src/app/netcache/nc_utils.hpp File Reference

#include <corelib/ncbidiag.hpp>
#include <corelib/request_ctx.hpp>
#include <corelib/ncbistr.hpp>
#include <corelib/ncbitime.hpp>
#include <corelib/ncbimtx.hpp>
#include <corelib/ncbithr.hpp>

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Classes
class	CQuickStrStream
	Stream-like class to accumulate all in one string without actual streams-related overhead. More...
class	CPrintTextProxy
	Stream-like class to help unify printing some text messages to diagnostics and to any iostream. More...
class	CNCStatFigure< T >
	Class representing one statistical value. More...
class	CNCBGThread< Functor >
	Thread running background task. More...
class	CNCMethodWrap< Executor >
	Special wrapper for object's method that can be used as functor, e.g. More...
class	CNCBitMaskBase< num_elems >
	Base class for bit masks of any size. More...
class	CNCBitMaskBase< 1 >
	Optimized specialization of bit mask that fits entirely in 1 element of type TNCBitMaskElem. More...
class	CNCBitMaskBase< 2 >
	Optimized specialization of bit mask that fits entirely in 2 elements of type TNCBitMaskElem. More...
class	CNCBitMask< num_bits >
	Class for working with bit masks containing given number of bits. More...
class	CNCTlsObject< Derived, ObjType >
	Base class for the object specific for each thread. More...
struct	SNCFastMutex
	Special equivalent of SSystemFastMutex that exposes necessary method to public. More...
Defines
#define	NCTlsGet   pthread_getspecific
#define	NCTlsSet   pthread_setspecific
#define	NCTlsFree   pthread_key_delete
#define	NCTlsCreate(key, destr)   pthread_key_create(&key, destr)
	Special define for creation of the TLS key.
Typedefs
typedef size_t	TNCBitMaskElem
	Type to use for bit masks.
typedef pthread_key_t	TNCTlsKey
	Synonyms for TLS-related functions on different platforms.
typedef unsigned int	TNCThreadIndex
	Type for index of the current thread.
Functions
CNcbiOstream &	operator<< (CNcbiOstream &stream, const CQuickStrStream &str)
	Additional overloaded operator to allow automatic transformation of CQuickStrStream to string when outputting to any standard stream.
template<class Functor>
CNCBGThread< Functor > *	NewBGThread (Functor functor)
	Convenient function creating new background thread for given functor.
template<class Executor>
CNCBGThread< CNCMethodWrap< Executor > > *	NewBGThread (Executor *executor, void(Executor::*method)(void))
	Convenient function creating new background thread for given executor object and given method in it.
void	g_InitNCThreadIndexes (void)
	Initialize system that will acquire thread indexes for each thread.
TNCThreadIndex	g_GetNCThreadIndex (void)
	Get index of the current thread.
template<class TLeft, class TRight>
TLeft	g_SafeDiv (TLeft left, TRight right)
	Utility function to safely do division even if divisor is 0.
unsigned int	g_GetLogBase2 (size_t value)
	Get integer part of the logarithm with base 2.
unsigned int	g_GetLeastSetBit (size_t value)
	Get number of least bit set.
unsigned int	g_GetBitsCnt (size_t value)
	Get number of bits set.
Variables
static const unsigned int	kNCMaxThreadsCnt = 25
	Maximum number of threads when NetCache will most effectively avoid contention between threads for some internal data structures.
static const unsigned int	kNCMaskElemSize = SIZEOF_SIZE_T * 8
	Number of bits in one element of type TNCBitMaskElem.

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Define Documentation

#define NCTlsCreate (  key, destr   )     pthread_key_create(&key, destr)

Special define for creation of the TLS key. Parameter 'key' must be a variable. Definition at line 377 of file nc_utils.hpp. Referenced by g_InitNCThreadIndexes(), and CNCTlsObject< Derived, ObjType >::Initialize().

#define NCTlsFree   pthread_key_delete

Definition at line 374 of file nc_utils.hpp. Referenced by CNCTlsObject< Derived, ObjType >::Finalize().

#define NCTlsGet   pthread_getspecific

Definition at line 372 of file nc_utils.hpp. Referenced by g_GetNCThreadIndex(), and CNCTlsObject< Derived, ObjType >::GetObjPtr().

#define NCTlsSet   pthread_setspecific

Definition at line 373 of file nc_utils.hpp. Referenced by g_GetNCThreadIndex(), and CNCTlsObject< Derived, ObjType >::GetObjPtr().

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Typedef Documentation

typedef size_t TNCBitMaskElem

Type to use for bit masks. Definition at line 254 of file nc_utils.hpp.

typedef unsigned int TNCThreadIndex

Type for index of the current thread. See also: g_GetNCThreadIndex Definition at line 382 of file nc_utils.hpp.

typedef pthread_key_t TNCTlsKey

Synonyms for TLS-related functions on different platforms. Definition at line 371 of file nc_utils.hpp.

