Class BaseContainerHandle

java.lang.Object
org.apache.derby.iapi.services.monitor.DerbyObservable
org.apache.derby.impl.store.raw.data.BaseContainerHandle
All Implemented Interfaces:
DerbyObserver, ContainerHandle, RawContainerHandle
public class BaseContainerHandle extends DerbyObservable implements RawContainerHandle, DerbyObserver
A handle to an open container, implememts RawContainerHandle.

This class is a DerbyObserver to observe RawTransactions and is also a DerbyObservable to handle the list of pages accessed thorough this handle.
This class implements Lockable (defined to be ContainerHandle) and is the object used to logically lock the container.
MT - Mutable - Immutable identity - Thread Aware

  • Field Details

    • identity

      private ContainerKey identity
      Container identifier
      MT - Immutable

    • active

      private boolean active
      Is this ContainerHandle active.
      MT - Mutable : scoped

    • container

      protected BaseContainer container
      The actual container we are accessing. Only valid when active is true.
      MT - Mutable : scoped

    • locking

      private LockingPolicy locking
      the locking policy we opened the container with. Only valid when active is true.
      MT - Mutable : scoped

    • xact

      private RawTransaction xact
      our transaction. Only valid when active is true.
      MT - Mutable : scoped

    • forUpdate

      private boolean forUpdate
      are we going to update?
      MT - Immutable after container handle becomes active

    • mode

      private int mode
      mode the conainter was opened in.

    • actionsSet

      private PageActions actionsSet

    • allocActionsSet

      private AllocationActions allocActionsSet

  • Constructor Details

  • Method Details

    • addPage

      public Page addPage() throws StandardException
      Add a page to the container The page returned will be observing me.
      Specified by:
      addPage in interface ContainerHandle
      Returns:
      a reference to the page that was added.
      Throws:
      StandardException - Standard Derby error policy
      See Also:

    • compressContainer

      public void compressContainer() throws StandardException
      Release free space to the OS.

      As is possible release any free space to the operating system. This will usually mean releasing any free pages located at the end of the file using the java truncate() interface.

      Specified by:
      compressContainer in interface ContainerHandle
      Throws:
      StandardException - Standard Derby error policy

    • getReusableRecordIdSequenceNumber

      public long getReusableRecordIdSequenceNumber() throws StandardException
      Get the reusable recordId sequence number.
      Specified by:
      getReusableRecordIdSequenceNumber in interface ContainerHandle
      Returns:
      version sequence number
      Throws:
      StandardException - Standard Derby error policy
      See Also:

    • addPage

      public Page addPage(int flag) throws StandardException
      Add a page to the container, if flag == ContainerHandle.ADD_PAGE_BULK, tell the container about it. The page returned will be observing me.
      Specified by:
      addPage in interface ContainerHandle
      Returns:
      a reference to the page that was added.
      Throws:
      StandardException - Standard Derby error policy
      See Also:

    • preAllocate

      public void preAllocate(int numPage)
      Preallocate numPage if possible.
      Specified by:
      preAllocate in interface ContainerHandle

    • getContainerProperties

      public void getContainerProperties(Properties prop) throws StandardException
      Request the system properties associated with a container.

      Request the value of properties that are associated with a container. The following properties can be requested: derby.storage.pageSize derby.storage.pageReservedSpace derby.storage.minimumRecordSize

      To get the value of a particular property add it to the property list, and on return the value of the property will be set to it's current value. For example: get_prop(BaseContainerHandle ch) { Properties prop = new Properties(); prop.put("derby.storage.pageSize", ""); ch.getContainerProperties(prop); System.out.println( "conatainer's page size = " + prop.getProperty("derby.storage.pageSize"); }

      Specified by:
      getContainerProperties in interface ContainerHandle
      Parameters:
      prop - Property list to fill in.
      Throws:
      StandardException - Standard exception policy.

    • removePage

      public void removePage(Page page) throws StandardException
      Remove a page from the container.
      Specified by:
      removePage in interface ContainerHandle
      Throws:
      StandardException - Standard Derby error policy
      See Also:

    • getPage

      public Page getPage(long pageNumber) throws StandardException
      Description copied from interface: ContainerHandle
      Obtain exclusive access to the page with the given page number. Once the Page is no longer required the Page's unlatch() method must be called.

