Author: timbo
Date: Fri Apr 13 05:41:48 2007
New Revision: 9406
Modified:
dbi/trunk/lib/DBI/Gofer/Execute.pm
Log:
Add forced_single_resultset, max_cached_sth_per_dbh and max_cached_dbh_per_drh
to gofer executor config.
Rename check_connect to check_request.
Added docs.
Modified: dbi/trunk/lib/DBI/Gofer/Execute.pm
==============================================================================
--- dbi/trunk/lib/DBI/Gofer/Execute.pm (original)
+++ dbi/trunk/lib/DBI/Gofer/Execute.pm Fri Apr 13 05:41:48 2007
@@ -30,11 +30,14 @@
__PACKAGE__->mk_accessors(qw(
- check_connect
+ check_request
default_connect_dsn
forced_connect_dsn
default_connect_attributes
forced_connect_attributes
+ forced_single_resultset
+ max_cached_dbh_per_drh
+ max_cached_sth_per_dbh
track_recent
stats
));
@@ -44,6 +47,7 @@
my ($self, $args) = @_;
$args->{default_connect_attributes} ||= {};
$args->{forced_connect_attributes} ||= {};
+ $args->{max_cached_sth_per_dbh} ||= 1000;
$args->{stats} ||= {};
return $self->SUPER::new($args);
}
@@ -60,11 +64,9 @@
);
my %extra_attr = (
- # what driver-specific attributes should be returned for the driver being
used?
# Only referenced if the driver doesn't support private_attribute_info
method.
+ # what driver-specific attributes should be returned for the driver being
used?
# keyed by $dbh->{Driver}{Name}
- # XXX for dbh attr only need to be returned on first access by client
- # the client should then cache them. So need a way to indicate that.
# XXX for sth should split into attr specific to resultsets (where
NUM_OF_FIELDS > 0) and others
# which would reduce processing/traffic for non-select statements
mysql => {
@@ -114,26 +116,26 @@
sub _connect {
my ($self, $request) = @_;
- # just a quick hack for now
my $stats = $self->{stats};
- if (++$stats->{_requests_served} % 1000 == 0) { # XXX config
- # discard CachedKids from time to time
+
+ # discard CachedKids from time to time
+ if (++$stats->{_requests_served} % 1000 == 0 # XXX config?
+ and my $max_cached_dbh_per_drh = $self->{max_cached_dbh_per_drh}
+ ) {
my %drivers = DBI->installed_drivers();
while ( my ($driver, $drh) = each %drivers ) {
- next if $driver eq 'Gofer'; # ie transport=null when testing
next unless my $CK = $drh->{CachedKids};
- # XXX currently we discard all regardless
- # because that avoids the need to also handle
- # limiting the prepared statement cache
- my $cached_dbh_count = keys %$CK;
- #next unless $cached_dbh_count > 20; # XXX config
-
- DBI->trace_msg("Clearing $cached_dbh_count cached dbh from
$driver");
+ next unless keys %$CK > $max_cached_dbh_per_drh;
+ next if $driver eq 'Gofer'; # ie transport=null when testing
+ DBI->trace_msg(sprintf "Clearing %d cached dbh from $driver",
+ scalar keys %$CK, $self->{max_cached_dbh_per_drh});
$_->{Active} && $_->disconnect for values %$CK;
%$CK = ();
}
}
+ local $ENV{DBI_AUTOPROXY}; # limit the insanity
+
my ($connect_method, $dsn, $username, $password, $attr) = @{
$request->dbh_connect_call };
$connect_method ||= 'connect_cached';
@@ -141,16 +143,10 @@
# (Could just do this on client-side and trust the client. DoS?)
delete @{$attr}{qw(Profile InactiveDestroy HandleError HandleSetErr
TraceLevel Taint TaintIn TaintOut)};
- if (my $check_connect = $self->check_connect) {
- $check_connect->($dsn, $attr, $connect_method, $request);
- }
-
$dsn = $self->forced_connect_dsn || $dsn || $self->default_connect_dsn
or die "No forced_connect_dsn, requested dsn, or default_connect_dsn
for request";
- local $ENV{DBI_AUTOPROXY}; # limit the insanity
-
- # XXX implement our own private connect_cached method?
