oracular (3) pmParseHighResTimeWindow.3.gz

NAME

       pmParseTimeWindow, pmParseHighResTimeWindow - parse time window command line arguments

C SYNOPSIS

       #include <pcp/pmapi.h>

       int pmParseTimeWindow(const char *swStart, const char *swEnd, const char *swAlign, const char *swOffset,
               const struct timeval *logStart, const struct timeval *logEnd, struct timeval *rsltStart,
               struct timeval *rsltEnd, struct timeval *rsltOffset, char **errMsg);
       int pmParseHighResTimeWindow(const char *swStart, const char *swEnd, const char *swAlign,
               const char *swOffset, const struct timespec *logStart, const struct timespec *logEnd,
               struct timespec *rsltStart, struct timespec *rsltEnd, struct timespec *rsltOffset,
               char **errMsg);

       cc ... -lpcp

DESCRIPTION

       pmParseTimeWindow and pmParseHighResTimeWindow are designed to encapsulate the interpretation of the  -S,
       -T,  -A  and  -O  command  line  options used by Performance Co-Pilot (PCP) applications to define a time
       window of interest.  The time window is defined by a start time and an end time that constrains the  time
       interval  during which the PCP application will retrieve and display performance metrics.  In the absence
       of the -O and -A options to specify an initial sample time origin and time alignment (see below), the PCP
       application will retrieve the first sample at the start of the time window.

       The syntax and meaning of the various argument formats for these options is described in PCPIntro(1).

USAGE

       pmParseTimeWindow  and pmParseHighResTimeWindow expect to be called with the argument of the -S option as
       swStart, the argument of the -T option as swEnd, the argument of  the  -A  option  as  swAlign,  and  the
       argument  of  the -O option as swOffset.  Any or all of these parameters may be NULL to indicate that the
       corresponding command line option was not present.

       If the application is using a set of PCP archives as the source of performance metrics, you also need  to
       supply the time of the first archive entry as logStart, and the time of the last archive entry as logEnd.
       See pmGetArchiveLabel(3) and pmGetArchiveEnd(3) for how to obtain values for these times.

       If the application is manipulating multiple concurrent archives, then the caller  must  resolve  how  the
       default  time  window  is  to  be  defined  (the  union of the time intervals in all archives is a likely
       interpretation).

       If the application is using a live feed of performance data, logStart should be  the  current  time  (but
       could  be  aligned  on the next second for example), while logEnd should have its tv_sec component set to
       PM_MAX_TIME_T.

       The rsltStart, rsltEnd and rsltOffset structures must be allocated before  calling  pmParseTimeWindow  or
       pmParseHighResTimeWindow.

       You  also need to set the current PCP reporting time zone to correctly reflect the -z and -Z command line
       parameters before calling these routines.  See pmUseZone(3) and friends for information on  how  this  is
       done.

DIAGNOSTICS

       If  the  conversion  is  successful,  pmParseTimeWindow and pmParseHighResTimeWindow return 1 and fill in
       rsltStart, rsltEnd and rsltOffset with the start, end, and offset times for the time  window  defined  by
       the   input   parameters.   The  errMsg  parameter  is  not  changed  when  either  pmParseTimeWindow  or
       pmParseHighResTimeWindow returns 1.

       If the conversion is successful, but the requested alignment could not be performed (e.g. the set of  PCP
       archives  is  too  short)  the  alignment is ignored, rsltStart, rsltEnd and rsltOffset are filled in and
       pmParseTimeWindow and pmParseHighResTimeWindow return 0.  In this case, errMsg will point  to  a  warning
       message in a dynamically allocated buffer.  The caller is responsible for releasing the buffer by calling
       free(3).

       If the argument strings could not be parsed, pmParseTimeWindow and  pmParseHighResTimeWindow  return  -1.
       In  this  case,  errMsg  will point to an error message in a dynamically allocated buffer.  The caller is
       responsible for releasing the buffer by calling free(3).

SEE ALSO

       free(3),   PMAPI(3),   pmGetArchiveEnd(3),   pmGetArchiveLabel(3),   pmNewContextZone(3),   pmNewZone(3),
       pmParseInterval(3) and pmUseZone(3).