db/pg_probackup
db/pg_probackup
1
0
Fork 0
mirror of https://github.com/postgrespro/pg_probackup.git synced 2025-02-08 14:28:36 +02:00
Code Issues Releases Activity

PGPRO-2432: Improve reading of compressed WAL's if Postgrestries to read same record many times

Browse Source
This commit is contained in:
Arthur Zakirov 2019-02-11 15:16:59 +03:00
parent bed0a45121
commit 04a7d45647
1 changed files with 26 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

40
src/parsexlog.c
View File

@ -104,6 +104,9 @@ typedef struct XLogPageReadPrivate
#ifdef HAVE_LIBZ
gzFile gz_xlogfile;
char gz_xlogpath[MAXPGPATH];
char gz_buf[XLOG_BLCKSZ];
uint32 gz_prev_off;
#endif
} XLogPageReadPrivate;
@ -1057,22 +1060,30 @@ SimpleXLogPageRead(XLogReaderState *xlogreader, XLogRecPtr targetPagePtr,
#ifdef HAVE_LIBZ
else
{
if (gzseek(private_data->gz_xlogfile, (z_off_t) targetPageOff, SEEK_SET) == -1)
if (private_data->gz_prev_off != 0 &&
private_data->gz_prev_off == targetPageOff)
memcpy(readBuf, private_data->gz_buf, XLOG_BLCKSZ);
else
{
elog(WARNING, "Thread [%d]: Could not seek in compressed WAL segment \"%s\": %s",
private_data->thread_num,
private_data->gz_xlogpath,
get_gz_error(private_data->gz_xlogfile));
return -1;
}
if (gzseek(private_data->gz_xlogfile, (z_off_t) targetPageOff, SEEK_SET) == -1)
{
elog(WARNING, "Thread [%d]: Could not seek in compressed WAL segment \"%s\": %s",
private_data->thread_num,
private_data->gz_xlogpath,
get_gz_error(private_data->gz_xlogfile));
return -1;
}
if (gzread(private_data->gz_xlogfile, readBuf, XLOG_BLCKSZ) != XLOG_BLCKSZ)
{
elog(WARNING, "Thread [%d]: Could not read from compressed WAL segment \"%s\": %s",
private_data->thread_num,
private_data->gz_xlogpath,
get_gz_error(private_data->gz_xlogfile));
return -1;
if (gzread(private_data->gz_xlogfile, readBuf, XLOG_BLCKSZ) != XLOG_BLCKSZ)
{
elog(WARNING, "Thread [%d]: Could not read from compressed WAL segment \"%s\": %s",
private_data->thread_num,
private_data->gz_xlogpath,
get_gz_error(private_data->gz_xlogfile));
return -1;
}
private_data->gz_prev_off = targetPageOff;
memcpy(private_data->gz_buf, readBuf, XLOG_BLCKSZ);
}
}
#endif
@ -1131,6 +1142,7 @@ CleanupXLogPageRead(XLogReaderState *xlogreader)
{
gzclose(private_data->gz_xlogfile);
private_data->gz_xlogfile = NULL;
private_data->gz_prev_off = 0;
}
#endif
private_data->xlogexists = false;