README

Create simple pipelines as well as complex graphs which may be used to process data or compute only when a stage's dependencies are resolved.

Getting started

A simple pipeline (sequential)

$a = function($payload) {
	return $payload * -1;
};

$b = function($payload) {
	return $payload * 10000;
};

$pipeline = (new Pipeline)
	->pipe($a)
	->pipe($b);

// Returns 100000
$pipeline->process(-10);

// Can also be built as the following

$stages = [
	1 => [$a],
	2 => [$b, 1],
];

$pipeline = new Pipeline($stages);

A graph flow

$p1 = function($payload) {
	return $payload . '1';
};

$p2 = function($payloadP1) {
	return $payloadP1 . '2';
};

$p3 = function($payloadP1) {
	return $payloadP1 . '3';
};

$p4 = function($payloadP1) {
	return $payloadP1 . '4';
};

$p5 = function($payloadP2, $payloadP3) {
	return $payloadP2 . ' ' . $payloadP3 . '5';
};

$p6 = function($payloadP5) {
	return $payloadP5 . '6';
};

$stages = [
	1 => [$p1],
	2 => [$p2, 1],
	3 => [$p3, 1],
	4 => [$p4, 1],
	5 => [$p5, 2, 3],
	6 => [$p6, 5],
];

$pipeline = new Pipeline($stages);

// Returns Test 12 Test 1356
$pipeline->process('Test ');

// May also be built using the Graph class

$graph = new Graph($stages, new Sequential);
// or $graph = new Graph($stages, new Parallel);

$results = $graph->process('Test ');

// You may inspect the output of every node
// Returns Test 1
$result->output(1);
// Returns Test 12
$result->output(2);
// Returns Test 13
$result->output(3);
// Returns Test 14
$result->output(4);
// Returns Test 12 Test 135
$result->output(5);
// Returns Test 12 Test 1356
$result->output(6);

Processors

In order to process your graph, you are provided with two processors: a Sequential processor and a Parallel processor.

The Sequential processor takes a graph and turns it into a sequence of operations to accomplish. It basically will compute the graph dependencies and ensure that those dependencies are resolved by the time each stage is to be executed. With the Sequential processor, only a single task may be executed at a time.

The Parallel processor is useful when many tasks can be executed in parallel. Similar to the Sequential processor, it will validate that the given graph can be resolved. Then, it will execute all the tasks that can be executed in parallel at the same time. On a multi-core processor, it is expected that the Parallel processor will complete faster if it is given parallelizable tasks.

License

The code is licensed under the MIT license. See LICENSE.

tomzx / dataflow

Maintainers

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