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#line 1 "DBI/Gofer/Execute.pm"
package DBI::Gofer::Execute;
# $Id: Execute.pm 14282 2010-07-26 00:12:54Z David $
#
# Copyright (c) 2007, Tim Bunce, Ireland
#
# You may distribute under the terms of either the GNU General Public
# License or the Artistic License, as specified in the Perl README file.
use strict;
use warnings;
use Carp;
use DBI qw(dbi_time);
use DBI::Gofer::Request;
use DBI::Gofer::Response;
use base qw(DBI::Util::_accessor);
our $VERSION = "0.014283";
our @all_dbh_methods = sort map { keys %$_ } $DBI::DBI_methods{db}, $DBI::DBI_methods{common};
our %all_dbh_methods = map { $_ => (DBD::_::db->can($_)||undef) } @all_dbh_methods;
our $local_log = $ENV{DBI_GOFER_LOCAL_LOG}; # do extra logging to stderr
our $current_dbh; # the dbh we're using for this request
# set trace for server-side gofer
# Could use DBI_TRACE env var when it's an unrelated separate process
# but using DBI_GOFER_TRACE makes testing easier for subprocesses (eg stream)
DBI->trace(split /=/, $ENV{DBI_GOFER_TRACE}, 2) if $ENV{DBI_GOFER_TRACE};
# define valid configuration attributes (args to new())
# the values here indicate the basic type of values allowed
my %configuration_attributes = (
gofer_execute_class => 1,
default_connect_dsn => 1,
forced_connect_dsn => 1,
default_connect_attributes => {},
forced_connect_attributes => {},
track_recent => 1,
check_request_sub => sub {},
check_response_sub => sub {},
forced_single_resultset => 1,
max_cached_dbh_per_drh => 1,
max_cached_sth_per_dbh => 1,
forced_response_attributes => {},
forced_gofer_random => 1,
stats => {},
);
__PACKAGE__->mk_accessors(
keys %configuration_attributes
);
sub new {
my ($self, $args) = @_;
$args->{default_connect_attributes} ||= {};
$args->{forced_connect_attributes} ||= {};
$args->{max_cached_sth_per_dbh} ||= 1000;
$args->{stats} ||= {};
return $self->SUPER::new($args);
}
sub valid_configuration_attributes {
my $self = shift;
return { %configuration_attributes };
}
my %extra_attr = (
# 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 $dbh->{Driver}{Name}
# XXX for sth should split into attr specific to resultsets (where NUM_OF_FIELDS > 0) and others
# which would reduce processing/traffic for non-select statements
mysql => {
dbh => [qw(
mysql_errno mysql_error mysql_hostinfo mysql_info mysql_insertid
mysql_protoinfo mysql_serverinfo mysql_stat mysql_thread_id
)],
sth => [qw(
mysql_is_blob mysql_is_key mysql_is_num mysql_is_pri_key mysql_is_auto_increment
mysql_length mysql_max_length mysql_table mysql_type mysql_type_name mysql_insertid
)],
# XXX this dbh_after_sth stuff is a temporary, but important, hack.
# should be done via hash instead of arrays where the hash value contains
# flags that can indicate which attributes need to be handled in this way
dbh_after_sth => [qw(
mysql_insertid
)],
},
Pg => {
dbh => [qw(
pg_protocol pg_lib_version pg_server_version
pg_db pg_host pg_port pg_default_port
pg_options pg_pid
)],
sth => [qw(
pg_size pg_type pg_oid_status pg_cmd_status
)],
},
Sybase => {
dbh => [qw(
syb_dynamic_supported syb_oc_version syb_server_version syb_server_version_string
)],
sth => [qw(
syb_types syb_proc_status syb_result_type
)],
},
SQLite => {
dbh => [qw(
sqlite_version
)],
sth => [qw(
)],
},
ExampleP => {
dbh => [qw(
examplep_private_dbh_attrib
)],
sth => [qw(
examplep_private_sth_attrib
)],
dbh_after_sth => [qw(
examplep_insertid
)],
},
);
sub _connect {
my ($self, $request) = @_;
my $stats = $self->{stats};
# discard CachedKids from time to time
if (++$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 unless my $CK = $drh->{CachedKids};
next unless keys %$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{...} can leak, so only do it if required
local $ENV{DBI_AUTOPROXY} if $ENV{DBI_AUTOPROXY};
my ($connect_method, $dsn, $username, $password, $attr) = @{ $request->dbh_connect_call };
$connect_method ||= 'connect_cached';
$stats->{method_calls_dbh}->{$connect_method}++;
