README

Installation

To install the Transactional PHP library in your project using Composer, first add the following to your composer.json config file.

{
    "require": {
        "gielfeldt/transactionalphp": "^0.8"
    }
}

Then run Composer's install or update commands to complete installation. Please visit the Composer homepage for more information about how to use Composer.

Transactional PHP

This class allows to buffer php code in a simulated transaction, thereby postponing the execution of the code until a commit occurs.

Motivation

1. Problem of keeping external cache in sync with the database, see the Drupal module Cache Consistent.

Using the Transactional PHP library

Example 1 - Simple

namespace Gielfeldt\TransactionalPHP\Example;

require 'vendor/autoload.php';

use Gielfeldt\TransactionalPHP\Connection;

$connection = new Connection();

// Start outer transaction.
$connection->startTransaction();

$connection->onCommit(function () {
    print "THIS WILL BE PRINTED, BECAUSE THIS WILL BE COMMITTED\n";
});

// Start inner transaction.
$connection->startTransaction();

$connection->onCommit(function () {
    print "THIS WILL NOT BE PRINTED, BECAUSE THIS WILL BE ROLLED BACK\n";
});

// Rollback inner transaction.
$connection->rollbackTransaction();

// Commit inner transaction.
$connection->commitTransaction();

Example 2 - Commit and rollback

namespace Gielfeldt\TransactionalPHP\Example;

require 'vendor/autoload.php';

use Gielfeldt\TransactionalPHP\Connection;
use Gielfeldt\TransactionalPHP\Operation;

$connection = new Connection();

$operation = new Operation();
$operation->onCommit(function () {
    print "THIS WILL BE PRINTED IMMEDIATELY, BECAUSE NO TRANSACTION HAS BEGUN\n";
})
->onRollback(function () {
    print "THIS WILL NEVER BE PRINTED, BECAUSE NO TRANSACTION HAS BEGUN\n";
});
$connection->addOperation($operation);

// Start outer transaction.
$connection->startTransaction();

$operation = new Operation();
$operation->onCommit(function () {
    print "THIS WILL BE PRINTED, BECAUSE THIS WILL BE COMMITTED\n";
})
->onRollback(function () {
    print "THIS WILL NEVER BE PRINTED, BECAUSE THIS WILL BE COMMITTED\n";
});
$connection->addOperation($operation);

// Start inner transaction.
$connection->startTransaction();

$operation = new Operation();
$operation->onCommit(function () {
    print "THIS WILL NOT BE PRINTED, BECAUSE THIS WILL BE ROLLED BACK\n";
})
->onRollback(function () {
    print "THIS WILL BE PRINTED, BECAUSE THIS WILL BE ROLLED BACK\n";
});
$connection->addOperation($operation);

// Rollback inner transaction.
$connection->rollbackTransaction();

// Commit inner transaction.
$connection->commitTransaction();

Example 3 - Using the indexer

namespace Gielfeldt\TransactionalPHP\Example;

require 'vendor/autoload.php';

use Gielfeldt\TransactionalPHP\Connection;
use Gielfeldt\TransactionalPHP\Indexer;
use Gielfeldt\TransactionalPHP\Operation;

$connection = new Connection();
$indexer = new Indexer($connection);

$operation = (new Operation())
    ->onCommit(function () {
        print "THIS WILL BE PRINTED IMMEDIATELY, BECAUSE NO TRANSACTION HAS BEGUN\n";
    })
    ->onRollback(function () {
        print "THIS WILL NEVER BE PRINTED, BECAUSE NO TRANSACTION HAS BEGUN\n";
    })
    ->onBuffer(function ($operation) use ($indexer) {
        print "INDEXING test1\n";
        $indexer->index($operation, 'test1');
    })
    ->setMetadata('value', 'test1');
$connection->addOperation($operation);

// Start outer transaction.
$connection->startTransaction();

$operation = (new Operation())
    ->onCommit(function () {
        print "THIS WILL BE PRINTED, BECAUSE THIS WILL BE COMMITTED\n";
    })
    ->onRollback(function () {
        print "THIS WILL NEVER BE PRINTED, BECAUSE THIS WILL BE COMMITTED\n";
    })
    ->onBuffer(function ($operation) use ($indexer) {
        print "INDEXING test2\n";
        $indexer->index($operation, 'test2');
    })
    ->setMetadata('value', 'test2');
$connection->addOperation($operation);