      The Page object is guaranteed to remain in-memory and exclusive to the caller until its unlatch() method is called.

      Specified by:
      getPage in interface ContainerHandle
      Returns:
      the required Page or null if the page does not exist or is not valid (i.e, it has been deallocated or freed or never initialized) Note that an overflow page will be returned since it is a valid page.
      Throws:
      StandardException - Standard Derby error policy

    • getAllocPage

      public Page getAllocPage(long pageNumber) throws StandardException
      Throws:
      StandardException

    • getUserPageNoWait

      public Page getUserPageNoWait(long pageNumber) throws StandardException
      Description copied from interface: ContainerHandle
      Obtain exclusive access to the page with the given page number. Will only return a valid, non-overflow user page - so can be used by routines in post commit to get pages to attempt deleted row space reclamation. If for some reason a request is made for an overflow page a null will be returned. Once the Page is no longer required the Page's unlatch() method must be called.

      The Page object is guaranteed to remain in-memory and exclusive to the caller until its unlatch() method is called.

      Specified by:
      getUserPageNoWait in interface ContainerHandle
      Returns:
      the required Page or null if the page does not exist or is not valid (i.e, it has been deallocated, freed, never initialized, or is an allocation page or overflow page)
      Throws:
      StandardException - Standard Derby error policy

    • getUserPageWait

      public Page getUserPageWait(long pageNumber) throws StandardException
      Description copied from interface: ContainerHandle
      Obtain exclusive access to the page with the given page number. Will only return a valid, non-overflow user page - so can be used by routines in post commit to get pages to attempt deleted row space reclamation. If for some reason a request is made for an overflow page a null will be returned. Once the Page is no longer required the Page's unlatch() method must be called.

      The Page object is guaranteed to remain in-memory and exclusive to the caller until its unlatch() method is called.

      Specified by:
      getUserPageWait in interface ContainerHandle
      Returns:
      the required Page or null if the page does not exist or is not valid (i.e, it has been deallocated, freed, never initialized, or is an allocation page or overflow page)
      Throws:
      StandardException - Standard Derby error policy

    • getPageNoWait

      public Page getPageNoWait(long pageNumber) throws StandardException
      Description copied from interface: ContainerHandle
      Identical to getPage but returns null immediately if the desired page is already latched by another Container.
      Specified by:
      getPageNoWait in interface ContainerHandle
      Returns:
      the required Page or null if the page does not exist or the page is already latched.
      Throws:
      StandardException - Standard Derby error policy

    • getFirstPage

      public Page getFirstPage() throws StandardException
      Description copied from interface: ContainerHandle
      Obtain exclusive access to the current first page of the container. Only a valid, non overflow page will be returned. Pages in the container are ordered in an internally defined ordering.

      Note that once this method returns this page may no longer be the first page of the container. I.e, other threads may allocate pages prior to this page number while this page is latched. It is up to the caller of this routine to synchronize this call with addPage to assure that this is the first page.
      As long as the client provide the necessary lock to ensure that no addPage is called, then this page is guaranteed to be the first page of the container in some internally defined ordering of the pages.

      Specified by:
      getFirstPage in interface ContainerHandle
      Returns:
      latched page or null if there is no page in the container
      Throws:
      StandardException - Standard Derby error policy
      See Also:

    • getNextPage

      public Page getNextPage(long pageNumber) throws StandardException
      Description copied from interface: ContainerHandle
      Obtain exclusive access to the next valid page of the given page number in the container. Only a valid, non overflow page will be returned. Pages in the container are ordered in an internally defined ordering.