+ # XXX implement our own private connect_cached method? (with rate-limited
ping)
my $dbh = DBI->$connect_method($dsn, undef, undef, {
# the configured default attributes, if any
@@ -175,6 +171,12 @@
dbi_go_execute_unique => __PACKAGE__."$$",
});
$dbh->{ShowErrorStatement} = 1 if $local_log;
+
+ my $CK = $dbh->{CachedKids};
+ if ($CK && keys %$CK > $self->{max_cached_sth_per_dbh}) {
+ %$CK = (); # clear all statement handles
+ }
+
#$dbh->trace(0);
return $dbh;
}
@@ -223,6 +225,11 @@
my $response = eval {
+ if (my $check_request = $self->check_request) {
+ $request = $check_request->($request)
+ or die "check_request failed";
+ }
+
my $version = $request->version || 0;
die ref($request)." version $version is not supported"
if $version < 0.009116 or $version >= 1;
@@ -411,6 +418,7 @@
if (my $rows = $rs->{rowset}) {
$row_count += @$rows;
}
+ last if $self->{forced_single_resultset};
} while $sth->more_results
|| $sth->{syb_more_results};
@@ -470,9 +478,80 @@
1;
__END__
-TODO
+=head1 NAME
+
+DBI::Gofer::Execute - Executes Gofer requests and returns Gofer responses
+
+=head1 SYNOPSIS
+
+ $executor = DBI::Gofer::Execute->new( { ...config... });
+
+ $response = $executor->execute_request( $request );
+
+=head1 DESCRIPTION
+
+Accepts a DBI::Gofer::Request object, executes the requested DBI method calls,
+and returns a DBI::Gofer::Response object.
+
+Any error, including any internal 'fatal' errors are caught and converted into
+a DBI::Gofer::Response object.
+
+=head1 CONFIGURATION
+
+=head2 check_request
+
+If defined, it must be a reference to a subroutine that will 'check' the
request.
+
+The subroutine can either return the original request object or die with a
+suitable error message (which will be turned into a Gofer response).
+
+It can also construct and return a new request that should be executed instead
+of the original request.
+
+=head2 forced_connect_dsn
+
+If set, this DSN is always used instead of the one in the request.
+
+=head2 default_connect_dsn
+
+If set, this DSN is used if C<forced_connect_dsn> is not set and the request
does not contain a DSN.
+
+=head2 forced_connect_attributes
+
+A reference to a hash of connect() attributes. Individual attributes in
+C<forced_connect_attributes> will take precedence over corresponding attributes
+in the request.
+
+=head2 default_connect_attributes
+
+A reference to a hash of connect() attributes. Individual attributes in the
+request take precedence over corresponding attributes in
C<default_connect_attributes>.
+
+=head2 max_cached_dbh_per_drh
+
+If set, the loaded drivers will be checked to ensure they don't have more than
+this number of cached connections. There is no default value. This limit is not
+enforced for every request.
+
+=head2 max_cached_sth_per_dbh
+
+If set, all the cached statement handles will be cleared once the number of
+cached statement handles rises above this limit. The default is 1000.
+
+=head2 forced_single_resultset
+
+If true, then only a single result set will be fetched and returned in the
response.
+
+=head2 track_recent
+
+If set, specifies the number of recent requests and responses that (the
+transport) should keep for diagnostics. See L<DBI::Gofer::Transport::mod_perl>
+Note that this setting can significantly increase memory use.
+
+=head1 TO DO
-Pruning of cached dbh and sth
+Currently every 1000 requests all the cached dbh are disconnected cleared to
avoid
+the connection and statement handle caches growing too large. A smarter system
is needed.
=head1 AUTHOR AND COPYRIGHT