// Start inner transaction.
$connection->startTransaction();

$operation = (new Operation())
    ->onCommit(function () {
        print "THIS WILL NOT BE PRINTED, BECAUSE THIS WILL BE ROLLED BACK\n";
    })
    ->onRollback(function () {
        print "THIS WILL BE PRINTED, BECAUSE THIS WILL BE ROLLED BACK\n";
    })
    ->onBuffer(function ($operation) use ($indexer) {
        print "INDEXING test3\n";
        $indexer->index($operation, 'test3');
    })
    ->setMetadata('value', 'test3');
$connection->addOperation($operation);

$operation = (new Operation())
    ->onCommit(function () {
        print "THIS WILL NOT BE PRINTED, BECAUSE THIS WILL BE ROLLED BACK - second\n";
    })
    ->onRollback(function () {
        print "THIS WILL BE PRINTED, BECAUSE THIS WILL BE ROLLED BACK - second\n";
    })
    ->onBuffer(function ($operation) use ($indexer) {
        print "INDEXING test3 - second\n";
        $indexer->index($operation, 'test3');
    })
    ->setMetadata('value', 'test3 - second');
$connection->addOperation($operation);

foreach ($indexer->lookup('test1') as $operation) {
    print "Looked up test1 - found: " . $operation->getMetadata('value') . "\n";
}
foreach ($indexer->lookup('test2') as $operation) {
    print "Looked up test2 - found: " . $operation->getMetadata('value') . "\n";
}
foreach ($indexer->lookup('test3') as $operation) {
    print "Looked up test3 - found: " . $operation->getMetadata('value') . "\n";
}

// Rollback inner transaction.
$connection->rollbackTransaction();

// Commit inner transaction.
$connection->commitTransaction();

Example 4 - Value store using the indexer for lookups

namespace Gielfeldt\TransactionalPHP\Example;

require 'vendor/autoload.php';

use Gielfeldt\TransactionalPHP\Connection;
use Gielfeldt\TransactionalPHP\Indexer;

$connection = new Connection();
$indexer = new Indexer($connection);

// Start outer transaction.
$connection->startTransaction();
print "Started outer transaction\n";

$indexer->index($connection->addMetadata('value', 'value1'), 'test1');
$indexer->index($connection->addMetadata('value', 'value2'), 'test1');
$indexer->index($connection->addMetadata('value', 'value1'), 'test2');
$indexer->index($connection->addMetadata('value', 'value2'), 'test2');
print "Added data to indexer\n";

foreach ($indexer->lookup('test1') as $operation) {
    print "Looked up test1 - found: " . $operation->getMetadata('value'). "\n";
}
foreach ($indexer->lookup('test2') as $operation) {
    print "Looked up test2 - found: " . $operation->getMetadata('value'). "\n";
}

// Start inner transaction.
$connection->startTransaction();
print "Started inner transaction\n";

$indexer->index($connection->addMetadata('value', 'value3'), 'test1');
$indexer->index($connection->addMetadata('value', 'value3'), 'test2');
print "Added data to indexer\n";

foreach ($indexer->lookup('test1') as $operation) {
    print "Looked up test1 - found: " . $operation->getMetadata('value'). "\n";
}
foreach ($indexer->lookup('test2') as $operation) {
    print "Looked up test2 - found: " . $operation->getMetadata('value'). "\n";
}

// Rollback inner transaction.
$connection->rollbackTransaction();
print "Rolled back inner transaction\n";

foreach ($indexer->lookup('test1') as $operation) {
    print "Looked up test1 - found: " . $operation->getMetadata('value'). "\n";
}
foreach ($indexer->lookup('test2') as $operation) {
    print "Looked up test2 - found: " . $operation->getMetadata('value'). "\n";
}

// Easy values lookup.
var_dump($indexer->lookupMetadata('test1', 'value'));
var_dump($indexer->lookupMetadata('test2', 'value'));

// Commit inner transaction.
$connection->commitTransaction();
print "Committed outer transaction\n";

foreach ($indexer->lookup('test1') as $operation) {
    print "Looked up test1 - found: " . $operation->getMetadata('value'). "\n";
}
foreach ($indexer->lookup('test2') as $operation) {
    print "Looked up test2 - found: " . $operation->getMetadata('value'). "\n";
}

For more examples see the examples/ folder.

Features

• Transactionalize PHP code.
• Index operations for lookup.

Caveats

1. Lots probably.