pmprintvalue(3) [centos man page]

PMPRINTVALUE(3) 					     Library Functions Manual						   PMPRINTVALUE(3)

NAME

       pmPrintValue - print a performance metric value

C SYNOPSIS

       #include <stdio.h>
       #include <pcp/pmapi.h>

       void pmPrintValue(FILE *f, int valfmt, int type, const pmValue *val, int minwidth);

       cc ... -lpcp

DESCRIPTION

       The value of a single performance metric (as identified by val) is printed on the standard I/O stream identified by f.

       The value of the performance metric is interpreted according to the format of val as defined by valfmt (from a pmValueSet within a pmResult
       structure; see pmFetch(3)) and the generic description of the metrics type passed in via type.

       The value for type is typically extracted from a pmDesc structure, following a call to pmLookupDesc(3) for a particular performance metric.

       The output will be optionally padded to be at least minwidth characters wide.

       pmPrintValue is most useful for displaying values of performance metrics from pmFetch(3) (which returns a set of valfmt and val	pairs  for
       each requested metric), based upon the metrics type as returned from pmLookupDesc(3).

SEE ALSO

       PMAPI(3), pmAtomStr(3), pmConvScale(3), pmExtractValue(3), pmFetch(3), pmLookupDesc(3), pmTypeStr(3) and pmUnitsStr(3).

Performance Co-Pilot							PCP							   PMPRINTVALUE(3)

PMCONVSCALE(3)						     Library Functions Manual						    PMCONVSCALE(3)

NAME

       pmConvScale - rescale a performance metric value

C SYNOPSIS

       #include <pcp/pmapi.h>

       int pmConvScale(int type, const pmAtomValue *ival, const pmUnits *iunit, pmAtomValue *oval, const pmUnits *ounit);

       cc ... -lpcp

DESCRIPTION

       All performance metric values may be encoded in a pmAtomValue union, defined as follows;

	    typedef union {
		__int32_t    l;     /* 32-bit signed */
		__uint32_t   ul;    /* 32-bit unsigned */
		__int64_t    ll;    /* 64-bit signed */
		__uint64_t   ull;   /* 64-bit unsigned */
		float	     f;     /* 32-bit floating point */
		double	     d;     /* 64-bit floating point */
		char	     *cp;   /* char ptr */
		pmValueBlock *vbp;  /* pmValueBlock ptr */
	    } pmAtomValue;

       The encoding of a performance metric's dimensionality and scale uses a pmUnits structure; see pmLookupDesc(3).

       Given  a  performance  metric value pointed to by ival multiply it by a scale factor and return the value in oval.  The scaling takes place
       from the units defined by iunit into the units defined by ounit.  Both input and output units must have the same dimensionality.

       The performance metric type for both input and output values is determined by type, the value for which is typically extracted from a pmDe-
       sc structure, following a call to pmLookupDesc(3) for a particular performance metric.

       pmConvScale is most useful when values returned via pmFetch(3), (and possibly extracted using pmExtractValue(3)) need to be normalized into
       some canonical scale and units for the purposes of computation.

       As a special case, if all components of the dimension are zero, then this is treated as synonymous with a ``count'' dimension of  one,  and
       so  the ``count'' scale components determine the relative scaling.  This accommodates the case where performance metrics are dimensionless,
       without special case handling on the part of the caller.

SEE ALSO

       PMAPI(3), pmAtomStr(3), pmExtractValue(3), pmFetch(3), pmLookupDesc(3), pmPrintValue(3), pmTypeStr(3) and pmUnitsStr(3).

DIAGNOSTICS

       PM_ERR_CONV

	      iunit and ounit have different dimensionality, or have inappropriate type

       PM_ERR_UNIT

	      Inappropriate iunit or ounit parameter

Performance Co-Pilot							PCP							    PMCONVSCALE(3)