# delete attributes we don't want to affect the server-side
# (Could just do this on client-side and trust the client. DoS?)
delete @{$attr}{qw(Profile InactiveDestroy AutoInactiveDestroy HandleError HandleSetErr TraceLevel Taint TaintIn TaintOut)};
$dsn = $self->forced_connect_dsn || $dsn || $self->default_connect_dsn
or die "No forced_connect_dsn, requested dsn, or default_connect_dsn for request";
my $random = $self->{forced_gofer_random} || $ENV{DBI_GOFER_RANDOM} || '';
my $connect_attr = {
# the configured default attributes, if any
%{ $self->default_connect_attributes },
# pass username and password as attributes
# then they can be overridden by forced_connect_attributes
Username => $username,
Password => $password,
# the requested attributes
%$attr,
# force some attributes the way we'd like them
PrintWarn => $local_log,
PrintError => $local_log,
# the configured default attributes, if any
%{ $self->forced_connect_attributes },
# RaiseError must be enabled
RaiseError => 1,
# reset Executed flag (of the cached handle) so we can use it to tell
# if errors happened before the main part of the request was executed
Executed => 0,
# ensure this connect_cached doesn't have the same args as the client
# because that causes subtle issues if in the same process (ie transport=null)
# include pid to avoid problems with forking (ie null transport in mod_perl)
# include gofer-random to avoid random behaviour leaking to other handles
dbi_go_execute_unique => join("|", __PACKAGE__, $$, $random),
};
# XXX implement our own private connect_cached method? (with rate-limited ping)
my $dbh = DBI->$connect_method($dsn, undef, undef, $connect_attr);
$dbh->{ShowErrorStatement} = 1 if $local_log;
# XXX should probably just be a Callbacks => arg to connect_cached
# with a cache of pre-built callback hooks (memoized, without $self)
if (my $random = $self->{forced_gofer_random} || $ENV{DBI_GOFER_RANDOM}) {
$self->_install_rand_callbacks($dbh, $random);
}
my $CK = $dbh->{CachedKids};
if ($CK && keys %$CK > $self->{max_cached_sth_per_dbh}) {
%$CK = (); # clear all statement handles
}
#$dbh->trace(0);
$current_dbh = $dbh;
return $dbh;
}
sub reset_dbh {
my ($self, $dbh) = @_;
$dbh->set_err(undef, undef); # clear any error state
}
sub new_response_with_err {
my ($self, $rv, $eval_error, $dbh) = @_;
# this is the usual way to create a response for both success and failure
# capture err+errstr etc and merge in $eval_error ($@)
my ($err, $errstr, $state) = ($DBI::err, $DBI::errstr, $DBI::state);
if ($eval_error) {
$err ||= $DBI::stderr || 1; # ensure err is true
if ($errstr) {
$eval_error =~ s/(?: : \s)? \Q$errstr//x if $errstr;
chomp $errstr;
$errstr .= "; $eval_error";
}
else {
$errstr = $eval_error;
}
}
chomp $errstr if $errstr;
my $flags;
# (XXX if we ever add transaction support then we'll need to take extra
# steps because the commit/rollback would reset Executed before we get here)
$flags |= GOf_RESPONSE_EXECUTED if $dbh && $dbh->{Executed};
my $response = DBI::Gofer::Response->new({
rv => $rv,
err => $err,
errstr => $errstr,
state => $state,
flags => $flags,
});
return $response;
}
sub execute_request {
my ($self, $request) = @_;
# should never throw an exception
DBI->trace_msg("-----> execute_request\n");
my @warnings;
