Provided by: pcp_3.5.11_amd64
pmUnpackEventRecords - unpack event records
#include <pcp/pmapi.h> void pmUnpackEventRecords(pmValueSet *vsp, int idx, pmResult ***rap); cc ... -lpcp
Event records are encoded as a packed array of records within a pmResult using a container metric with a value of type PM_TYPE_EVENT. pmUnpackEventRecords may be used to unpack event records from a metric value identified by vsp and idx. If the metric has a singular value, idx should be 0, else the ordinal instance value identified by idx will be unpacked, i.e. vsp->vlist[idx]. The unpacked records are turned into pmResult structures, one per event record and one metic per event parameter, and rap is returned as a pointer to an array (NULL pointer terminated) of pointers to the pmResult structures. Some control information from the packed event records is unpacked into additional ``anonymous'' metrics as follows: 1. If the event record has a non-zero flags value, then the corresponding pmResult will have the flags value encoded with the additional metric event.flags that is inserted ahead of all other event parameters. 2. If the event record flag is set to PM_EVENT_FLAG_MISSED, then the corresponding pmResult will have one metric event.missed with a value that equals the number of event records ``missed'' because either the PMDA could not keep up, or the PMAPI client did not collect the event records fast enough. pmUnpackEventRecords returns the number of pmResult structures as the return value, which is >= 0 for success. rset and the associated pmResult structures may be freed using the convenience function pmFreeEventResult(3).
The following errors are possible: PM_ERR_CONV The values associated with vsp are not encoded using the format PM_VAL_DPTR or PM_VAL_SPTR, or the flags at the head of the event record has an unexpected value. PM_ERR_INST The value associated with vsp is not singular as expected. PM_ERR_TYPE vsp is not a value of type PM_TYPE_EVENT. PM_ERR_TOOSMALL The value identifed by vbp is not legal because the value length is less than the minimum size, or the number of event records encoded in the (value header) pmEventArray structure is negative, or the number of missed event records in the pmEventArray array is negative. PM_ERR_TOOBIG Either vsp indicates more than one value is present (all the event records are expected to be packed in a single metric value), or when unpacking the event records, the processing continues past the end of the enclosing value. Indicates corruption of the packed event record. PM_ERR_TYPE Event parameters must have one of the arithmetic types, else PM_TYPE_AGGREGATE, PM_TYPE_STRING or PM_TYPE_AGGREGATE_STATIC. other values < 0 refer to pmErrStr(3).
PMAPI(3) and pmFreeEventResult(3).