StatHist Class Reference

#include <StatHist.h>

Inheritance diagram for StatHist:

Collaboration diagram for StatHist:

Public Types
typedef uint64_t	bins_type

Public Member Functions
	StatHist ()=default
	StatHist (const StatHist &)
	~StatHist ()
StatHist &	operator= (const StatHist &)
double	deltaPctile (const StatHist &B, double pctile) const
double	val (unsigned int bin) const
void	count (double val)
void	dump (StoreEntry *sentry, StatHistBinDumper *bd) const
void	logInit (unsigned int capacity, double min, double max)
void	enumInit (unsigned int last_enum)
StatHist &	operator+= (const StatHist &B)

Protected Member Functions
void	init (unsigned int capacity, hbase_f *val_in, hbase_f *val_out, double min, double max)
unsigned int	findBin (double v)

Protected Attributes
bins_type *	bins = nullptr
	the histogram counters More...
unsigned int	capacity_ = 0
double	min_ = 0.0
	minimum value to be stored, corresponding to the first bin More...
double	max_ = 0.0
	value of the maximum counter in the histogram More...
double	scale_ = 1.0
	scaling factor when looking for a bin More...
hbase_f *	val_in = nullptr
hbase_f *	val_out = nullptr

Detailed Description

Generic histogram class

see important comments on hbase_f restrictions in StatHist.cc

Definition at line 25 of file StatHist.h.

Member Typedef Documentation

bins_type

typedef uint64_t StatHist::bins_type

Definition at line 44 of file StatHist.h.

Constructor & Destructor Documentation

StatHist() [1/2]

StatHist::StatHist ( )

default

Note

the default constructor doesn't fully initialize. you have to call one of the *init functions to specialize the histogram TODO: merge functionality from the *init functions to the constructor and drop these TODO: specialize the class in a small hierarchy so that all relevant initializations are done at build-time

StatHist() [2/2]

StatHist::StatHist

(

const StatHist &

src

)

Definition at line 39 of file StatHist.cc.

References bins, capacity_, and xcalloc().

~StatHist()

StatHist::~StatHist ( )

inline

Definition at line 39 of file StatHist.h.

References bins, capacity_, and xfree.

Member Function Documentation

count()

void StatHist::count

(

double

val

)

increment the counter for the histogram entry associated to the supplied value

Definition at line 55 of file StatHist.cc.

References bins, and findBin().

Referenced by CacheDigest::add(), clientUpdateHierCounters(), clientUpdateStatHistCounters(), comm_poll_dns_incoming(), comm_poll_tcp_incoming(), comm_poll_udp_incoming(), comm_select_dns_incoming(), comm_select_tcp_incoming(), comm_select_udp_incoming(), Comm::DoSelect(), fqdncacheHandleReply(), httpHdrCcUpdateStats(), icpCount(), ipcacheHandleReply(), recordMemBlobSizeAtDestruct(), recordSBufSizeAtDestruct(), TestStatHist::testStatHistBaseAssignment(), TestStatHist::testStatHistBaseEquality(), TestStatHist::testStatHistLog(), TestStatHist::testStatHistSum(), and HttpHdrScTarget::updateStats().

deltaPctile()

double StatHist::deltaPctile	(	const StatHist &	B,
		double	pctile
	)		const

Calculate the percentile for value pctile for the difference between this and the supplied histogram.

Definition at line 103 of file StatHist.cc.

References assert, B, bins, capacity_, D, int, s1, val(), xcalloc(), and xfree.

dump()

void StatHist::dump	(	StoreEntry *	sentry,
		StatHistBinDumper *	bd
	)		const

iterate the supplied bd function over the histogram values

Definition at line 171 of file StatHist.cc.

References assert, bins, capacity_, min_, statHistBinDumper, and val().

Referenced by commIncomingStats(), SBufStatsAction::dump(), httpHeaderStatDump(), and statCountersHistograms().

enumInit()

void StatHist::enumInit

(

unsigned int

last_enum

)

initialize the histogram to count occurrences in an enum-represented set

Definition at line 235 of file StatHist.cc.