local $SIG{__WARN__} = sub {
push @warnings, @_;
warn @_ if $local_log;
};
my $response = eval {
if (my $check_request_sub = $self->check_request_sub) {
$request = $check_request_sub->($request, $self)
or die "check_request_sub failed";
}
my $version = $request->version || 0;
die ref($request)." version $version is not supported"
if $version < 0.009116 or $version >= 1;
($request->is_sth_request)
? $self->execute_sth_request($request)
: $self->execute_dbh_request($request);
};
$response ||= $self->new_response_with_err(undef, $@, $current_dbh);
if (my $check_response_sub = $self->check_response_sub) {
# not protected with an eval so it can choose to throw an exception
my $new = $check_response_sub->($response, $self, $request);
$response = $new if ref $new;
}
undef $current_dbh;
$response->warnings(\@warnings) if @warnings;
DBI->trace_msg("<----- execute_request\n");
return $response;
}
sub execute_dbh_request {
my ($self, $request) = @_;
my $stats = $self->{stats};
my $dbh;
my $rv_ref = eval {
$dbh = $self->_connect($request);
my $args = $request->dbh_method_call; # [ wantarray, 'method_name', @args ]
my $wantarray = shift @$args;
my $meth = shift @$args;
$stats->{method_calls_dbh}->{$meth}++;
my @rv = ($wantarray)
? $dbh->$meth(@$args)
: scalar $dbh->$meth(@$args);
\@rv;
} || [];
my $response = $self->new_response_with_err($rv_ref, $@, $dbh);
return $response if not $dbh;
# does this request also want any dbh attributes returned?
if (my $dbh_attributes = $request->dbh_attributes) {
$response->dbh_attributes( $self->gather_dbh_attributes($dbh, $dbh_attributes) );
}
if ($rv_ref and my $lid_args = $request->dbh_last_insert_id_args) {
$stats->{method_calls_dbh}->{last_insert_id}++;
my $id = $dbh->last_insert_id( @$lid_args );
$response->last_insert_id( $id );
}
if ($rv_ref and UNIVERSAL::isa($rv_ref->[0],'DBI::st')) {
# dbh_method_call was probably a metadata method like table_info
# that returns a statement handle, so turn the $sth into resultset
my $sth = $rv_ref->[0];
$response->sth_resultsets( $self->gather_sth_resultsets($sth, $request, $response) );
$response->rv("(sth)"); # don't try to return actual sth
}
# we're finished with this dbh for this request
$self->reset_dbh($dbh);
return $response;
}
sub gather_dbh_attributes {
my ($self, $dbh, $dbh_attributes) = @_;
my @req_attr_names = @$dbh_attributes;
if ($req_attr_names[0] eq '*') { # auto include std + private
shift @req_attr_names;
push @req_attr_names, @{ $self->_std_response_attribute_names($dbh) };
}
my %dbh_attr_values;
@dbh_attr_values{@req_attr_names} = $dbh->FETCH_many(@req_attr_names);
# XXX piggyback installed_methods onto dbh_attributes for now
$dbh_attr_values{dbi_installed_methods} = { DBI->installed_methods };
# XXX piggyback default_methods onto dbh_attributes for now
$dbh_attr_values{dbi_default_methods} = _get_default_methods($dbh);
return \%dbh_attr_values;
}
sub _std_response_attribute_names {
my ($self, $h) = @_;
$h = tied(%$h) || $h; # switch to inner handle
# cache the private_attribute_info data for each handle
# XXX might be better to cache it in the executor
# as it's unlikely to change
# or perhaps at least cache it in the dbh even for sth
# as the sth are typically very short lived
my ($dbh, $h_type, $driver_name, @attr_names);
