анализировать аргументы командной строки временного окна (parse time window command line arguments)
Имя (Name)
pmParseTimeWindow - parse time window command line arguments
Синопсис C (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
Описание (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).
Использование (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 set of PCP archive logs 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 defined (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 pmParseTimeWindow. See pmUseZone(3) and friends for
information on how this is done.
Диагностика (Diagnostic)
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 set of PCP archive logs 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 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
returns -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).
Смотри также (See also)
free(3), PMAPI(3), pmGetArchiveEnd(3), pmGetArchiveLabel(3),
pmNewContextZone(3), pmNewZone(3), pmParseInterval(3) and
pmUseZone(3).
