Sub::Override doesn't override DBI methods. Why? - perl

I'm writing a fork of DBI::Log, my purpose is to make it conditionally-pluggable to be able to log SQL queries more flexible, e.g. only from particular module or after specified call.
I faced with strange problem - Sub::Override can not override DBI::db::* and DBI::st::execute methods.
Scheme of overriding is following
1) I save reference to original method to variable, e.g. my $orig_execute = \&DBI::st::execute;
2) Create a new function with adding some additional logging code, e.g.
sub _execute {
my ( $sth, #args ) = #_;
warn "Execute is working!";
my $log = dbilog( "execute", $sth->{Database}, $sth->{Statement}, \#args );
my $retval = $orig_execute->( $sth, #args );
dbilog2($log);
return $retval;
}
3) Replace old to new function using Sub::Override
my $sub = Sub::Override->new;
$sub->replace( 'DBI::st::execute', \&_execute );
Here is a full code of changed DBI::Log module. It must do same as original DBI::Log, just use Sub::Override, so original unit tests must pass.
If I run test.pl and added debug output script I see that Sub::Override is working, but for some reason overrided function can not start - no Execute is working! message.

Related

Sybase Warning messages from perl DBI

I am connecting to sybase 12 from a perl script and calling storedprocs, I get the following warnings
DBD::Sybase::db prepare failed: Server message number=2401 severity=11 state=2 line=0 server=SERVER_NAME text=Character
set conversion is not available between client character set 'utf8' and server character set 'iso_1'.
Server message number=2411 severity=10 state=1 line=0 server=SERVER_NAME text=No conversions will be done.
at line 210.
Now, I understand these are only warnings, and my process works perfectly fine, but I am calling my stored proc in a loop and throughout the day and hence it creates a lot of warning message in my log files which causes the entire process to run a bit slower than expected. Can someone help me how can i suppress these please?
You can use a callback to handle the messages you want ignored. See the DBD::Sybase docs. The below is derived from the docs. You specify the message numbers you would like to ignore.
%blocked_msgs = map { $_ => 1 } ( 2401, 2411 );
sub err_handler {
my($err, $sev, $state, $line, $server, $proc, $msg, $sql, $err_type) = #_;
if ( exists $blocked_msgs{$err} ) { # it's a blocked message
return 0; # This is not an error
}
return 1;
}
This is how you might use it:
$dbh = DBI->connect('dbi:Sybase:server=troll', 'sa', '');
$dbh->{syb_err_handler} = \&err_handler;
$dbh->do("exec someproc");
$dbh->disconnect;

Can't use object methods of SOAP object with SOAP::Lite

I am reading data from our Jira via SOAP and recieve an array of RemoteIssue-Objects. Now I want to iterate over these and get the status of each ticket. The documentation of RemoteIssue says that there is a getStatus()-Method. When I call it on the objects my program throws an error.
Some code:
my $soap = SOAP::Lite->uri($soap_uri)->proxy($soap_proxy);
my $login = $soap->login( $soap_user, $soap_password)->result;
if ($login) {
# This works
my $issues = $soap->getIssuesFromJqlSearch( $login, "project = \"$project\" AND fixVersion = \"$project_version\"", 500 );
if ($issues) {
foreach my $issue (#{$issues->result}) {
my $foo = $issue->getStatus(); # This doesn't work
print Dumper $foo;
}
}
}
$soap->logout();
The thrown error:
Can't locate object method "getStatus" via package "RemoteIssue" at D:\ZeuS\lib/ZeuS.pm line 81
Every other object method doesn't work either.
Does anyone know what I am doing wrong?
From what I gather, you're under the impression that you're receiving the Java object that you would manipulate on a Java consumer.
Unless $issue->getStatus() is a SOAP call (which I don't think it is) you're not dealing with the API, you're dealing with SOAP::Lite's representation in Perl of the response in XML.
getIssuesFromJqlSearch seems to be the remote call. From that, you should get $issues as a SOAP::SOM object. Which you then properly address with the result method.
This will have whatever methods are defined for the class this object is blessed into.
To see what all this object responds to try this:
use mro ();
use Scalar::Util qw<blessed>;
...
foreach my $issue (#{$issues->result}) {
say '$issue ISA ('
. join( ',', #{ mro::get_linear_isa( blessed( $issue )) } )
. ')'
;
...
}
$issue will only have those methods that have been defined for it on the Perl side.
NOTE: It is not clear from your code where ZeuS.pm comes into this thing.