if ($dbh = $h->{Database}) { # is an sth
# does the dbh already have the answer cached?
return $dbh->{private_gofer_std_attr_names_sth} if $dbh->{private_gofer_std_attr_names_sth};
($h_type, $driver_name) = ('sth', $dbh->{Driver}{Name});
push @attr_names, qw(NUM_OF_PARAMS NUM_OF_FIELDS NAME TYPE NULLABLE PRECISION SCALE);
}
else { # is a dbh
return $h->{private_gofer_std_attr_names_dbh} if $h->{private_gofer_std_attr_names_dbh};
($h_type, $driver_name, $dbh) = ('dbh', $h->{Driver}{Name}, $h);
# explicitly add these because drivers may have different defaults
# add Name so the client gets the real Name of the connection
push @attr_names, qw(ChopBlanks LongReadLen LongTruncOk ReadOnly Name);
}
if (my $pai = $h->private_attribute_info) {
push @attr_names, keys %$pai;
}
else {
push @attr_names, @{ $extra_attr{ $driver_name }{$h_type} || []};
}
if (my $fra = $self->{forced_response_attributes}) {
push @attr_names, @{ $fra->{ $driver_name }{$h_type} || []}
}
$dbh->trace_msg("_std_response_attribute_names for $driver_name $h_type: @attr_names\n");
# cache into the dbh even for sth, as the dbh is usually longer lived
return $dbh->{"private_gofer_std_attr_names_$h_type"} = \@attr_names;
}
sub execute_sth_request {
my ($self, $request) = @_;
my $dbh;
my $sth;
my $last_insert_id;
my $stats = $self->{stats};
my $rv = eval {
$dbh = $self->_connect($request);
my $args = $request->dbh_method_call; # [ wantarray, 'method_name', @args ]
shift @$args; # discard wantarray
my $meth = shift @$args;
$stats->{method_calls_sth}->{$meth}++;
$sth = $dbh->$meth(@$args);
my $last = '(sth)'; # a true value (don't try to return actual sth)
# execute methods on the sth, e.g., bind_param & execute
if (my $calls = $request->sth_method_calls) {
for my $meth_call (@$calls) {
my $method = shift @$meth_call;
$stats->{method_calls_sth}->{$method}++;
$last = $sth->$method(@$meth_call);
}
}
if (my $lid_args = $request->dbh_last_insert_id_args) {
$stats->{method_calls_sth}->{last_insert_id}++;
$last_insert_id = $dbh->last_insert_id( @$lid_args );
}
$last;
};
my $response = $self->new_response_with_err($rv, $@, $dbh);
return $response if not $dbh;
$response->last_insert_id( $last_insert_id )
if defined $last_insert_id;
# even if the eval failed we still want to try to gather attribute values
# (XXX would be nice to be able to support streaming of results.
# which would reduce memory usage and latency for large results)
if ($sth) {
$response->sth_resultsets( $self->gather_sth_resultsets($sth, $request, $response) );
$sth->finish;
