File Coverage

blib/script/narada-mysqldump

Criterion	Covered	Total	%
statement	83	222	37.3
branch	0	52	0.0
condition	0	18	0.0
subroutine	28	42	66.6
pod			n/a
total	111	334	33.2

#!/usr/bin/env perl
use 5.010001;
use warnings;
use strict;
use utf8;

our $VERSION = 'v2.3.6';

use FindBin;
use lib "$FindBin::Bin/../lib/perl5";
use Narada;
use Narada::Lock qw( exclusive_lock unlock_new unlock );;
use Narada::Config qw( get_config get_config_line get_db_config );
use DBI;
use Time::Local;
use List::Util qw( max );
use File::Temp qw( tempfile );
use Fcntl qw(F_SETFD);

use constant IS_NARADA      => Narada::detect() eq 'narada';
use constant CONFIG_DIR     => IS_NARADA ? 'mysql'      : 'db';
use constant SQL_DIR        => IS_NARADA ? 'var/mysql'  : 'var/sql';
use constant SCHEME         => SQL_DIR.'/db.scheme.sql';
use constant REQUIRED_TABLE => 0;
use constant OPTIONAL_TABLE => 1;
use constant TIMELOCAL_MONTH=> 4;
use constant STAT_MTIME     => 9;
use constant DESC_FIELD     => 0;
use constant DESC_TYPE      => 1;
use constant DESC_NULL      => 2;
use constant DESC_KEY       => 3;
use constant DESC_DEFAULT   => 4;
use constant DESC_EXTRA     => 5;

# GLOBALS:  $::dbh, $::mycnf, $::MYSQLDUMP


main(@ARGV) if !caller;


sub err { die "narada-mysqldump: @_\n" }

sub main {
    die "Usage: narada-mysqldump\n" if @_;

    init_globals() or return;

    exclusive_lock();
    unlock_new();

    my ($full, $incremental, $ignore) = list_tables();
    my $unchanged = detect_unchanged($full);

    del_dumps_except($incremental, $unchanged);
    dump_scheme_except($ignore);
    dump_full($full, $unchanged);
    dump_incremental($incremental);

    # To correctly detect_unchanged() we should guarantee next table's
    # Update_time after executing narada-mysqldump will be at least 1
    # second later than previous (which kept in dump file's mtime).
    sleep 1;

    unlock();

    return;
}

sub init_globals {
    my $db = get_db_config() or return;
    $::dbh = DBI->connect($db->{dsn}, $db->{login}, $db->{pass},
        {RaiseError=>1}) or err DBI->errstr;
    $::mycnf = tempfile(DIR=>'tmp');
    print {$::mycnf} "[client]\n";
    print {$::mycnf} "user     = $db->{login}\n";
    print {$::mycnf} "password = $db->{pass}\n"  if length $db->{pass}; ## no critic (ProhibitPostfixControls)
    print {$::mycnf} "host     = $db->{host}\n"  if length $db->{host}; ## no critic (ProhibitPostfixControls)
    print {$::mycnf} "port     = $db->{port}\n"  if length $db->{port}; ## no critic (ProhibitPostfixControls)
    $::mycnf->flush;
    sysseek $::mycnf, 0, 0 or err "sysseek: $!";
    fcntl $::mycnf, F_SETFD, 0 or err "fcntl: $!";
    my $fd = fileno $::mycnf;
    $::MYSQLDUMP = "mysqldump --defaults-file=/proc/self/fd/\Q$fd\E \Q$db->{db}\E";
    return 1;
}

sub list_tables {
    my $incremental = load_db_conf('dump/incremental', REQUIRED_TABLE);
    my $empty       = load_db_conf('dump/empty', REQUIRED_TABLE);
    my $ignore      = load_db_conf('dump/ignore', OPTIONAL_TABLE);
    my %other = map {$_=>1} @{$incremental}, @{$empty}, @{$ignore};
    my @full;
    for my $table (@{ $::dbh->selectcol_arrayref('SHOW TABLES') }) {
        next if $other{$table};
        push @full, $table;
    }
    return ([sort @full], $incremental, $ignore);
}

sub load_db_conf {
    my ($conf, $required) = @_;
    my @conf = eval { split /\s*\n/xms, get_config(CONFIG_DIR."/$conf") };
    my @tables;
    for my $table (@conf) {
        local ($::dbh->{RaiseError}, $::dbh->{PrintError});
        my $desc = $::dbh->selectall_arrayref('DESC '.$table);
        if ($desc) {
            push @tables, $table;
        }
        elsif ($required == REQUIRED_TABLE) {
            err "Table $table listed in ".CONFIG_DIR."/$conf does not exists\n";
        }
    }
    return [sort @tables];
}

