PMPARSETIMEWINDOW(3) Library Functions Manual PMPARSETIMEWINDOW(3)
NAME
pmParseTimeWindow - 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);
cc ... -lpcp
DESCRIPTION
pmParseTimeWindow is 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 expects 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 PCP archive log as the source of performance metrics, you also need to supply the time of the first archive
log entry as logStart, and the time of the last archive log entry as logEnd. See pmGetArchiveLabel(3) and pmGetArchiveEnd(3) for how to
obtain values for these times.
If the application is manipulating multiple concurrent archive logs, then the caller must resolve how the default time window is to be de-
fined (the union of the time intervals in all archive logs 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 INT_MAX.
The rsltStart, rsltEnd and rsltOffset structures must be allocated before calling pmParseTimeWindow.
You also need to set the current PCP reporting time zone to correctly reflect the -z and -Z command line parameters before calling pmParse-
TimeWindow. See pmUseZone(3) and friends for information on how this is done.
SEE ALSO
PMAPI(3), pmGetArchiveEnd(3), pmGetArchiveLabel(3), pmNewContextZone(3), pmNewZone(3), pmParseInterval(3) and pmUseZone(3).
DIAGNOSTICS
If the conversion is successful, pmParseTimeWindow returns 1 and fills 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 pmParseTimeWindow returns 1.
If the conversion is successful, but the requested alignment could not be performed (e.g. the PCP archive log is too short) the alignment
is ignored, rsltStart, rsltEnd and rsltOffset are filled in and pmParseTimeWindow returns 0. In this case, errMsg will point to a warning
message in an internal static buffer. This buffer should not be freed.
If the argument strings could not be parsed, pmParseTimeWindow returns -1. In this case, errMsg will point to an error message in a static
internal buffer.
Performance Co-Pilot PCP PMPARSETIMEWINDOW(3)