postgresql/src/include/catalog/reformat_dat_file.pl

313 lines
8.4 KiB
Perl
Executable File

#!/usr/bin/perl
#----------------------------------------------------------------------
#
# reformat_dat_file.pl
# Perl script that reads in catalog data file(s) and writes out
# functionally equivalent file(s) in a standard format.
#
# In each entry of a reformatted file, metadata fields (if present)
# come first, with normal attributes starting on the following line,
# in the same order as the columns of the corresponding catalog.
# Comments and blank lines are preserved.
#
# Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
# Portions Copyright (c) 1994, Regents of the University of California
#
# src/include/catalog/reformat_dat_file.pl
#
#----------------------------------------------------------------------
use strict;
use warnings FATAL => 'all';
use FindBin;
use Getopt::Long;
# If you copy this script to somewhere other than src/include/catalog,
# you'll need to modify this "use lib" or provide a suitable -I switch.
use lib "$FindBin::RealBin/../../backend/catalog/";
use Catalog;
# Names of the metadata fields of a catalog entry.
# Note: oid is a normal column from a storage perspective, but it's more
# important than the rest, so it's listed first among the metadata fields.
# Note: line_number is also a metadata field, but we never write it out,
# so it's not listed here.
my @METADATA =
('oid', 'oid_symbol', 'array_type_oid', 'descr', 'autogenerated');
# Process command line switches.
my $output_path = '';
my $full_tuples = 0;
GetOptions(
'output=s' => \$output_path,
'full-tuples' => \$full_tuples) || usage();
# Sanity check arguments.
die "No input files.\n" unless @ARGV;
# Make sure output_path ends in a slash.
if ($output_path ne '' && substr($output_path, -1) ne '/')
{
$output_path .= '/';
}
# Read all the input files into internal data structures.
# We pass data file names as arguments and then look for matching
# headers to parse the schema from.
my %catalogs;
my %catalog_data;
my @catnames;
foreach my $datfile (@ARGV)
{
$datfile =~ /(.+)\.dat$/
or die "Input files need to be data (.dat) files.\n";
my $header = "$1.h";
die "There in no header file corresponding to $datfile"
if !-e $header;
my $catalog = Catalog::ParseHeader($header);
my $catname = $catalog->{catname};
my $schema = $catalog->{columns};
push @catnames, $catname;
$catalogs{$catname} = $catalog;
$catalog_data{$catname} = Catalog::ParseData($datfile, $schema, 1);
}
########################################################################
# At this point, we have read all the data. If you are modifying this
# script for bulk editing, this is a good place to build lookup tables,
# if you need to. In the following example, the "next if !ref $row"
# check below is a hack to filter out non-hash objects. This is because
# we build the lookup tables from data that we read using the
# "preserve_formatting" parameter.
#
##Index access method lookup.
#my %amnames;
#foreach my $row (@{ $catalog_data{pg_am} })
#{
# next if !ref $row;
# $amnames{$row->{oid}} = $row->{amname};
#}
########################################################################
# Write the data.
foreach my $catname (@catnames)
{
my $catalog = $catalogs{$catname};
my @attnames;
my $schema = $catalog->{columns};
foreach my $column (@$schema)
{
my $attname = $column->{name};
# We may have ordinary columns at the storage level that we still
# want to format as a special value. Exclude these from the column
# list so they are not written twice.
push @attnames, $attname
if !(grep { $_ eq $attname } @METADATA);
}
# Write output files to specified directory.
my $datfile = "$output_path$catname.dat";
open my $dat, '>', $datfile
or die "can't open $datfile: $!";
foreach my $data (@{ $catalog_data{$catname} })
{
# Hash ref representing a data entry.
if (ref $data eq 'HASH')
{
my %values = %$data;