      Note that once this method returns this page may no longer be the next page of the container. I.e, other threads may allocate pages prior to this page number while this page is latched. It is up to the caller of this routine to synchronize this call with addPage to assure that this is the first page.
      As long as the client provide the necessary lock to ensure that no addPage is called, then this page is guaranteed to be the next page of the container in some internally defined ordering of the pages.
      If no pages are added or removed, then an iteration such as: 

      for (Page p = containerHandle.getFirstPage();
         p != null;
         p = containerHandle.getNextPage(p.getPageNumber()))

      will guarentee to iterate thru and latched all the valid pages 
in the container
      Specified by:
      getNextPage in interface ContainerHandle
      Parameters:
      pageNumber - the pagenumber of the page previous to the page that is to be gotten. The page which correspond to prevNum may or may not be latched by the caller, but it must be gotten via a page which was (or currently still is) latched, and the page number must be gotten while the container must not have been closed or dropped or removed in the interim. In other words, if the user manufactures a page number, or remembers the page number from a previous session or a previous openContainer, then the behavior of this routine is undefined.
      Returns:
      latched page or null if there is no next page in the container
      Throws:
      StandardException - Standard Derby error policy
      See Also:

    • getPageForInsert

      public Page getPageForInsert(int flag) throws StandardException
      Description copied from interface: ContainerHandle
      Get a page for insert. If RawStore thinks it knows where a potentially suitable page is for insert, it will return it. If RawStore doesn't know where a suitable page for insert is, or if there are no allocated page, then null is returned. If a page is returned, it will be a valid, non-overflow page. A potentially suitable page is one which has enough space for a minium sized record.
      Specified by:
      getPageForInsert in interface ContainerHandle
      Parameters:
      flag - a GET_PAGE_* flag.
      Returns:
      a valid, non-overflow page. Or null if RawStore doesn't know where to find a good valid, non-overflow page.
      Throws:
      StandardException - Standard Derby error policy

    • getPageForCompress

      public Page getPageForCompress(int flag, long pageno) throws StandardException
      Specified by:
      getPageForCompress in interface ContainerHandle
      Throws:
      StandardException

    • isReadOnly

      public final boolean isReadOnly()
      Description copied from interface: ContainerHandle
      Is the container opened for read only or update?
      Specified by:
      isReadOnly in interface ContainerHandle
      Returns:
      true if container is opened for read only, else false.
      See Also:

    • close

      public void close()
      Description copied from interface: ContainerHandle
      Close me. After using this method the caller must throw away the reference to the Container object, e.g. 
              ref.close();
        ref = null;

      The container will be closed automatically at the commit or abort of the transaction if this method is not called explictly.
      Any pages that were obtained using me and have not been released using Page's unlatch method are released, and references to them must be thrown away.
      Specified by:
      close in interface ContainerHandle
      See Also:

    • getEstimatedRowCount

      public long getEstimatedRowCount(int flag) throws StandardException
      Description copied from interface: ContainerHandle
      Get the total estimated number of rows in the container, not including overflow rows. This number is a rough estimate and may be grossly off.
      Specified by:
      getEstimatedRowCount in interface ContainerHandle
      Parameters:
      flag - different flavors of row count (reserved for future use)
      Throws:
      StandardException - Standard Derby error policy
      See Also:

    • setEstimatedRowCount

      public void setEstimatedRowCount(long count, int flag) throws StandardException
      Description copied from interface: ContainerHandle
      Set the total estimated number of rows in the container. Often, after a scan, the client of RawStore has a much better estimate of the number of rows in the container then what RawStore has. Use this better number for future reference.
      It is OK for a ReadOnly ContainerHandle to set the estimated row count.
      Specified by:
      setEstimatedRowCount in interface ContainerHandle
      Parameters:
      count - the estimated number of rows in the container.
      flag - different flavors of row count (reserved for future use)
      Throws:
      StandardException - Standard Derby error policy
      See Also:

    • getEstimatedPageCount

      public long getEstimatedPageCount(int flag) throws StandardException
      Description copied from interface: ContainerHandle
      Get the total estimated number of allocated (not freed, not deallocated) user pages in the container, including overflow pages. this number is a rough estimate and may be grossly off.
      Specified by:
      getEstimatedPageCount in interface ContainerHandle
      Parameters:
      flag - different flavors of page count (reserved for future use)
      Throws:
      StandardException - Standard Derby error policy
      See Also:

    • flushContainer

      public void flushContainer() throws StandardException
      Description copied from interface: ContainerHandle
      Flush all dirty pages of the container to disk. Used mainly for UNLOGGED or CREATE_UNLOGGED operation.
      Specified by:
      flushContainer in interface ContainerHandle
      Throws:
      StandardException - Standard Derby error policy
      See Also:

    • compactRecord

      public void compactRecord(RecordHandle record) throws StandardException
      Description copied from interface: ContainerHandle
      This record probably has shrunk considerably. Free its reserved space or compact it.
      Specified by:
      compactRecord in interface ContainerHandle
      Parameters:
      record - The record handle, the record must have been locked execlusively already.
      Throws:
      StandardException - Standard Derby error policy
      See Also:

    • getContainerStatus

      public int getContainerStatus() throws StandardException
      Get the container status.
      Specified by:
      getContainerStatus in interface RawContainerHandle
      Throws:
      StandardException - Standard Derby error policy
      See Also:

    • removeContainer

      public void removeContainer(LogInstant instant) throws StandardException
      remove the container
      Specified by:
      removeContainer in interface RawContainerHandle
      Throws:
      StandardException - Standard Derby error policy
      See Also:

    • getId

      public ContainerKey getId()
      Description copied from interface: ContainerHandle
      Return my identifier.
      Specified by:
      getId in interface ContainerHandle
      See Also:

    • getUniqueId

      public Object getUniqueId()
      Description copied from interface: ContainerHandle
      Return my unique identifier, this identifier will be unique to each instance of an open container handle. This id is used by the locking system to group locks to an open container handle.
      Specified by:
      getUniqueId in interface ContainerHandle
      See Also:

    • dropContainer

      public void dropContainer(LogInstant instant, boolean drop) throws StandardException
      Description copied from interface: RawContainerHandle
      If drop is true, drop the container. if drop is false, un-drop the container
      Specified by:
      dropContainer in interface RawContainerHandle
      Throws:
      StandardException - Standard Derby exception policy
      See Also:

    • getContainerVersion

      public long getContainerVersion() throws StandardException
      Description copied from interface: RawContainerHandle
      Get the logged container version
      Specified by:
      getContainerVersion in interface RawContainerHandle
      Throws:
      StandardException - Standard Derby exception policy
      See Also:

    • getAnyPage

      public Page getAnyPage(long pageNumber) throws StandardException
      Get this page with no check - any page type or status is fine. Caller must be prepared to handle freed, deallocated,or alloc page Called by recovery ONLY.
      Specified by:
      getAnyPage in interface RawContainerHandle
      Throws:
      StandardException - Derby Standard error policy

    • reCreatePageForRedoRecovery

      public Page reCreatePageForRedoRecovery(int pageFormat, long pageNumber, long pageOffset) throws StandardException
      ReCreate a page for rollforward recovery.

      During redo recovery it is possible for the system to try to redo the creation of a page (ie. going from non-existence to version 0). It first trys to read the page from disk, but a few different types of errors can occur: o the page does not exist at all on disk, this can happen during rollforward recovery applied to a backup where the file was copied and the page was added to the file during the time frame of the backup but after the physical file was copied. o space in the file exists, but it was never initalized. This can happen if you happen to crash at just the right moment during the allocation process. Also on some OS's it is possible to read from a part of the file that was not ever written - resulting in garbage from the store's point of view (often the result is all 0's). All these errors are easy to recover from as the system can easily create a version 0 from scratch and write it to disk. Because the system does not sync allocation of data pages, it is also possible at this point that whlie writing the version 0 to disk to create it we may encounter an out of disk space error (caught in this routine as a StandardException from the create() call. We can't recovery from this without help from outside, so the caught exception is nested and a new exception thrown which the recovery system will output to the user asking them to check their disk for space/errors.

      Specified by:
      reCreatePageForRedoRecovery in interface RawContainerHandle
      Throws:
      StandardException - Standard exception policy.