}
# does this request also want any dbh attributes returned?
my $dbh_attr_set;
if (my $dbh_attributes = $request->dbh_attributes) {
$dbh_attr_set = $self->gather_dbh_attributes($dbh, $dbh_attributes);
}
# XXX needs to be integrated with private_attribute_info() etc
if (my $dbh_attr = $extra_attr{$dbh->{Driver}{Name}}{dbh_after_sth}) {
@{$dbh_attr_set}{@$dbh_attr} = $dbh->FETCH_many(@$dbh_attr);
}
$response->dbh_attributes($dbh_attr_set) if $dbh_attr_set && %$dbh_attr_set;
$self->reset_dbh($dbh);
return $response;
}
sub gather_sth_resultsets {
my ($self, $sth, $request, $response) = @_;
my $resultsets = eval {
my $attr_names = $self->_std_response_attribute_names($sth);
my $sth_attr = {};
$sth_attr->{$_} = 1 for @$attr_names;
# let the client add/remove sth attributes
if (my $sth_result_attr = $request->sth_result_attr) {
$sth_attr->{$_} = $sth_result_attr->{$_}
for keys %$sth_result_attr;
}
my @sth_attr = grep { $sth_attr->{$_} } keys %$sth_attr;
my $row_count = 0;
my $rs_list = [];
while (1) {
my $rs = $self->fetch_result_set($sth, \@sth_attr);
push @$rs_list, $rs;
if (my $rows = $rs->{rowset}) {
$row_count += @$rows;
}
last if $self->{forced_single_resultset};
last if !($sth->more_results || $sth->{syb_more_results});
}
my $stats = $self->{stats};
$stats->{rows_returned_total} += $row_count;
$stats->{rows_returned_max} = $row_count
if $row_count > ($stats->{rows_returned_max}||0);
$rs_list;
};
$response->add_err(1, $@) if $@;
return $resultsets;
}
sub fetch_result_set {
my ($self, $sth, $sth_attr) = @_;
my %meta;
eval {
@meta{ @$sth_attr } = $sth->FETCH_many(@$sth_attr);
# we assume @$sth_attr contains NUM_OF_FIELDS
$meta{rowset} = $sth->fetchall_arrayref()
if (($meta{NUM_OF_FIELDS}||0) > 0); # is SELECT
# the fetchall_arrayref may fail with a 'not executed' kind of error
# because gather_sth_resultsets/fetch_result_set are called even if
# execute() failed, or even if there was no execute() call at all.
# The corresponding error goes into the resultset err, not the top-level
# response err, so in most cases this resultset err is never noticed.
};
if ($@) {
chomp $@;
$meta{err} = $DBI::err || 1;
$meta{errstr} = $DBI::errstr || $@;
$meta{state} = $DBI::state;
}
return \%meta;
}
sub _get_default_methods {
my ($dbh) = @_;
# returns a ref to a hash of dbh method names for methods which the driver
# hasn't overridden i.e., quote(). These don't need to be forwarded via gofer.
my $ImplementorClass = $dbh->{ImplementorClass} or die;
my %default_methods;
for my $method (@all_dbh_methods) {
my $dbi_sub = $all_dbh_methods{$method} || 42;
my $imp_sub = $ImplementorClass->can($method) || 42;
next if $imp_sub != $dbi_sub;
#warn("default $method\n");
$default_methods{$method} = 1;
}
return \%default_methods;
}
# XXX would be nice to make this a generic DBI module
sub _install_rand_callbacks {
my ($self, $dbh, $dbi_gofer_random) = @_;
my $callbacks = $dbh->{Callbacks} || {};
my $prev = $dbh->{private_gofer_rand_fail_callbacks} || {};
# return if we've already setup this handle with callbacks for these specs
return if (($callbacks->{_dbi_gofer_random_spec}||'') eq $dbi_gofer_random);
#warn "$dbh # $callbacks->{_dbi_gofer_random_spec}";
$callbacks->{_dbi_gofer_random_spec} = $dbi_gofer_random;
my ($fail_percent, $fail_err, $delay_percent, $delay_duration, %spec_part, @spec_note);
my @specs = split /,/, $dbi_gofer_random;
for my $spec (@specs) {
if ($spec =~ m/^fail=(-?[.\d]+)%?$/) {
$fail_percent = $1;
$spec_part{fail} = $spec;
next;
}
if ($spec =~ m/^err=(-?\d+)$/) {
$fail_err = $1;
$spec_part{err} = $spec;
next;
}
if ($spec =~ m/^delay([.\d]+)=(-?[.\d]+)%?$/) {
$delay_duration = $1;
$delay_percent = $2;
$spec_part{delay} = $spec;
next;
}
