pstsdk::data_block Class Reference

A block which represents end user data. More...

#include <node.h>

Inheritance diagram for pstsdk::data_block:

Collaboration diagram for pstsdk::data_block:

Public Member Functions
	data_block (const shared_db_ptr &db, const block_info &info, size_t total_size)
	Constructor for a data_block.
virtual	~data_block ()
size_t	read (std::vector< byte > &buffer, ulong offset) const
	Read data from this block.
template<typename T >
T	read (ulong offset) const
	Read data from this block.
virtual size_t	read_raw (byte *pdest_buffer, size_t size, ulong offset) const =0
	Read data from this block.
virtual uint	get_page_count () const =0
	Get the number of physical pages in this data_block.
virtual std::shared_ptr< external_block >	get_page (uint page_num) const =0
	Get a specific page of this data_block.
size_t	get_total_size () const
	Get the total logical size of this block.
Public Member Functions inherited from pstsdk::block
	block (const shared_db_ptr &db, const block_info &info)
	Basic block constructor.
virtual	~block ()
virtual bool	is_internal () const =0
	Returns the blocks internal/external state.
size_t	get_disk_size () const
	Get the last known size of this block on disk.
block_id	get_id () const
	Get the block_id of this block.
ulonglong	get_address () const
	Get the address of this block on disk.

Protected Attributes
size_t	m_total_size
	the total or logical size (sum of all external child blocks)
Protected Attributes inherited from pstsdk::block
bool	m_modified
	True if this block has been modified and needs to be saved.
size_t	m_size
	The size of this specific block on disk at last save.
block_id	m_id
	The id of this block.
ulonglong	m_address
	The address of this specific block on disk, 0 if unknown.
weak_db_ptr	m_db

Additional Inherited Members
Protected Member Functions inherited from pstsdk::block
shared_db_ptr	get_db_ptr () const
virtual void	trim ()

Detailed Description

A block which represents end user data.

This class is the base class of both extended_block and external_block. This base class exists to abstract away their differences, so a node can treat a given block (be it extended or external) simply as a stream of bytes.

Definition at line 550 of file node.h.

Constructor & Destructor Documentation

data_block()

pstsdk::data_block::data_block ( const shared_db_ptr &  db, const block_info &  info, size_t  total_size  )

inline

Constructor for a data_block.

Parameters

[in]	db	The database context
[in]	info	Information about this block
[in]	total_size	The total logical size of this block

Definition at line 557 of file node.h.

~data_block()

virtual pstsdk::data_block::~data_block ( )

inlinevirtual

Definition at line 559 of file node.h.

Member Function Documentation

get_page()

virtual std::shared_ptr< external_block > pstsdk::data_block::get_page ( uint  page_num ) const

pure virtual

Get a specific page of this data_block.

Note

In this context, "page" refers to an external_block

Exceptions

out_of_range

If page_num >= get_page_count()

Parameters

[in]

page_num

The ordinal of the external_block to get, zero based

Returns

The requested external_block

Implemented in pstsdk::extended_block, and pstsdk::external_block.

get_page_count()

virtual uint pstsdk::data_block::get_page_count ( ) const

pure virtual

Get the number of physical pages in this data_block.

Note

In this context, "page" refers to an external_block

Returns

The total number of external_blocks under this data_block

Implemented in pstsdk::extended_block, and pstsdk::external_block.

get_total_size()

size_t pstsdk::data_block::get_total_size ( ) const

inline

Get the total logical size of this block.

Returns

The total logical size of this block

Definition at line 605 of file node.h.

read() [1/2]

size_t pstsdk::data_block::read ( std::vector< byte > &  buffer, ulong  offset  ) const

inline

Read data from this block.

Fills the specified buffer with data starting at the specified offset. The size of the buffer indicates how much data to read.

Parameters

[in,out]	buffer	The buffer to fill
[in]	offset	The location to read from

Returns

The amount of data read

Definition at line 1060 of file node.h.

read() [2/2]

template<typename T >

T pstsdk::data_block::read ( ulong  offset ) const

inline

Read data from this block.

Returns a "T" located as the specified offset

Template Parameters

T	The type to read

Parameters

[in]

offset

The location to read from

Returns

The type read

Definition at line 1076 of file node.h.

read_raw()

virtual size_t pstsdk::data_block::read_raw ( byte *  pdest_buffer, size_t  size, ulong  offset  ) const

pure virtual

Read data from this block.

Parameters

[out]	pdest_buffer	The location to read the data into
[in]	size	The amount of data to read
[in]	offset	The location to read from

Returns

The amount of data read

Implemented in pstsdk::extended_block, and pstsdk::external_block.

Member Data Documentation

m_total_size

size_t pstsdk::data_block::m_total_size

protected

the total or logical size (sum of all external child blocks)

Definition at line 611 of file node.h.

---

The documentation for this class was generated from the following file:

• pstsdk/ndb/node.h