    • logCreateContainerInfo

      public ByteArray logCreateContainerInfo() throws StandardException
      Log all information necessary to recreate the container during a load tran.
      Specified by:
      logCreateContainerInfo in interface RawContainerHandle
      Throws:
      StandardException - Standard Derby error policy

    • makeRecordHandle

      public RecordHandle makeRecordHandle(long pageNumber, int recordId) throws StandardException
      Return a record handle that is initialized to the given page number and record id.
      Specified by:
      makeRecordHandle in interface ContainerHandle
      Parameters:
      pageNumber - the page number of the RecordHandle.
      recordId - the record id of the RecordHandle.
      Throws:
      StandardException - Standard Derby exception policy.
      See Also:

    • update

      public void update(DerbyObservable obj, Object arg)
      Called when the transaction is about to complete.
      Specified by:
      update in interface DerbyObserver
      Parameters:
      obj - The object which is being observed
      arg - Extra information being passed to the callback
      See Also:

    • getActionSet

      public PageActions getActionSet()

    • getAllocationActionSet

      public AllocationActions getAllocationActionSet()

    • useContainer

      public boolean useContainer(boolean droppedOK, boolean waitForLock) throws StandardException
      Attach me to a container. If this method returns false then I cannot be used anymore, and any reference to me must be discarded.
      Parameters:
      droppedOK - if true, use this container even if it is dropped, otherwise, return false if container is dropped.
      waitForLock - if true, wait on lock, otherwise, get lock no wait.
      Throws:
      StandardException - Standard Derby error policy

    • getTransaction

      public final RawTransaction getTransaction()
      Return the RawTransaction I was opened in.

    • getLockingPolicy

      public final LockingPolicy getLockingPolicy()
      Return my locking policy, may be different from the Transaction's default locking policy.
      Specified by:
      getLockingPolicy in interface ContainerHandle

    • setLockingPolicy

      public final void setLockingPolicy(LockingPolicy newLockingPolicy)
      Description copied from interface: ContainerHandle
      Set the locking policy for this open container
      Specified by:
      setLockingPolicy in interface ContainerHandle

    • updateOK

      public final boolean updateOK()
      Was I opened for updates?


      MT - thread safe

    • getMode

      public int getMode()
      Get the mode I was opened with.

    • preDirty

      public void preDirty(boolean preDirtyOn) throws StandardException
      The container is about to be modified. Loggable actions use this to make sure the container gets cleaned if a checkpoint is taken after any log record is sent to the log stream but before the container is actually dirtied.
      Specified by:
      preDirty in interface RawContainerHandle
      Throws:
      StandardException - Standard Derby error policy

    • isTemporaryContainer

      public boolean isTemporaryContainer() throws StandardException
      Description copied from interface: ContainerHandle
      Return true if this containerHandle refers to a temporary container.
      Specified by:
      isTemporaryContainer in interface ContainerHandle
      Throws:
      StandardException - Standard Derby error policy
      See Also:

    • checkOpen

      protected void checkOpen() throws StandardException
      Throws:
      StandardException

    • checkUpdateOpen

      private void checkUpdateOpen() throws StandardException
      Throws:
      StandardException

    • informObservers

      protected void informObservers()

    • getSpaceInfo

      public SpaceInfo getSpaceInfo() throws StandardException
      Get information about space used by the container.
      Specified by:
      getSpaceInfo in interface ContainerHandle
      Throws:
      StandardException

    • backupContainer

      public void backupContainer(String backupContainerPath) throws StandardException
      Backup the container to the specified path.
      Specified by:
      backupContainer in interface ContainerHandle
      Parameters:
      backupContainerPath - location of the backup container.
      Throws:
      StandardException - Standard Derby error policy

    • encryptOrDecryptContainer

      public void encryptOrDecryptContainer(String newFilePath, boolean doEncrypt) throws StandardException
      Creates an encrypted or decrypted version of the container.
      Specified by:
      encryptOrDecryptContainer in interface RawContainerHandle
      Parameters:
      newFilePath - file to store the new version of the container
      doEncrypt - tells whether to encrypt or decrypt
      Throws:
      StandardException - Standard Derby error policy

    • toString

      public String toString()
      Overrides:
      toString in class Object