Perl -- 'Not a HASH reference' error when using JSON::RPC::Client

I'm a newbie in Perl.
I have a JSON-RPC server running at http://localhost:19000 and I need to call checkEmail() method.
use JSON::RPC::Client;
my $client = new JSON::RPC::Client;
my $url = 'http://localhost:19000';
my $callobj = {
method => 'checkEmail',
params => [ 'rprikhodchenko#gmail.com' ],
};
my $res = $client->call($url, $callobj);
if($res) {
if ($res->is_error) {
print "Error : ", $res->error_message;
}
else {
print $res->result;
}
}
else {
print $client->status_line;
}
When I try to launch it it tells following:
perl ./check_ac.pl
Not a HASH reference at /usr/local/share/perl/5.10.1/JSON/RPC/Client.pm line 193.
UPD:
Full stack-trace:
perl -MCarp::Always ./check_ac.pl
Not a HASH reference at /usr/local/share/perl/5.10.1/JSON/RPC/Client.pm line 193
JSON::RPC::ReturnObject::new('JSON::RPC::ReturnObject', 'HTTP::Response=HASH(0x9938d48)', 'JSON=SCALAR(0x96f1518)') called at /usr/local/share/perl/5.10.1/JSON/RPC/Client.pm line 118
JSON::RPC::Client::call('JSON::RPC::Client=HASH(0x944a818)', 'http://localhost:19000', 'HASH(0x96f1578)') called at ./check_ac.pl line 11
This error means that your JSON-RPC server is not actually one, inasmuch as it does not satisfy requirement 7.3. The error is triggered when JSON::RPC::Client assumes the document returned by the JSON-RPC service is well-formed (i.e., a JSON Object), and this assumptions turns out to have been in error. A bug report to the author of JSON::RPC::Client would be an appropriate way to request better error messaging.
I would attack this sort of problem by finding out what the server was returning that was causing JSON::RPC::Client to choke. Unfortunately, JRC fails to provide adequate hookpoints for finding this out, so you'll have to be a little bit tricky.
I don't like editing external libraries, so I recommend an extend-and-override approach to instrumenting traffic with the JSON-RPC server. Something like this (in check_ac.pl):
use Data::Dumper qw();
package JSON::RPC::InstrumentedClient;
use base 'JSON::RPC::Client';
# This would be better done with Module::Install, but I'm limiting dependencies today.
sub _get {
my ($self, #args) = #_;
return $self->_dump_response($self->SUPER::_get(#args));
}
sub _post {
my ($self, #args) = #_;
return $self->_dump_response($self->SUPER::_post(#args));
}
sub _dump_response {
my ($self, $response) = #_;
warn Data::Dumper::Dump([$response->decoded_content], [qw(content)]);
return $response;
}
package main;
my $client = JSON::RPC::InstrumentedClient->new();
my $url = 'http://localhost:19000';
... # rest of check_ac.pl
This wraps the calls to _get and _post that JSON::RPC::Client makes internally in such a way as to let you examine what the web server actually said in response to the request we made. The above code dumps the text content of the page; this might not be the right thing in your case and will blow up if an error is encountered. It's a debugging aid only, to help you figure out from the client code side what is wrong with the server.
That's enough caveats for now, I think. Good luck.
It seems to be a bug in method new of JSON::RPC::ReturnObject.
sub new {
my ($class, $obj, $json) = #_;
my $content = ( $json || JSON->new->utf8 )->decode( $obj->content );
#...
# line 193
$content->{error} ? $self->is_success(0) : $self->is_success(1);
#...
}
$content's value will be something returned from a JSON::decode() call. But looking at the documentation, it seems that JSON->decode() returns a scalar which could be a number, a string, an array reference, or a hash reference.
Unfortunately, JSON::RPC::ReturnObject->new() doesn't check what sort of thing JSON->decode() returned before trying to access it as a hashref. Given your error, I'm going to go ahead and assume what it got in your case was not one. :-)
I don't know if there's a way to force a fix from your code. I'd recommend contacting the author and letting him know about the issue, and/or filing a bug.

Perl referencing and deferencing hash values when passing to subroutine?