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Function Documentation

unsigned int g_GetBitsCnt (  size_t  value  )  [inline]

Get number of bits set. Implementation uses minimum number of operations without using additional variables or memory. Trick was taken from http://graphics.stanford.edu/~seander/bithacks.html#CountBitsSetParallel. Definition at line 508 of file nc_utils.hpp. Referenced by CNCBitMaskBase< 2 >::GetCntSet(), CNCBitMaskBase< 1 >::GetCntSet(), and CNCBitMaskBase< num_elems >::GetCntSet().

unsigned int g_GetLeastSetBit (  size_t  value  )  [inline]

Get number of least bit set. For instance for the binary number 10010100 it will return 2. Definition at line 495 of file nc_utils.hpp. References g_GetLogBase2(). Referenced by CNCBitMaskBase< 2 >::GetClosestSet(), and CNCBitMaskBase< 1 >::GetClosestSet().

unsigned int g_GetLogBase2 (  size_t  value  )  [inline]

Get integer part of the logarithm with base 2. In other words function returns index of the greatest bit set when bits are indexed from lowest to highest starting with 0 (e.g. for binary number 10010001 it will return 7). Definition at line 462 of file nc_utils.hpp. Referenced by g_GetLeastSetBit(), and CNCDBStat::x_GetSizeIndex().

TNCThreadIndex g_GetNCThreadIndex (  void   )

Get index of the current thread. All threads are indexed with incrementing numbers starting from 1. Thread is indexed only when this function is called and if it wasn't indexed yet. Definition at line 51 of file nc_utils.cpp. References CAtomicCounter::Add(), NCTlsGet, NCTlsSet, s_NCThreadIndexKey, and s_NextThreadIndex. Referenced by CNCDBStat::CreateTlsObject(), CNCMMStats_Getter::CreateTlsObject(), CNCMMChunksPool_Getter::CreateTlsObject(), CNCMMChainsPool_Getter::CreateTlsObject(), CNCMMSizePool_Getter::CreateTlsObject(), and CNCServerStat_Getter::CreateTlsObject().

void g_InitNCThreadIndexes (  void   )

Initialize system that will acquire thread indexes for each thread. This function must be called before g_GetNCThreadIndex() is used. Definition at line 44 of file nc_utils.cpp. References NCTlsCreate, s_NCThreadIndexKey, s_NextThreadIndex, and CAtomicCounter::Set().

template<class TLeft, class TRight> TLeft g_SafeDiv (  TLeft  left, TRight  right )

Utility function to safely do division even if divisor is 0. Definition at line 452 of file nc_utils.hpp.

template<class Executor> CNCBGThread< CNCMethodWrap< Executor > > * NewBGThread (  Executor *  executor, void(Executor::*)(void)  method )  [inline]

Convenient function creating new background thread for given executor object and given method in it. Convenience is in automatic instantiation based on parameter value so that you don't need to state template parameters for CNCBGThread and CNCMethodWrap. Definition at line 801 of file nc_utils.hpp.

template<class Functor> CNCBGThread< Functor > * NewBGThread (  Functor  functor  )  [inline]

Convenient function creating new background thread for given functor. Convenience is in automatic instantiation based on parameter value so that you don't need to state template parameter for CNCBGThread. Definition at line 794 of file nc_utils.hpp. Referenced by CNCFileSystem::Initialize(), and CNCMMCentral::RunLateInit().

CNcbiOstream & operator<< (  CNcbiOstream &  stream, const CQuickStrStream &  str )  [inline]

Additional overloaded operator to allow automatic transformation of CQuickStrStream to string when outputting to any standard stream. Definition at line 640 of file nc_utils.hpp.

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Variable Documentation

const unsigned int kNCMaskElemSize = SIZEOF_SIZE_T * 8 [static]

Number of bits in one element of type TNCBitMaskElem. Definition at line 256 of file nc_utils.hpp.

const unsigned int kNCMaxThreadsCnt = 25 [static]

Maximum number of threads when NetCache will most effectively avoid contention between threads for some internal data structures. This constant was made different from kNCMMMaxThreadsCnt (though with similar meaning) because in memory manager changing in number of threads can result in pretty significant change in memory consumption when in all other parts of NetCache it's not so significant. So this constant is much more flexible for changes than kNCMMMaxThreadsCnt. Definition at line 53 of file nc_utils.hpp. Referenced by CNCServerStat_Getter::CreateTlsObject(), CNCDBStat::CreateTlsObject(), CNCServerStat::Print(), and CNCDBStat::Print().

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