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NAME | C SYNOPSIS | DESCRIPTION | DIAGNOSTICS | PCP ENVIRONMENT | SEE ALSO | COLOPHON |
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PMGETARCHIVEEND(3) Library Functions Manual PMGETARCHIVEEND(3)
pmGetArchiveEnd, pmGetHighResArchiveEnd - locate logical end of
file for a set of archives
#include <pcp/pmapi.h>
int pmGetArchiveEnd(struct timeval *tp);
int pmGetHighResArchiveEnd(struct timespec *tp);
cc ... -lpcp
Assuming the current PMAPI context is associated with a set of
archives, pmGetArchiveEnd and pmGetHighResArchiveEnd will attempt
to find the logical end of file (after the last complete record
in the set of archives), and return the last recorded timestamp
via tp. This timestamp may be passed to pmSetMode(3) or
pmSetModeHighRes(3) to reliably position the context at the last
valid archive record, e.g. in preparation for subsequent reading
in reverse chronological order.
For archives that are not concurrently being written, the
physical end of file and the logical end of file are co-incident.
However if an archive is being written by pmlogger(1) at the same
time an application is trying to read the archive, the logical
end of file may be before the physical end of file due to write
buffering that is not aligned with the logical record boundaries.
pmGetArchiveEnd and pmGetHighResArchiveEnd return an error less
than zero if the context is neither valid, nor associated with a
set of archives, or the set of archives is seriously corrupted.
Otherwise, the return value is 0 if there has been no change of
state since the last call, or 1 if the logical end of file has
advanced since the last call.
In the absence of an error, the result returned via tp is well-
defined.
Both pmGetArchiveEnd and pmGetHighResArchiveEnd preserve the
positioning state of the archive file prior to this function
call.
PM_ERR_NOCONTEXT
the current PMAPI context is either invalid, or not
associated with a set of archives
PM_ERR_LOGREC
the set of archives is sufficiently damaged, that not a
single valid record can be found
Environment variables with the prefix PCP_ are used to
parameterize the file and directory names used by PCP. On each
installation, the file /etc/pcp.conf contains the local values
for these variables. The $PCP_CONF variable may be used to
specify an alternative configuration file, as described in
pcp.conf(5). Values for these variables may be obtained
programmatically using the pmGetConfig(3) function.
PMAPI(3), pmFetch(3), pmFetchArchive(3), pmFetchHighRes(3),
pmFetchHighResArchive(3), pmGetArchiveLabel(3), pmGetConfig(3),
pmGetHighResArchiveLabel(3), pmSetMode(3), pmSetModeHighRes(3),
pcp.conf(5) and pcp.env(5).
This page is part of the PCP (Performance Co-Pilot) project.
Information about the project can be found at
⟨http://www.pcp.io/⟩. If you have a bug report for this manual
page, send it to [email protected]. This page was obtained from the
project's upstream Git repository
⟨https://github.com/performancecopilot/pcp.git⟩ on 2024-06-14.
(At that time, the date of the most recent commit that was found
in the repository was 2024-06-14.) If you discover any rendering
problems in this HTML version of the page, or you believe there
is a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
[email protected]
Performance Co-Pilot PCP PMGETARCHIVEEND(3)
Pages that refer to this page: __pmparsetime(3), pmparsetimewindow(3)
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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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