diff options
Diffstat (limited to 'src/test/perl/PostgreSQL/Test/Cluster.pm')
| -rw-r--r-- | src/test/perl/PostgreSQL/Test/Cluster.pm | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/src/test/perl/PostgreSQL/Test/Cluster.pm b/src/test/perl/PostgreSQL/Test/Cluster.pm index ad9eba8a3b5..50ccc0a1cb8 100644 --- a/src/test/perl/PostgreSQL/Test/Cluster.pm +++ b/src/test/perl/PostgreSQL/Test/Cluster.pm @@ -2608,6 +2608,154 @@ sub lsn =pod +=item $node->write_wal($tli, $lsn, $segment_size, $data) + +Write some arbitrary data in WAL for the given segment at $lsn (in bytes). +This should be called while the cluster is not running. + +Returns the path of the WAL segment written to. + +=cut + +sub write_wal +{ + my ($self, $tli, $lsn, $segment_size, $data) = @_; + + # Calculate segment number and offset position in segment based on the + # input LSN. + my $segment = $lsn / $segment_size; + my $offset = $lsn % $segment_size; + my $path = + sprintf("%s/pg_wal/%08X%08X%08X", $self->data_dir, $tli, 0, $segment); + + open my $fh, "+<:raw", $path or die "could not open WAL segment $path"; + seek($fh, $offset, SEEK_SET) or die "could not seek WAL segment $path"; + print $fh $data; + close $fh; + + return $path; +} + +=pod + +=item $node->emit_wal($size) + +Emit a WAL record of arbitrary size, using pg_logical_emit_message(). + +Returns the end LSN of the record inserted, in bytes. + +=cut + +sub emit_wal +{ + my ($self, $size) = @_; + + return int( + $self->safe_psql( + 'postgres', + "SELECT pg_logical_emit_message(true, '', repeat('a', $size)) - '0/0'" + )); +} + + +# Private routine returning the current insert LSN of a node, in bytes. +# Used by the routines below in charge of advancing WAL to arbitrary +# positions. The insert LSN is returned in bytes. +sub _get_insert_lsn +{ + my ($self) = @_; + return int( + $self->safe_psql( + 'postgres', "SELECT pg_current_wal_insert_lsn() - '0/0'")); +} + +=pod + +=item $node->advance_wal_out_of_record_splitting_zone($wal_block_size) + +Advance WAL at the end of a page, making sure that we are far away enough +from the end of a page that we could insert a couple of small records. + +This inserts a few records of a fixed size, until the threshold gets close +enough to the end of the WAL page inserting records to. + +Returns the end LSN up to which WAL has advanced, in bytes. + +=cut + +sub advance_wal_out_of_record_splitting_zone +{ + my ($self, $wal_block_size) = @_; + + my $page_threshold = $wal_block_size / 4; + my $end_lsn = $self->_get_insert_lsn(); + my $page_offset = $end_lsn % $wal_block_size; + while ($page_offset >= $wal_block_size - $page_threshold) + { + $self->emit_wal($page_threshold); + $end_lsn = $self->_get_insert_lsn(); + $page_offset = $end_lsn % $wal_block_size; + } + return $end_lsn; +} + +=pod + +=item $node->advance_wal_to_record_splitting_zone($wal_block_size) + +Advance WAL so close to the end of a page that an XLogRecordHeader would not +fit on it. + +Returns the end LSN up to which WAL has advanced, in bytes. + +=cut + +sub advance_wal_to_record_splitting_zone +{ + my ($self, $wal_block_size) = @_; + + # Size of record header. + my $RECORD_HEADER_SIZE = 24; + + my $end_lsn = $self->_get_insert_lsn(); + my $page_offset = $end_lsn % $wal_block_size; + + # Get fairly close to the end of a page in big steps + while ($page_offset <= $wal_block_size - 512) + { + $self->emit_wal($wal_block_size - $page_offset - 256); + $end_lsn = $self->_get_insert_lsn(); + $page_offset = $end_lsn % $wal_block_size; + } + + # Calibrate our message size so that we can get closer 8 bytes at + # a time. + my $message_size = $wal_block_size - 80; + while ($page_offset <= $wal_block_size - $RECORD_HEADER_SIZE) + { + $self->emit_wal($message_size); + $end_lsn = $self->_get_insert_lsn(); + + my $old_offset = $page_offset; + $page_offset = $end_lsn % $wal_block_size; + + # Adjust the message size until it causes 8 bytes changes in + # offset, enough to be able to split a record header. + my $delta = $page_offset - $old_offset; + if ($delta > 8) + { + $message_size -= 8; + } + elsif ($delta <= 0) + { + $message_size += 8; + } + } + return $end_lsn; +} + +=pod + =item $node->wait_for_catchup(standby_name, mode, target_lsn) Wait for the replication connection with application_name standby_name until |