преобразовать значение метрики производительности в строку (convert a performance metric value into a string)
Дубль
(статьи:
pmatomstr - преобразовать значение метрики производительности в строку )
Имя (Name)
pmAtomStr, pmAtomStr_r - convert a performance metric value into
a string
Синопсис C (C Synopsis)
#include <pcp/pmapi.h>
const char *pmAtomStr(const pmAtomValue *avp, int type);
char *pmAtomStr_r(const pmAtomValue *avp, int type, char *buf,
int buflen);
cc ... -lpcp
Описание (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;
Given the performance metric value pointed to by avp, and a
performance metric type defined by type, pmAtomStr will generate
the corresponding metric value as a string, suitable for
diagnostic or report output. The pmAtomStr_r function does the
same, but stores the result in a user-supplied buffer buf of
length buflen, which should have room for at least 80 bytes.
The value for type is typically extracted from a pmDesc
structure, following a call to pmLookupDesc(3) for a particular
performance metric.
If the type is PM_TYPE_STRING values longer than 38 characters
will be truncated after 34 characters, and truncation shown with
ellipsis ``...'' at the end of the value.
If the type is PM_TYPE_AGGREGATE then up to the first three
32-bit words are displayed as hexadecimal values.
If the type is PM_TYPE_EVENT then a summary of the number of
event records found in the value is generated.
The return value from pmAtomStr is held in a single static
buffer, so the returned value is only valid until the next call
to pmAtomStr.
Примечание (Note)
pmAtomStr returns a pointer to a static buffer and hence is not
thread-safe. Multi-threaded applications should use pmAtomStr_r
instead.
Смотри также (See also)
PMAPI(3), pmConvScale(3), pmExtractValue(3), pmLookupDesc(3),
pmPrintValue(3), pmTypeStr(3) and pmUnitsStr(3).
