Uses of Class
edu.caltech.nanodb.storage.DBPage

Packages that use DBPage

Package	Description
edu.caltech.nanodb.storage	This package contains the classes for the Storage Manager, which is responsible for how data is stored in and retrieved from database files.
edu.caltech.nanodb.storage.heapfile	This package provides a naive implementation of the heap file organization for NanoDB.
edu.caltech.nanodb.storage.writeahead	This package contains the implementation for the write-ahead log, which allows us to provide transaction atomicity, consistency and durability.
edu.caltech.nanodb.transactions	This package contains classes for managing transactions at the logical level, such as concurrency control and isolation, deadlock detection and aborting transactions.

Uses of DBPage in edu.caltech.nanodb.storage

Fields in edu.caltech.nanodb.storage declared as DBPage

Modifier and Type	Field	Description
(package private) DBPage	BufferManager.SessionPinCount.dbPage	The page that is pinned.
protected DBPage	DBFileReader.dbPage	The last page used for reading the database file.
protected DBPage	PageReader.dbPage	The page that the reader will read from.
private DBPage	PageTuple.dbPage	The database page that contains the tuple's data.

Fields in edu.caltech.nanodb.storage with type parameters of type DBPage

Modifier and Type	Field	Description
private java.util.LinkedHashMap<BufferManager.CachedPageInfo,DBPage>	BufferManager.cachedPages	This collection holds database pages (not WAL pages) that the database is currently working with, so that they don't continually need to be reloaded.

Methods in edu.caltech.nanodb.storage that return DBPage

Modifier and Type	Method	Description
DBPage	PageReader.getDBPage()
DBPage	PageTuple.getDBPage()
DBPage	BufferManager.getPage(DBFile dbFile, int pageNo, boolean create)	Retrieves the specified DBPage from the Buffer Manager if it's currently buffered, or null if the page is not currently buffered.
DBPage	StorageManager.loadDBPage(DBFile dbFile, int pageNo)	This method returns a database page to use, retrieving it from the buffer manager if it is already loaded, or reading it from the specified data file if it is not already loaded.
DBPage	StorageManager.loadDBPage(DBFile dbFile, int pageNo, boolean create)	This method returns a database page to use, retrieving it from the buffer manager if it is already loaded, or reading it from the specified data file if it is not already loaded.

Methods in edu.caltech.nanodb.storage with parameters of type DBPage

Modifier and Type	Method	Description
void	StorageManager.logDBPageWrite(DBPage dbPage)	This method causes any changes to the specified page to be logged by the transaction manager's write-ahead log, so that the changes can be redone or undone as may be appropriate.
void	BufferManager.recordPageInvalidated(DBPage dbPage)
void	BufferManager.recordPagePinned(DBPage dbPage)	Records that the page was pinned by the current session.
void	BufferManager.recordPageUnpinned(DBPage dbPage)	Records that the page was unpinned by the current session.
static void	PageTuple.setNullFlag(DBPage dbPage, int tupleStart, int colIndex, boolean value)	This is a helper function to set or clear the value of a column's NULL flag.
static int	PageTuple.storeTuple(DBPage dbPage, int pageOffset, Schema schema, Tuple tuple)
static int	PageTuple.writeNonNullValue(DBPage dbPage, int offset, ColumnType colType, java.lang.Object value)	This helper function is used by the PageTuple.setColumnValue(int, java.lang.Object) method in the specific case when a column is being set to a non-NULL value.

Method parameters in edu.caltech.nanodb.storage with type arguments of type DBPage

Modifier and Type	Method	Description
void	BufferManagerObserver.beforeWriteDirtyPages(java.util.List<DBPage> pages)	This method is called before the buffer manager writes the specified collection of pages.
private void	BufferManager.writeDirtyPages(java.util.List<DBPage> dirtyPages, boolean invalidate)	This helper method writes out a list of dirty pages from the buffer manager, ensuring that if transactions are enabled, the write-ahead-logging rule is satisfied.

Constructors in edu.caltech.nanodb.storage with parameters of type DBPage

Constructor	Description
DBPageID(DBPage dbPage)
PageReader(DBPage dbPage)
PageTuple(DBPage dbPage, int pageOffset, Schema schema)	Construct a new tuple object that is backed by the data in the database page.
PageWriter(DBPage dbPage)
SessionPinCount(DBPage dbPage)

