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=head1 NAME |
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|
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AnyEvent::DBI::Slave - implement AnyEvent::DBI child/server processes |
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|
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=head1 SYNOPSIS |
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|
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# this module is normally loaded automatically |
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|
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=head1 DESCRIPTION |
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|
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This module contains the code that implements the DBI server part of |
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C<AnyEvent::DBI>. It is normally loaded automatically into each child |
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process, but can be loaded explicitly to save memory or startup time |
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(search for C<AnyEvent::DBI::Slave> in the L<AnyEvent::DBI> manpage). |
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|
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=cut |
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|
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package AnyEvent::DBI::Slave; |
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|
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use common::sense; |
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|
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use DBI (); |
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use Convert::Scalar (); |
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use CBOR::XS (); |
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use AnyEvent (); |
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|
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our $VERSION = '3.0'; |
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|
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# this is the forked server code, could/should be bundled as it's own file |
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|
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our $DBH; |
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our $STH; |
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|
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sub req_pid { |
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[1, $$] |
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} |
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|
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sub req_open { |
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my (undef, $dbi, $user, $pass, %attr) = @{+shift}; |
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|
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$DBH = DBI->connect ($dbi, $user, $pass, \%attr) or die $DBI::errstr; |
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|
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[1, 1] |
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} |
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|
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sub req_attr { |
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my (undef, $attr_name, @attr_val) = @{+shift}; |
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|
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$DBH->{$attr_name} = $attr_val[0] |
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if @attr_val; |
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|
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[1, $DBH->{$attr_name}] |
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} |
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|
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sub req_exec { |
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my (undef, $st, @args) = @{+shift}; |
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$STH = $DBH->prepare_cached ($st, undef, 1) |
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or die [$DBI::errstr]; |
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|
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my $rv = $STH->execute (@args) |
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or die [$STH->errstr]; |
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|
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[1, $STH->{NUM_OF_FIELDS} ? $STH->fetchall_arrayref : undef, $rv] |
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} |
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|
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sub req_stattr { |
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my (undef, $attr_name) = @{+shift}; |
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|
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[1, $STH->{$attr_name}] |
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} |
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|
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sub req_begin_work { |
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[1, $DBH->begin_work || die [$DBI::errstr]] |
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} |
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|
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sub req_commit { |
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[1, $DBH->commit || die [$DBI::errstr]] |
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} |
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|
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sub req_rollback { |
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[1, $DBH->rollback || die [$DBI::errstr]] |
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} |
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|
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sub req_func { |
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my (undef, $arg_string, $function) = @{+shift}; |
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my @args = eval $arg_string; |
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|
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die "error evaling \$dbh->func() arg_string: $@" |
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if $@; |
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|
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my $rc = $DBH->func (@args, $function); |
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return [1, $rc, $DBI::err, $DBI::errstr]; |
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} |
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|
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sub serve($$) { |
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my ($fork_fh, $version, $fh) = @_; |
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|
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$0 = "dbi slave"; |
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|
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close $fork_fh; |
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|
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if ($VERSION != $version) { |
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Convert::Scalar::write_all $fh, CBOR::XS::encode_cbor |
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[undef, "AnyEvent::DBI version mismatch ($VERSION vs. $version)"]; |
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return; |
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} |
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|
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eval { |
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my $cbor = new CBOR::XS; |
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my $rbuf; |
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|
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while (Convert::Scalar::extend_read $fh, $rbuf, 16000) { |
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for my $req ($cbor->incr_parse_multiple ($rbuf)) { |
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my $wbuf = eval { CBOR::XS::encode_cbor $req->[0]($req) }; |
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$wbuf = CBOR::XS::encode_cbor [undef, ref $@ ? ("$@->[0]", $@->[1]) : ("$@", 1)] |
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if $@; |
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|
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Convert::Scalar::write_all $fh, $wbuf |
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or die "unable to write results"; |
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} |
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} |
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}; |
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} |
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|
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=head1 SEE ALSO |
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|
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L<AnyEvent::DBI>. |
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|
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=head1 AUTHOR AND CONTACT |
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|
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Marc Lehmann <schmorp@schmorp.de> (current maintainer) |
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http://home.schmorp.de/ |
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|
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Adam Rosenstein <adam@redcondor.com> |
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http://www.redcondor.com/ |
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|
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=cut |
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|
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1 |
