pmarewritemeta(3) — Linux manual page

PMAREWRITEMETA(3)       Library Functions Manual       PMAREWRITEMETA(3)

NAME

       pmaRewriteMeta - try to change the version of an archive metadata
       record

C SYNOPSIS

       #include <pcp/pmapi.h>
       #include <pcp/libpcp.h>
       #include <pcp/archive.h>

       int pmaRewriteMeta(__pmLogCtl *inlcp, __pmLogCtl *outlcp,
       __int32_t *rbuf);

       cc ... -lpcp_archive -lpcp

CAVEAT

       This documentation is intended for internal Performance Co-Pilot
       (PCP) developer use.

       These interfaces are not part of the PCP APIs that are guaranteed
       to remain fixed across releases, and they may not work, or may
       provide different semantics at some point in the future.

DESCRIPTION

       A physical metadata record from the input archive identified by
       inlcp is passed in via rbuf and this is reformatted if required
       to produce the equivalent metadata record for the output archive
       identified by outlcp.

       Combined with the input and output archive versions, the type of
       the metadata record (as extracted from rbuf) is used to decide
       if; for some record types and version changes no rewriting is
       required.

       pmaRewriteMeta is intended to be used in cases where the archive
       version of inlcp and outlcp are different.  The only sane choice
       of archive versions today is PM_LOG_VERS02 for inlcp and
       PM_LOG_VERS03 for outlcp, which would be requesting a rewrite
       from archive version 2 format to archive version 3 format (as
       only versions 2 and 3 are currently supported).

       If rewriting takes place the old rbuf will have been free'd and a
       new rbuf allocated with malloc(3).  It is the caller's
       responsibility to make sure this potential free-and-allocate will
       be safe, e.g. no dangling references into the contents of rbuf,
       or pass in a copy of the record if it is precious.

DIAGNOSTICS AND RETURN VALUES

       In several places, fatal errors will trigger an error message and
       force the application to exit.

       If there is no defined translation for the versions of inlcp and
       outlcp then pmaRewriteMeta returns PM_ERR_APPVERSION (a slight
       perversion of this error code).

       If no rewrite is performed, the return value is 0, otherwise a
       return value of 1 indicates a rewrite has taken place and rbuf
       has been reallocated.

SEE ALSO

       free(3), malloc(3), PMAPI(3), and pmaRewriteData(3).

COLOPHON

       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 pcp@groups.io.  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
       man-pages@man7.org

Performance Co-Pilot               PCP                 PMAREWRITEMETA(3)

Pages that refer to this page: pmarewritedata(3)

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