Uses of DBPage in edu.caltech.nanodb.storage.heapfile

Methods in edu.caltech.nanodb.storage.heapfile with parameters of type DBPage

Modifier and Type	Method	Description
static int	DataPage.allocNewTuple(DBPage dbPage, int len)	Update the data page so that it has space for a new tuple of the specified size.
static void	DataPage.deleteTuple(DBPage dbPage, int slot)	Deletes the tuple at the specified slot from the data page.
static void	DataPage.deleteTupleDataRange(DBPage dbPage, int off, int len)	This static helper function removes a sequence of bytes from the current tuple data in the page, sliding tuple data below the offset forward to fill in the gap.
static int	DataPage.getFreeSpaceInPage(DBPage dbPage)	This static helper function returns the amount of free space in a tuple data page.
static int	DataPage.getNumSlots(DBPage dbPage)	Returns the number of slots in this data page.
static int	HeaderPage.getSchemaSize(DBPage dbPage)	Returns the number of bytes that the table's schema occupies for storage in the header page.
static int	DataPage.getSlotIndexFromOffset(DBPage dbPage, int offset)
static int	DataPage.getSlotsEndIndex(DBPage dbPage)	This static helper function returns the index where the slot list ends in the data page.
static int	DataPage.getSlotValue(DBPage dbPage, int slot)	This static helper function returns the value stored in the specified slot.
static int	HeaderPage.getStatsOffset(DBPage dbPage)	Returns the offset in the header page that the table statistics start at.
static int	HeaderPage.getStatsSize(DBPage dbPage)	Returns the number of bytes that the table's statistics occupy for storage in the header page.
static int	DataPage.getTupleDataEnd(DBPage dbPage)	This static helper function returns the index of where tuple data currently ends in the specified data page.
static int	DataPage.getTupleDataStart(DBPage dbPage)	This static helper function returns the index of where tuple data currently starts in the specified data page.
static int	DataPage.getTupleLength(DBPage dbPage, int slot)	Returns the length of the tuple stored at the specified slot.
static void	DataPage.initNewPage(DBPage dbPage)	Initialize a newly allocated data page.
static void	DataPage.insertTupleDataRange(DBPage dbPage, int off, int len)	This static helper function creates a space in the data page of the specified size, sliding tuple data below the offset down to create a gap.
static void	DataPage.sanityCheck(DBPage dbPage)	This static helper method verifies that the specified data page has proper structure and organization by performing various sanity checks.
static void	DataPage.setNumSlots(DBPage dbPage, int numSlots)	Sets the number of slots in this data page.
static void	HeaderPage.setSchemaSize(DBPage dbPage, int numBytes)	Sets the number of bytes that the table's schema occupies for storage in the header page.
static void	DataPage.setSlotValue(DBPage dbPage, int slot, int value)	This static helper function sets the value for the specified slot.
static void	HeaderPage.setStatsSize(DBPage dbPage, int numBytes)	Sets the number of bytes that the table's statistics occupy for storage in the header page.
static HeapFilePageTuple	HeapFilePageTuple.storeNewTuple(Schema schema, DBPage dbPage, int slot, int pageOffset, Tuple tuple)
private static void	HeaderPage.verifyIsHeaderPage(DBPage dbPage)	This helper method simply verifies that the data page provided to the HeaderPage class is in fact a header-page (i.e.

Constructors in edu.caltech.nanodb.storage.heapfile with parameters of type DBPage

Constructor	Description
HeapFilePageTuple(Schema schema, DBPage dbPage, int slot, int pageOffset)	Construct a new tuple object that is backed by the data in the database page.

Uses of DBPage in edu.caltech.nanodb.storage.writeahead

Methods in edu.caltech.nanodb.storage.writeahead with parameters of type DBPage

Modifier and Type	Method	Description
private void	WALManager.applyRedo(WALRecordType type, DBFileReader walReader, DBPage dbPage, int numSegments)	This helper function writes a sequence of redo-segments from an WALRecordType.UPDATE_PAGE or WALRecordType.UPDATE_PAGE_REDO_ONLY record.
private byte[]	WALManager.applyUndoAndGenRedoOnlyData(DBFileReader walReader, DBPage dbPage, int numSegments)	This helper method uses a WALRecordType.UPDATE_PAGE record to undo changes to a data page, and at the same time the method generates the data that must go into a corresponding redo-only WAL record.
private LogSequenceNumber	WALManager.writeRedoOnlyUpdatePageRecord(int transactionID, LogSequenceNumber prevLSN, DBPage dbPage, int numSegments, byte[] changes)	This method writes a redo-only update-page record to the write-ahead log, including only redo details.
private LogSequenceNumber	WALManager.writeRedoOnlyUpdatePageRecord(DBPage dbPage, int numSegments, byte[] changes)	This method writes a redo-only update-page record to the write-ahead log, including only redo details.
void	WALManager.writeUpdatePageRecord(DBPage dbPage)	This method writes an update-page record to the write-ahead log, including both undo and redo details.

Uses of DBPage in edu.caltech.nanodb.transactions

Fields in edu.caltech.nanodb.transactions declared as DBPage

Modifier and Type	Field	Description
private DBPage	TransactionStatePage.dbPage

Methods in edu.caltech.nanodb.transactions with parameters of type DBPage

Modifier and Type	Method	Description
void	TransactionManager.recordPageUpdate(DBPage dbPage)

Method parameters in edu.caltech.nanodb.transactions with type arguments of type DBPage

Modifier and Type	Method	Description
void	TransactionManager.beforeWriteDirtyPages(java.util.List<DBPage> pages)	This method is registered on the BufferManager, to ensure that the write-ahead logging rule is enforced.

Constructors in edu.caltech.nanodb.transactions with parameters of type DBPage

Constructor	Description
TransactionStatePage(DBPage dbPage)