Hypertable::ScanBlock Class Reference

Encapsulates a block of scan results. More...

#include <ScanBlock.h>

Collaboration diagram for Hypertable::ScanBlock:

Public Types
typedef std::vector< std::pair < SerializedKey, ByteString > >	Vector

Public Member Functions
	ScanBlock ()
int	load (EventPtr &event)
	Loads scanblock data returned from RangeServer. More...
size_t	size ()
	Returns the number of key/value pairs in the scanblock. More...
void	reset ()
	Resets iterator to first key/value pair in the scanblock. More...
bool	next (SerializedKey &key, ByteString &value)
	Returns the next key/value pair in the scanblock. More...
bool	eos ()
	Returns true if this is the final scanblock returned by the scanner. More...
bool	more ()
	Indicates whether or not there are more key/value pairs in block. More...
size_t	memory_used () const
	Approximate estimate of memory used by scanblock (returns the size of the event payload) which contains most of the data. More...
int	get_scanner_id ()
	Returns scanner ID associated with this scanblock. More...
int	get_skipped_rows ()
	Returns number of skipped rows because of an OFFSET predicate. More...
int	get_skipped_cells ()
	Returns number of skipped rows because of a CELL_OFFSET predicate. More...
const ProfileDataScanner &	profile_data ()
	Returns reference to profile data. More...

Private Attributes
int	m_error {}
Vector	m_vec
Vector::iterator	m_iter
EventPtr	m_event
Lib::RangeServer::Response::Parameters::CreateScanner	m_response

Detailed Description

Encapsulates a block of scan results.

The CREATE_SCANNER and FETCH_SCANBLOCK RangeServer methods return a block of scan results and this class parses and provides easy access to the key/value pairs in that result.

Definition at line 50 of file ScanBlock.h.

Member Typedef Documentation

typedef std::vector< std::pair<SerializedKey, ByteString> > Hypertable::ScanBlock::Vector

Definition at line 53 of file ScanBlock.h.

Constructor & Destructor Documentation

ScanBlock::ScanBlock

(

)

Definition at line 41 of file ScanBlock.cc.

Member Function Documentation

bool Hypertable::ScanBlock::eos ( )

inline

Returns true if this is the final scanblock returned by the scanner.

Returns

true if this is the final scanblock, or false if more to come

Definition at line 85 of file ScanBlock.h.

int Hypertable::ScanBlock::get_scanner_id ( )

inline

Returns scanner ID associated with this scanblock.

Returns

scanner ID

Definition at line 109 of file ScanBlock.h.

int Hypertable::ScanBlock::get_skipped_cells ( )

inline

Returns number of skipped rows because of a CELL_OFFSET predicate.

Definition at line 115 of file ScanBlock.h.

int Hypertable::ScanBlock::get_skipped_rows ( )

inline

Returns number of skipped rows because of an OFFSET predicate.

Definition at line 112 of file ScanBlock.h.

int ScanBlock::load

(

EventPtr &

event

)

Loads scanblock data returned from RangeServer.

Both the CREATE_SCANNER and FETCH_SCANBLOCK methods return a block of key/value pairs.

Parameters

event

smart pointer to response MESSAGE event

Returns

Error::OK on success or error code on failure

Definition at line 46 of file ScanBlock.cc.

size_t Hypertable::ScanBlock::memory_used ( ) const

inline

Approximate estimate of memory used by scanblock (returns the size of the event payload) which contains most of the data.

Definition at line 100 of file ScanBlock.h.

bool Hypertable::ScanBlock::more ( )

inline

Indicates whether or not there are more key/value pairs in block.

Returns

ture if next will return more key/value pairs, false otherwise

Definition at line 90 of file ScanBlock.h.

bool ScanBlock::next	(	SerializedKey &	key,
		ByteString &	value
	)

Returns the next key/value pair in the scanblock.

NOTE: invoking the load method invalidates all pointers previously returned from this method.

Parameters

key	reference to return key pointer
value	reference to return value pointer

Returns

true if key/value returned, false if no more key/value pairs

Definition at line 84 of file ScanBlock.cc.

const ProfileDataScanner& Hypertable::ScanBlock::profile_data ( )

inline

Returns reference to profile data.

Returns

Reference to profile data

Definition at line 119 of file ScanBlock.h.

void Hypertable::ScanBlock::reset ( )

inline

Resets iterator to first key/value pair in the scanblock.

Definition at line 71 of file ScanBlock.h.

size_t Hypertable::ScanBlock::size ( )

inline

Returns the number of key/value pairs in the scanblock.

Returns

number of key/value pairs in the scanblock

Definition at line 68 of file ScanBlock.h.

Member Data Documentation

int Hypertable::ScanBlock::m_error {}

private

Definition at line 122 of file ScanBlock.h.

EventPtr Hypertable::ScanBlock::m_event

private

Definition at line 125 of file ScanBlock.h.

Vector::iterator Hypertable::ScanBlock::m_iter

private

Definition at line 124 of file ScanBlock.h.

Lib::RangeServer::Response::Parameters::CreateScanner Hypertable::ScanBlock::m_response

private

Definition at line 126 of file ScanBlock.h.

Vector Hypertable::ScanBlock::m_vec

private

Definition at line 123 of file ScanBlock.h.

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

• /home/doug/src/hypertable/src/cc/Hypertable/Lib/ScanBlock.h
• /home/doug/src/hypertable/src/cc/Hypertable/Lib/ScanBlock.cc