elsif ($spec !~ m/^(\w+|\*)$/) {
warn "Ignored DBI_GOFER_RANDOM item '$spec' which isn't a config or a dbh method name";
next;
}
my $method = $spec;
if ($callbacks->{$method} && $prev->{$method} && $callbacks->{$method} != $prev->{$method}) {
warn "Callback for $method method already installed so DBI_GOFER_RANDOM callback not installed\n";
next;
}
unless (defined $fail_percent or defined $delay_percent) {
warn "Ignored DBI_GOFER_RANDOM item '$spec' because not preceded by 'fail=N' and/or 'delayN=N'";
next;
}
push @spec_note, join(",", values(%spec_part), $method);
$callbacks->{$method} = $self->_mk_rand_callback($method, $fail_percent, $delay_percent, $delay_duration, $fail_err);
}
warn "DBI_GOFER_RANDOM failures/delays enabled: @spec_note\n"
if @spec_note;
$dbh->{Callbacks} = $callbacks;
$dbh->{private_gofer_rand_fail_callbacks} = $callbacks;
}
my %_mk_rand_callback_seqn;
sub _mk_rand_callback {
my ($self, $method, $fail_percent, $delay_percent, $delay_duration, $fail_err) = @_;
my ($fail_modrate, $delay_modrate);
$fail_percent ||= 0; $fail_modrate = int(1/(-$fail_percent )*100) if $fail_percent;
$delay_percent ||= 0; $delay_modrate = int(1/(-$delay_percent)*100) if $delay_percent;
# note that $method may be "*" but that's not recommended or documented or wise
return sub {
my ($h) = @_;
my $seqn = ++$_mk_rand_callback_seqn{$method};
my $delay = ($delay_percent > 0) ? rand(100) < $delay_percent :
($delay_percent < 0) ? !($seqn % $delay_modrate): 0;
my $fail = ($fail_percent > 0) ? rand(100) < $fail_percent :
($fail_percent < 0) ? !($seqn % $fail_modrate) : 0;
#no warnings 'uninitialized';
#warn "_mk_rand_callback($fail_percent:$fail_modrate, $delay_percent:$delay_modrate): seqn=$seqn fail=$fail delay=$delay";
if ($delay) {
my $msg = "DBI_GOFER_RANDOM delaying execution of $method() by $delay_duration seconds\n";
# Note what's happening in a trace message. If the delay percent is an even
# number then use warn() instead so it's sent back to the client.
($delay_percent % 2 == 1) ? warn($msg) : $h->trace_msg($msg);
select undef, undef, undef, $delay_duration; # allows floating point value
}
if ($fail) {
undef $_; # tell DBI to not call the method
# the "induced by DBI_GOFER_RANDOM" is special and must be included in errstr
# as it's checked for in a few places, such as the gofer retry logic
return $h->set_err($fail_err || $DBI::stderr,
"fake error from $method method induced by DBI_GOFER_RANDOM env var ($fail_percent%)");
}
return;
}
}
sub update_stats {
my ($self,
$request, $response,
$frozen_request, $frozen_response,
$time_received,
$store_meta, $other_meta,
) = @_;
# should always have a response object here
carp("No response object provided") unless $request;
my $stats = $self->{stats};
$stats->{frozen_request_max_bytes} = length($frozen_request)
if $frozen_request
&& length($frozen_request) > ($stats->{frozen_request_max_bytes}||0);
$stats->{frozen_response_max_bytes} = length($frozen_response)
if $frozen_response
&& length($frozen_response) > ($stats->{frozen_response_max_bytes}||0);
my $recent;
if (my $track_recent = $self->{track_recent}) {
$recent = {
request => $frozen_request,
response => $frozen_response,
time_received => $time_received,
duration => dbi_time()-$time_received,
# for any other info
($store_meta) ? (meta => $store_meta) : (),
};
$recent->{request_object} = $request
if !$frozen_request && $request;
$recent->{response_object} = $response
if !$frozen_response;
my @queues = ($stats->{recent_requests} ||= []);
push @queues, ($stats->{recent_errors} ||= [])
if !$response or $response->err;
for my $queue (@queues) {
push @$queue, $recent;
shift @$queue if @$queue > $track_recent;
}
}
return $recent;
}
1;
__END__
#line 901