sub detect_unchanged {
    my ($full) = @_;
    my @unchanged;
    for my $table (@{$full}) {
        my $file = SQL_DIR."/$table.sql";
        if (-f $file && mtime($file) == get_table_status($table, 'Update_time')) {
            push @unchanged, $table;
        }
    }
    return \@unchanged;
}

sub del_dumps_except {
    my ($incremental, $unchanged) = @_;
    my %incremental = map {$_=>1} @{$incremental};
    my %unchanged   = map {$_=>1} @{$unchanged};
    for my $file (glob SQL_DIR.'/*.sql') {
        if ($file =~ m{\A\Q${\SQL_DIR}\E/([^.]*)[.]sql\z}xms) {
            my $table = $1;
            next if $unchanged{$table};
        }
        elsif ($file =~ m{\A\Q${\SQL_DIR}\E/([^.]*)[.]\d+-(\d+)[.]sql\z}xms) {
            my $table = $1;
            next if $incremental{$table}
                && mtime($file) >= get_table_status($table, 'Create_time');
        }
        unlink $file or err "unlink($file): $!\n";
    }
    return;
}

sub dump_scheme_except {
    my ($ignore) = @_;
    my $db = get_config_line(CONFIG_DIR.'/db');
    my $tables = join q{ }, map {"--ignore-table=\Q$db\E.\Q$_\E"} @{$ignore};
    mysqldump("--opt -d $tables", SCHEME, time);
    return;
}

sub dump_full {
    my ($full, $unchanged) = @_;
    my %unchanged = map {$_=>1} @{$unchanged};
    for my $table (@{$full}) {
        next if $unchanged{$table};
        my $file = SQL_DIR."/$table.sql";
        my $t = get_table_status($table, 'Update_time');
        mysqldump("--opt -t \Q$table\E", $file, $t);
    }
    return;
}

sub dump_incremental {
    my ($incremental) = @_;
    for my $table (@{$incremental}) {
        my $key  = get_key($table);
        my $prev = max(0, map {m/-(\d+)[.]sql\z/xms} glob SQL_DIR."/\Q$table\E.*.sql");
        my $next = get_table_status($table, 'Auto_increment');
        if ($prev < $next-1) {
            my $from = $prev+1;
            my $to   = $next-1;
            my $file = SQL_DIR."/$table.$from-$to.sql";
            my $where= "$key>=$from AND $key<=$to";
            my $t    = get_table_status($table, 'Update_time');
            mysqldump("--opt -t -w \Q$where\E \Q$table\E", $file, $t);
        }
    }
    return;
}

###

sub get_table_status {
    my ($table, $field) = @_;
    my $val = $::dbh->selectrow_hashref('SHOW TABLE STATUS LIKE ?',
        undef, $table)->{$field};
    if ($field =~ /_time\z/xms) {
        if (!defined $val) {
            $val = 0;
        }
        else {
            my @datetime = reverse split /\D+/xms, $val;
            $datetime[TIMELOCAL_MONTH]--;
            $val = timelocal(@datetime);
        }
    }
    return $val;
}

sub get_key {
    my ($table) = @_;
    my $desc = $::dbh->selectall_arrayref('DESC '.$table);
    err "First field in table $table must be: INT AUTO_INCREMENT PRIMARY KEY\n"
        if !(@{ $desc }
        && $desc->[0][DESC_TYPE]=~/\A\w*int\b/xms
        && $desc->[0][DESC_KEY] eq 'PRI'
        && $desc->[0][DESC_EXTRA] eq 'auto_increment'
        && 1 == grep {$_->[DESC_KEY] eq 'PRI'} @{$desc});
    return $desc->[0][DESC_FIELD];
}

sub mtime {
    my ($file) = @_;
    return (stat $file)[STAT_MTIME];
}

sub mysqldump {
    my ($opt, $file, $t) = @_;
    system("$::MYSQLDUMP $opt > \Q$file\E.tmp")
        == 0 or err "system($::MYSQLDUMP $opt > $file.tmp): $?";
    rename "$file.tmp", $file       or err "rename($file.tmp, $file): $!";
    utime $t, $t, $file             or err "utime($file): $!";
    return;
}


1; # Magic true value required at end of module
__END__