t_digest.h File Reference

The declarations in this header file correspond to the definitions in t_digest.c. More...

#include <stdbool.h>
#include "configuration.h"
#include "cdi_logger_api.h"

Go to the source code of this file.

Macros
#define	MAX_MERGED_CLUSTERS   (200)
	The maximum number of clusters allowed in a fully-merged digest.
#define	MAX_UNMERGED_CLUSTERS   (50)
	The maximum number of clusters allowed in the incoming sample buffer (i.e unmerged clusters).
#define	MAX_CLUSTERS   (MAX_MERGED_CLUSTERS + MAX_UNMERGED_CLUSTERS)
	The maximum number of clusters allowed in this algorithm. This determines how many cluster structrues are preallocated when the digest is created.
#define	TDIGEST_LOG_THREAD(log_level, ...)
	Macro to allow t-Digest logging to be turned on or off via define DEBUG_T_DIGEST_LOGGING.

Typedefs
typedef struct TDigest *	TDigestHandle
	Opaque pointer for TDigest structure.

Functions
bool	TDigestCreate (TDigestHandle *ret_td_handle_ptr)
	Function used to create a new t-digest.
void	TDigestDestroy (TDigestHandle td_handle)
	Function used to free t-digest memory.
void	TDigestClear (TDigestHandle td_handle)
	Function used to reset t-digest to begin collecting a new set of statistics. This function initializes all the TDigest data members.
void	TDigestAddSample (TDigestHandle td_handle, uint32_t value)
	Function used to create a new t-digest.
bool	TDigestGetPercentileValue (TDigestHandle td_handle, int percentile, uint32_t *value_at_percentile_ptr)
	Function used to get the value at a given percentile.
int	TDigestGetCount (TDigestHandle td_handle)
	Function used to get the number of samples in the digest.

Detailed Description

The declarations in this header file correspond to the definitions in t_digest.c.

Function Documentation

TDigestAddSample()

void TDigestAddSample	(	TDigestHandle	td_handle,
		uint32_t	value )

Function used to create a new t-digest.

Parameters

td_handle	Handle for the TDigest object to use.
value	The value of the new sample to add to the digest.

TDigestClear()

void TDigestClear

(

TDigestHandle

td_handle

)

Function used to reset t-digest to begin collecting a new set of statistics. This function initializes all the TDigest data members.

Parameters

td_handle

Handle for the TDigest object to use.

TDigestCreate()

bool TDigestCreate

(

TDigestHandle *

ret_td_handle_ptr

)

Function used to create a new t-digest.

Parameters

ret_td_handle_ptr

Pointer for the handle for the new TDigest object.

Returns

True if successful; false if not.

TDigestDestroy()

void TDigestDestroy

(

TDigestHandle

td_handle

)

Function used to free t-digest memory.

Parameters

td_handle

Handle for the TDigest object to use.

TDigestGetCount()

int TDigestGetCount

(

TDigestHandle

td_handle

)

Function used to get the number of samples in the digest.

Parameters

td_handle

Handle for the TDigest object to use.

Returns

The number of samples in the digest.

TDigestGetPercentileValue()

bool TDigestGetPercentileValue	(	TDigestHandle	td_handle,
		int	percentile,
		uint32_t *	value_at_percentile_ptr )

Function used to get the value at a given percentile.

Parameters

td_handle	Handle for the TDigest object to use.
percentile	The desired percentile between 0 and 1, inclusive.
value_at_percentile_ptr	Pointer to the return value where resulting value of percentile search is stored.

Returns

True if successful; false if not.