References init(), and Math::Null.

Referenced by HttpHeaderStat::HttpHeaderStat(), TestStatHist::testStatHistBaseAssignment(), and TestStatHist::testStatHistBaseEquality().

findBin()

unsigned int StatHist::findBin ( double  v )

protected

find what entry in the histogram corresponds to v, by applying the preset input transformation function

Definition at line 64 of file StatHist.cc.

References capacity_, min_, scale_, and val_in.

Referenced by count(), and InspectingStatHist::counter().

init()

void StatHist::init ( unsigned int  capacity, hbase_f *  val_in, hbase_f *  val_out, double  min, double  max  )

protected

low-level initialize function. called by *Init high-level functions

Note

Important restrictions on val_in and val_out functions:

• val_in: ascending, defined on [0, oo), val_in(0) == 0;
• val_out: x == val_out(val_in(x)) where val_in(x) is defined

In practice, the requirements are less strict, but then it gets hard to define them without math notation. val_in is applied after offsetting the value but before scaling See log and linear based histograms for examples

Definition at line 26 of file StatHist.cc.

References assert, bins, capacity_, max_, min_, scale_, val_in, val_out, and xcalloc().

Referenced by enumInit(), and logInit().

logInit()

void StatHist::logInit	(	unsigned int	capacity,
		double	min,
		double	max
	)

Initialize the Histogram using a logarithmic values distribution

Definition at line 221 of file StatHist.cc.

References Math::Exp, init(), Math::Log, max(), and min().

Referenced by TestStatHist::testStatHistLog(), and TestStatHist::testStatHistSum().

operator+=()

StatHist & StatHist::operator+=

(

const StatHist &

B

)

Import values from another histogram

Note

: the two histograms MUST have the same capicity, min and max or an exception will be raised

Definition at line 187 of file StatHist.cc.

References B, bins, capacity_, max_, min_, and Must.

operator=()

StatHist & StatHist::operator= ( const StatHist &  src )

inline

Definition at line 122 of file StatHist.h.

References bins, capacity_, max_, min_, scale_, val_in, val_out, xcalloc(), and xfree.

val()

double StatHist::val

(

unsigned int

bin

)

const

obtain the output-transformed value from the specified bin

Definition at line 85 of file StatHist.cc.

References min_, scale_, and val_out.

Referenced by deltaPctile(), and dump().

Member Data Documentation

bins

bins_type* StatHist::bins = nullptr

protected

Definition at line 101 of file StatHist.h.

Referenced by StatHist(), ~StatHist(), count(), InspectingStatHist::counter(), deltaPctile(), dump(), init(), operator+=(), operator=(), and InspectingStatHist::operator==().

capacity_

unsigned int StatHist::capacity_ = 0

protected

Definition at line 102 of file StatHist.h.

Referenced by StatHist(), ~StatHist(), deltaPctile(), dump(), findBin(), init(), operator+=(), operator=(), and InspectingStatHist::operator==().

max_

double StatHist::max_ = 0.0

protected

Definition at line 108 of file StatHist.h.

Referenced by init(), operator+=(), operator=(), and InspectingStatHist::operator==().

min_

double StatHist::min_ = 0.0

protected

Definition at line 105 of file StatHist.h.

Referenced by dump(), findBin(), init(), operator+=(), operator=(), InspectingStatHist::operator==(), and val().

scale_

double StatHist::scale_ = 1.0

protected

Definition at line 111 of file StatHist.h.

Referenced by findBin(), init(), operator=(), InspectingStatHist::operator==(), and val().

val_in

hbase_f* StatHist::val_in = nullptr

protected

Definition at line 112 of file StatHist.h.

Referenced by findBin(), init(), operator=(), and InspectingStatHist::operator==().

val_out

hbase_f* StatHist::val_out = nullptr

protected

Definition at line 113 of file StatHist.h.

Referenced by init(), operator=(), InspectingStatHist::operator==(), and val().

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

• src/StatHist.h
• src/StatHist.cc
• src/tests/stub_StatHist.cc