Transactional PHP
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][8]
[
][7]
, (*1)
, (*2)
Installation
To install the Transactional PHP library in your project using Composer, first add the following to your composer.json
config file., (*3)
{
"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., (*4)
Transactional PHP
This class allows to buffer php code in a simulated transaction, thereby postponing the execution of the code until a
commit occurs., (*5)
Motivation
- 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., (*6)
Features
- Transactionalize PHP code.
- Index operations for lookup.
Caveats
- Lots probably.
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