinate entries as necessary. This must ensure that an entry already exists with the provided current DN, and that no entry exists with the target DN of the provided entry. The caller must hold write locks on both the current DN and the new DN for the entry.
        Specified by:
        renameEntry in class LocalBackend<MemoryBackendCfg>
        Parameters:
        currentDN - The current DN of the entry to be moved/renamed.
        entry - The new content to use for the entry.
        modifyDNOperation - The modify DN operation with which this action is associated. This may be null for modify DN operations performed internally.
        Throws:
        LdapException - If a problem occurs while trying to perform the rename.
        CancelledResultException - If this backend noticed and reacted to a request to cancel or abandon the modify DN operation.

      • search

        public void search​(SearchOperation searchOperation)
            throws LdapException
        Description copied from class: LocalBackend
        Processes the specified search in this backend. Matching entries should be provided back to the core server using the SearchOperation.returnEntry method. The caller is not required to have any locks when calling this operation.
        Specified by:
        search in class LocalBackend<MemoryBackendCfg>
        Parameters:
        searchOperation - The search operation to be processed.
        Throws:
        LdapException - If a problem occurs while processing the search.
        CancelledResultException - If this backend noticed and reacted to a request to cancel or abandon the search operation.

      • getSupportedControls

        public Set<String> getSupportedControls()
        Description copied from class: Backend
        Retrieves the OIDs of the controls that may be supported by this backend.
        Overrides:
        getSupportedControls in class Backend<MemoryBackendCfg>
        Returns:
        The OIDs of the controls that may be supported by this backend.

      • supports

        public boolean supports​(LocalBackend.BackendOperation backendOperation)
        Description copied from class: LocalBackend
        Indicates whether this backend supports the provided backend operation.
        Overrides:
        supports in class LocalBackend<MemoryBackendCfg>
        Parameters:
        backendOperation - the backend operation
        Returns:
        true if this backend supports the provided backend operation, false otherwise.