I've been banging my head over this issue for about 5 hours now, I'm really frustrated and need some assistance.
I'm writing a Perl script that pulls jobs out of a MySQL table and then preforms various database admin tasks. The current task is "creating databases". The script successfully creates the database(s), but when I got to generating the config file for PHP developers it blows up.
I believe it is an issue with referencing and dereferencing variables, but I'm not quite sure what exactly is happening. I think after this function call, something happens to
$$result{'databaseName'}. This is how I get result: $result = $select->fetchrow_hashref()
Here is my function call, and the function implementation:
Function call (line 127):
generateConfig($$result{'databaseName'}, $newPassword, "php");
Function implementation:
sub generateConfig {
my($inName) = $_[0];
my($inPass) = $_[1];
my($inExt) = $_[2];
my($goodData) = 1;
my($select) = $dbh->prepare("SELECT id FROM $databasesTableName WHERE name = '$inName'");
my($path) = $documentRoot.$inName."_config.".$inExt;
$select->execute();
if ($select->rows < 1 ) {
$goodData = 0;
}
while ( $result = $select->fetchrow_hashref() )
{
my($insert) = $dbh->do("INSERT INTO $configTableName(databaseId, username, password, path)".
"VALUES('$$result{'id'}', '$inName', '$inPass', '$path')");
}
return 1;
}
Errors:
Use of uninitialized value in concatenation (.) or string at ./dbcreator.pl line 142.
Use of uninitialized value in concatenation (.) or string at ./dbcreator.pl line 154.
Line 142:
$update = $dbh->do("UPDATE ${tablename}
SET ${jobStatus}='${newStatus}'
WHERE id = '$$result{'id'}'");
Line 154:
print "Successfully created $$result{'databaseName'}\n";
The reason I think the problem comes from the function call is because if I comment out the function call, everything works great!
If anyone could help me understand what's going on, that would be great.
Thanks,
p.s. If you notice a security issue with the whole storing passwords as plain text in a database, that's going to be addressed after this is working correctly. =P
Dylan
You do not want to store a reference to the $result returned from fetchrow_hashref, as each subsequent call will overwrite that reference.
That's ok, you're not using the reference when you are calling generate_config, as you are passing data in by value.
Are you using the same $result variable in generate_config and in the calling function? You should be using your own 'my $result' in generate_config.
while ( my $result = $select->fetchrow_hashref() )
# ^^ #add my
That's all that can be said with the current snippets of code you've included.
Some cleanup:
When calling generate_config you are passing by value, not by reference. This is fine.
you are getting an undef warning, this means you are running with 'use strict;'. Good!
create lexical $result within the function, via my.
While $$hashr{key} is valid code, $hashr->{key} is preferred.
you're using dbh->prepare, might as well use placeholders.
sub generateConfig {
my($inName, inPass, $inExt) = #_;
my $goodData = 1;
my $select = $dbh->prepare("SELECT id FROM $databasesTableName WHERE name = ?");
my $insert = $dbh->prepare("
INSERT INTO $configTableName(
databaseID
,username
,password
,path)
VALUES( ?, ?, ?, ?)" );
my $path = $documentRoot . $inName . "_config." . $inExt;
$select->execute( $inName );
if ($select->rows < 1 ) {
$goodData = 0;
}
while ( my $result = $select->fetchrow_hashref() )
{
insert->execute( $result->{id}, $inName, $inPass, $path );
}
return 1;
}
EDIT: after reading your comment
I think that both errors have to do with your using $$result. If $result is the return value of fetchrow_hashref, like in:
$result = $select->fetchrow_hashref()
then the correct way to refer to its values should be:
print "Successfully created " . $result{'databaseName'} . "\n";
and:
$update = $dbh->do("UPDATE ${tablename}
SET ${jobStatus}='${newStatus}'
WHERE id = '$result{'id'}'");
OLD ANSWER:
In function generateConfig, you can pass a reference in using this syntax:
generateConfig(\$result{'databaseName'},$newPassword, "php");
($$ is used to dereference a reference to a string; \ gives you a reference to the object it is applied to).
Then, in the print statement itself, I would try:
print "Successfully created $result->{'databaseName'}->{columnName}\n";
indeed, fetchrow_hashref returns a hash (not a string).
This should fix one problem.
Furthermore, you are using the variable named $dbh but you don't show where it is set. Is it a global variable so that you can use it in generateConfig? Has it been initialized when generateConfig is executed?
This was driving me crazy when I was running hetchrow_hashref from Oracle result set.
Turened out the column names are always returned in upper case.
So once I started referencing the colum in upper case, problem went away:
insert->execute( $result->{ID}, $inName, $inPass, $path );

"Can't call method "dir_path" on an undefined value" when running Mason component on the command line

Greetings,
I'm trying to develop some tests for Mason components which requires running them on the command line instead of the web server. When I try this, I get an error:
perl -MHTML::Mason::Request -MHTML::Mason::Interp -I./lib \
-e '$int = HTML::Mason::Interp->new( data_dir => "/home/friedo/cache", comp_root => "/home/friedo/comps" ); $m = HTML::Mason::Request->new( comp => "/dummy", interp => $int ); $m->comp("/dummy")'
Results in:
Can't call method "dir_path" on an undefined value at lib/HTML/Mason/Request.pm line 1123.
The error is thrown when the call to ->comp is attempted. I can't figure out what's wrong with the configuration. The component is there and appears to be compiled just fine, and it works via Apache.
This is using HTML::Mason 1.35.
Edit: Let's try a bounty for this one. The alternative is me having to dive deep into Mason's guts! :)
Edit again: Thanks very much to David for pointing out the crucial detail that I missed for getting this to work.
This was actually for a test framework that needed to exercise a module that calls some Mason comps -- under normal operation the module is provided with a Mason request object to use for that purpose, but I couldn't get that to work offline. The key was using an Interpreter object instead, so I ended up doing the following, which is a little silly but makes the tests work:
sub _mason_out {
...
my $buf;
if ( $ENV{MASON_TEST} ) {
my $int = HTML::Mason::Interp->new( comp_root => $self->{env}->comp_dir,
out_method => \$buf );
$int->exec( $comp, %args );
} else {
my $m = $self->{mason_object};
$m->comp( { store => \$buf }, $comp, %args );
}
return $buf;
}
I think this fails because your Request object hasn't built a component stack at the point that it is called. Use the Interp->exec() method instead as described in Using Mason from a Standalone Script
perl -MHTML::Mason::Interp -I./lib \
-e 'HTML::Mason::Interp->new( data_dir => "/home/friedo/cache", comp_root => "/home/friedo/comps" )->exec("/dummy")'