Decoding BLOB / CLOB resources

[phansys]

I'd like to know what is the status of https://bugs.php.net/bug.php?id=59158.
Is the issue still present? Is there something I can do in order to collaborate with the fix?
doctrine/dbal dropped the support for this extension because that problem, and I'd like to restore that support.

Thank you!

[NattyNarwhal]

I'm attempting to reproduce this, but it works, at least with a simple table (one made by the ibm_db2 test suite) on IBM i and LUW.

<?
$conn = new PDO("ibm:[...]", "", "");
$stmt = $conn->prepare("select * from blob_stream");
$res = $stmt->execute();
while (($row = $stmt->fetch()) != false) {
        $stream = $row["MY_BLOB"];
        $contents = stream_get_contents($stream);
        var_dump($contents);
}

$ php -d extension=$PWD/modules/pdo_ibm.so ../testpdoibmlob.php 
string(41) "THIS IS A BLOB TEST. THIS IS A BLOB TEST."

[NattyNarwhal]

(I should mention I've tested this w/ PHP 8.2 on i and PHP 8.1 on Linux+LUW)

[NattyNarwhal]

FWIW I re-read the issue and I think I saw an implication it's about the lifetimes of the LOB stream. Unfortunately, without a sample, it's hard to reproduce and determine what/why. Especially since it's PHP 5.x era, and a lot of things have changed since then.

[phansys]

Thanks for your response and sorry for the delay.
I got a segfault on the doctrine/dbal test suite trying to use this extension: https://github.com/doctrine/dbal/actions/runs/4179111783/jobs/7238686229#step:9:727.
This is the test producing the error.
Please, let me know if it is enough or if I should try to create a reproducer here.

[NattyNarwhal]

A case that reproduces would be useful. I'm not familiar enough with Doctrine to tell what SQL it generates.

[NattyNarwhal]

I think this would be the right translation from Doctrine to raw SQL/PDO:

<?php
  
$conn = new PDO("ibm:DRIVER={IBM DB2 ODBC DRIVER};DATABASE=sample;HOSTNAME=localhost;PORT=60000;PROTOCOL=TCPIP", "db2inst1", "password", [PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION]);

$stmt = $conn->prepare("drop table blob_table");
$res = $stmt->execute();

$stmt = $conn->prepare("create table blob_table (id integer, clobcolumn clob, blobcolumn blob)");
$res = $stmt->execute();

$longBlob = str_repeat('x', 4 * 8192);

$stmt = $conn->prepare("insert into blob_table values (?, ?, ?)");
$stmt->bindValue(1, 1, PDO::PARAM_INT);
$stmt->bindValue(2, "ignored", PDO::PARAM_STR);
$stmt->bindValue(3, fopen('data://text/plain,' . $longBlob, 'r'), PDO::PARAM_LOB);
$res = $stmt->execute();

I don't get a crash or userland exception from this. (edit: LUW, Linux amd64, PHP 8.1)

[phansys]

Yes, that's exactly what I'm trying to reproduce, without errors: https://github.com/phansys/pecl-database-pdo_ibm/actions/runs/4186046386/jobs/7253998644.
I'll try to investigate if there are some different settings affecting the results.

[NattyNarwhal]

What would be the best way to run that test from dbal? I have the branch checked out, but the setup for CI looks very complex and I haven't figured out how to untangle it and just run the DB2 relevant tests against PDO_IBM only (...and successfully).

[NattyNarwhal]

(That is, I'm running ./vendor/bin/phpunit -d extension=/home/calvin/src/pecl-database-pdo_ibm/modules/pdo_ibm.so -c ci/github/phpunit/pdo_ibm.xml --debug -vvv and I modified just db_password - do I need to change anything else or run anything to initialize it?)

[phansys]

I'd say your approach is enough to achieve a very similar setup. Only two things to consider on the doctrine/dbal CI:

• zend.assertions=1;
• PCOV is enabled.

https://github.com/doctrine/dbal/pull/5924/files#diff-c471496bcb3ed47397b73d2e3e3aa41a8a679c86accaed9e05676fd9d5987434R567-R570.

[NattyNarwhal]

Hmmm, running ./vendor/bin/phpunit -c ci/github/phpunit/pdo_ibm.xml --debug -vvv with XML such as:

<?xml version="1.0" encoding="utf-8"?>
<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:noNamespaceSchemaLocation="../../../vendor/phpunit/phpunit/phpunit.xsd"
         colors="true"
         beStrictAboutOutputDuringTests="true"
         beStrictAboutTodoAnnotatedTests="true"
         failOnRisky="true"
         failOnWarning="true"
         convertDeprecationsToExceptions="true"
>
    <php>
        <ini name="error_reporting" value="-1" />
        <ini name="extension" value="/home/calvin/src/pecl-database-pdo_ibm/modules/pdo_ibm.so" />
        <ini name="zend.assertions" value="1" />

        <var name="db_driver" value="pdo_ibm"/>
        <var name="db_host" value="127.0.0.1"/>
        <var name="db_user" value="db2inst1"/>
        <!--
        <var name="db_password" value="Doctrine2018"/>
        <var name="db_dbname" value="doctrine"/>
        -->
        <var name="db_password" value="password"/>
        <var name="db_dbname" value="sample"/>
    </php>

    <testsuites>
        <testsuite name="Doctrine DBAL Test Suite">
                <!--<directory>../../../tests</directory>-->
                <directory>../../../tests/Functional</directory>
        </testsuite>
    </testsuites>

    <coverage>
        <include>
            <directory suffix=".php">../../../src</directory>
        </include>
    </coverage>
</phpunit>

...I'm getting PDOException from everything basically. Clearly I'm not getting it to load correctly in the context of PHPUnit...

[phansys]

What if you filter only the BlobTest?

vendor/bin/phpunit -c ci/github/phpunit/pdo_ibm.xml --debug -vvv --filter BlobTest

[NattyNarwhal]

That cuts the number of tests down to a manageable number, though I still need to figure out why it's not finding PDO_IBM.

[phansys]

What is the message you're receiving? Is it from Doctrine or from PDO?