############################################################
# At this point we have the full tuple in memory as a hash
# and can do any operations we want. As written, it only
# removes default values, but this script can be adapted to
# do one-off bulk-editing.
############################################################
if (!$full_tuples)
{
# If it's an autogenerated entry, drop it completely.
next if $values{autogenerated};
# Else, just drop any default/computed fields.
strip_default_values(\%values, $schema, $catname);
}
print $dat "{";
# Separate out metadata fields for readability.
my $metadata_str = format_hash(\%values, @METADATA);
if ($metadata_str)
{
print $dat $metadata_str;
# User attributes start on next line.
print $dat ",\n ";
}
my $data_str = format_hash(\%values, @attnames);
print $dat $data_str;
print $dat " },\n";
}
# Preserve blank lines.
elsif ($data =~ /^\s*$/)
{
print $dat "\n";
}
# Preserve comments or brackets that are on their own line.
elsif ($data =~ /^\s*(\[|\]|#.*?)\s*$/)
{
print $dat "$1\n";
}
}
close $dat;
}
# Remove column values for which there is a matching default,
# or if the value can be computed from other columns.
sub strip_default_values
{
my ($row, $schema, $catname) = @_;
# Delete values that match defaults.
foreach my $column (@$schema)
{
my $attname = $column->{name};
# It's okay if we have no oid value, since it will be assigned
# automatically before bootstrap.
die "strip_default_values: $catname.$attname undefined\n"
if !defined $row->{$attname} and $attname ne 'oid';
if (defined $column->{default}
and ($row->{$attname} eq $column->{default}))
{
delete $row->{$attname};
}
}
# Delete computed values. See AddDefaultValues() in Catalog.pm.
# Note: This must be done after deleting values matching defaults.
if ($catname eq 'pg_proc')
{
delete $row->{pronargs} if defined $row->{proargtypes};
}
# If a pg_type entry has an auto-generated array type, then its
# typarray field is a computed value too (see GenerateArrayTypes).
if ($catname eq 'pg_type')
{
delete $row->{typarray} if defined $row->{array_type_oid};
}
return;
}
# Format the individual elements of a Perl hash into a valid string
# representation. We do this ourselves, rather than use native Perl
# facilities, so we can keep control over the exact formatting of the
# data files.
sub format_hash
{
my $data = shift;
my @orig_attnames = @_;
# Copy attname to new array if it has a value, so we can determine
# the last populated element. We do this because we may have default
# values or empty metadata fields.
my @attnames;
foreach my $orig_attname (@orig_attnames)
{
push @attnames, $orig_attname
if defined $data->{$orig_attname};
}
# When calling this function, we ether have an open-bracket or a
# leading space already.
my $char_count = 1;
my $threshold;
my $hash_str = '';
my $element_count = 0;
foreach my $attname (@attnames)
{
$element_count++;
# To limit the line to 80 chars, we need to account for the
# trailing characters.
if ($element_count == $#attnames + 1)
{
# Last element, so allow space for ' },'
$threshold = 77;
}
else
{
# Just need space for trailing comma
$threshold = 79;
}
if ($element_count > 1)
{
$hash_str .= ',';
$char_count++;
}
my $value = $data->{$attname};
# Escape single quotes.
$value =~ s/'/\\'/g;
# Include a leading space in the key-value pair, since this will
# always go after either a comma or an additional padding space on
# the next line.
my $element = " $attname => '$value'";
my $element_length = length($element);
# If adding the element to the current line would expand the line
# beyond 80 chars, put it on the next line. We don't do this for
# the first element, since that would create a blank line.
if ($element_count > 1 and $char_count + $element_length > $threshold)
{
# Put on next line with an additional space preceding. There
# are now two spaces in front of the key-value pair, lining
# it up with the line above it.
$hash_str .= "\n $element";
$char_count = $element_length + 1;
}
else
{
$hash_str .= $element;
$char_count += $element_length;
}
}
return $hash_str;
}
sub usage
{
die <<EOM;
Usage: reformat_dat_file.pl [options] datafile...
Options:
--output PATH output directory (default '.')
--full-tuples write out full tuples, including default values
Non-option arguments are the names of input .dat files.
Updated files are written to the output directory,
possibly overwriting the input files.
EOM
}